diff options
Diffstat (limited to 'drivers/misc/eeprom')
| -rw-r--r-- | drivers/misc/eeprom/Kconfig | 141 | ||||
| -rw-r--r-- | drivers/misc/eeprom/Makefile | 10 | ||||
| -rw-r--r-- | drivers/misc/eeprom/at24.c | 871 | ||||
| -rw-r--r-- | drivers/misc/eeprom/at25.c | 585 | ||||
| -rw-r--r-- | drivers/misc/eeprom/digsy_mtc_eeprom.c | 97 | ||||
| -rw-r--r-- | drivers/misc/eeprom/ee1004.c | 351 | ||||
| -rw-r--r-- | drivers/misc/eeprom/eeprom_93cx6.c | 383 | ||||
| -rw-r--r-- | drivers/misc/eeprom/eeprom_93xx46.c | 560 | ||||
| -rw-r--r-- | drivers/misc/eeprom/idt_89hpesx.c | 1515 | ||||
| -rw-r--r-- | drivers/misc/eeprom/m24lr.c | 606 | ||||
| -rw-r--r-- | drivers/misc/eeprom/max6875.c | 204 |
11 files changed, 5323 insertions, 0 deletions
diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig new file mode 100644 index 000000000..4d0ce47aa --- /dev/null +++ b/drivers/misc/eeprom/Kconfig @@ -0,0 +1,141 @@ +# SPDX-License-Identifier: GPL-2.0-only +menu "EEPROM support" + +config EEPROM_AT24 + tristate "I2C EEPROMs / RAMs / ROMs from most vendors" + depends on I2C && SYSFS + select NVMEM + select NVMEM_SYSFS + select REGMAP + select REGMAP_I2C + help + Enable this driver to get read/write support to most I2C EEPROMs + and compatible devices like FRAMs, SRAMs, ROMs etc. After you + configure the driver to know about each chip on your target + board. Use these generic chip names, instead of vendor-specific + ones like at24c64, 24lc02 or fm24c04: + + 24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08, + 24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024, 24c2048 + + Unless you like data loss puzzles, always be sure that any chip + you configure as a 24c32 (32 kbit) or larger is NOT really a + 24c16 (16 kbit) or smaller, and vice versa. Marking the chip + as read-only won't help recover from this. Also, if your chip + has any software write-protect mechanism you may want to review the + code to make sure this driver won't turn it on by accident. + + If you use this with an SMBus adapter instead of an I2C adapter, + full functionality is not available. Only smaller devices are + supported (24c16 and below, max 4 kByte). + + This driver can also be built as a module. If so, the module + will be called at24. + +config EEPROM_AT25 + tristate "SPI EEPROMs (FRAMs) from most vendors" + depends on SPI && SYSFS + select NVMEM + select NVMEM_SYSFS + select SPI_MEM + help + Enable this driver to get read/write support to most SPI EEPROMs + and Cypress FRAMs, + after you configure the board init code to know about each eeprom + on your target board. + + This driver can also be built as a module. If so, the module + will be called at25. + +config EEPROM_MAX6875 + tristate "Maxim MAX6874/5 power supply supervisor" + depends on I2C + help + If you say yes here you get read-only support for the user EEPROM of + the Maxim MAX6874/5 EEPROM-programmable, quad power-supply + sequencer/supervisor. + + All other features of this chip should be accessed via i2c-dev. + + This driver can also be built as a module. If so, the module + will be called max6875. + + +config EEPROM_93CX6 + tristate "EEPROM 93CX6 support" + help + This is a driver for the EEPROM chipsets 93c46 and 93c66. + The driver supports both read as well as write commands. + + If unsure, say N. + +config EEPROM_93XX46 + tristate "Microwire EEPROM 93XX46 support" + depends on SPI && SYSFS + select REGMAP + select NVMEM + select NVMEM_SYSFS + help + Driver for the microwire EEPROM chipsets 93xx46x. The driver + supports both read and write commands and also the command to + erase the whole EEPROM. + + This driver can also be built as a module. If so, the module + will be called eeprom_93xx46. + + If unsure, say N. + +config EEPROM_DIGSY_MTC_CFG + bool "DigsyMTC display configuration EEPROMs device" + depends on GPIO_MPC5200 && SPI_GPIO + help + This option enables access to display configuration EEPROMs + on digsy_mtc board. You have to additionally select Microwire + EEPROM 93XX46 driver. sysfs entries will be created for that + EEPROM allowing to read/write the configuration data or to + erase the whole EEPROM. + + If unsure, say N. + +config EEPROM_IDT_89HPESX + tristate "IDT 89HPESx PCIe-switches EEPROM / CSR support" + depends on I2C && SYSFS + help + Enable this driver to get read/write access to EEPROM / CSRs + over IDT PCIe-switch i2c-slave interface. + + This driver can also be built as a module. If so, the module + will be called idt_89hpesx. + +config EEPROM_EE1004 + tristate "SPD EEPROMs on DDR4 memory modules" + depends on I2C && SYSFS + select NVMEM + select NVMEM_SYSFS + help + Enable this driver to get read support to SPD EEPROMs following + the JEDEC EE1004 standard. These are typically found on DDR4 + SDRAM memory modules. + + This driver can also be built as a module. If so, the module + will be called ee1004. + +config EEPROM_M24LR + tristate "STMicroelectronics M24LR RFID/NFC EEPROM support" + depends on I2C && SYSFS + select REGMAP_I2C + select NVMEM + select NVMEM_SYSFS + help + This enables support for STMicroelectronics M24LR RFID/NFC EEPROM + chips. These dual-interface devices expose two I2C addresses: + one for EEPROM memory access and another for control and system + configuration (e.g. UID, password handling). + + This driver provides a sysfs interface for control functions and + integrates with the nvmem subsystem for EEPROM access. + + To compile this driver as a module, choose M here: the + module will be called m24lr. + +endmenu diff --git a/drivers/misc/eeprom/Makefile b/drivers/misc/eeprom/Makefile new file mode 100644 index 000000000..8f311fd6a --- /dev/null +++ b/drivers/misc/eeprom/Makefile @@ -0,0 +1,10 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_EEPROM_AT24) += at24.o +obj-$(CONFIG_EEPROM_AT25) += at25.o +obj-$(CONFIG_EEPROM_MAX6875) += max6875.o +obj-$(CONFIG_EEPROM_93CX6) += eeprom_93cx6.o +obj-$(CONFIG_EEPROM_93XX46) += eeprom_93xx46.o +obj-$(CONFIG_EEPROM_DIGSY_MTC_CFG) += digsy_mtc_eeprom.o +obj-$(CONFIG_EEPROM_IDT_89HPESX) += idt_89hpesx.o +obj-$(CONFIG_EEPROM_EE1004) += ee1004.o +obj-$(CONFIG_EEPROM_M24LR) += m24lr.o diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c new file mode 100644 index 000000000..772c4d9fa --- /dev/null +++ b/drivers/misc/eeprom/at24.c @@ -0,0 +1,871 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * at24.c - handle most I2C EEPROMs + * + * Copyright (C) 2005-2007 David Brownell + * Copyright (C) 2008 Wolfram Sang, Pengutronix + */ + +#include <linux/acpi.h> +#include <linux/bitops.h> +#include <linux/capability.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/nvmem-provider.h> +#include <linux/pm_runtime.h> +#include <linux/property.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/slab.h> + +/* Address pointer is 16 bit. */ +#define AT24_FLAG_ADDR16 BIT(7) +/* sysfs-entry will be read-only. */ +#define AT24_FLAG_READONLY BIT(6) +/* sysfs-entry will be world-readable. */ +#define AT24_FLAG_IRUGO BIT(5) +/* Take always 8 addresses (24c00). */ +#define AT24_FLAG_TAKE8ADDR BIT(4) +/* Factory-programmed serial number. */ +#define AT24_FLAG_SERIAL BIT(3) +/* Factory-programmed mac address. */ +#define AT24_FLAG_MAC BIT(2) +/* Does not auto-rollover reads to the next slave address. */ +#define AT24_FLAG_NO_RDROL BIT(1) + +/* + * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable. + * Differences between different vendor product lines (like Atmel AT24C or + * MicroChip 24LC, etc) won't much matter for typical read/write access. + * There are also I2C RAM chips, likewise interchangeable. One example + * would be the PCF8570, which acts like a 24c02 EEPROM (256 bytes). + * + * However, misconfiguration can lose data. "Set 16-bit memory address" + * to a part with 8-bit addressing will overwrite data. Writing with too + * big a page size also loses data. And it's not safe to assume that the + * conventional addresses 0x50..0x57 only hold eeproms; a PCF8563 RTC + * uses 0x51, for just one example. + * + * Accordingly, explicit board-specific configuration data should be used + * in almost all cases. (One partial exception is an SMBus used to access + * "SPD" data for DRAM sticks. Those only use 24c02 EEPROMs.) + * + * So this driver uses "new style" I2C driver binding, expecting to be + * told what devices exist. That may be in arch/X/mach-Y/board-Z.c or + * similar kernel-resident tables; or, configuration data coming from + * a bootloader. + * + * Other than binding model, current differences from "eeprom" driver are + * that this one handles write access and isn't restricted to 24c02 devices. + * It also handles larger devices (32 kbit and up) with two-byte addresses, + * which won't work on pure SMBus systems. + */ + +struct at24_data { + /* + * Lock protects against activities from other Linux tasks, + * but not from changes by other I2C masters. + */ + struct mutex lock; + + unsigned int write_max; + unsigned int num_addresses; + unsigned int offset_adj; + + u32 byte_len; + u16 page_size; + u8 flags; + + struct nvmem_device *nvmem; + struct regulator *vcc_reg; + void (*read_post)(unsigned int off, char *buf, size_t count); + + /* + * Some chips tie up multiple I2C addresses; dummy devices reserve + * them for us. + */ + u8 bank_addr_shift; + struct regmap *client_regmaps[] __counted_by(num_addresses); +}; + +/* + * This parameter is to help this driver avoid blocking other drivers out + * of I2C for potentially troublesome amounts of time. With a 100 kHz I2C + * clock, one 256 byte read takes about 1/43 second which is excessive; + * but the 1/170 second it takes at 400 kHz may be quite reasonable; and + * at 1 MHz (Fm+) a 1/430 second delay could easily be invisible. + * + * This value is forced to be a power of two so that writes align on pages. + */ +static unsigned int at24_io_limit = 128; +module_param_named(io_limit, at24_io_limit, uint, 0); +MODULE_PARM_DESC(at24_io_limit, "Maximum bytes per I/O (default 128)"); + +/* + * Specs often allow 5 msec for a page write, sometimes 20 msec; + * it's important to recover from write timeouts. + */ +static unsigned int at24_write_timeout = 25; +module_param_named(write_timeout, at24_write_timeout, uint, 0); +MODULE_PARM_DESC(at24_write_timeout, "Time (in ms) to try writes (default 25)"); + +struct at24_chip_data { + u32 byte_len; + u8 flags; + u8 bank_addr_shift; + void (*read_post)(unsigned int off, char *buf, size_t count); +}; + +#define AT24_CHIP_DATA(_name, _len, _flags) \ + static const struct at24_chip_data _name = { \ + .byte_len = _len, .flags = _flags, \ + } + +#define AT24_CHIP_DATA_CB(_name, _len, _flags, _read_post) \ + static const struct at24_chip_data _name = { \ + .byte_len = _len, .flags = _flags, \ + .read_post = _read_post, \ + } + +#define AT24_CHIP_DATA_BS(_name, _len, _flags, _bank_addr_shift) \ + static const struct at24_chip_data _name = { \ + .byte_len = _len, .flags = _flags, \ + .bank_addr_shift = _bank_addr_shift \ + } + +static void at24_read_post_vaio(unsigned int off, char *buf, size_t count) +{ + int i; + + if (capable(CAP_SYS_ADMIN)) + return; + + /* + * Hide VAIO private settings to regular users: + * - BIOS passwords: bytes 0x00 to 0x0f + * - UUID: bytes 0x10 to 0x1f + * - Serial number: 0xc0 to 0xdf + */ + for (i = 0; i < count; i++) { + if ((off + i <= 0x1f) || + (off + i >= 0xc0 && off + i <= 0xdf)) + buf[i] = 0; + } +} + +/* needs 8 addresses as A0-A2 are ignored */ +AT24_CHIP_DATA(at24_data_24c00, 128 / 8, AT24_FLAG_TAKE8ADDR); +/* old variants can't be handled with this generic entry! */ +AT24_CHIP_DATA(at24_data_24c01, 1024 / 8, 0); +AT24_CHIP_DATA(at24_data_24cs01, 16, + AT24_FLAG_SERIAL | AT24_FLAG_READONLY); +AT24_CHIP_DATA(at24_data_24c02, 2048 / 8, 0); +AT24_CHIP_DATA(at24_data_24cs02, 16, + AT24_FLAG_SERIAL | AT24_FLAG_READONLY); +AT24_CHIP_DATA(at24_data_24mac402, 48 / 8, + AT24_FLAG_MAC | AT24_FLAG_READONLY); +AT24_CHIP_DATA(at24_data_24mac602, 64 / 8, + AT24_FLAG_MAC | AT24_FLAG_READONLY); +AT24_CHIP_DATA(at24_data_24aa025e48, 48 / 8, + AT24_FLAG_READONLY); +AT24_CHIP_DATA(at24_data_24aa025e64, 64 / 8, + AT24_FLAG_READONLY); +/* spd is a 24c02 in memory DIMMs */ +AT24_CHIP_DATA(at24_data_spd, 2048 / 8, + AT24_FLAG_READONLY | AT24_FLAG_IRUGO); +/* 24c02_vaio is a 24c02 on some Sony laptops */ +AT24_CHIP_DATA_CB(at24_data_24c02_vaio, 2048 / 8, + AT24_FLAG_READONLY | AT24_FLAG_IRUGO, + at24_read_post_vaio); +AT24_CHIP_DATA(at24_data_24c04, 4096 / 8, 0); +AT24_CHIP_DATA(at24_data_24cs04, 16, + AT24_FLAG_SERIAL | AT24_FLAG_READONLY); +/* 24rf08 quirk is handled at i2c-core */ +AT24_CHIP_DATA(at24_data_24c08, 8192 / 8, 0); +AT24_CHIP_DATA(at24_data_24cs08, 16, + AT24_FLAG_SERIAL | AT24_FLAG_READONLY); +AT24_CHIP_DATA(at24_data_24c16, 16384 / 8, 0); +AT24_CHIP_DATA(at24_data_24cs16, 16, + AT24_FLAG_SERIAL | AT24_FLAG_READONLY); +AT24_CHIP_DATA(at24_data_24c32, 32768 / 8, AT24_FLAG_ADDR16); +/* M24C32-D Additional Write lockable page (M24C32-D order codes) */ +AT24_CHIP_DATA(at24_data_24c32d_wlp, 32, AT24_FLAG_ADDR16); +AT24_CHIP_DATA(at24_data_24cs32, 16, + AT24_FLAG_ADDR16 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); +AT24_CHIP_DATA(at24_data_24c64, 65536 / 8, AT24_FLAG_ADDR16); +/* M24C64-D Additional Write lockable page (M24C64-D order codes) */ +AT24_CHIP_DATA(at24_data_24c64d_wlp, 32, AT24_FLAG_ADDR16); +AT24_CHIP_DATA(at24_data_24cs64, 16, + AT24_FLAG_ADDR16 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY); +AT24_CHIP_DATA(at24_data_24c128, 131072 / 8, AT24_FLAG_ADDR16); +AT24_CHIP_DATA(at24_data_24c256, 262144 / 8, AT24_FLAG_ADDR16); +/* M24256E Additional Write lockable page (M24256E-F order codes) */ +AT24_CHIP_DATA(at24_data_24256e_wlp, 64, AT24_FLAG_ADDR16); +AT24_CHIP_DATA(at24_data_24c512, 524288 / 8, AT24_FLAG_ADDR16); +AT24_CHIP_DATA(at24_data_24c1024, 1048576 / 8, AT24_FLAG_ADDR16); +AT24_CHIP_DATA_BS(at24_data_24c1025, 1048576 / 8, AT24_FLAG_ADDR16, 2); +AT24_CHIP_DATA(at24_data_24c2048, 2097152 / 8, AT24_FLAG_ADDR16); +/* identical to 24c08 ? */ +AT24_CHIP_DATA(at24_data_INT3499, 8192 / 8, 0); + +static const struct i2c_device_id at24_ids[] = { + { .name = "24c00", .driver_data = (kernel_ulong_t)&at24_data_24c00 }, + { .name = "24c01", .driver_data = (kernel_ulong_t)&at24_data_24c01 }, + { .name = "24cs01", .driver_data = (kernel_ulong_t)&at24_data_24cs01 }, + { .name = "24c02", .driver_data = (kernel_ulong_t)&at24_data_24c02 }, + { .name = "24cs02", .driver_data = (kernel_ulong_t)&at24_data_24cs02 }, + { .name = "24mac402", .driver_data = (kernel_ulong_t)&at24_data_24mac402 }, + { .name = "24mac602", .driver_data = (kernel_ulong_t)&at24_data_24mac602 }, + { .name = "24aa025e48", .driver_data = (kernel_ulong_t)&at24_data_24aa025e48 }, + { .name = "24aa025e64", .driver_data = (kernel_ulong_t)&at24_data_24aa025e64 }, + { .name = "spd", .driver_data = (kernel_ulong_t)&at24_data_spd }, + { .name = "24c02-vaio", .driver_data = (kernel_ulong_t)&at24_data_24c02_vaio }, + { .name = "24c04", .driver_data = (kernel_ulong_t)&at24_data_24c04 }, + { .name = "24cs04", .driver_data = (kernel_ulong_t)&at24_data_24cs04 }, + { .name = "24c08", .driver_data = (kernel_ulong_t)&at24_data_24c08 }, + { .name = "24cs08", .driver_data = (kernel_ulong_t)&at24_data_24cs08 }, + { .name = "24c16", .driver_data = (kernel_ulong_t)&at24_data_24c16 }, + { .name = "24cs16", .driver_data = (kernel_ulong_t)&at24_data_24cs16 }, + { .name = "24c32", .driver_data = (kernel_ulong_t)&at24_data_24c32 }, + { .name = "24c32d-wl", .driver_data = (kernel_ulong_t)&at24_data_24c32d_wlp }, + { .name = "24cs32", .driver_data = (kernel_ulong_t)&at24_data_24cs32 }, + { .name = "24c64", .driver_data = (kernel_ulong_t)&at24_data_24c64 }, + { .name = "24c64-wl", .driver_data = (kernel_ulong_t)&at24_data_24c64d_wlp }, + { .name = "24cs64", .driver_data = (kernel_ulong_t)&at24_data_24cs64 }, + { .name = "24c128", .driver_data = (kernel_ulong_t)&at24_data_24c128 }, + { .name = "24c256", .driver_data = (kernel_ulong_t)&at24_data_24c256 }, + { .name = "24256e-wl", .driver_data = (kernel_ulong_t)&at24_data_24256e_wlp }, + { .name = "24c512", .driver_data = (kernel_ulong_t)&at24_data_24c512 }, + { .name = "24c1024", .driver_data = (kernel_ulong_t)&at24_data_24c1024 }, + { .name = "24c1025", .driver_data = (kernel_ulong_t)&at24_data_24c1025 }, + { .name = "24c2048", .driver_data = (kernel_ulong_t)&at24_data_24c2048 }, + { .name = "at24", .driver_data = 0 }, + { /* END OF LIST */ } +}; +MODULE_DEVICE_TABLE(i2c, at24_ids); + +static const struct of_device_id at24_of_match[] = { + { .compatible = "atmel,24c00", .data = &at24_data_24c00 }, + { .compatible = "atmel,24c01", .data = &at24_data_24c01 }, + { .compatible = "atmel,24cs01", .data = &at24_data_24cs01 }, + { .compatible = "atmel,24c02", .data = &at24_data_24c02 }, + { .compatible = "atmel,24cs02", .data = &at24_data_24cs02 }, + { .compatible = "atmel,24mac402", .data = &at24_data_24mac402 }, + { .compatible = "atmel,24mac602", .data = &at24_data_24mac602 }, + { .compatible = "atmel,spd", .data = &at24_data_spd }, + { .compatible = "atmel,24c04", .data = &at24_data_24c04 }, + { .compatible = "atmel,24cs04", .data = &at24_data_24cs04 }, + { .compatible = "atmel,24c08", .data = &at24_data_24c08 }, + { .compatible = "atmel,24cs08", .data = &at24_data_24cs08 }, + { .compatible = "atmel,24c16", .data = &at24_data_24c16 }, + { .compatible = "atmel,24cs16", .data = &at24_data_24cs16 }, + { .compatible = "atmel,24c32", .data = &at24_data_24c32 }, + { .compatible = "atmel,24c32d-wl", .data = &at24_data_24c32d_wlp }, + { .compatible = "atmel,24cs32", .data = &at24_data_24cs32 }, + { .compatible = "atmel,24c64", .data = &at24_data_24c64 }, + { .compatible = "atmel,24c64d-wl", .data = &at24_data_24c64d_wlp }, + { .compatible = "atmel,24cs64", .data = &at24_data_24cs64 }, + { .compatible = "atmel,24c128", .data = &at24_data_24c128 }, + { .compatible = "atmel,24c256", .data = &at24_data_24c256 }, + { .compatible = "atmel,24c512", .data = &at24_data_24c512 }, + { .compatible = "atmel,24c1024", .data = &at24_data_24c1024 }, + { .compatible = "atmel,24c1025", .data = &at24_data_24c1025 }, + { .compatible = "atmel,24c2048", .data = &at24_data_24c2048 }, + { .compatible = "microchip,24aa025e48", .data = &at24_data_24aa025e48 }, + { .compatible = "microchip,24aa025e64", .data = &at24_data_24aa025e64 }, + { .compatible = "st,24256e-wl", .data = &at24_data_24256e_wlp }, + { /* END OF LIST */ }, +}; +MODULE_DEVICE_TABLE(of, at24_of_match); + +static const struct acpi_device_id at24_acpi_ids[] = { + { "INT3499", (kernel_ulong_t)&at24_data_INT3499 }, + { "TPF0001", (kernel_ulong_t)&at24_data_24c1024 }, + { /* END OF LIST */ } +}; +MODULE_DEVICE_TABLE(acpi, at24_acpi_ids); + +/* + * This routine supports chips which consume multiple I2C addresses. It + * computes the addressing information to be used for a given r/w request. + * Assumes that sanity checks for offset happened at sysfs-layer. + * + * Slave address and byte offset derive from the offset. Always + * set the byte address; on a multi-master board, another master + * may have changed the chip's "current" address pointer. + */ +static struct regmap *at24_translate_offset(struct at24_data *at24, + unsigned int *offset) +{ + unsigned int i; + + if (at24->flags & AT24_FLAG_ADDR16) { + i = *offset >> 16; + *offset &= 0xffff; + } else { + i = *offset >> 8; + *offset &= 0xff; + } + + return at24->client_regmaps[i]; +} + +static struct device *at24_base_client_dev(struct at24_data *at24) +{ + return regmap_get_device(at24->client_regmaps[0]); +} + +static size_t at24_adjust_read_count(struct at24_data *at24, + unsigned int offset, size_t count) +{ + unsigned int bits; + size_t remainder; + + /* + * In case of multi-address chips that don't rollover reads to + * the next slave address: truncate the count to the slave boundary, + * so that the read never straddles slaves. + */ + if (at24->flags & AT24_FLAG_NO_RDROL) { + bits = (at24->flags & AT24_FLAG_ADDR16) ? 16 : 8; + remainder = BIT(bits) - offset; + if (count > remainder) + count = remainder; + } + + if (count > at24_io_limit) + count = at24_io_limit; + + return count; +} + +static ssize_t at24_regmap_read(struct at24_data *at24, char *buf, + unsigned int offset, size_t count) +{ + unsigned long timeout, read_time; + struct regmap *regmap; + int ret; + + regmap = at24_translate_offset(at24, &offset); + count = at24_adjust_read_count(at24, offset, count); + + /* adjust offset for mac and serial read ops */ + offset += at24->offset_adj; + + timeout = jiffies + msecs_to_jiffies(at24_write_timeout); + do { + /* + * The timestamp shall be taken before the actual operation + * to avoid a premature timeout in case of high CPU load. + */ + read_time = jiffies; + + ret = regmap_bulk_read(regmap, offset, buf, count); + dev_dbg(regmap_get_device(regmap), "read %zu@%d --> %d (%ld)\n", + count, offset, ret, jiffies); + if (!ret) + return count; + + usleep_range(1000, 1500); + } while (time_before(read_time, timeout)); + + return -ETIMEDOUT; +} + +/* + * Note that if the hardware write-protect pin is pulled high, the whole + * chip is normally write protected. But there are plenty of product + * variants here, including OTP fuses and partial chip protect. + * + * We only use page mode writes; the alternative is sloooow. These routines + * write at most one page. + */ + +static size_t at24_adjust_write_count(struct at24_data *at24, + unsigned int offset, size_t count) +{ + unsigned int next_page; + + /* write_max is at most a page */ + if (count > at24->write_max) + count = at24->write_max; + + /* Never roll over backwards, to the start of this page */ + next_page = roundup(offset + 1, at24->page_size); + if (offset + count > next_page) + count = next_page - offset; + + return count; +} + +static ssize_t at24_regmap_write(struct at24_data *at24, const char *buf, + unsigned int offset, size_t count) +{ + unsigned long timeout, write_time; + struct regmap *regmap; + int ret; + + regmap = at24_translate_offset(at24, &offset); + count = at24_adjust_write_count(at24, offset, count); + timeout = jiffies + msecs_to_jiffies(at24_write_timeout); + + do { + /* + * The timestamp shall be taken before the actual operation + * to avoid a premature timeout in case of high CPU load. + */ + write_time = jiffies; + + ret = regmap_bulk_write(regmap, offset, buf, count); + dev_dbg(regmap_get_device(regmap), "write %zu@%d --> %d (%ld)\n", + count, offset, ret, jiffies); + if (!ret) + return count; + + usleep_range(1000, 1500); + } while (time_before(write_time, timeout)); + + return -ETIMEDOUT; +} + +static int at24_read(void *priv, unsigned int off, void *val, size_t count) +{ + struct at24_data *at24; + struct device *dev; + char *buf = val; + int i, ret; + + at24 = priv; + dev = at24_base_client_dev(at24); + + if (unlikely(!count)) + return count; + + if (off + count > at24->byte_len) + return -EINVAL; + + ret = pm_runtime_resume_and_get(dev); + if (ret) + return ret; + /* + * Read data from chip, protecting against concurrent updates + * from this host, but not from other I2C masters. + */ + mutex_lock(&at24->lock); + + for (i = 0; count; i += ret, count -= ret) { + ret = at24_regmap_read(at24, buf + i, off + i, count); + if (ret < 0) { + mutex_unlock(&at24->lock); + pm_runtime_put(dev); + return ret; + } + } + + mutex_unlock(&at24->lock); + + pm_runtime_put(dev); + + if (unlikely(at24->read_post)) + at24->read_post(off, buf, i); + + return 0; +} + +static int at24_write(void *priv, unsigned int off, void *val, size_t count) +{ + struct at24_data *at24; + struct device *dev; + char *buf = val; + int ret; + + at24 = priv; + dev = at24_base_client_dev(at24); + + if (unlikely(!count)) + return -EINVAL; + + if (off + count > at24->byte_len) + return -EINVAL; + + ret = pm_runtime_resume_and_get(dev); + if (ret) + return ret; + /* + * Write data to chip, protecting against concurrent updates + * from this host, but not from other I2C masters. + */ + mutex_lock(&at24->lock); + + while (count) { + ret = at24_regmap_write(at24, buf, off, count); + if (ret < 0) { + mutex_unlock(&at24->lock); + pm_runtime_put(dev); + return ret; + } + buf += ret; + off += ret; + count -= ret; + } + + mutex_unlock(&at24->lock); + + pm_runtime_put(dev); + + return 0; +} + +static int at24_make_dummy_client(struct at24_data *at24, unsigned int index, + struct i2c_client *base_client, + struct regmap_config *regmap_config) +{ + struct i2c_client *dummy_client; + struct regmap *regmap; + + dummy_client = devm_i2c_new_dummy_device(&base_client->dev, + base_client->adapter, + base_client->addr + + (index << at24->bank_addr_shift)); + if (IS_ERR(dummy_client)) + return PTR_ERR(dummy_client); + + regmap = devm_regmap_init_i2c(dummy_client, regmap_config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + at24->client_regmaps[index] = regmap; + + return 0; +} + +static unsigned int at24_get_offset_adj(u8 flags, unsigned int byte_len) +{ + if (flags & AT24_FLAG_MAC) { + /* EUI-48 starts from 0x9a, EUI-64 from 0x98 */ + return 0xa0 - byte_len; + } else if (flags & AT24_FLAG_SERIAL && flags & AT24_FLAG_ADDR16) { + /* + * For 16 bit address pointers, the word address must contain + * a '10' sequence in bits 11 and 10 regardless of the + * intended position of the address pointer. + */ + return 0x0800; + } else if (flags & AT24_FLAG_SERIAL) { + /* + * Otherwise the word address must begin with a '10' sequence, + * regardless of the intended address. + */ + return 0x0080; + } else { + return 0; + } +} + +static void at24_probe_temp_sensor(struct i2c_client *client) +{ + struct at24_data *at24 = i2c_get_clientdata(client); + struct i2c_board_info info = { .type = "jc42" }; + int ret; + u8 val; + + /* + * Byte 2 has value 11 for DDR3, earlier versions don't + * support the thermal sensor present flag + */ + ret = at24_read(at24, 2, &val, 1); + if (ret || val != 11) + return; + + /* Byte 32, bit 7 is set if temp sensor is present */ + ret = at24_read(at24, 32, &val, 1); + if (ret || !(val & BIT(7))) + return; + + info.addr = 0x18 | (client->addr & 7); + + i2c_new_client_device(client->adapter, &info); +} + +static int at24_probe(struct i2c_client *client) +{ + struct regmap_config regmap_config = { }; + struct nvmem_config nvmem_config = { }; + u32 byte_len, page_size, flags, addrw; + const struct at24_chip_data *cdata; + struct device *dev = &client->dev; + bool i2c_fn_i2c, i2c_fn_block; + unsigned int i, num_addresses; + struct at24_data *at24; + bool full_power; + struct regmap *regmap; + bool writable; + u8 test_byte; + int err; + + i2c_fn_i2c = i2c_check_functionality(client->adapter, I2C_FUNC_I2C); + i2c_fn_block = i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_WRITE_I2C_BLOCK); + + cdata = i2c_get_match_data(client); + if (!cdata) + return -ENODEV; + + err = device_property_read_u32(dev, "pagesize", &page_size); + if (err) + /* + * This is slow, but we can't know all eeproms, so we better + * play safe. Specifying custom eeprom-types via device tree + * or properties is recommended anyhow. + */ + page_size = 1; + + flags = cdata->flags; + if (device_property_present(dev, "read-only")) + flags |= AT24_FLAG_READONLY; + if (device_property_present(dev, "no-read-rollover")) + flags |= AT24_FLAG_NO_RDROL; + + err = device_property_read_u32(dev, "address-width", &addrw); + if (!err) { + switch (addrw) { + case 8: + if (flags & AT24_FLAG_ADDR16) + dev_warn(dev, + "Override address width to be 8, while default is 16\n"); + flags &= ~AT24_FLAG_ADDR16; + break; + case 16: + flags |= AT24_FLAG_ADDR16; + break; + default: + dev_warn(dev, "Bad \"address-width\" property: %u\n", + addrw); + } + } + + err = device_property_read_u32(dev, "size", &byte_len); + if (err) + byte_len = cdata->byte_len; + + if (!i2c_fn_i2c && !i2c_fn_block) + page_size = 1; + + if (!page_size) + return dev_err_probe(dev, -EINVAL, "page_size must not be 0!\n"); + + if (!is_power_of_2(page_size)) + dev_warn(dev, "page_size looks suspicious (no power of 2)!\n"); + + err = device_property_read_u32(dev, "num-addresses", &num_addresses); + if (err) { + if (flags & AT24_FLAG_TAKE8ADDR) + num_addresses = 8; + else + num_addresses = DIV_ROUND_UP(byte_len, + (flags & AT24_FLAG_ADDR16) ? 65536 : 256); + } + + if ((flags & AT24_FLAG_SERIAL) && (flags & AT24_FLAG_MAC)) + return dev_err_probe(dev, -EINVAL, + "invalid device data - cannot have both AT24_FLAG_SERIAL & AT24_FLAG_MAC."); + + regmap_config.val_bits = 8; + regmap_config.reg_bits = (flags & AT24_FLAG_ADDR16) ? 16 : 8; + regmap_config.disable_locking = true; + + regmap = devm_regmap_init_i2c(client, ®map_config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + at24 = devm_kzalloc(dev, struct_size(at24, client_regmaps, num_addresses), + GFP_KERNEL); + if (!at24) + return -ENOMEM; + + mutex_init(&at24->lock); + at24->byte_len = byte_len; + at24->page_size = page_size; + at24->flags = flags; + at24->read_post = cdata->read_post; + at24->bank_addr_shift = cdata->bank_addr_shift; + at24->num_addresses = num_addresses; + at24->offset_adj = at24_get_offset_adj(flags, byte_len); + at24->client_regmaps[0] = regmap; + + at24->vcc_reg = devm_regulator_get(dev, "vcc"); + if (IS_ERR(at24->vcc_reg)) + return PTR_ERR(at24->vcc_reg); + + writable = !(flags & AT24_FLAG_READONLY); + if (writable) { + at24->write_max = min_t(unsigned int, + page_size, at24_io_limit); + if (!i2c_fn_i2c && at24->write_max > I2C_SMBUS_BLOCK_MAX) + at24->write_max = I2C_SMBUS_BLOCK_MAX; + } + + /* use dummy devices for multiple-address chips */ + for (i = 1; i < num_addresses; i++) { + err = at24_make_dummy_client(at24, i, client, ®map_config); + if (err) + return err; + } + + /* + * We initialize nvmem_config.id to NVMEM_DEVID_AUTO even if the + * label property is set as some platform can have multiple eeproms + * with same label and we can not register each of those with same + * label. Failing to register those eeproms trigger cascade failure + * on such platform. + */ + nvmem_config.id = NVMEM_DEVID_AUTO; + + if (device_property_present(dev, "label")) { + err = device_property_read_string(dev, "label", + &nvmem_config.name); + if (err) + return err; + } else { + nvmem_config.name = dev_name(dev); + } + + nvmem_config.type = NVMEM_TYPE_EEPROM; + nvmem_config.dev = dev; + nvmem_config.read_only = !writable; + nvmem_config.root_only = !(flags & AT24_FLAG_IRUGO); + nvmem_config.owner = THIS_MODULE; + nvmem_config.compat = true; + nvmem_config.base_dev = dev; + nvmem_config.reg_read = at24_read; + nvmem_config.reg_write = at24_write; + nvmem_config.priv = at24; + nvmem_config.stride = 1; + nvmem_config.word_size = 1; + nvmem_config.size = byte_len; + + i2c_set_clientdata(client, at24); + + full_power = acpi_dev_state_d0(&client->dev); + if (full_power) { + err = regulator_enable(at24->vcc_reg); + if (err) + return dev_err_probe(dev, err, "Failed to enable vcc regulator\n"); + + pm_runtime_set_active(dev); + } + pm_runtime_enable(dev); + + /* + * Perform a one-byte test read to verify that the chip is functional, + * unless powering on the device is to be avoided during probe (i.e. + * it's powered off right now). + */ + if (full_power) { + err = at24_read(at24, 0, &test_byte, 1); + if (err) { + pm_runtime_disable(dev); + if (!pm_runtime_status_suspended(dev)) + regulator_disable(at24->vcc_reg); + return -ENODEV; + } + } + + at24->nvmem = devm_nvmem_register(dev, &nvmem_config); + if (IS_ERR(at24->nvmem)) { + pm_runtime_disable(dev); + if (!pm_runtime_status_suspended(dev)) + regulator_disable(at24->vcc_reg); + return dev_err_probe(dev, PTR_ERR(at24->nvmem), + "failed to register nvmem\n"); + } + + /* If this a SPD EEPROM, probe for DDR3 thermal sensor */ + if (cdata == &at24_data_spd) + at24_probe_temp_sensor(client); + + pm_runtime_idle(dev); + + if (writable) + dev_info(dev, "%u byte %s EEPROM, writable, %u bytes/write\n", + byte_len, client->name, at24->write_max); + else + dev_info(dev, "%u byte %s EEPROM, read-only\n", + byte_len, client->name); + + return 0; +} + +static void at24_remove(struct i2c_client *client) +{ + struct at24_data *at24 = i2c_get_clientdata(client); + + pm_runtime_disable(&client->dev); + if (acpi_dev_state_d0(&client->dev)) { + if (!pm_runtime_status_suspended(&client->dev)) + regulator_disable(at24->vcc_reg); + pm_runtime_set_suspended(&client->dev); + } +} + +static int __maybe_unused at24_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct at24_data *at24 = i2c_get_clientdata(client); + + return regulator_disable(at24->vcc_reg); +} + +static int __maybe_unused at24_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct at24_data *at24 = i2c_get_clientdata(client); + + return regulator_enable(at24->vcc_reg); +} + +static const struct dev_pm_ops at24_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) + SET_RUNTIME_PM_OPS(at24_suspend, at24_resume, NULL) +}; + +static struct i2c_driver at24_driver = { + .driver = { + .name = "at24", + .pm = &at24_pm_ops, + .of_match_table = at24_of_match, + .acpi_match_table = at24_acpi_ids, + }, + .probe = at24_probe, + .remove = at24_remove, + .id_table = at24_ids, + .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE, +}; + +static int __init at24_init(void) +{ + if (!at24_io_limit) { + pr_err("at24: at24_io_limit must not be 0!\n"); + return -EINVAL; + } + + at24_io_limit = rounddown_pow_of_two(at24_io_limit); + return i2c_add_driver(&at24_driver); +} +module_init(at24_init); + +static void __exit at24_exit(void) +{ + i2c_del_driver(&at24_driver); +} +module_exit(at24_exit); + +MODULE_DESCRIPTION("Driver for most I2C EEPROMs"); +MODULE_AUTHOR("David Brownell and Wolfram Sang"); +MODULE_LICENSE("GPL"); diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c new file mode 100644 index 000000000..bc2cfb75d --- /dev/null +++ b/drivers/misc/eeprom/at25.c @@ -0,0 +1,585 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Driver for most of the SPI EEPROMs, such as Atmel AT25 models + * and Cypress FRAMs FM25 models. + * + * Copyright (C) 2006 David Brownell + */ + +#include <linux/bits.h> +#include <linux/cleanup.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/property.h> +#include <linux/sched.h> +#include <linux/slab.h> + +#include <linux/spi/eeprom.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi-mem.h> + +#include <linux/nvmem-provider.h> + +/* + * NOTE: this is an *EEPROM* driver. The vagaries of product naming + * mean that some AT25 products are EEPROMs, and others are FLASH. + * Handle FLASH chips with the drivers/mtd/devices/m25p80.c driver, + * not this one! + * + * EEPROMs that can be used with this driver include, for example: + * AT25M02, AT25128B + */ + +#define FM25_SN_LEN 8 /* serial number length */ +#define FM25_MAX_ID_LEN 9 /* ID length */ +#define EE_MAXADDRLEN 3 /* 24 bit addresses, up to 2 MBytes */ + +struct at25_data { + struct spi_eeprom chip; + struct spi_mem *spimem; + struct mutex lock; + unsigned addrlen; + struct nvmem_config nvmem_config; + struct nvmem_device *nvmem; + u8 sernum[FM25_SN_LEN]; + u8 id[FM25_MAX_ID_LEN]; + u8 id_len; +}; + +#define AT25_WREN 0x06 /* latch the write enable */ +#define AT25_WRDI 0x04 /* reset the write enable */ +#define AT25_RDSR 0x05 /* read status register */ +#define AT25_WRSR 0x01 /* write status register */ +#define AT25_READ 0x03 /* read byte(s) */ +#define AT25_WRITE 0x02 /* write byte(s)/sector */ +#define FM25_SLEEP 0xb9 /* enter sleep mode */ +#define FM25_RDID 0x9f /* read device ID */ +#define FM25_RDSN 0xc3 /* read S/N */ + +#define AT25_SR_nRDY 0x01 /* nRDY = write-in-progress */ +#define AT25_SR_WEN 0x02 /* write enable (latched) */ +#define AT25_SR_BP0 0x04 /* BP for software writeprotect */ +#define AT25_SR_BP1 0x08 +#define AT25_SR_WPEN 0x80 /* writeprotect enable */ + +#define AT25_INSTR_BIT3 0x08 /* additional address bit in instr */ + +/* + * Specs often allow 5ms for a page write, sometimes 20ms; + * it's important to recover from write timeouts. + */ +#define EE_TIMEOUT 25 + +/*-------------------------------------------------------------------------*/ + +#define io_limit PAGE_SIZE /* bytes */ + +/* Handle the address MSB as part of instruction byte */ +static u8 at25_instr(struct at25_data *at25, u8 instr, unsigned int off) +{ + if (!(at25->chip.flags & EE_INSTR_BIT3_IS_ADDR)) + return instr; + if (off < BIT(at25->addrlen * 8)) + return instr; + return instr | AT25_INSTR_BIT3; +} + +static int at25_ee_read(void *priv, unsigned int offset, + void *val, size_t count) +{ + u8 *bounce __free(kfree) = kmalloc(min(count, io_limit), GFP_KERNEL); + struct at25_data *at25 = priv; + char *buf = val; + unsigned int msg_offset = offset; + size_t bytes_left = count; + size_t segment; + int status; + + if (!bounce) + return -ENOMEM; + + if (unlikely(offset >= at25->chip.byte_len)) + return -EINVAL; + if ((offset + count) > at25->chip.byte_len) + count = at25->chip.byte_len - offset; + if (unlikely(!count)) + return -EINVAL; + + do { + struct spi_mem_op op; + + segment = min(bytes_left, io_limit); + + op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(at25_instr(at25, AT25_READ, + msg_offset), 1), + SPI_MEM_OP_ADDR(at25->addrlen, msg_offset, 1), + SPI_MEM_OP_NO_DUMMY, + SPI_MEM_OP_DATA_IN(segment, bounce, 1)); + + status = spi_mem_adjust_op_size(at25->spimem, &op); + if (status) + return status; + segment = op.data.nbytes; + + mutex_lock(&at25->lock); + status = spi_mem_exec_op(at25->spimem, &op); + mutex_unlock(&at25->lock); + if (status) + return status; + memcpy(buf, bounce, segment); + + msg_offset += segment; + buf += segment; + bytes_left -= segment; + } while (bytes_left > 0); + + dev_dbg(&at25->spimem->spi->dev, "read %zu bytes at %d\n", + count, offset); + return 0; +} + +/* + * Read extra registers as ID or serial number + * + * Allow for the callers to provide @buf on stack (not necessary DMA-capable) + * by allocating a bounce buffer internally. + */ +static int fm25_aux_read(struct at25_data *at25, u8 *buf, uint8_t command, + int len) +{ + u8 *bounce __free(kfree) = kmalloc(len, GFP_KERNEL); + struct spi_mem_op op; + int status; + + if (!bounce) + return -ENOMEM; + + op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(command, 1), + SPI_MEM_OP_NO_ADDR, + SPI_MEM_OP_NO_DUMMY, + SPI_MEM_OP_DATA_IN(len, bounce, 1)); + + status = spi_mem_exec_op(at25->spimem, &op); + dev_dbg(&at25->spimem->spi->dev, "read %d aux bytes --> %d\n", len, status); + if (status) + return status; + + memcpy(buf, bounce, len); + + return 0; +} + +static ssize_t sernum_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct at25_data *at25; + + at25 = dev_get_drvdata(dev); + return sysfs_emit(buf, "%*ph\n", (int)sizeof(at25->sernum), at25->sernum); +} +static DEVICE_ATTR_RO(sernum); + +static ssize_t jedec_id_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct at25_data *at25; + + at25 = dev_get_drvdata(dev); + + if (!at25->id_len) + return -EOPNOTSUPP; + + return sysfs_emit(buf, "%*phN\n", at25->id_len, at25->id); +} +static DEVICE_ATTR_RO(jedec_id); + +static struct attribute *at25_attrs[] = { + &dev_attr_sernum.attr, + &dev_attr_jedec_id.attr, + NULL, +}; +ATTRIBUTE_GROUPS(at25); + +/* + * Poll Read Status Register with timeout + * + * Return: + * 0, if the chip is ready + * [positive] Status Register value as-is, if the chip is busy + * [negative] error code in case of read failure + */ +static int at25_wait_ready(struct at25_data *at25) +{ + u8 *bounce __free(kfree) = kmalloc(1, GFP_KERNEL); + struct spi_mem_op op; + int status; + + if (!bounce) + return -ENOMEM; + + op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(AT25_RDSR, 1), + SPI_MEM_OP_NO_ADDR, + SPI_MEM_OP_NO_DUMMY, + SPI_MEM_OP_DATA_IN(1, bounce, 1)); + + read_poll_timeout(spi_mem_exec_op, status, + status || !(bounce[0] & AT25_SR_nRDY), false, + USEC_PER_MSEC, USEC_PER_MSEC * EE_TIMEOUT, + at25->spimem, &op); + if (status < 0) + return status; + if (!(bounce[0] & AT25_SR_nRDY)) + return 0; + + return bounce[0]; +} + +static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count) +{ + u8 *bounce __free(kfree) = kmalloc(min(count, io_limit), GFP_KERNEL); + struct at25_data *at25 = priv; + const char *buf = val; + unsigned int buf_size; + int status; + + if (unlikely(off >= at25->chip.byte_len)) + return -EFBIG; + if ((off + count) > at25->chip.byte_len) + count = at25->chip.byte_len - off; + if (unlikely(!count)) + return -EINVAL; + + buf_size = at25->chip.page_size; + + if (!bounce) + return -ENOMEM; + + /* + * For write, rollover is within the page ... so we write at + * most one page, then manually roll over to the next page. + */ + guard(mutex)(&at25->lock); + do { + struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(AT25_WREN, 1), + SPI_MEM_OP_NO_ADDR, + SPI_MEM_OP_NO_DUMMY, + SPI_MEM_OP_NO_DATA); + unsigned int segment; + + status = spi_mem_exec_op(at25->spimem, &op); + if (status < 0) { + dev_dbg(&at25->spimem->spi->dev, "WREN --> %d\n", status); + return status; + } + + /* Write as much of a page as we can */ + segment = buf_size - (off % buf_size); + if (segment > count) + segment = count; + if (segment > io_limit) + segment = io_limit; + + op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(at25_instr(at25, AT25_WRITE, off), + 1), + SPI_MEM_OP_ADDR(at25->addrlen, off, 1), + SPI_MEM_OP_NO_DUMMY, + SPI_MEM_OP_DATA_OUT(segment, bounce, 1)); + + status = spi_mem_adjust_op_size(at25->spimem, &op); + if (status) + return status; + segment = op.data.nbytes; + + memcpy(bounce, buf, segment); + + status = spi_mem_exec_op(at25->spimem, &op); + dev_dbg(&at25->spimem->spi->dev, "write %u bytes at %u --> %d\n", + segment, off, status); + if (status) + return status; + + /* + * REVISIT this should detect (or prevent) failed writes + * to read-only sections of the EEPROM... + */ + + status = at25_wait_ready(at25); + if (status < 0) { + dev_err_probe(&at25->spimem->spi->dev, status, + "Read Status Redister command failed\n"); + return status; + } + if (status) { + dev_dbg(&at25->spimem->spi->dev, + "Status %02x\n", status); + dev_err(&at25->spimem->spi->dev, + "write %u bytes offset %u, timeout after %u msecs\n", + segment, off, EE_TIMEOUT); + return -ETIMEDOUT; + } + + off += segment; + buf += segment; + count -= segment; + + } while (count > 0); + + return status; +} + +/*-------------------------------------------------------------------------*/ + +static int at25_fw_to_chip(struct device *dev, struct spi_eeprom *chip) +{ + u32 val; + int err; + + strscpy(chip->name, "at25", sizeof(chip->name)); + + err = device_property_read_u32(dev, "size", &val); + if (err) + err = device_property_read_u32(dev, "at25,byte-len", &val); + if (err) { + dev_err(dev, "Error: missing \"size\" property\n"); + return err; + } + chip->byte_len = val; + + err = device_property_read_u32(dev, "pagesize", &val); + if (err) + err = device_property_read_u32(dev, "at25,page-size", &val); + if (err) { + dev_err(dev, "Error: missing \"pagesize\" property\n"); + return err; + } + chip->page_size = val; + + err = device_property_read_u32(dev, "address-width", &val); + if (err) { + err = device_property_read_u32(dev, "at25,addr-mode", &val); + if (err) { + dev_err(dev, "Error: missing \"address-width\" property\n"); + return err; + } + chip->flags = (u16)val; + } else { + switch (val) { + case 9: + chip->flags |= EE_INSTR_BIT3_IS_ADDR; + fallthrough; + case 8: + chip->flags |= EE_ADDR1; + break; + case 16: + chip->flags |= EE_ADDR2; + break; + case 24: + chip->flags |= EE_ADDR3; + break; + default: + dev_err(dev, + "Error: bad \"address-width\" property: %u\n", + val); + return -ENODEV; + } + if (device_property_present(dev, "read-only")) + chip->flags |= EE_READONLY; + } + return 0; +} + +static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip) +{ + struct at25_data *at25 = container_of(chip, struct at25_data, chip); + u8 sernum[FM25_SN_LEN]; + u8 id[FM25_MAX_ID_LEN]; + u32 val; + int i; + + strscpy(chip->name, "fm25", sizeof(chip->name)); + + if (!device_property_read_u32(dev, "size", &val)) { + chip->byte_len = val; + } else { + /* Get ID of chip */ + fm25_aux_read(at25, id, FM25_RDID, FM25_MAX_ID_LEN); + + /* Store the unprocessed ID for exposing via sysfs */ + memcpy(at25->id, id, FM25_MAX_ID_LEN); + at25->id_len = FM25_MAX_ID_LEN; + + /* There are inside-out FRAM variations, detect them and reverse the ID bytes */ + if (id[6] == 0x7f && id[2] == 0xc2) + for (i = 0; i < ARRAY_SIZE(id) / 2; i++) { + u8 tmp = id[i]; + int j = ARRAY_SIZE(id) - i - 1; + + id[i] = id[j]; + id[j] = tmp; + } + + if (id[6] == 0xc2) { + at25->id_len = 9; + switch (id[7]) { + case 0x21 ... 0x26: + chip->byte_len = BIT(id[7] - 0x21 + 4) * 1024; + break; + case 0x2a ... 0x30: + /* CY15B102QN ... CY15B116QN */ + chip->byte_len = BIT(((id[7] >> 1) & 0xf) + 13); + break; + default: + dev_err(dev, "Error: unsupported size (id %02x)\n", id[7]); + return -ENODEV; + } + } else if (id[2] == 0x82 && id[3] == 0x06) { + at25->id_len = 8; + switch (id[1]) { + case 0x51 ... 0x54: + /* CY15B102QSN ... CY15B204QSN */ + chip->byte_len = BIT(((id[0] >> 3) & 0x1F) + 9); + break; + default: + dev_err(dev, "Error: unsupported product id %02x\n", id[1]); + return -ENODEV; + } + } else { + dev_err(dev, "Error: unrecognized JEDEC ID format: %*ph\n", + FM25_MAX_ID_LEN, id); + return -ENODEV; + } + + fm25_aux_read(at25, sernum, FM25_RDSN, FM25_SN_LEN); + /* Swap byte order */ + for (i = 0; i < FM25_SN_LEN; i++) + at25->sernum[i] = sernum[FM25_SN_LEN - 1 - i]; + } + + if (chip->byte_len > 64 * 1024) + chip->flags |= EE_ADDR3; + else + chip->flags |= EE_ADDR2; + + chip->page_size = PAGE_SIZE; + return 0; +} + +static const struct of_device_id at25_of_match[] = { + { .compatible = "atmel,at25" }, + { .compatible = "cypress,fm25" }, + { } +}; +MODULE_DEVICE_TABLE(of, at25_of_match); + +static const struct spi_device_id at25_spi_ids[] = { + { .name = "at25" }, + { .name = "fm25" }, + { } +}; +MODULE_DEVICE_TABLE(spi, at25_spi_ids); + +static int at25_probe(struct spi_mem *mem) +{ + struct spi_device *spi = mem->spi; + struct spi_eeprom *pdata; + struct at25_data *at25; + bool is_fram; + int err; + + at25 = devm_kzalloc(&spi->dev, sizeof(*at25), GFP_KERNEL); + if (!at25) + return -ENOMEM; + + at25->spimem = mem; + + /* + * Ping the chip ... the status register is pretty portable, + * unlike probing manufacturer IDs. + */ + err = at25_wait_ready(at25); + if (err < 0) + return dev_err_probe(&spi->dev, err, "Read Status Register command failed\n"); + if (err) { + dev_err(&spi->dev, "Not ready (%02x)\n", err); + return -ENXIO; + } + + mutex_init(&at25->lock); + spi_set_drvdata(spi, at25); + + is_fram = fwnode_device_is_compatible(dev_fwnode(&spi->dev), "cypress,fm25"); + + /* Chip description */ + pdata = dev_get_platdata(&spi->dev); + if (pdata) { + at25->chip = *pdata; + } else { + if (is_fram) + err = at25_fram_to_chip(&spi->dev, &at25->chip); + else + err = at25_fw_to_chip(&spi->dev, &at25->chip); + if (err) + return err; + } + + /* For now we only support 8/16/24 bit addressing */ + if (at25->chip.flags & EE_ADDR1) + at25->addrlen = 1; + else if (at25->chip.flags & EE_ADDR2) + at25->addrlen = 2; + else if (at25->chip.flags & EE_ADDR3) + at25->addrlen = 3; + else { + dev_dbg(&spi->dev, "unsupported address type\n"); + return -EINVAL; + } + + at25->nvmem_config.type = is_fram ? NVMEM_TYPE_FRAM : NVMEM_TYPE_EEPROM; + at25->nvmem_config.name = dev_name(&spi->dev); + at25->nvmem_config.dev = &spi->dev; + at25->nvmem_config.read_only = at25->chip.flags & EE_READONLY; + at25->nvmem_config.root_only = true; + at25->nvmem_config.owner = THIS_MODULE; + at25->nvmem_config.compat = true; + at25->nvmem_config.base_dev = &spi->dev; + at25->nvmem_config.reg_read = at25_ee_read; + at25->nvmem_config.reg_write = at25_ee_write; + at25->nvmem_config.priv = at25; + at25->nvmem_config.stride = 1; + at25->nvmem_config.word_size = 1; + at25->nvmem_config.size = at25->chip.byte_len; + + at25->nvmem = devm_nvmem_register(&spi->dev, &at25->nvmem_config); + if (IS_ERR(at25->nvmem)) + return PTR_ERR(at25->nvmem); + + dev_info(&spi->dev, "%d %s %s %s%s, pagesize %u\n", + (at25->chip.byte_len < 1024) ? + at25->chip.byte_len : (at25->chip.byte_len / 1024), + (at25->chip.byte_len < 1024) ? "Byte" : "KByte", + at25->chip.name, is_fram ? "fram" : "eeprom", + (at25->chip.flags & EE_READONLY) ? " (readonly)" : "", + at25->chip.page_size); + return 0; +} + +/*-------------------------------------------------------------------------*/ + +static struct spi_mem_driver at25_driver = { + .spidrv = { + .driver = { + .name = "at25", + .of_match_table = at25_of_match, + .dev_groups = at25_groups, + }, + .id_table = at25_spi_ids, + }, + .probe = at25_probe, +}; + +module_spi_mem_driver(at25_driver); + +MODULE_DESCRIPTION("Driver for most SPI EEPROMs"); +MODULE_AUTHOR("David Brownell"); +MODULE_LICENSE("GPL"); diff --git a/drivers/misc/eeprom/digsy_mtc_eeprom.c b/drivers/misc/eeprom/digsy_mtc_eeprom.c new file mode 100644 index 000000000..ee58f7ce5 --- /dev/null +++ b/drivers/misc/eeprom/digsy_mtc_eeprom.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * EEPROMs access control driver for display configuration EEPROMs + * on DigsyMTC board. + * + * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de> + * + * FIXME: this driver is used on a device-tree probed platform: it + * should be defined as a bit-banged SPI device and probed from the device + * tree and not like this with static grabbing of a few numbered GPIO + * lines at random. + * + * Add proper SPI and EEPROM in arch/powerpc/boot/dts/digsy_mtc.dts + * and delete this driver. + */ + +#include <linux/gpio/machine.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/property.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_gpio.h> + +#define GPIO_EEPROM_CLK 216 +#define GPIO_EEPROM_CS 210 +#define GPIO_EEPROM_DI 217 +#define GPIO_EEPROM_DO 249 +#define GPIO_EEPROM_OE 255 +#define EE_SPI_BUS_NUM 1 + +static const struct property_entry digsy_mtc_spi_properties[] = { + PROPERTY_ENTRY_U32("data-size", 8), + { } +}; + +static const struct software_node digsy_mtc_spi_node = { + .properties = digsy_mtc_spi_properties, +}; + +static struct spi_gpio_platform_data eeprom_spi_gpio_data = { + .num_chipselect = 1, +}; + +static struct platform_device digsy_mtc_eeprom = { + .name = "spi_gpio", + .id = EE_SPI_BUS_NUM, + .dev = { + .platform_data = &eeprom_spi_gpio_data, + }, +}; + +static struct gpiod_lookup_table eeprom_spi_gpiod_table = { + .dev_id = "spi_gpio.1", + .table = { + GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CLK, + "sck", GPIO_ACTIVE_HIGH), + GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DI, + "mosi", GPIO_ACTIVE_HIGH), + GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DO, + "miso", GPIO_ACTIVE_HIGH), + GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CS, + "cs", GPIO_ACTIVE_HIGH), + GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_OE, + "select", GPIO_ACTIVE_LOW), + { }, + }, +}; + +static struct spi_board_info digsy_mtc_eeprom_info[] __initdata = { + { + .modalias = "eeprom-93xx46", + .max_speed_hz = 1000000, + .bus_num = EE_SPI_BUS_NUM, + .chip_select = 0, + .mode = SPI_MODE_0, + }, +}; + +static int __init digsy_mtc_eeprom_devices_init(void) +{ + int ret; + + gpiod_add_lookup_table(&eeprom_spi_gpiod_table); + spi_register_board_info(digsy_mtc_eeprom_info, + ARRAY_SIZE(digsy_mtc_eeprom_info)); + + ret = device_add_software_node(&digsy_mtc_eeprom.dev, &digsy_mtc_spi_node); + if (ret) + return ret; + + ret = platform_device_register(&digsy_mtc_eeprom); + if (ret) + device_remove_software_node(&digsy_mtc_eeprom.dev); + + return ret; +} +device_initcall(digsy_mtc_eeprom_devices_init); diff --git a/drivers/misc/eeprom/ee1004.c b/drivers/misc/eeprom/ee1004.c new file mode 100644 index 000000000..923f404a4 --- /dev/null +++ b/drivers/misc/eeprom/ee1004.c @@ -0,0 +1,351 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ee1004 - driver for DDR4 SPD EEPROMs + * + * Copyright (C) 2017-2019 Jean Delvare + * + * Based on the at24 driver: + * Copyright (C) 2005-2007 David Brownell + * Copyright (C) 2008 Wolfram Sang, Pengutronix + */ + +#include <linux/device.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/nvmem-provider.h> + +/* + * DDR4 memory modules use special EEPROMs following the Jedec EE1004 + * specification. These are 512-byte EEPROMs using a single I2C address + * in the 0x50-0x57 range for data. One of two 256-byte page is selected + * by writing a command to I2C address 0x36 or 0x37 on the same I2C bus. + * + * Therefore we need to request these 2 additional addresses, and serialize + * access to all such EEPROMs with a single mutex. + * + * We assume it is safe to read up to 32 bytes at once from these EEPROMs. + * We use SMBus access even if I2C is available, these EEPROMs are small + * enough, and reading from them infrequent enough, that we favor simplicity + * over performance. + */ + +#define EE1004_MAX_BUSSES 8 +#define EE1004_ADDR_SET_PAGE 0x36 +#define EE1004_NUM_PAGES 2 +#define EE1004_PAGE_SIZE 256 +#define EE1004_PAGE_SHIFT 8 +#define EE1004_EEPROM_SIZE (EE1004_PAGE_SIZE * EE1004_NUM_PAGES) + +/* + * Mutex protects ee1004_set_page and ee1004_dev_count, and must be held + * from page selection to end of read. + */ +static DEFINE_MUTEX(ee1004_bus_lock); + +static struct ee1004_bus_data { + struct i2c_adapter *adap; + struct i2c_client *set_page[EE1004_NUM_PAGES]; + unsigned int dev_count; + int current_page; +} ee1004_bus_data[EE1004_MAX_BUSSES]; + +static const struct i2c_device_id ee1004_ids[] = { + { "ee1004" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ee1004_ids); + +/*-------------------------------------------------------------------------*/ + +static struct ee1004_bus_data *ee1004_get_bus_data(struct i2c_adapter *adap) +{ + int i; + + for (i = 0; i < EE1004_MAX_BUSSES; i++) + if (ee1004_bus_data[i].adap == adap) + return ee1004_bus_data + i; + + /* If not existent yet, create new entry */ + for (i = 0; i < EE1004_MAX_BUSSES; i++) + if (!ee1004_bus_data[i].adap) { + ee1004_bus_data[i].adap = adap; + return ee1004_bus_data + i; + } + + return NULL; +} + +static int ee1004_get_current_page(struct ee1004_bus_data *bd) +{ + int err; + + err = i2c_smbus_read_byte(bd->set_page[0]); + if (err == -ENXIO) { + /* Nack means page 1 is selected */ + return 1; + } + if (err < 0) { + /* Anything else is a real error, bail out */ + return err; + } + + /* Ack means page 0 is selected, returned value meaningless */ + return 0; +} + +static int ee1004_set_current_page(struct i2c_client *client, int page) +{ + struct ee1004_bus_data *bd = i2c_get_clientdata(client); + int ret; + + if (page == bd->current_page) + return 0; + + /* Data is ignored */ + ret = i2c_smbus_write_byte(bd->set_page[page], 0x00); + /* + * Don't give up just yet. Some memory modules will select the page + * but not ack the command. Check which page is selected now. + */ + if (ret == -ENXIO && ee1004_get_current_page(bd) == page) + ret = 0; + if (ret < 0) { + dev_err(&client->dev, "Failed to select page %d (%d)\n", page, ret); + return ret; + } + + dev_dbg(&client->dev, "Selected page %d\n", page); + bd->current_page = page; + + return 0; +} + +static ssize_t ee1004_eeprom_read(struct i2c_client *client, char *buf, + unsigned int offset, size_t count) +{ + int status, page; + + page = offset >> EE1004_PAGE_SHIFT; + offset &= (1 << EE1004_PAGE_SHIFT) - 1; + + status = ee1004_set_current_page(client, page); + if (status) + return status; + + /* Can't cross page boundaries */ + if (offset + count > EE1004_PAGE_SIZE) + count = EE1004_PAGE_SIZE - offset; + + if (count > I2C_SMBUS_BLOCK_MAX) + count = I2C_SMBUS_BLOCK_MAX; + + return i2c_smbus_read_i2c_block_data_or_emulated(client, offset, count, buf); +} + +static int ee1004_read(void *priv, unsigned int off, void *val, size_t count) +{ + struct i2c_client *client = priv; + char *buf = val; + int ret; + + if (unlikely(!count)) + return count; + + if (off + count > EE1004_EEPROM_SIZE) + return -EINVAL; + + /* + * Read data from chip, protecting against concurrent access to + * other EE1004 SPD EEPROMs on the same adapter. + */ + mutex_lock(&ee1004_bus_lock); + + while (count) { + ret = ee1004_eeprom_read(client, buf, off, count); + if (ret < 0) { + mutex_unlock(&ee1004_bus_lock); + return ret; + } + + buf += ret; + off += ret; + count -= ret; + } + + mutex_unlock(&ee1004_bus_lock); + + return 0; +} + +static void ee1004_probe_temp_sensor(struct i2c_client *client) +{ + struct i2c_board_info info = { .type = "jc42" }; + unsigned short addr = 0x18 | (client->addr & 7); + unsigned short addr_list[] = { addr, I2C_CLIENT_END }; + u8 data[2]; + int ret; + + /* byte 14, bit 7 is set if temp sensor is present */ + ret = ee1004_eeprom_read(client, data, 14, 1); + if (ret != 1) + return; + + if (!(data[0] & BIT(7))) { + /* + * If the SPD data suggests that there is no temperature + * sensor, it may still be there for SPD revision 1.0. + * See SPD Annex L, Revision 1 and 2, for details. + * Check DIMM type and SPD revision; if it is a DDR4 + * with SPD revision 1.0, check the thermal sensor address + * and instantiate the jc42 driver if a chip is found at + * that address. + * It is not necessary to check if there is a chip at the + * temperature sensor address since i2c_new_scanned_device() + * will do that and return silently if no chip is found. + */ + ret = ee1004_eeprom_read(client, data, 1, 2); + if (ret != 2 || data[0] != 0x10 || data[1] != 0x0c) + return; + } + i2c_new_scanned_device(client->adapter, &info, addr_list, NULL); +} + +static void ee1004_cleanup(int idx, struct ee1004_bus_data *bd) +{ + if (--bd->dev_count == 0) { + while (--idx >= 0) + i2c_unregister_device(bd->set_page[idx]); + memset(bd, 0, sizeof(struct ee1004_bus_data)); + } +} + +static void ee1004_cleanup_bus_data(void *data) +{ + struct ee1004_bus_data *bd = data; + + /* Remove page select clients if this is the last device */ + mutex_lock(&ee1004_bus_lock); + ee1004_cleanup(EE1004_NUM_PAGES, bd); + mutex_unlock(&ee1004_bus_lock); +} + +static int ee1004_init_bus_data(struct i2c_client *client) +{ + struct ee1004_bus_data *bd; + int err, cnr = 0; + + bd = ee1004_get_bus_data(client->adapter); + if (!bd) + return dev_err_probe(&client->dev, -ENOSPC, "Only %d busses supported", + EE1004_MAX_BUSSES); + + i2c_set_clientdata(client, bd); + + if (++bd->dev_count == 1) { + /* Use 2 dummy devices for page select command */ + for (cnr = 0; cnr < EE1004_NUM_PAGES; cnr++) { + struct i2c_client *cl; + + cl = i2c_new_dummy_device(client->adapter, EE1004_ADDR_SET_PAGE + cnr); + if (IS_ERR(cl)) { + err = PTR_ERR(cl); + goto err_out; + } + + bd->set_page[cnr] = cl; + } + + /* Remember current page to avoid unneeded page select */ + err = ee1004_get_current_page(bd); + if (err < 0) + goto err_out; + + dev_dbg(&client->dev, "Currently selected page: %d\n", err); + bd->current_page = err; + } + + return 0; + +err_out: + ee1004_cleanup(cnr, bd); + + return err; +} + +static int ee1004_probe(struct i2c_client *client) +{ + struct nvmem_config config = { + .dev = &client->dev, + .name = dev_name(&client->dev), + .id = NVMEM_DEVID_NONE, + .owner = THIS_MODULE, + .type = NVMEM_TYPE_EEPROM, + .read_only = true, + .root_only = false, + .reg_read = ee1004_read, + .size = EE1004_EEPROM_SIZE, + .word_size = 1, + .stride = 1, + .priv = client, + .compat = true, + .base_dev = &client->dev, + }; + struct nvmem_device *ndev; + int err; + + /* Make sure we can operate on this adapter */ + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_READ_I2C_BLOCK) && + !i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_READ_BYTE_DATA)) + return -EPFNOSUPPORT; + + err = i2c_smbus_read_byte(client); + if (err < 0) + return -ENODEV; + + mutex_lock(&ee1004_bus_lock); + + err = ee1004_init_bus_data(client); + if (err < 0) { + mutex_unlock(&ee1004_bus_lock); + return err; + } + + ee1004_probe_temp_sensor(client); + + mutex_unlock(&ee1004_bus_lock); + + err = devm_add_action_or_reset(&client->dev, ee1004_cleanup_bus_data, + i2c_get_clientdata(client)); + if (err < 0) + return err; + + ndev = devm_nvmem_register(&client->dev, &config); + if (IS_ERR(ndev)) + return PTR_ERR(ndev); + + dev_info(&client->dev, + "%u byte EE1004-compliant SPD EEPROM, read-only\n", + EE1004_EEPROM_SIZE); + + return 0; +} + +/*-------------------------------------------------------------------------*/ + +static struct i2c_driver ee1004_driver = { + .driver = { + .name = "ee1004", + }, + .probe = ee1004_probe, + .id_table = ee1004_ids, +}; +module_i2c_driver(ee1004_driver); + +MODULE_DESCRIPTION("Driver for EE1004-compliant DDR4 SPD EEPROMs"); +MODULE_AUTHOR("Jean Delvare"); +MODULE_LICENSE("GPL"); diff --git a/drivers/misc/eeprom/eeprom_93cx6.c b/drivers/misc/eeprom/eeprom_93cx6.c new file mode 100644 index 000000000..e6f0e0fc1 --- /dev/null +++ b/drivers/misc/eeprom/eeprom_93cx6.c @@ -0,0 +1,383 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2004 - 2006 rt2x00 SourceForge Project + * <http://rt2x00.serialmonkey.com> + * + * Module: eeprom_93cx6 + * Abstract: EEPROM reader routines for 93cx6 chipsets. + * Supported chipsets: 93c46 & 93c66. + */ + +#include <linux/bits.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/eeprom_93cx6.h> + +MODULE_AUTHOR("http://rt2x00.serialmonkey.com"); +MODULE_VERSION("1.0"); +MODULE_DESCRIPTION("EEPROM 93cx6 chip driver"); +MODULE_LICENSE("GPL"); + +static inline void eeprom_93cx6_pulse_high(struct eeprom_93cx6 *eeprom) +{ + eeprom->reg_data_clock = 1; + eeprom->register_write(eeprom); + + /* + * Add a short delay for the pulse to work. + * According to the specifications the "maximum minimum" + * time should be 450ns. + */ + ndelay(450); +} + +static inline void eeprom_93cx6_pulse_low(struct eeprom_93cx6 *eeprom) +{ + eeprom->reg_data_clock = 0; + eeprom->register_write(eeprom); + + /* + * Add a short delay for the pulse to work. + * According to the specifications the "maximum minimum" + * time should be 450ns. + */ + ndelay(450); +} + +static void eeprom_93cx6_startup(struct eeprom_93cx6 *eeprom) +{ + /* + * Clear all flags, and enable chip select. + */ + eeprom->register_read(eeprom); + eeprom->reg_data_in = 0; + eeprom->reg_data_out = 0; + eeprom->reg_data_clock = 0; + eeprom->reg_chip_select = 1; + eeprom->drive_data = 1; + eeprom->register_write(eeprom); + + /* + * kick a pulse. + */ + eeprom_93cx6_pulse_high(eeprom); + eeprom_93cx6_pulse_low(eeprom); +} + +static void eeprom_93cx6_cleanup(struct eeprom_93cx6 *eeprom) +{ + /* + * Clear chip_select and data_in flags. + */ + eeprom->register_read(eeprom); + eeprom->reg_data_in = 0; + eeprom->reg_chip_select = 0; + eeprom->register_write(eeprom); + + /* + * kick a pulse. + */ + eeprom_93cx6_pulse_high(eeprom); + eeprom_93cx6_pulse_low(eeprom); +} + +static void eeprom_93cx6_write_bits(struct eeprom_93cx6 *eeprom, + const u16 data, const u16 count) +{ + unsigned int i; + + eeprom->register_read(eeprom); + + /* + * Clear data flags. + */ + eeprom->reg_data_in = 0; + eeprom->reg_data_out = 0; + eeprom->drive_data = 1; + + /* + * Start writing all bits. + */ + for (i = count; i > 0; i--) { + /* + * Check if this bit needs to be set. + */ + eeprom->reg_data_in = !!(data & BIT(i - 1)); + + /* + * Write the bit to the eeprom register. + */ + eeprom->register_write(eeprom); + + /* + * Kick a pulse. + */ + eeprom_93cx6_pulse_high(eeprom); + eeprom_93cx6_pulse_low(eeprom); + } + + eeprom->reg_data_in = 0; + eeprom->register_write(eeprom); +} + +static void eeprom_93cx6_read_bits(struct eeprom_93cx6 *eeprom, + u16 *data, const u16 count) +{ + unsigned int i; + u16 buf = 0; + + eeprom->register_read(eeprom); + + /* + * Clear data flags. + */ + eeprom->reg_data_in = 0; + eeprom->reg_data_out = 0; + eeprom->drive_data = 0; + + /* + * Start reading all bits. + */ + for (i = count; i > 0; i--) { + eeprom_93cx6_pulse_high(eeprom); + + eeprom->register_read(eeprom); + + /* + * Clear data_in flag. + */ + eeprom->reg_data_in = 0; + + /* + * Read if the bit has been set. + */ + if (eeprom->reg_data_out) + buf |= BIT(i - 1); + + eeprom_93cx6_pulse_low(eeprom); + } + + *data = buf; +} + +/** + * eeprom_93cx6_read - Read a word from eeprom + * @eeprom: Pointer to eeprom structure + * @word: Word index from where we should start reading + * @data: target pointer where the information will have to be stored + * + * This function will read the eeprom data as host-endian word + * into the given data pointer. + */ +void eeprom_93cx6_read(struct eeprom_93cx6 *eeprom, const u8 word, + u16 *data) +{ + u16 command; + + /* + * Initialize the eeprom register + */ + eeprom_93cx6_startup(eeprom); + + /* + * Select the read opcode and the word to be read. + */ + command = (PCI_EEPROM_READ_OPCODE << eeprom->width) | word; + eeprom_93cx6_write_bits(eeprom, command, + PCI_EEPROM_WIDTH_OPCODE + eeprom->width); + + if (has_quirk_extra_read_cycle(eeprom)) { + eeprom_93cx6_pulse_high(eeprom); + eeprom_93cx6_pulse_low(eeprom); + } + + /* + * Read the requested 16 bits. + */ + eeprom_93cx6_read_bits(eeprom, data, 16); + + /* + * Cleanup eeprom register. + */ + eeprom_93cx6_cleanup(eeprom); +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_read); + +/** + * eeprom_93cx6_multiread - Read multiple words from eeprom + * @eeprom: Pointer to eeprom structure + * @word: Word index from where we should start reading + * @data: target pointer where the information will have to be stored + * @words: Number of words that should be read. + * + * This function will read all requested words from the eeprom, + * this is done by calling eeprom_93cx6_read() multiple times. + * But with the additional change that while the eeprom_93cx6_read + * will return host ordered bytes, this method will return little + * endian words. + */ +void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom, const u8 word, + __le16 *data, const u16 words) +{ + unsigned int i; + u16 tmp; + + for (i = 0; i < words; i++) { + tmp = 0; + eeprom_93cx6_read(eeprom, word + i, &tmp); + data[i] = cpu_to_le16(tmp); + } +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_multiread); + +/** + * eeprom_93cx6_readb - Read a byte from eeprom + * @eeprom: Pointer to eeprom structure + * @byte: Byte index from where we should start reading + * @data: target pointer where the information will have to be stored + * + * This function will read a byte of the eeprom data + * into the given data pointer. + */ +void eeprom_93cx6_readb(struct eeprom_93cx6 *eeprom, const u8 byte, + u8 *data) +{ + u16 command; + u16 tmp; + + /* + * Initialize the eeprom register + */ + eeprom_93cx6_startup(eeprom); + + /* + * Select the read opcode and the byte to be read. + */ + command = (PCI_EEPROM_READ_OPCODE << (eeprom->width + 1)) | byte; + eeprom_93cx6_write_bits(eeprom, command, + PCI_EEPROM_WIDTH_OPCODE + eeprom->width + 1); + + if (has_quirk_extra_read_cycle(eeprom)) { + eeprom_93cx6_pulse_high(eeprom); + eeprom_93cx6_pulse_low(eeprom); + } + + /* + * Read the requested 8 bits. + */ + eeprom_93cx6_read_bits(eeprom, &tmp, 8); + *data = tmp & 0xff; + + /* + * Cleanup eeprom register. + */ + eeprom_93cx6_cleanup(eeprom); +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_readb); + +/** + * eeprom_93cx6_multireadb - Read multiple bytes from eeprom + * @eeprom: Pointer to eeprom structure + * @byte: Index from where we should start reading + * @data: target pointer where the information will have to be stored + * @bytes: Number of bytes that should be read. + * + * This function will read all requested bytes from the eeprom, + * this is done by calling eeprom_93cx6_readb() multiple times. + */ +void eeprom_93cx6_multireadb(struct eeprom_93cx6 *eeprom, const u8 byte, + u8 *data, const u16 bytes) +{ + unsigned int i; + + for (i = 0; i < bytes; i++) + eeprom_93cx6_readb(eeprom, byte + i, &data[i]); +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_multireadb); + +/** + * eeprom_93cx6_wren - set the write enable state + * @eeprom: Pointer to eeprom structure + * @enable: true to enable writes, otherwise disable writes + * + * Set the EEPROM write enable state to either allow or deny + * writes depending on the @enable value. + */ +void eeprom_93cx6_wren(struct eeprom_93cx6 *eeprom, bool enable) +{ + u16 command; + + /* start the command */ + eeprom_93cx6_startup(eeprom); + + /* create command to enable/disable */ + + command = enable ? PCI_EEPROM_EWEN_OPCODE : PCI_EEPROM_EWDS_OPCODE; + command <<= (eeprom->width - 2); + + eeprom_93cx6_write_bits(eeprom, command, + PCI_EEPROM_WIDTH_OPCODE + eeprom->width); + + eeprom_93cx6_cleanup(eeprom); +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_wren); + +/** + * eeprom_93cx6_write - write data to the EEPROM + * @eeprom: Pointer to eeprom structure + * @addr: Address to write data to. + * @data: The data to write to address @addr. + * + * Write the @data to the specified @addr in the EEPROM and + * waiting for the device to finish writing. + * + * Note, since we do not expect large number of write operations + * we delay in between parts of the operation to avoid using excessive + * amounts of CPU time busy waiting. + */ +void eeprom_93cx6_write(struct eeprom_93cx6 *eeprom, u8 addr, u16 data) +{ + int timeout = 100; + u16 command; + + /* start the command */ + eeprom_93cx6_startup(eeprom); + + command = PCI_EEPROM_WRITE_OPCODE << eeprom->width; + command |= addr; + + /* send write command */ + eeprom_93cx6_write_bits(eeprom, command, + PCI_EEPROM_WIDTH_OPCODE + eeprom->width); + + /* send data */ + eeprom_93cx6_write_bits(eeprom, data, 16); + + /* get ready to check for busy */ + eeprom->drive_data = 0; + eeprom->reg_chip_select = 1; + eeprom->register_write(eeprom); + + /* wait at-least 250ns to get DO to be the busy signal */ + usleep_range(1000, 2000); + + /* wait for DO to go high to signify finish */ + + while (true) { + eeprom->register_read(eeprom); + + if (eeprom->reg_data_out) + break; + + usleep_range(1000, 2000); + + if (--timeout <= 0) { + printk(KERN_ERR "%s: timeout\n", __func__); + break; + } + } + + eeprom_93cx6_cleanup(eeprom); +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_write); diff --git a/drivers/misc/eeprom/eeprom_93xx46.c b/drivers/misc/eeprom/eeprom_93xx46.c new file mode 100644 index 000000000..f9c3ab52c --- /dev/null +++ b/drivers/misc/eeprom/eeprom_93xx46.c @@ -0,0 +1,560 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for 93xx46 EEPROMs + * + * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de> + */ + +#include <linux/array_size.h> +#include <linux/bits.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/gpio/consumer.h> +#include <linux/kstrtox.h> +#include <linux/log2.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/property.h> +#include <linux/slab.h> +#include <linux/spi/spi.h> +#include <linux/string_choices.h> + +#include <linux/nvmem-provider.h> + +struct eeprom_93xx46_platform_data { + unsigned char flags; +#define EE_ADDR8 0x01 /* 8 bit addr. cfg */ +#define EE_ADDR16 0x02 /* 16 bit addr. cfg */ +#define EE_READONLY 0x08 /* forbid writing */ +#define EE_SIZE1K 0x10 /* 1 kb of data, that is a 93xx46 */ +#define EE_SIZE2K 0x20 /* 2 kb of data, that is a 93xx56 */ +#define EE_SIZE4K 0x40 /* 4 kb of data, that is a 93xx66 */ + + unsigned int quirks; +/* Single word read transfers only; no sequential read. */ +#define EEPROM_93XX46_QUIRK_SINGLE_WORD_READ (1 << 0) +/* Instructions such as EWEN are (addrlen + 2) in length. */ +#define EEPROM_93XX46_QUIRK_INSTRUCTION_LENGTH (1 << 1) +/* Add extra cycle after address during a read */ +#define EEPROM_93XX46_QUIRK_EXTRA_READ_CYCLE BIT(2) + + struct gpio_desc *select; +}; + +#define OP_START 0x4 +#define OP_WRITE (OP_START | 0x1) +#define OP_READ (OP_START | 0x2) +/* The following addresses are offset for the 1K EEPROM variant in 16-bit mode */ +#define ADDR_EWDS 0x00 +#define ADDR_ERAL 0x20 +#define ADDR_EWEN 0x30 + +struct eeprom_93xx46_devtype_data { + unsigned int quirks; + unsigned char flags; +}; + +static const struct eeprom_93xx46_devtype_data at93c46_data = { + .flags = EE_SIZE1K, +}; + +static const struct eeprom_93xx46_devtype_data at93c56_data = { + .flags = EE_SIZE2K, +}; + +static const struct eeprom_93xx46_devtype_data at93c66_data = { + .flags = EE_SIZE4K, +}; + +static const struct eeprom_93xx46_devtype_data atmel_at93c46d_data = { + .flags = EE_SIZE1K, + .quirks = EEPROM_93XX46_QUIRK_SINGLE_WORD_READ | + EEPROM_93XX46_QUIRK_INSTRUCTION_LENGTH, +}; + +static const struct eeprom_93xx46_devtype_data microchip_93lc46b_data = { + .flags = EE_SIZE1K, + .quirks = EEPROM_93XX46_QUIRK_EXTRA_READ_CYCLE, +}; + +struct eeprom_93xx46_dev { + struct spi_device *spi; + struct eeprom_93xx46_platform_data *pdata; + struct mutex lock; + struct nvmem_config nvmem_config; + struct nvmem_device *nvmem; + int addrlen; + int size; +}; + +static inline bool has_quirk_single_word_read(struct eeprom_93xx46_dev *edev) +{ + return edev->pdata->quirks & EEPROM_93XX46_QUIRK_SINGLE_WORD_READ; +} + +static inline bool has_quirk_instruction_length(struct eeprom_93xx46_dev *edev) +{ + return edev->pdata->quirks & EEPROM_93XX46_QUIRK_INSTRUCTION_LENGTH; +} + +static inline bool has_quirk_extra_read_cycle(struct eeprom_93xx46_dev *edev) +{ + return edev->pdata->quirks & EEPROM_93XX46_QUIRK_EXTRA_READ_CYCLE; +} + +static int eeprom_93xx46_read(void *priv, unsigned int off, + void *val, size_t count) +{ + struct eeprom_93xx46_dev *edev = priv; + char *buf = val; + int err = 0; + int bits; + + if (unlikely(off >= edev->size)) + return 0; + if ((off + count) > edev->size) + count = edev->size - off; + if (unlikely(!count)) + return count; + + mutex_lock(&edev->lock); + + gpiod_set_value_cansleep(edev->pdata->select, 1); + + /* The opcode in front of the address is three bits. */ + bits = edev->addrlen + 3; + + while (count) { + struct spi_message m; + struct spi_transfer t[2] = {}; + u16 cmd_addr = OP_READ << edev->addrlen; + size_t nbytes = count; + + if (edev->pdata->flags & EE_ADDR8) { + cmd_addr |= off; + if (has_quirk_single_word_read(edev)) + nbytes = 1; + } else { + cmd_addr |= (off >> 1); + if (has_quirk_single_word_read(edev)) + nbytes = 2; + } + + dev_dbg(&edev->spi->dev, "read cmd 0x%x, %d Hz\n", + cmd_addr, edev->spi->max_speed_hz); + + if (has_quirk_extra_read_cycle(edev)) { + cmd_addr <<= 1; + bits += 1; + } + + t[0].tx_buf = (char *)&cmd_addr; + t[0].len = 2; + t[0].bits_per_word = bits; + + t[1].rx_buf = buf; + t[1].len = count; + t[1].bits_per_word = 8; + + spi_message_init_with_transfers(&m, t, ARRAY_SIZE(t)); + + err = spi_sync(edev->spi, &m); + /* have to wait at least Tcsl ns */ + ndelay(250); + + if (err) { + dev_err(&edev->spi->dev, "read %zu bytes at %u: err. %d\n", + nbytes, off, err); + break; + } + + buf += nbytes; + off += nbytes; + count -= nbytes; + } + + gpiod_set_value_cansleep(edev->pdata->select, 0); + + mutex_unlock(&edev->lock); + + return err; +} + +static int eeprom_93xx46_ew(struct eeprom_93xx46_dev *edev, int is_on) +{ + struct spi_message m; + struct spi_transfer t = {}; + int bits, ret; + u16 cmd_addr; + + /* The opcode in front of the address is three bits. */ + bits = edev->addrlen + 3; + + cmd_addr = OP_START << edev->addrlen; + cmd_addr |= (is_on ? ADDR_EWEN : ADDR_EWDS) << (edev->addrlen - 6); + + if (has_quirk_instruction_length(edev)) { + cmd_addr <<= 2; + bits += 2; + } + + dev_dbg(&edev->spi->dev, "ew %s cmd 0x%04x, %d bits\n", + str_enable_disable(is_on), cmd_addr, bits); + + t.tx_buf = &cmd_addr; + t.len = 2; + t.bits_per_word = bits; + + spi_message_init_with_transfers(&m, &t, 1); + + mutex_lock(&edev->lock); + + gpiod_set_value_cansleep(edev->pdata->select, 1); + + ret = spi_sync(edev->spi, &m); + /* have to wait at least Tcsl ns */ + ndelay(250); + if (ret) + dev_err(&edev->spi->dev, "erase/write %s error %d\n", + str_enable_disable(is_on), ret); + + gpiod_set_value_cansleep(edev->pdata->select, 0); + + mutex_unlock(&edev->lock); + return ret; +} + +static ssize_t +eeprom_93xx46_write_word(struct eeprom_93xx46_dev *edev, + const char *buf, unsigned int off) +{ + struct spi_message m; + struct spi_transfer t[2] = {}; + int bits, data_len, ret; + u16 cmd_addr; + + if (unlikely(off >= edev->size)) + return -EINVAL; + + /* The opcode in front of the address is three bits. */ + bits = edev->addrlen + 3; + + cmd_addr = OP_WRITE << edev->addrlen; + + if (edev->pdata->flags & EE_ADDR8) { + cmd_addr |= off; + data_len = 1; + } else { + cmd_addr |= (off >> 1); + data_len = 2; + } + + dev_dbg(&edev->spi->dev, "write cmd 0x%x\n", cmd_addr); + + t[0].tx_buf = (char *)&cmd_addr; + t[0].len = 2; + t[0].bits_per_word = bits; + + t[1].tx_buf = buf; + t[1].len = data_len; + t[1].bits_per_word = 8; + + spi_message_init_with_transfers(&m, t, ARRAY_SIZE(t)); + + ret = spi_sync(edev->spi, &m); + /* have to wait program cycle time Twc ms */ + mdelay(6); + return ret; +} + +static int eeprom_93xx46_write(void *priv, unsigned int off, + void *val, size_t count) +{ + struct eeprom_93xx46_dev *edev = priv; + char *buf = val; + int ret, step = 1; + unsigned int i; + + if (unlikely(off >= edev->size)) + return -EFBIG; + if ((off + count) > edev->size) + count = edev->size - off; + if (unlikely(!count)) + return count; + + /* only write even number of bytes on 16-bit devices */ + if (edev->pdata->flags & EE_ADDR16) { + step = 2; + count &= ~1; + } + + /* erase/write enable */ + ret = eeprom_93xx46_ew(edev, 1); + if (ret) + return ret; + + mutex_lock(&edev->lock); + + gpiod_set_value_cansleep(edev->pdata->select, 1); + + for (i = 0; i < count; i += step) { + ret = eeprom_93xx46_write_word(edev, &buf[i], off + i); + if (ret) { + dev_err(&edev->spi->dev, "write failed at %u: %d\n", off + i, ret); + break; + } + } + + gpiod_set_value_cansleep(edev->pdata->select, 0); + + mutex_unlock(&edev->lock); + + /* erase/write disable */ + eeprom_93xx46_ew(edev, 0); + return ret; +} + +static int eeprom_93xx46_eral(struct eeprom_93xx46_dev *edev) +{ + struct spi_message m; + struct spi_transfer t = {}; + int bits, ret; + u16 cmd_addr; + + /* The opcode in front of the address is three bits. */ + bits = edev->addrlen + 3; + + cmd_addr = OP_START << edev->addrlen; + cmd_addr |= ADDR_ERAL << (edev->addrlen - 6); + + if (has_quirk_instruction_length(edev)) { + cmd_addr <<= 2; + bits += 2; + } + + dev_dbg(&edev->spi->dev, "eral cmd 0x%04x, %d bits\n", cmd_addr, bits); + + t.tx_buf = &cmd_addr; + t.len = 2; + t.bits_per_word = bits; + + spi_message_init_with_transfers(&m, &t, 1); + + mutex_lock(&edev->lock); + + gpiod_set_value_cansleep(edev->pdata->select, 1); + + ret = spi_sync(edev->spi, &m); + if (ret) + dev_err(&edev->spi->dev, "erase error %d\n", ret); + /* have to wait erase cycle time Tec ms */ + mdelay(6); + + gpiod_set_value_cansleep(edev->pdata->select, 0); + + mutex_unlock(&edev->lock); + return ret; +} + +static ssize_t erase_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct eeprom_93xx46_dev *edev = dev_get_drvdata(dev); + bool erase; + int ret; + + ret = kstrtobool(buf, &erase); + if (ret) + return ret; + + if (erase) { + ret = eeprom_93xx46_ew(edev, 1); + if (ret) + return ret; + ret = eeprom_93xx46_eral(edev); + if (ret) + return ret; + ret = eeprom_93xx46_ew(edev, 0); + if (ret) + return ret; + } + return count; +} +static DEVICE_ATTR_WO(erase); + +static const struct of_device_id eeprom_93xx46_of_table[] = { + { .compatible = "eeprom-93xx46", .data = &at93c46_data, }, + { .compatible = "atmel,at93c46", .data = &at93c46_data, }, + { .compatible = "atmel,at93c46d", .data = &atmel_at93c46d_data, }, + { .compatible = "atmel,at93c56", .data = &at93c56_data, }, + { .compatible = "atmel,at93c66", .data = &at93c66_data, }, + { .compatible = "microchip,93lc46b", .data = µchip_93lc46b_data, }, + {} +}; +MODULE_DEVICE_TABLE(of, eeprom_93xx46_of_table); + +static const struct spi_device_id eeprom_93xx46_spi_ids[] = { + { .name = "eeprom-93xx46", + .driver_data = (kernel_ulong_t)&at93c46_data, }, + { .name = "at93c46", + .driver_data = (kernel_ulong_t)&at93c46_data, }, + { .name = "at93c46d", + .driver_data = (kernel_ulong_t)&atmel_at93c46d_data, }, + { .name = "at93c56", + .driver_data = (kernel_ulong_t)&at93c56_data, }, + { .name = "at93c66", + .driver_data = (kernel_ulong_t)&at93c66_data, }, + { .name = "93lc46b", + .driver_data = (kernel_ulong_t)µchip_93lc46b_data, }, + {} +}; +MODULE_DEVICE_TABLE(spi, eeprom_93xx46_spi_ids); + +static int eeprom_93xx46_probe_fw(struct device *dev) +{ + const struct eeprom_93xx46_devtype_data *data; + struct eeprom_93xx46_platform_data *pd; + u32 tmp; + int ret; + + pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL); + if (!pd) + return -ENOMEM; + + ret = device_property_read_u32(dev, "data-size", &tmp); + if (ret < 0) { + dev_err(dev, "data-size property not found\n"); + return ret; + } + + if (tmp == 8) { + pd->flags |= EE_ADDR8; + } else if (tmp == 16) { + pd->flags |= EE_ADDR16; + } else { + dev_err(dev, "invalid data-size (%d)\n", tmp); + return -EINVAL; + } + + if (device_property_read_bool(dev, "read-only")) + pd->flags |= EE_READONLY; + + pd->select = devm_gpiod_get_optional(dev, "select", GPIOD_OUT_LOW); + if (IS_ERR(pd->select)) + return PTR_ERR(pd->select); + gpiod_set_consumer_name(pd->select, "93xx46 EEPROMs OE"); + + data = spi_get_device_match_data(to_spi_device(dev)); + if (data) { + pd->quirks = data->quirks; + pd->flags |= data->flags; + } + + dev->platform_data = pd; + + return 0; +} + +static int eeprom_93xx46_probe(struct spi_device *spi) +{ + struct eeprom_93xx46_platform_data *pd; + struct eeprom_93xx46_dev *edev; + struct device *dev = &spi->dev; + int err; + + err = eeprom_93xx46_probe_fw(dev); + if (err < 0) + return err; + + pd = spi->dev.platform_data; + if (!pd) { + dev_err(&spi->dev, "missing platform data\n"); + return -ENODEV; + } + + edev = devm_kzalloc(&spi->dev, sizeof(*edev), GFP_KERNEL); + if (!edev) + return -ENOMEM; + + if (pd->flags & EE_SIZE1K) + edev->size = 128; + else if (pd->flags & EE_SIZE2K) + edev->size = 256; + else if (pd->flags & EE_SIZE4K) + edev->size = 512; + else { + dev_err(&spi->dev, "unspecified size\n"); + return -EINVAL; + } + + if (pd->flags & EE_ADDR8) + edev->addrlen = ilog2(edev->size); + else if (pd->flags & EE_ADDR16) + edev->addrlen = ilog2(edev->size) - 1; + else { + dev_err(&spi->dev, "unspecified address type\n"); + return -EINVAL; + } + + mutex_init(&edev->lock); + + edev->spi = spi; + edev->pdata = pd; + + edev->nvmem_config.type = NVMEM_TYPE_EEPROM; + edev->nvmem_config.name = dev_name(&spi->dev); + edev->nvmem_config.dev = &spi->dev; + edev->nvmem_config.read_only = pd->flags & EE_READONLY; + edev->nvmem_config.root_only = true; + edev->nvmem_config.owner = THIS_MODULE; + edev->nvmem_config.compat = true; + edev->nvmem_config.base_dev = &spi->dev; + edev->nvmem_config.reg_read = eeprom_93xx46_read; + edev->nvmem_config.reg_write = eeprom_93xx46_write; + edev->nvmem_config.priv = edev; + edev->nvmem_config.stride = 4; + edev->nvmem_config.word_size = 1; + edev->nvmem_config.size = edev->size; + + edev->nvmem = devm_nvmem_register(&spi->dev, &edev->nvmem_config); + if (IS_ERR(edev->nvmem)) + return PTR_ERR(edev->nvmem); + + dev_info(&spi->dev, "%d-bit eeprom containing %d bytes %s\n", + (pd->flags & EE_ADDR8) ? 8 : 16, + edev->size, + (pd->flags & EE_READONLY) ? "(readonly)" : ""); + + if (!(pd->flags & EE_READONLY)) { + if (device_create_file(&spi->dev, &dev_attr_erase)) + dev_err(&spi->dev, "can't create erase interface\n"); + } + + spi_set_drvdata(spi, edev); + return 0; +} + +static void eeprom_93xx46_remove(struct spi_device *spi) +{ + struct eeprom_93xx46_dev *edev = spi_get_drvdata(spi); + + if (!(edev->pdata->flags & EE_READONLY)) + device_remove_file(&spi->dev, &dev_attr_erase); +} + +static struct spi_driver eeprom_93xx46_driver = { + .driver = { + .name = "93xx46", + .of_match_table = eeprom_93xx46_of_table, + }, + .probe = eeprom_93xx46_probe, + .remove = eeprom_93xx46_remove, + .id_table = eeprom_93xx46_spi_ids, +}; + +module_spi_driver(eeprom_93xx46_driver); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Driver for 93xx46 EEPROMs"); +MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>"); +MODULE_ALIAS("spi:93xx46"); diff --git a/drivers/misc/eeprom/idt_89hpesx.c b/drivers/misc/eeprom/idt_89hpesx.c new file mode 100644 index 000000000..e056d2dea --- /dev/null +++ b/drivers/misc/eeprom/idt_89hpesx.c @@ -0,0 +1,1515 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2016 T-Platforms. All Rights Reserved. + * + * IDT PCIe-switch NTB Linux driver + * + * Contact Information: + * Serge Semin <fancer.lancer@gmail.com>, <Sergey.Semin@t-platforms.ru> + */ +/* + * NOTE of the IDT 89HPESx SMBus-slave interface driver + * This driver primarily is developed to have an access to EEPROM device of + * IDT PCIe-switches. IDT provides a simple SMBus interface to perform IO- + * operations from/to EEPROM, which is located at private (so called Master) + * SMBus of switches. Using that interface this the driver creates a simple + * binary sysfs-file in the device directory: + * /sys/bus/i2c/devices/<bus>-<devaddr>/eeprom + * In case if read-only flag is specified in the dts-node of device desription, + * User-space applications won't be able to write to the EEPROM sysfs-node. + * Additionally IDT 89HPESx SMBus interface has an ability to write/read + * data of device CSRs. This driver exposes debugf-file to perform simple IO + * operations using that ability for just basic debug purpose. Particularly + * next file is created in the specific debugfs-directory: + * /sys/kernel/debug/idt_csr/ + * Format of the debugfs-node is: + * $ cat /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>; + * <CSR address>:<CSR value> + * So reading the content of the file gives current CSR address and it value. + * If User-space application wishes to change current CSR address, + * it can just write a proper value to the sysfs-file: + * $ echo "<CSR address>" > /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname> + * If it wants to change the CSR value as well, the format of the write + * operation is: + * $ echo "<CSR address>:<CSR value>" > \ + * /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>; + * CSR address and value can be any of hexadecimal, decimal or octal format. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/sizes.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/sysfs.h> +#include <linux/debugfs.h> +#include <linux/property.h> +#include <linux/i2c.h> +#include <linux/pci_ids.h> +#include <linux/delay.h> + +#define IDT_NAME "89hpesx" +#define IDT_89HPESX_DESC "IDT 89HPESx SMBus-slave interface driver" +#define IDT_89HPESX_VER "1.0" + +MODULE_DESCRIPTION(IDT_89HPESX_DESC); +MODULE_VERSION(IDT_89HPESX_VER); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("T-platforms"); + +/* + * struct idt_89hpesx_dev - IDT 89HPESx device data structure + * @eesize: Size of EEPROM in bytes (calculated from "idt,eecompatible") + * @eero: EEPROM Read-only flag + * @eeaddr: EEPROM custom address + * + * @inieecmd: Initial cmd value for EEPROM read/write operations + * @inicsrcmd: Initial cmd value for CSR read/write operations + * @iniccode: Initialial command code value for IO-operations + * + * @csr: CSR address to perform read operation + * + * @smb_write: SMBus write method + * @smb_read: SMBus read method + * @smb_mtx: SMBus mutex + * + * @client: i2c client used to perform IO operations + * + * @ee_file: EEPROM read/write sysfs-file + */ +struct idt_smb_seq; +struct idt_89hpesx_dev { + u32 eesize; + bool eero; + u8 eeaddr; + + u8 inieecmd; + u8 inicsrcmd; + u8 iniccode; + + u16 csr; + + int (*smb_write)(struct idt_89hpesx_dev *, const struct idt_smb_seq *); + int (*smb_read)(struct idt_89hpesx_dev *, struct idt_smb_seq *); + struct mutex smb_mtx; + + struct i2c_client *client; + + struct bin_attribute *ee_file; + struct dentry *csr_dir; +}; + +/* + * struct idt_smb_seq - sequence of data to be read/written from/to IDT 89HPESx + * @ccode: SMBus command code + * @bytecnt: Byte count of operation + * @data: Data to by written + */ +struct idt_smb_seq { + u8 ccode; + u8 bytecnt; + u8 *data; +}; + +/* + * struct idt_eeprom_seq - sequence of data to be read/written from/to EEPROM + * @cmd: Transaction CMD + * @eeaddr: EEPROM custom address + * @memaddr: Internal memory address of EEPROM + * @data: Data to be written at the memory address + */ +struct idt_eeprom_seq { + u8 cmd; + u8 eeaddr; + __le16 memaddr; + u8 data; +} __packed; + +/* + * struct idt_csr_seq - sequence of data to be read/written from/to CSR + * @cmd: Transaction CMD + * @csraddr: Internal IDT device CSR address + * @data: Data to be read/written from/to the CSR address + */ +struct idt_csr_seq { + u8 cmd; + __le16 csraddr; + __le32 data; +} __packed; + +/* + * SMBus command code macros + * @CCODE_END: Indicates the end of transaction + * @CCODE_START: Indicates the start of transaction + * @CCODE_CSR: CSR read/write transaction + * @CCODE_EEPROM: EEPROM read/write transaction + * @CCODE_BYTE: Supplied data has BYTE length + * @CCODE_WORD: Supplied data has WORD length + * @CCODE_BLOCK: Supplied data has variable length passed in bytecnt + * byte right following CCODE byte + */ +#define CCODE_END ((u8)0x01) +#define CCODE_START ((u8)0x02) +#define CCODE_CSR ((u8)0x00) +#define CCODE_EEPROM ((u8)0x04) +#define CCODE_BYTE ((u8)0x00) +#define CCODE_WORD ((u8)0x20) +#define CCODE_BLOCK ((u8)0x40) +#define CCODE_PEC ((u8)0x80) + +/* + * EEPROM command macros + * @EEPROM_OP_WRITE: EEPROM write operation + * @EEPROM_OP_READ: EEPROM read operation + * @EEPROM_USA: Use specified address of EEPROM + * @EEPROM_NAERR: EEPROM device is not ready to respond + * @EEPROM_LAERR: EEPROM arbitration loss error + * @EEPROM_MSS: EEPROM misplace start & stop bits error + * @EEPROM_WR_CNT: Bytes count to perform write operation + * @EEPROM_WRRD_CNT: Bytes count to write before reading + * @EEPROM_RD_CNT: Bytes count to perform read operation + * @EEPROM_DEF_SIZE: Fall back size of EEPROM + * @EEPROM_DEF_ADDR: Defatul EEPROM address + * @EEPROM_TOUT: Timeout before retry read operation if eeprom is busy + */ +#define EEPROM_OP_WRITE ((u8)0x00) +#define EEPROM_OP_READ ((u8)0x01) +#define EEPROM_USA ((u8)0x02) +#define EEPROM_NAERR ((u8)0x08) +#define EEPROM_LAERR ((u8)0x10) +#define EEPROM_MSS ((u8)0x20) +#define EEPROM_WR_CNT ((u8)5) +#define EEPROM_WRRD_CNT ((u8)4) +#define EEPROM_RD_CNT ((u8)5) +#define EEPROM_DEF_SIZE ((u16)4096) +#define EEPROM_DEF_ADDR ((u8)0x50) +#define EEPROM_TOUT (100) + +/* + * CSR command macros + * @CSR_DWE: Enable all four bytes of the operation + * @CSR_OP_WRITE: CSR write operation + * @CSR_OP_READ: CSR read operation + * @CSR_RERR: Read operation error + * @CSR_WERR: Write operation error + * @CSR_WR_CNT: Bytes count to perform write operation + * @CSR_WRRD_CNT: Bytes count to write before reading + * @CSR_RD_CNT: Bytes count to perform read operation + * @CSR_MAX: Maximum CSR address + * @CSR_DEF: Default CSR address + * @CSR_REAL_ADDR: CSR real unshifted address + */ +#define CSR_DWE ((u8)0x0F) +#define CSR_OP_WRITE ((u8)0x00) +#define CSR_OP_READ ((u8)0x10) +#define CSR_RERR ((u8)0x40) +#define CSR_WERR ((u8)0x80) +#define CSR_WR_CNT ((u8)7) +#define CSR_WRRD_CNT ((u8)3) +#define CSR_RD_CNT ((u8)7) +#define CSR_MAX ((u32)0x3FFFF) +#define CSR_DEF ((u16)0x0000) +#define CSR_REAL_ADDR(val) ((unsigned int)val << 2) + +/* + * IDT 89HPESx basic register + * @IDT_VIDDID_CSR: PCIe VID and DID of IDT 89HPESx + * @IDT_VID_MASK: Mask of VID + */ +#define IDT_VIDDID_CSR ((u32)0x0000) +#define IDT_VID_MASK ((u32)0xFFFF) + +/* + * IDT 89HPESx can send NACK when new command is sent before previous one + * fininshed execution. In this case driver retries operation + * certain times. + * @RETRY_CNT: Number of retries before giving up and fail + * @idt_smb_safe: Generate a retry loop on corresponding SMBus method + */ +#define RETRY_CNT (128) +#define idt_smb_safe(ops, args...) ({ \ + int __retry = RETRY_CNT; \ + s32 __sts; \ + do { \ + __sts = i2c_smbus_ ## ops ## _data(args); \ + } while (__retry-- && __sts < 0); \ + __sts; \ +}) + +/*=========================================================================== + * i2c bus level IO-operations + *=========================================================================== + */ + +/* + * idt_smb_write_byte() - SMBus write method when I2C_SMBUS_BYTE_DATA operation + * is only available + * @pdev: Pointer to the driver data + * @seq: Sequence of data to be written + */ +static int idt_smb_write_byte(struct idt_89hpesx_dev *pdev, + const struct idt_smb_seq *seq) +{ + s32 sts; + u8 ccode; + int idx; + + /* Loop over the supplied data sending byte one-by-one */ + for (idx = 0; idx < seq->bytecnt; idx++) { + /* Collect the command code byte */ + ccode = seq->ccode | CCODE_BYTE; + if (idx == 0) + ccode |= CCODE_START; + if (idx == seq->bytecnt - 1) + ccode |= CCODE_END; + + /* Send data to the device */ + sts = idt_smb_safe(write_byte, pdev->client, ccode, + seq->data[idx]); + if (sts != 0) + return (int)sts; + } + + return 0; +} + +/* + * idt_smb_read_byte() - SMBus read method when I2C_SMBUS_BYTE_DATA operation + * is only available + * @pdev: Pointer to the driver data + * @seq: Buffer to read data to + */ +static int idt_smb_read_byte(struct idt_89hpesx_dev *pdev, + struct idt_smb_seq *seq) +{ + s32 sts; + u8 ccode; + int idx; + + /* Loop over the supplied buffer receiving byte one-by-one */ + for (idx = 0; idx < seq->bytecnt; idx++) { + /* Collect the command code byte */ + ccode = seq->ccode | CCODE_BYTE; + if (idx == 0) + ccode |= CCODE_START; + if (idx == seq->bytecnt - 1) + ccode |= CCODE_END; + + /* Read data from the device */ + sts = idt_smb_safe(read_byte, pdev->client, ccode); + if (sts < 0) + return (int)sts; + + seq->data[idx] = (u8)sts; + } + + return 0; +} + +/* + * idt_smb_write_word() - SMBus write method when I2C_SMBUS_BYTE_DATA and + * I2C_FUNC_SMBUS_WORD_DATA operations are available + * @pdev: Pointer to the driver data + * @seq: Sequence of data to be written + */ +static int idt_smb_write_word(struct idt_89hpesx_dev *pdev, + const struct idt_smb_seq *seq) +{ + s32 sts; + u8 ccode; + int idx, evencnt; + + /* Calculate the even count of data to send */ + evencnt = seq->bytecnt - (seq->bytecnt % 2); + + /* Loop over the supplied data sending two bytes at a time */ + for (idx = 0; idx < evencnt; idx += 2) { + /* Collect the command code byte */ + ccode = seq->ccode | CCODE_WORD; + if (idx == 0) + ccode |= CCODE_START; + if (idx == evencnt - 2) + ccode |= CCODE_END; + + /* Send word data to the device */ + sts = idt_smb_safe(write_word, pdev->client, ccode, + *(u16 *)&seq->data[idx]); + if (sts != 0) + return (int)sts; + } + + /* If there is odd number of bytes then send just one last byte */ + if (seq->bytecnt != evencnt) { + /* Collect the command code byte */ + ccode = seq->ccode | CCODE_BYTE | CCODE_END; + if (idx == 0) + ccode |= CCODE_START; + + /* Send byte data to the device */ + sts = idt_smb_safe(write_byte, pdev->client, ccode, + seq->data[idx]); + if (sts != 0) + return (int)sts; + } + + return 0; +} + +/* + * idt_smb_read_word() - SMBus read method when I2C_SMBUS_BYTE_DATA and + * I2C_FUNC_SMBUS_WORD_DATA operations are available + * @pdev: Pointer to the driver data + * @seq: Buffer to read data to + */ +static int idt_smb_read_word(struct idt_89hpesx_dev *pdev, + struct idt_smb_seq *seq) +{ + s32 sts; + u8 ccode; + int idx, evencnt; + + /* Calculate the even count of data to send */ + evencnt = seq->bytecnt - (seq->bytecnt % 2); + + /* Loop over the supplied data reading two bytes at a time */ + for (idx = 0; idx < evencnt; idx += 2) { + /* Collect the command code byte */ + ccode = seq->ccode | CCODE_WORD; + if (idx == 0) + ccode |= CCODE_START; + if (idx == evencnt - 2) + ccode |= CCODE_END; + + /* Read word data from the device */ + sts = idt_smb_safe(read_word, pdev->client, ccode); + if (sts < 0) + return (int)sts; + + *(u16 *)&seq->data[idx] = (u16)sts; + } + + /* If there is odd number of bytes then receive just one last byte */ + if (seq->bytecnt != evencnt) { + /* Collect the command code byte */ + ccode = seq->ccode | CCODE_BYTE | CCODE_END; + if (idx == 0) + ccode |= CCODE_START; + + /* Read last data byte from the device */ + sts = idt_smb_safe(read_byte, pdev->client, ccode); + if (sts < 0) + return (int)sts; + + seq->data[idx] = (u8)sts; + } + + return 0; +} + +/* + * idt_smb_write_block() - SMBus write method when I2C_SMBUS_BLOCK_DATA + * operation is available + * @pdev: Pointer to the driver data + * @seq: Sequence of data to be written + */ +static int idt_smb_write_block(struct idt_89hpesx_dev *pdev, + const struct idt_smb_seq *seq) +{ + u8 ccode; + + /* Return error if too much data passed to send */ + if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX) + return -EINVAL; + + /* Collect the command code byte */ + ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END; + + /* Send block of data to the device */ + return idt_smb_safe(write_block, pdev->client, ccode, seq->bytecnt, + seq->data); +} + +/* + * idt_smb_read_block() - SMBus read method when I2C_SMBUS_BLOCK_DATA + * operation is available + * @pdev: Pointer to the driver data + * @seq: Buffer to read data to + */ +static int idt_smb_read_block(struct idt_89hpesx_dev *pdev, + struct idt_smb_seq *seq) +{ + s32 sts; + u8 ccode; + + /* Return error if too much data passed to send */ + if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX) + return -EINVAL; + + /* Collect the command code byte */ + ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END; + + /* Read block of data from the device */ + sts = idt_smb_safe(read_block, pdev->client, ccode, seq->data); + if (sts != seq->bytecnt) + return (sts < 0 ? sts : -ENODATA); + + return 0; +} + +/* + * idt_smb_write_i2c_block() - SMBus write method when I2C_SMBUS_I2C_BLOCK_DATA + * operation is available + * @pdev: Pointer to the driver data + * @seq: Sequence of data to be written + * + * NOTE It's usual SMBus write block operation, except the actual data length is + * sent as first byte of data + */ +static int idt_smb_write_i2c_block(struct idt_89hpesx_dev *pdev, + const struct idt_smb_seq *seq) +{ + u8 ccode, buf[I2C_SMBUS_BLOCK_MAX + 1]; + + /* Return error if too much data passed to send */ + if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX) + return -EINVAL; + + /* Collect the data to send. Length byte must be added prior the data */ + buf[0] = seq->bytecnt; + memcpy(&buf[1], seq->data, seq->bytecnt); + + /* Collect the command code byte */ + ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END; + + /* Send length and block of data to the device */ + return idt_smb_safe(write_i2c_block, pdev->client, ccode, + seq->bytecnt + 1, buf); +} + +/* + * idt_smb_read_i2c_block() - SMBus read method when I2C_SMBUS_I2C_BLOCK_DATA + * operation is available + * @pdev: Pointer to the driver data + * @seq: Buffer to read data to + * + * NOTE It's usual SMBus read block operation, except the actual data length is + * retrieved as first byte of data + */ +static int idt_smb_read_i2c_block(struct idt_89hpesx_dev *pdev, + struct idt_smb_seq *seq) +{ + u8 ccode, buf[I2C_SMBUS_BLOCK_MAX + 1]; + s32 sts; + + /* Return error if too much data passed to send */ + if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX) + return -EINVAL; + + /* Collect the command code byte */ + ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END; + + /* Read length and block of data from the device */ + sts = idt_smb_safe(read_i2c_block, pdev->client, ccode, + seq->bytecnt + 1, buf); + if (sts != seq->bytecnt + 1) + return (sts < 0 ? sts : -ENODATA); + if (buf[0] != seq->bytecnt) + return -ENODATA; + + /* Copy retrieved data to the output data buffer */ + memcpy(seq->data, &buf[1], seq->bytecnt); + + return 0; +} + +/*=========================================================================== + * EEPROM IO-operations + *=========================================================================== + */ + +/* + * idt_eeprom_read_byte() - read just one byte from EEPROM + * @pdev: Pointer to the driver data + * @memaddr: Start EEPROM memory address + * @data: Data to be written to EEPROM + */ +static int idt_eeprom_read_byte(struct idt_89hpesx_dev *pdev, u16 memaddr, + u8 *data) +{ + struct device *dev = &pdev->client->dev; + struct idt_eeprom_seq eeseq; + struct idt_smb_seq smbseq; + int ret, retry; + + /* Initialize SMBus sequence fields */ + smbseq.ccode = pdev->iniccode | CCODE_EEPROM; + smbseq.data = (u8 *)&eeseq; + + /* + * Sometimes EEPROM may respond with NACK if it's busy with previous + * operation, so we need to perform a few attempts of read cycle + */ + retry = RETRY_CNT; + do { + /* Send EEPROM memory address to read data from */ + smbseq.bytecnt = EEPROM_WRRD_CNT; + eeseq.cmd = pdev->inieecmd | EEPROM_OP_READ; + eeseq.eeaddr = pdev->eeaddr; + eeseq.memaddr = cpu_to_le16(memaddr); + ret = pdev->smb_write(pdev, &smbseq); + if (ret != 0) { + dev_err(dev, "Failed to init eeprom addr 0x%02x", + memaddr); + break; + } + + /* Perform read operation */ + smbseq.bytecnt = EEPROM_RD_CNT; + ret = pdev->smb_read(pdev, &smbseq); + if (ret != 0) { + dev_err(dev, "Failed to read eeprom data 0x%02x", + memaddr); + break; + } + + /* Restart read operation if the device is busy */ + if (retry && (eeseq.cmd & EEPROM_NAERR)) { + dev_dbg(dev, "EEPROM busy, retry reading after %d ms", + EEPROM_TOUT); + msleep(EEPROM_TOUT); + continue; + } + + /* Check whether IDT successfully read data from EEPROM */ + if (eeseq.cmd & (EEPROM_NAERR | EEPROM_LAERR | EEPROM_MSS)) { + dev_err(dev, + "Communication with eeprom failed, cmd 0x%hhx", + eeseq.cmd); + ret = -EREMOTEIO; + break; + } + + /* Save retrieved data and exit the loop */ + *data = eeseq.data; + break; + } while (retry--); + + /* Return the status of operation */ + return ret; +} + +/* + * idt_eeprom_write() - EEPROM write operation + * @pdev: Pointer to the driver data + * @memaddr: Start EEPROM memory address + * @len: Length of data to be written + * @data: Data to be written to EEPROM + */ +static int idt_eeprom_write(struct idt_89hpesx_dev *pdev, u16 memaddr, u16 len, + const u8 *data) +{ + struct device *dev = &pdev->client->dev; + struct idt_eeprom_seq eeseq; + struct idt_smb_seq smbseq; + int ret; + u16 idx; + + /* Initialize SMBus sequence fields */ + smbseq.ccode = pdev->iniccode | CCODE_EEPROM; + smbseq.data = (u8 *)&eeseq; + + /* Send data byte-by-byte, checking if it is successfully written */ + for (idx = 0; idx < len; idx++, memaddr++) { + /* Lock IDT SMBus device */ + mutex_lock(&pdev->smb_mtx); + + /* Perform write operation */ + smbseq.bytecnt = EEPROM_WR_CNT; + eeseq.cmd = pdev->inieecmd | EEPROM_OP_WRITE; + eeseq.eeaddr = pdev->eeaddr; + eeseq.memaddr = cpu_to_le16(memaddr); + eeseq.data = data[idx]; + ret = pdev->smb_write(pdev, &smbseq); + if (ret != 0) { + dev_err(dev, + "Failed to write 0x%04hx:0x%02hhx to eeprom", + memaddr, data[idx]); + goto err_mutex_unlock; + } + + /* + * Check whether the data is successfully written by reading + * from the same EEPROM memory address. + */ + eeseq.data = ~data[idx]; + ret = idt_eeprom_read_byte(pdev, memaddr, &eeseq.data); + if (ret != 0) + goto err_mutex_unlock; + + /* Check whether the read byte is the same as written one */ + if (eeseq.data != data[idx]) { + dev_err(dev, "Values don't match 0x%02hhx != 0x%02hhx", + eeseq.data, data[idx]); + ret = -EREMOTEIO; + goto err_mutex_unlock; + } + + /* Unlock IDT SMBus device */ +err_mutex_unlock: + mutex_unlock(&pdev->smb_mtx); + if (ret != 0) + return ret; + } + + return 0; +} + +/* + * idt_eeprom_read() - EEPROM read operation + * @pdev: Pointer to the driver data + * @memaddr: Start EEPROM memory address + * @len: Length of data to read + * @buf: Buffer to read data to + */ +static int idt_eeprom_read(struct idt_89hpesx_dev *pdev, u16 memaddr, u16 len, + u8 *buf) +{ + int ret; + u16 idx; + + /* Read data byte-by-byte, retrying if it wasn't successful */ + for (idx = 0; idx < len; idx++, memaddr++) { + /* Lock IDT SMBus device */ + mutex_lock(&pdev->smb_mtx); + + /* Just read the byte to the buffer */ + ret = idt_eeprom_read_byte(pdev, memaddr, &buf[idx]); + + /* Unlock IDT SMBus device */ + mutex_unlock(&pdev->smb_mtx); + + /* Return error if read operation failed */ + if (ret != 0) + return ret; + } + + return 0; +} + +/*=========================================================================== + * CSR IO-operations + *=========================================================================== + */ + +/* + * idt_csr_write() - CSR write operation + * @pdev: Pointer to the driver data + * @csraddr: CSR address (with no two LS bits) + * @data: Data to be written to CSR + */ +static int idt_csr_write(struct idt_89hpesx_dev *pdev, u16 csraddr, + const u32 data) +{ + struct device *dev = &pdev->client->dev; + struct idt_csr_seq csrseq; + struct idt_smb_seq smbseq; + int ret; + + /* Initialize SMBus sequence fields */ + smbseq.ccode = pdev->iniccode | CCODE_CSR; + smbseq.data = (u8 *)&csrseq; + + /* Lock IDT SMBus device */ + mutex_lock(&pdev->smb_mtx); + + /* Perform write operation */ + smbseq.bytecnt = CSR_WR_CNT; + csrseq.cmd = pdev->inicsrcmd | CSR_OP_WRITE; + csrseq.csraddr = cpu_to_le16(csraddr); + csrseq.data = cpu_to_le32(data); + ret = pdev->smb_write(pdev, &smbseq); + if (ret != 0) { + dev_err(dev, "Failed to write 0x%04x: 0x%04x to csr", + CSR_REAL_ADDR(csraddr), data); + goto err_mutex_unlock; + } + + /* Send CSR address to read data from */ + smbseq.bytecnt = CSR_WRRD_CNT; + csrseq.cmd = pdev->inicsrcmd | CSR_OP_READ; + ret = pdev->smb_write(pdev, &smbseq); + if (ret != 0) { + dev_err(dev, "Failed to init csr address 0x%04x", + CSR_REAL_ADDR(csraddr)); + goto err_mutex_unlock; + } + + /* Perform read operation */ + smbseq.bytecnt = CSR_RD_CNT; + ret = pdev->smb_read(pdev, &smbseq); + if (ret != 0) { + dev_err(dev, "Failed to read csr 0x%04x", + CSR_REAL_ADDR(csraddr)); + goto err_mutex_unlock; + } + + /* Check whether IDT successfully retrieved CSR data */ + if (csrseq.cmd & (CSR_RERR | CSR_WERR)) { + dev_err(dev, "IDT failed to perform CSR r/w"); + ret = -EREMOTEIO; + goto err_mutex_unlock; + } + + /* Unlock IDT SMBus device */ +err_mutex_unlock: + mutex_unlock(&pdev->smb_mtx); + + return ret; +} + +/* + * idt_csr_read() - CSR read operation + * @pdev: Pointer to the driver data + * @csraddr: CSR address (with no two LS bits) + * @data: Data to be written to CSR + */ +static int idt_csr_read(struct idt_89hpesx_dev *pdev, u16 csraddr, u32 *data) +{ + struct device *dev = &pdev->client->dev; + struct idt_csr_seq csrseq; + struct idt_smb_seq smbseq; + int ret; + + /* Initialize SMBus sequence fields */ + smbseq.ccode = pdev->iniccode | CCODE_CSR; + smbseq.data = (u8 *)&csrseq; + + /* Lock IDT SMBus device */ + mutex_lock(&pdev->smb_mtx); + + /* Send CSR register address before reading it */ + smbseq.bytecnt = CSR_WRRD_CNT; + csrseq.cmd = pdev->inicsrcmd | CSR_OP_READ; + csrseq.csraddr = cpu_to_le16(csraddr); + ret = pdev->smb_write(pdev, &smbseq); + if (ret != 0) { + dev_err(dev, "Failed to init csr address 0x%04x", + CSR_REAL_ADDR(csraddr)); + goto err_mutex_unlock; + } + + /* Perform read operation */ + smbseq.bytecnt = CSR_RD_CNT; + ret = pdev->smb_read(pdev, &smbseq); + if (ret != 0) { + dev_err(dev, "Failed to read csr 0x%04x", + CSR_REAL_ADDR(csraddr)); + goto err_mutex_unlock; + } + + /* Check whether IDT successfully retrieved CSR data */ + if (csrseq.cmd & (CSR_RERR | CSR_WERR)) { + dev_err(dev, "IDT failed to perform CSR r/w"); + ret = -EREMOTEIO; + goto err_mutex_unlock; + } + + /* Save data retrieved from IDT */ + *data = le32_to_cpu(csrseq.data); + + /* Unlock IDT SMBus device */ +err_mutex_unlock: + mutex_unlock(&pdev->smb_mtx); + + return ret; +} + +/*=========================================================================== + * Sysfs/debugfs-nodes IO-operations + *=========================================================================== + */ + +/* + * eeprom_write() - EEPROM sysfs-node write callback + * @filep: Pointer to the file system node + * @kobj: Pointer to the kernel object related to the sysfs-node + * @attr: Attributes of the file + * @buf: Buffer to write data to + * @off: Offset at which data should be written to + * @count: Number of bytes to write + */ +static ssize_t eeprom_write(struct file *filp, struct kobject *kobj, + const struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct idt_89hpesx_dev *pdev; + int ret; + + /* Retrieve driver data */ + pdev = dev_get_drvdata(kobj_to_dev(kobj)); + + /* Perform EEPROM write operation */ + ret = idt_eeprom_write(pdev, (u16)off, (u16)count, (u8 *)buf); + return (ret != 0 ? ret : count); +} + +/* + * eeprom_read() - EEPROM sysfs-node read callback + * @filep: Pointer to the file system node + * @kobj: Pointer to the kernel object related to the sysfs-node + * @attr: Attributes of the file + * @buf: Buffer to write data to + * @off: Offset at which data should be written to + * @count: Number of bytes to write + */ +static ssize_t eeprom_read(struct file *filp, struct kobject *kobj, + const struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct idt_89hpesx_dev *pdev; + int ret; + + /* Retrieve driver data */ + pdev = dev_get_drvdata(kobj_to_dev(kobj)); + + /* Perform EEPROM read operation */ + ret = idt_eeprom_read(pdev, (u16)off, (u16)count, (u8 *)buf); + return (ret != 0 ? ret : count); +} + +/* + * idt_dbgfs_csr_write() - CSR debugfs-node write callback + * @filep: Pointer to the file system file descriptor + * @buf: Buffer to read data from + * @count: Size of the buffer + * @offp: Offset within the file + * + * It accepts either "0x<reg addr>:0x<value>" for saving register address + * and writing value to specified DWORD register or "0x<reg addr>" for + * just saving register address in order to perform next read operation. + * + * WARNING No spaces are allowed. Incoming string must be strictly formated as: + * "<reg addr>:<value>". Register address must be aligned within 4 bytes + * (one DWORD). + */ +static ssize_t idt_dbgfs_csr_write(struct file *filep, const char __user *ubuf, + size_t count, loff_t *offp) +{ + struct idt_89hpesx_dev *pdev = filep->private_data; + char *colon_ch, *csraddr_str, *csrval_str; + int ret; + u32 csraddr, csrval; + char *buf; + + if (*offp) + return 0; + + /* Copy data from User-space */ + buf = memdup_user_nul(ubuf, count); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + /* Find position of colon in the buffer */ + colon_ch = strnchr(buf, count, ':'); + + /* + * If there is colon passed then new CSR value should be parsed as + * well, so allocate buffer for CSR address substring. + * If no colon is found, then string must have just one number with + * no new CSR value + */ + if (colon_ch != NULL) { + /* Copy the register address to the substring buffer */ + csraddr_str = kmemdup_nul(buf, colon_ch - buf, GFP_KERNEL); + if (csraddr_str == NULL) { + ret = -ENOMEM; + goto free_buf; + } + /* Register value must follow the colon */ + csrval_str = colon_ch + 1; + } else /* if (str_colon == NULL) */ { + csraddr_str = (char *)buf; /* Just to shut warning up */ + csrval_str = NULL; + } + + /* Convert CSR address to u32 value */ + ret = kstrtou32(csraddr_str, 0, &csraddr); + if (ret != 0) + goto free_csraddr_str; + + /* Check whether passed register address is valid */ + if (csraddr > CSR_MAX || !IS_ALIGNED(csraddr, SZ_4)) { + ret = -EINVAL; + goto free_csraddr_str; + } + + /* Shift register address to the right so to have u16 address */ + pdev->csr = (csraddr >> 2); + + /* Parse new CSR value and send it to IDT, if colon has been found */ + if (colon_ch != NULL) { + ret = kstrtou32(csrval_str, 0, &csrval); + if (ret != 0) + goto free_csraddr_str; + + ret = idt_csr_write(pdev, pdev->csr, csrval); + if (ret != 0) + goto free_csraddr_str; + } + + /* Free memory only if colon has been found */ +free_csraddr_str: + if (colon_ch != NULL) + kfree(csraddr_str); + + /* Free buffer allocated for data retrieved from User-space */ +free_buf: + kfree(buf); + + return (ret != 0 ? ret : count); +} + +/* + * idt_dbgfs_csr_read() - CSR debugfs-node read callback + * @filep: Pointer to the file system file descriptor + * @buf: Buffer to write data to + * @count: Size of the buffer + * @offp: Offset within the file + * + * It just prints the pair "0x<reg addr>:0x<value>" to passed buffer. + */ +#define CSRBUF_SIZE ((size_t)32) +static ssize_t idt_dbgfs_csr_read(struct file *filep, char __user *ubuf, + size_t count, loff_t *offp) +{ + struct idt_89hpesx_dev *pdev = filep->private_data; + u32 csraddr, csrval; + char buf[CSRBUF_SIZE]; + int ret, size; + + /* Perform CSR read operation */ + ret = idt_csr_read(pdev, pdev->csr, &csrval); + if (ret != 0) + return ret; + + /* Shift register address to the left so to have real address */ + csraddr = ((u32)pdev->csr << 2); + + /* Print the "0x<reg addr>:0x<value>" to buffer */ + size = snprintf(buf, CSRBUF_SIZE, "0x%05x:0x%08x\n", + (unsigned int)csraddr, (unsigned int)csrval); + + /* Copy data to User-space */ + return simple_read_from_buffer(ubuf, count, offp, buf, size); +} + +/* + * eeprom_attribute - EEPROM sysfs-node attributes + * + * NOTE Size will be changed in compliance with OF node. EEPROM attribute will + * be read-only as well if the corresponding flag is specified in OF node. + */ +static const BIN_ATTR_RW(eeprom, EEPROM_DEF_SIZE); + +/* + * csr_dbgfs_ops - CSR debugfs-node read/write operations + */ +static const struct file_operations csr_dbgfs_ops = { + .owner = THIS_MODULE, + .open = simple_open, + .write = idt_dbgfs_csr_write, + .read = idt_dbgfs_csr_read +}; + +/*=========================================================================== + * Driver init/deinit methods + *=========================================================================== + */ + +/* + * idt_set_defval() - disable EEPROM access by default + * @pdev: Pointer to the driver data + */ +static void idt_set_defval(struct idt_89hpesx_dev *pdev) +{ + /* If OF info is missing then use next values */ + pdev->eesize = 0; + pdev->eero = true; + pdev->inieecmd = 0; + pdev->eeaddr = 0; +} + +static const struct i2c_device_id ee_ids[]; + +/* + * idt_ee_match_id() - check whether the node belongs to compatible EEPROMs + */ +static const struct i2c_device_id *idt_ee_match_id(struct fwnode_handle *fwnode) +{ + const struct i2c_device_id *id = ee_ids; + const char *compatible, *p; + char devname[I2C_NAME_SIZE]; + int ret; + + ret = fwnode_property_read_string(fwnode, "compatible", &compatible); + if (ret) + return NULL; + + p = strchr(compatible, ','); + strscpy(devname, p ? p + 1 : compatible, sizeof(devname)); + /* Search through the device name */ + while (id->name[0]) { + if (strcmp(devname, id->name) == 0) + return id; + id++; + } + return NULL; +} + +/* + * idt_get_fw_data() - get IDT i2c-device parameters from device tree + * @pdev: Pointer to the driver data + */ +static void idt_get_fw_data(struct idt_89hpesx_dev *pdev) +{ + struct device *dev = &pdev->client->dev; + struct fwnode_handle *fwnode; + const struct i2c_device_id *ee_id = NULL; + u32 eeprom_addr; + int ret; + + device_for_each_child_node(dev, fwnode) { + ee_id = idt_ee_match_id(fwnode); + if (ee_id) + break; + + dev_warn(dev, "Skip unsupported EEPROM device %pfw\n", fwnode); + } + + /* If there is no fwnode EEPROM device, then set zero size */ + if (!ee_id) { + dev_warn(dev, "No fwnode, EEPROM access disabled"); + idt_set_defval(pdev); + return; + } + + /* Retrieve EEPROM size */ + pdev->eesize = (u32)ee_id->driver_data; + + /* Get custom EEPROM address from 'reg' attribute */ + ret = fwnode_property_read_u32(fwnode, "reg", &eeprom_addr); + if (ret || (eeprom_addr == 0)) { + dev_warn(dev, "No EEPROM reg found, use default address 0x%x", + EEPROM_DEF_ADDR); + pdev->inieecmd = 0; + pdev->eeaddr = EEPROM_DEF_ADDR << 1; + } else { + pdev->inieecmd = EEPROM_USA; + pdev->eeaddr = eeprom_addr << 1; + } + + /* Check EEPROM 'read-only' flag */ + if (fwnode_property_read_bool(fwnode, "read-only")) + pdev->eero = true; + else /* if (!fwnode_property_read_bool(node, "read-only")) */ + pdev->eero = false; + + fwnode_handle_put(fwnode); + dev_info(dev, "EEPROM of %d bytes found by 0x%x", + pdev->eesize, pdev->eeaddr); +} + +/* + * idt_create_pdev() - create and init data structure of the driver + * @client: i2c client of IDT PCIe-switch device + */ +static struct idt_89hpesx_dev *idt_create_pdev(struct i2c_client *client) +{ + struct idt_89hpesx_dev *pdev; + + /* Allocate memory for driver data */ + pdev = devm_kmalloc(&client->dev, sizeof(struct idt_89hpesx_dev), + GFP_KERNEL); + if (pdev == NULL) + return ERR_PTR(-ENOMEM); + + /* Initialize basic fields of the data */ + pdev->client = client; + i2c_set_clientdata(client, pdev); + + /* Read firmware nodes information */ + idt_get_fw_data(pdev); + + /* Initialize basic CSR CMD field - use full DWORD-sized r/w ops */ + pdev->inicsrcmd = CSR_DWE; + pdev->csr = CSR_DEF; + + /* Enable Packet Error Checking if it's supported by adapter */ + if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_PEC)) { + pdev->iniccode = CCODE_PEC; + client->flags |= I2C_CLIENT_PEC; + } else /* PEC is unsupported */ { + pdev->iniccode = 0; + } + + return pdev; +} + +/* + * idt_free_pdev() - free data structure of the driver + * @pdev: Pointer to the driver data + */ +static void idt_free_pdev(struct idt_89hpesx_dev *pdev) +{ + /* Clear driver data from device private field */ + i2c_set_clientdata(pdev->client, NULL); +} + +/* + * idt_set_smbus_ops() - set supported SMBus operations + * @pdev: Pointer to the driver data + * Return status of smbus check operations + */ +static int idt_set_smbus_ops(struct idt_89hpesx_dev *pdev) +{ + struct i2c_adapter *adapter = pdev->client->adapter; + struct device *dev = &pdev->client->dev; + + /* Check i2c adapter read functionality */ + if (i2c_check_functionality(adapter, + I2C_FUNC_SMBUS_READ_BLOCK_DATA)) { + pdev->smb_read = idt_smb_read_block; + dev_dbg(dev, "SMBus block-read op chosen"); + } else if (i2c_check_functionality(adapter, + I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { + pdev->smb_read = idt_smb_read_i2c_block; + dev_dbg(dev, "SMBus i2c-block-read op chosen"); + } else if (i2c_check_functionality(adapter, + I2C_FUNC_SMBUS_READ_WORD_DATA) && + i2c_check_functionality(adapter, + I2C_FUNC_SMBUS_READ_BYTE_DATA)) { + pdev->smb_read = idt_smb_read_word; + dev_warn(dev, "Use slow word/byte SMBus read ops"); + } else if (i2c_check_functionality(adapter, + I2C_FUNC_SMBUS_READ_BYTE_DATA)) { + pdev->smb_read = idt_smb_read_byte; + dev_warn(dev, "Use slow byte SMBus read op"); + } else /* no supported smbus read operations */ { + dev_err(dev, "No supported SMBus read op"); + return -EPFNOSUPPORT; + } + + /* Check i2c adapter write functionality */ + if (i2c_check_functionality(adapter, + I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)) { + pdev->smb_write = idt_smb_write_block; + dev_dbg(dev, "SMBus block-write op chosen"); + } else if (i2c_check_functionality(adapter, + I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) { + pdev->smb_write = idt_smb_write_i2c_block; + dev_dbg(dev, "SMBus i2c-block-write op chosen"); + } else if (i2c_check_functionality(adapter, + I2C_FUNC_SMBUS_WRITE_WORD_DATA) && + i2c_check_functionality(adapter, + I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) { + pdev->smb_write = idt_smb_write_word; + dev_warn(dev, "Use slow word/byte SMBus write op"); + } else if (i2c_check_functionality(adapter, + I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) { + pdev->smb_write = idt_smb_write_byte; + dev_warn(dev, "Use slow byte SMBus write op"); + } else /* no supported smbus write operations */ { + dev_err(dev, "No supported SMBus write op"); + return -EPFNOSUPPORT; + } + + /* Initialize IDT SMBus slave interface mutex */ + mutex_init(&pdev->smb_mtx); + + return 0; +} + +/* + * idt_check_dev() - check whether it's really IDT 89HPESx device + * @pdev: Pointer to the driver data + * Return status of i2c adapter check operation + */ +static int idt_check_dev(struct idt_89hpesx_dev *pdev) +{ + struct device *dev = &pdev->client->dev; + u32 viddid; + int ret; + + /* Read VID and DID directly from IDT memory space */ + ret = idt_csr_read(pdev, IDT_VIDDID_CSR, &viddid); + if (ret != 0) { + dev_err(dev, "Failed to read VID/DID"); + return ret; + } + + /* Check whether it's IDT device */ + if ((viddid & IDT_VID_MASK) != PCI_VENDOR_ID_IDT) { + dev_err(dev, "Got unsupported VID/DID: 0x%08x", viddid); + return -ENODEV; + } + + dev_info(dev, "Found IDT 89HPES device VID:0x%04x, DID:0x%04x", + (viddid & IDT_VID_MASK), (viddid >> 16)); + + return 0; +} + +/* + * idt_create_sysfs_files() - create sysfs attribute files + * @pdev: Pointer to the driver data + * Return status of operation + */ +static int idt_create_sysfs_files(struct idt_89hpesx_dev *pdev) +{ + struct device *dev = &pdev->client->dev; + int ret; + + /* Don't do anything if EEPROM isn't accessible */ + if (pdev->eesize == 0) { + dev_dbg(dev, "Skip creating sysfs-files"); + return 0; + } + + /* + * Allocate memory for attribute file and copy the declared EEPROM attr + * structure to change some of fields + */ + pdev->ee_file = devm_kmemdup(dev, &bin_attr_eeprom, + sizeof(*pdev->ee_file), GFP_KERNEL); + if (!pdev->ee_file) + return -ENOMEM; + + /* In case of read-only EEPROM get rid of write ability */ + if (pdev->eero) { + pdev->ee_file->attr.mode &= ~0200; + pdev->ee_file->write = NULL; + } + /* Create EEPROM sysfs file */ + pdev->ee_file->size = pdev->eesize; + ret = sysfs_create_bin_file(&dev->kobj, pdev->ee_file); + if (ret != 0) { + dev_err(dev, "Failed to create EEPROM sysfs-node"); + return ret; + } + + return 0; +} + +/* + * idt_remove_sysfs_files() - remove sysfs attribute files + * @pdev: Pointer to the driver data + */ +static void idt_remove_sysfs_files(struct idt_89hpesx_dev *pdev) +{ + struct device *dev = &pdev->client->dev; + + /* Don't do anything if EEPROM wasn't accessible */ + if (pdev->eesize == 0) + return; + + /* Remove EEPROM sysfs file */ + sysfs_remove_bin_file(&dev->kobj, pdev->ee_file); +} + +/* + * idt_probe() - IDT 89HPESx driver probe() callback method + */ +static int idt_probe(struct i2c_client *client) +{ + struct idt_89hpesx_dev *pdev; + int ret; + + /* Create driver data */ + pdev = idt_create_pdev(client); + if (IS_ERR(pdev)) + return PTR_ERR(pdev); + + /* Set SMBus operations */ + ret = idt_set_smbus_ops(pdev); + if (ret != 0) + goto err_free_pdev; + + /* Check whether it is truly IDT 89HPESx device */ + ret = idt_check_dev(pdev); + if (ret != 0) + goto err_free_pdev; + + /* Create sysfs files */ + ret = idt_create_sysfs_files(pdev); + if (ret != 0) + goto err_free_pdev; + + /* Create debugfs files */ + debugfs_create_file(pdev->client->name, 0600, client->debugfs, pdev, &csr_dbgfs_ops); + + return 0; + +err_free_pdev: + idt_free_pdev(pdev); + + return ret; +} + +/* + * idt_remove() - IDT 89HPESx driver remove() callback method + */ +static void idt_remove(struct i2c_client *client) +{ + struct idt_89hpesx_dev *pdev = i2c_get_clientdata(client); + + /* Remove sysfs files */ + idt_remove_sysfs_files(pdev); + + /* Discard driver data structure */ + idt_free_pdev(pdev); +} + +/* + * ee_ids - array of supported EEPROMs + */ +static const struct i2c_device_id ee_ids[] = { + { "24c32", 4096}, + { "24c64", 8192}, + { "24c128", 16384}, + { "24c256", 32768}, + { "24c512", 65536}, + {} +}; +MODULE_DEVICE_TABLE(i2c, ee_ids); + +/* + * idt_ids - supported IDT 89HPESx devices + */ +static const struct i2c_device_id idt_ids[] = { + { "89hpes8nt2" }, + { "89hpes12nt3" }, + + { "89hpes24nt6ag2" }, + { "89hpes32nt8ag2" }, + { "89hpes32nt8bg2" }, + { "89hpes12nt12g2" }, + { "89hpes16nt16g2" }, + { "89hpes24nt24g2" }, + { "89hpes32nt24ag2" }, + { "89hpes32nt24bg2" }, + + { "89hpes12n3" }, + { "89hpes12n3a" }, + { "89hpes24n3" }, + { "89hpes24n3a" }, + + { "89hpes32h8" }, + { "89hpes32h8g2" }, + { "89hpes48h12" }, + { "89hpes48h12g2" }, + { "89hpes48h12ag2" }, + { "89hpes16h16" }, + { "89hpes22h16" }, + { "89hpes22h16g2" }, + { "89hpes34h16" }, + { "89hpes34h16g2" }, + { "89hpes64h16" }, + { "89hpes64h16g2" }, + { "89hpes64h16ag2" }, + + /* { "89hpes3t3" }, // No SMBus-slave iface */ + { "89hpes12t3g2" }, + { "89hpes24t3g2" }, + /* { "89hpes4t4" }, // No SMBus-slave iface */ + { "89hpes16t4" }, + { "89hpes4t4g2" }, + { "89hpes10t4g2" }, + { "89hpes16t4g2" }, + { "89hpes16t4ag2" }, + { "89hpes5t5" }, + { "89hpes6t5" }, + { "89hpes8t5" }, + { "89hpes8t5a" }, + { "89hpes24t6" }, + { "89hpes6t6g2" }, + { "89hpes24t6g2" }, + { "89hpes16t7" }, + { "89hpes32t8" }, + { "89hpes32t8g2" }, + { "89hpes48t12" }, + { "89hpes48t12g2" }, + { /* END OF LIST */ } +}; +MODULE_DEVICE_TABLE(i2c, idt_ids); + +static const struct of_device_id idt_of_match[] = { + { .compatible = "idt,89hpes8nt2", }, + { .compatible = "idt,89hpes12nt3", }, + + { .compatible = "idt,89hpes24nt6ag2", }, + { .compatible = "idt,89hpes32nt8ag2", }, + { .compatible = "idt,89hpes32nt8bg2", }, + { .compatible = "idt,89hpes12nt12g2", }, + { .compatible = "idt,89hpes16nt16g2", }, + { .compatible = "idt,89hpes24nt24g2", }, + { .compatible = "idt,89hpes32nt24ag2", }, + { .compatible = "idt,89hpes32nt24bg2", }, + + { .compatible = "idt,89hpes12n3", }, + { .compatible = "idt,89hpes12n3a", }, + { .compatible = "idt,89hpes24n3", }, + { .compatible = "idt,89hpes24n3a", }, + + { .compatible = "idt,89hpes32h8", }, + { .compatible = "idt,89hpes32h8g2", }, + { .compatible = "idt,89hpes48h12", }, + { .compatible = "idt,89hpes48h12g2", }, + { .compatible = "idt,89hpes48h12ag2", }, + { .compatible = "idt,89hpes16h16", }, + { .compatible = "idt,89hpes22h16", }, + { .compatible = "idt,89hpes22h16g2", }, + { .compatible = "idt,89hpes34h16", }, + { .compatible = "idt,89hpes34h16g2", }, + { .compatible = "idt,89hpes64h16", }, + { .compatible = "idt,89hpes64h16g2", }, + { .compatible = "idt,89hpes64h16ag2", }, + + { .compatible = "idt,89hpes12t3g2", }, + { .compatible = "idt,89hpes24t3g2", }, + + { .compatible = "idt,89hpes16t4", }, + { .compatible = "idt,89hpes4t4g2", }, + { .compatible = "idt,89hpes10t4g2", }, + { .compatible = "idt,89hpes16t4g2", }, + { .compatible = "idt,89hpes16t4ag2", }, + { .compatible = "idt,89hpes5t5", }, + { .compatible = "idt,89hpes6t5", }, + { .compatible = "idt,89hpes8t5", }, + { .compatible = "idt,89hpes8t5a", }, + { .compatible = "idt,89hpes24t6", }, + { .compatible = "idt,89hpes6t6g2", }, + { .compatible = "idt,89hpes24t6g2", }, + { .compatible = "idt,89hpes16t7", }, + { .compatible = "idt,89hpes32t8", }, + { .compatible = "idt,89hpes32t8g2", }, + { .compatible = "idt,89hpes48t12", }, + { .compatible = "idt,89hpes48t12g2", }, + { }, +}; +MODULE_DEVICE_TABLE(of, idt_of_match); + +/* + * idt_driver - IDT 89HPESx driver structure + */ +static struct i2c_driver idt_driver = { + .driver = { + .name = IDT_NAME, + .of_match_table = idt_of_match, + }, + .probe = idt_probe, + .remove = idt_remove, + .id_table = idt_ids, +}; +module_i2c_driver(idt_driver); diff --git a/drivers/misc/eeprom/m24lr.c b/drivers/misc/eeprom/m24lr.c new file mode 100644 index 000000000..7a9fd45a8 --- /dev/null +++ b/drivers/misc/eeprom/m24lr.c @@ -0,0 +1,606 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * m24lr.c - Sysfs control interface for ST M24LR series RFID/NFC chips + * + * Copyright (c) 2025 Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com> + * + * This driver implements both the sysfs-based control interface and EEPROM + * access for STMicroelectronics M24LR series chips (e.g., M24LR04E-R). + * It provides access to control registers for features such as password + * authentication, memory protection, and device configuration. In addition, + * it manages read and write operations to the EEPROM region of the chip. + */ + +#include <linux/device.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/nvmem-provider.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/regmap.h> + +#define M24LR_WRITE_TIMEOUT 25u +#define M24LR_READ_TIMEOUT (M24LR_WRITE_TIMEOUT) + +/** + * struct m24lr_chip - describes chip-specific sysfs layout + * @sss_len: the length of the sss region + * @page_size: chip-specific limit on the maximum number of bytes allowed + * in a single write operation. + * @eeprom_size: size of the EEPROM in byte + * + * Supports multiple M24LR chip variants (e.g., M24LRxx) by allowing each + * to define its own set of sysfs attributes, depending on its available + * registers and features. + */ +struct m24lr_chip { + unsigned int sss_len; + unsigned int page_size; + unsigned int eeprom_size; +}; + +/** + * struct m24lr - core driver data for M24LR chip control + * @uid: 64 bits unique identifier stored in the device + * @sss_len: the length of the sss region + * @page_size: chip-specific limit on the maximum number of bytes allowed + * in a single write operation. + * @eeprom_size: size of the EEPROM in byte + * @ctl_regmap: regmap interface for accessing the system parameter sector + * @eeprom_regmap: regmap interface for accessing the EEPROM + * @lock: mutex to synchronize operations to the device + * + * Central data structure holding the state and resources used by the + * M24LR device driver. + */ +struct m24lr { + u64 uid; + unsigned int sss_len; + unsigned int page_size; + unsigned int eeprom_size; + struct regmap *ctl_regmap; + struct regmap *eeprom_regmap; + struct mutex lock; /* synchronize operations to the device */ +}; + +static const struct regmap_range m24lr_ctl_vo_ranges[] = { + regmap_reg_range(0, 63), +}; + +static const struct regmap_access_table m24lr_ctl_vo_table = { + .yes_ranges = m24lr_ctl_vo_ranges, + .n_yes_ranges = ARRAY_SIZE(m24lr_ctl_vo_ranges), +}; + +static const struct regmap_config m24lr_ctl_regmap_conf = { + .name = "m24lr_ctl", + .reg_stride = 1, + .reg_bits = 16, + .val_bits = 8, + .disable_locking = false, + .cache_type = REGCACHE_RBTREE,/* Flat can't be used, there's huge gap */ + .volatile_table = &m24lr_ctl_vo_table, +}; + +/* Chip descriptor for M24LR04E-R variant */ +static const struct m24lr_chip m24lr04e_r_chip = { + .page_size = 4, + .eeprom_size = 512, + .sss_len = 4, +}; + +/* Chip descriptor for M24LR16E-R variant */ +static const struct m24lr_chip m24lr16e_r_chip = { + .page_size = 4, + .eeprom_size = 2048, + .sss_len = 16, +}; + +/* Chip descriptor for M24LR64E-R variant */ +static const struct m24lr_chip m24lr64e_r_chip = { + .page_size = 4, + .eeprom_size = 8192, + .sss_len = 64, +}; + +static const struct i2c_device_id m24lr_ids[] = { + { "m24lr04e-r", (kernel_ulong_t)&m24lr04e_r_chip}, + { "m24lr16e-r", (kernel_ulong_t)&m24lr16e_r_chip}, + { "m24lr64e-r", (kernel_ulong_t)&m24lr64e_r_chip}, + { } +}; +MODULE_DEVICE_TABLE(i2c, m24lr_ids); + +static const struct of_device_id m24lr_of_match[] = { + { .compatible = "st,m24lr04e-r", .data = &m24lr04e_r_chip}, + { .compatible = "st,m24lr16e-r", .data = &m24lr16e_r_chip}, + { .compatible = "st,m24lr64e-r", .data = &m24lr64e_r_chip}, + { } +}; +MODULE_DEVICE_TABLE(of, m24lr_of_match); + +/** + * m24lr_regmap_read - read data using regmap with retry on failure + * @regmap: regmap instance for the device + * @buf: buffer to store the read data + * @size: number of bytes to read + * @offset: starting register address + * + * Attempts to read a block of data from the device with retries and timeout. + * Some M24LR chips may transiently NACK reads (e.g., during internal write + * cycles), so this function retries with a short sleep until the timeout + * expires. + * + * Returns: + * Number of bytes read on success, + * -ETIMEDOUT if the read fails within the timeout window. + */ +static ssize_t m24lr_regmap_read(struct regmap *regmap, u8 *buf, + size_t size, unsigned int offset) +{ + int err; + unsigned long timeout, read_time; + ssize_t ret = -ETIMEDOUT; + + timeout = jiffies + msecs_to_jiffies(M24LR_READ_TIMEOUT); + do { + read_time = jiffies; + + err = regmap_bulk_read(regmap, offset, buf, size); + if (!err) { + ret = size; + break; + } + + usleep_range(1000, 2000); + } while (time_before(read_time, timeout)); + + return ret; +} + +/** + * m24lr_regmap_write - write data using regmap with retry on failure + * @regmap: regmap instance for the device + * @buf: buffer containing the data to write + * @size: number of bytes to write + * @offset: starting register address + * + * Attempts to write a block of data to the device with retries and a timeout. + * Some M24LR devices may NACK I2C writes while an internal write operation + * is in progress. This function retries the write operation with a short delay + * until it succeeds or the timeout is reached. + * + * Returns: + * Number of bytes written on success, + * -ETIMEDOUT if the write fails within the timeout window. + */ +static ssize_t m24lr_regmap_write(struct regmap *regmap, const u8 *buf, + size_t size, unsigned int offset) +{ + int err; + unsigned long timeout, write_time; + ssize_t ret = -ETIMEDOUT; + + timeout = jiffies + msecs_to_jiffies(M24LR_WRITE_TIMEOUT); + + do { + write_time = jiffies; + + err = regmap_bulk_write(regmap, offset, buf, size); + if (!err) { + ret = size; + break; + } + + usleep_range(1000, 2000); + } while (time_before(write_time, timeout)); + + return ret; +} + +static ssize_t m24lr_read(struct m24lr *m24lr, u8 *buf, size_t size, + unsigned int offset, bool is_eeprom) +{ + struct regmap *regmap; + ssize_t ret; + + if (is_eeprom) + regmap = m24lr->eeprom_regmap; + else + regmap = m24lr->ctl_regmap; + + mutex_lock(&m24lr->lock); + ret = m24lr_regmap_read(regmap, buf, size, offset); + mutex_unlock(&m24lr->lock); + + return ret; +} + +/** + * m24lr_write - write buffer to M24LR device with page alignment handling + * @m24lr: pointer to driver context + * @buf: data buffer to write + * @size: number of bytes to write + * @offset: target register address in the device + * @is_eeprom: true if the write should target the EEPROM, + * false if it should target the system parameters sector. + * + * Writes data to the M24LR device using regmap, split into chunks no larger + * than page_size to respect device-specific write limitations (e.g., page + * size or I2C hold-time concerns). Each chunk is aligned to the page boundary + * defined by page_size. + * + * Returns: + * Total number of bytes written on success, + * A negative error code if any write fails. + */ +static ssize_t m24lr_write(struct m24lr *m24lr, const u8 *buf, size_t size, + unsigned int offset, bool is_eeprom) +{ + unsigned int n, next_sector; + struct regmap *regmap; + ssize_t ret = 0; + ssize_t err; + + if (is_eeprom) + regmap = m24lr->eeprom_regmap; + else + regmap = m24lr->ctl_regmap; + + n = min_t(unsigned int, size, m24lr->page_size); + next_sector = roundup(offset + 1, m24lr->page_size); + if (offset + n > next_sector) + n = next_sector - offset; + + mutex_lock(&m24lr->lock); + while (n) { + err = m24lr_regmap_write(regmap, buf + offset, n, offset); + if (IS_ERR_VALUE(err)) { + if (!ret) + ret = err; + + break; + } + + offset += n; + size -= n; + ret += n; + n = min_t(unsigned int, size, m24lr->page_size); + } + mutex_unlock(&m24lr->lock); + + return ret; +} + +/** + * m24lr_write_pass - Write password to M24LR043-R using secure format + * @m24lr: Pointer to device control structure + * @buf: Input buffer containing hex-encoded password + * @count: Number of bytes in @buf + * @code: Operation code to embed between password copies + * + * This function parses a 4-byte password, encodes it in big-endian format, + * and constructs a 9-byte sequence of the form: + * + * [BE(password), code, BE(password)] + * + * The result is written to register 0x0900 (2304), which is the password + * register in M24LR04E-R chip. + * + * Return: Number of bytes written on success, or negative error code on failure + */ +static ssize_t m24lr_write_pass(struct m24lr *m24lr, const char *buf, + size_t count, u8 code) +{ + __be32 be_pass; + u8 output[9]; + ssize_t ret; + u32 pass; + int err; + + if (!count) + return -EINVAL; + + if (count > 8) + return -EINVAL; + + err = kstrtou32(buf, 16, &pass); + if (err) + return err; + + be_pass = cpu_to_be32(pass); + + memcpy(output, &be_pass, sizeof(be_pass)); + output[4] = code; + memcpy(output + 5, &be_pass, sizeof(be_pass)); + + mutex_lock(&m24lr->lock); + ret = m24lr_regmap_write(m24lr->ctl_regmap, output, 9, 2304); + mutex_unlock(&m24lr->lock); + + return ret; +} + +static ssize_t m24lr_read_reg_le(struct m24lr *m24lr, u64 *val, + unsigned int reg_addr, + unsigned int reg_size) +{ + ssize_t ret; + __le64 input = 0; + + ret = m24lr_read(m24lr, (u8 *)&input, reg_size, reg_addr, false); + if (IS_ERR_VALUE(ret)) + return ret; + + if (ret != reg_size) + return -EINVAL; + + switch (reg_size) { + case 1: + *val = *(u8 *)&input; + break; + case 2: + *val = le16_to_cpu((__le16)input); + break; + case 4: + *val = le32_to_cpu((__le32)input); + break; + case 8: + *val = le64_to_cpu((__le64)input); + break; + default: + return -EINVAL; + } + + return 0; +} + +static int m24lr_nvmem_read(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + ssize_t err; + struct m24lr *m24lr = priv; + + if (!bytes) + return bytes; + + if (offset + bytes > m24lr->eeprom_size) + return -EINVAL; + + err = m24lr_read(m24lr, val, bytes, offset, true); + if (IS_ERR_VALUE(err)) + return err; + + return 0; +} + +static int m24lr_nvmem_write(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + ssize_t err; + struct m24lr *m24lr = priv; + + if (!bytes) + return -EINVAL; + + if (offset + bytes > m24lr->eeprom_size) + return -EINVAL; + + err = m24lr_write(m24lr, val, bytes, offset, true); + if (IS_ERR_VALUE(err)) + return err; + + return 0; +} + +static ssize_t m24lr_ctl_sss_read(struct file *filep, struct kobject *kobj, + const struct bin_attribute *attr, char *buf, + loff_t offset, size_t count) +{ + struct m24lr *m24lr = attr->private; + + if (!count) + return count; + + if (size_add(offset, count) > m24lr->sss_len) + return -EINVAL; + + return m24lr_read(m24lr, buf, count, offset, false); +} + +static ssize_t m24lr_ctl_sss_write(struct file *filep, struct kobject *kobj, + const struct bin_attribute *attr, char *buf, + loff_t offset, size_t count) +{ + struct m24lr *m24lr = attr->private; + + if (!count) + return -EINVAL; + + if (size_add(offset, count) > m24lr->sss_len) + return -EINVAL; + + return m24lr_write(m24lr, buf, count, offset, false); +} +static BIN_ATTR(sss, 0600, m24lr_ctl_sss_read, m24lr_ctl_sss_write, 0); + +static ssize_t new_pass_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct m24lr *m24lr = i2c_get_clientdata(to_i2c_client(dev)); + + return m24lr_write_pass(m24lr, buf, count, 7); +} +static DEVICE_ATTR_WO(new_pass); + +static ssize_t unlock_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct m24lr *m24lr = i2c_get_clientdata(to_i2c_client(dev)); + + return m24lr_write_pass(m24lr, buf, count, 9); +} +static DEVICE_ATTR_WO(unlock); + +static ssize_t uid_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct m24lr *m24lr = i2c_get_clientdata(to_i2c_client(dev)); + + return sysfs_emit(buf, "%llx\n", m24lr->uid); +} +static DEVICE_ATTR_RO(uid); + +static ssize_t total_sectors_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct m24lr *m24lr = i2c_get_clientdata(to_i2c_client(dev)); + + return sysfs_emit(buf, "%x\n", m24lr->sss_len); +} +static DEVICE_ATTR_RO(total_sectors); + +static struct attribute *m24lr_ctl_dev_attrs[] = { + &dev_attr_unlock.attr, + &dev_attr_new_pass.attr, + &dev_attr_uid.attr, + &dev_attr_total_sectors.attr, + NULL, +}; + +static const struct m24lr_chip *m24lr_get_chip(struct device *dev) +{ + const struct m24lr_chip *ret; + const struct i2c_device_id *id; + + id = i2c_match_id(m24lr_ids, to_i2c_client(dev)); + + if (dev->of_node && of_match_device(m24lr_of_match, dev)) + ret = of_device_get_match_data(dev); + else if (id) + ret = (void *)id->driver_data; + else + ret = acpi_device_get_match_data(dev); + + return ret; +} + +static int m24lr_probe(struct i2c_client *client) +{ + struct regmap_config eeprom_regmap_conf = {0}; + struct nvmem_config nvmem_conf = {0}; + struct device *dev = &client->dev; + struct i2c_client *eeprom_client; + const struct m24lr_chip *chip; + struct regmap *eeprom_regmap; + struct nvmem_device *nvmem; + struct regmap *ctl_regmap; + struct m24lr *m24lr; + u32 regs[2]; + long err; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return -EOPNOTSUPP; + + chip = m24lr_get_chip(dev); + if (!chip) + return -ENODEV; + + m24lr = devm_kzalloc(dev, sizeof(struct m24lr), GFP_KERNEL); + if (!m24lr) + return -ENOMEM; + + err = device_property_read_u32_array(dev, "reg", regs, ARRAY_SIZE(regs)); + if (err) + return dev_err_probe(dev, err, "Failed to read 'reg' property\n"); + + /* Create a second I2C client for the eeprom interface */ + eeprom_client = devm_i2c_new_dummy_device(dev, client->adapter, regs[1]); + if (IS_ERR(eeprom_client)) + return dev_err_probe(dev, PTR_ERR(eeprom_client), + "Failed to create dummy I2C client for the EEPROM\n"); + + ctl_regmap = devm_regmap_init_i2c(client, &m24lr_ctl_regmap_conf); + if (IS_ERR(ctl_regmap)) + return dev_err_probe(dev, PTR_ERR(ctl_regmap), + "Failed to init regmap\n"); + + eeprom_regmap_conf.name = "m24lr_eeprom"; + eeprom_regmap_conf.reg_bits = 16; + eeprom_regmap_conf.val_bits = 8; + eeprom_regmap_conf.disable_locking = true; + eeprom_regmap_conf.max_register = chip->eeprom_size - 1; + + eeprom_regmap = devm_regmap_init_i2c(eeprom_client, + &eeprom_regmap_conf); + if (IS_ERR(eeprom_regmap)) + return dev_err_probe(dev, PTR_ERR(eeprom_regmap), + "Failed to init regmap\n"); + + mutex_init(&m24lr->lock); + m24lr->sss_len = chip->sss_len; + m24lr->page_size = chip->page_size; + m24lr->eeprom_size = chip->eeprom_size; + m24lr->eeprom_regmap = eeprom_regmap; + m24lr->ctl_regmap = ctl_regmap; + + nvmem_conf.dev = &eeprom_client->dev; + nvmem_conf.owner = THIS_MODULE; + nvmem_conf.type = NVMEM_TYPE_EEPROM; + nvmem_conf.reg_read = m24lr_nvmem_read; + nvmem_conf.reg_write = m24lr_nvmem_write; + nvmem_conf.size = chip->eeprom_size; + nvmem_conf.word_size = 1; + nvmem_conf.stride = 1; + nvmem_conf.priv = m24lr; + + nvmem = devm_nvmem_register(dev, &nvmem_conf); + if (IS_ERR(nvmem)) + return dev_err_probe(dev, PTR_ERR(nvmem), + "Failed to register nvmem\n"); + + i2c_set_clientdata(client, m24lr); + i2c_set_clientdata(eeprom_client, m24lr); + + bin_attr_sss.size = chip->sss_len; + bin_attr_sss.private = m24lr; + err = sysfs_create_bin_file(&dev->kobj, &bin_attr_sss); + if (err) + return dev_err_probe(dev, err, + "Failed to create sss bin file\n"); + + /* test by reading the uid, if success store it */ + err = m24lr_read_reg_le(m24lr, &m24lr->uid, 2324, sizeof(m24lr->uid)); + if (IS_ERR_VALUE(err)) + goto remove_bin_file; + + return 0; + +remove_bin_file: + sysfs_remove_bin_file(&dev->kobj, &bin_attr_sss); + + return err; +} + +static void m24lr_remove(struct i2c_client *client) +{ + sysfs_remove_bin_file(&client->dev.kobj, &bin_attr_sss); +} + +ATTRIBUTE_GROUPS(m24lr_ctl_dev); + +static struct i2c_driver m24lr_driver = { + .driver = { + .name = "m24lr", + .of_match_table = m24lr_of_match, + .dev_groups = m24lr_ctl_dev_groups, + }, + .probe = m24lr_probe, + .remove = m24lr_remove, + .id_table = m24lr_ids, +}; +module_i2c_driver(m24lr_driver); + +MODULE_AUTHOR("Abd-Alrhman Masalkhi"); +MODULE_DESCRIPTION("st m24lr control driver"); +MODULE_LICENSE("GPL"); diff --git a/drivers/misc/eeprom/max6875.c b/drivers/misc/eeprom/max6875.c new file mode 100644 index 000000000..5731d2dc8 --- /dev/null +++ b/drivers/misc/eeprom/max6875.c @@ -0,0 +1,204 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * max6875.c - driver for MAX6874/MAX6875 + * + * Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com> + * + * Based on eeprom.c + * + * The MAX6875 has a bank of registers and two banks of EEPROM. + * Address ranges are defined as follows: + * * 0x0000 - 0x0046 = configuration registers + * * 0x8000 - 0x8046 = configuration EEPROM + * * 0x8100 - 0x82FF = user EEPROM + * + * This driver makes the user EEPROM available for read. + * + * The registers & config EEPROM should be accessed via i2c-dev. + * + * The MAX6875 ignores the lowest address bit, so each chip responds to + * two addresses - 0x50/0x51 and 0x52/0x53. + * + * Note that the MAX6875 uses i2c_smbus_write_byte_data() to set the read + * address, so this driver is destructive if loaded for the wrong EEPROM chip. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/mutex.h> + +/* The MAX6875 can only read/write 16 bytes at a time */ +#define SLICE_SIZE 16 +#define SLICE_BITS 4 + +/* USER EEPROM is at addresses 0x8100 - 0x82FF */ +#define USER_EEPROM_BASE 0x8100 +#define USER_EEPROM_SIZE 0x0200 +#define USER_EEPROM_SLICES 32 + +/* MAX6875 commands */ +#define MAX6875_CMD_BLK_READ 0x84 + +/* Each client has this additional data */ +struct max6875_data { + struct i2c_client *fake_client; + struct mutex update_lock; + + u32 valid; + u8 data[USER_EEPROM_SIZE]; + unsigned long last_updated[USER_EEPROM_SLICES]; +}; + +static void max6875_update_slice(struct i2c_client *client, int slice) +{ + struct max6875_data *data = i2c_get_clientdata(client); + int i, j, addr; + u8 *buf; + + if (slice >= USER_EEPROM_SLICES) + return; + + mutex_lock(&data->update_lock); + + buf = &data->data[slice << SLICE_BITS]; + + if (!(data->valid & (1 << slice)) || + time_after(jiffies, data->last_updated[slice])) { + + dev_dbg(&client->dev, "Starting update of slice %u\n", slice); + + data->valid &= ~(1 << slice); + + addr = USER_EEPROM_BASE + (slice << SLICE_BITS); + + /* select the eeprom address */ + if (i2c_smbus_write_byte_data(client, addr >> 8, addr & 0xFF)) { + dev_err(&client->dev, "address set failed\n"); + goto exit_up; + } + + if (i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { + if (i2c_smbus_read_i2c_block_data(client, + MAX6875_CMD_BLK_READ, + SLICE_SIZE, + buf) != SLICE_SIZE) { + goto exit_up; + } + } else { + for (i = 0; i < SLICE_SIZE; i++) { + j = i2c_smbus_read_byte(client); + if (j < 0) { + goto exit_up; + } + buf[i] = j; + } + } + data->last_updated[slice] = jiffies; + data->valid |= (1 << slice); + } +exit_up: + mutex_unlock(&data->update_lock); +} + +static ssize_t max6875_read(struct file *filp, struct kobject *kobj, + const struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + struct i2c_client *client = kobj_to_i2c_client(kobj); + struct max6875_data *data = i2c_get_clientdata(client); + int slice, max_slice; + + /* refresh slices which contain requested bytes */ + max_slice = (off + count - 1) >> SLICE_BITS; + for (slice = (off >> SLICE_BITS); slice <= max_slice; slice++) + max6875_update_slice(client, slice); + + memcpy(buf, &data->data[off], count); + + return count; +} + +static const struct bin_attribute user_eeprom_attr = { + .attr = { + .name = "eeprom", + .mode = S_IRUGO, + }, + .size = USER_EEPROM_SIZE, + .read = max6875_read, +}; + +static int max6875_probe(struct i2c_client *client) +{ + struct i2c_adapter *adapter = client->adapter; + struct max6875_data *data; + int err; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA + | I2C_FUNC_SMBUS_READ_BYTE)) + return -ENODEV; + + /* Only bind to even addresses */ + if (client->addr & 1) + return -ENODEV; + + data = kzalloc_obj(struct max6875_data); + if (!data) + return -ENOMEM; + + /* A fake client is created on the odd address */ + data->fake_client = i2c_new_dummy_device(client->adapter, client->addr + 1); + if (IS_ERR(data->fake_client)) { + err = PTR_ERR(data->fake_client); + goto exit_kfree; + } + + /* Init real i2c_client */ + i2c_set_clientdata(client, data); + mutex_init(&data->update_lock); + + err = sysfs_create_bin_file(&client->dev.kobj, &user_eeprom_attr); + if (err) + goto exit_remove_fake; + + return 0; + +exit_remove_fake: + i2c_unregister_device(data->fake_client); +exit_kfree: + kfree(data); + return err; +} + +static void max6875_remove(struct i2c_client *client) +{ + struct max6875_data *data = i2c_get_clientdata(client); + + i2c_unregister_device(data->fake_client); + + sysfs_remove_bin_file(&client->dev.kobj, &user_eeprom_attr); + kfree(data); +} + +static const struct i2c_device_id max6875_id[] = { + { "max6875" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, max6875_id); + +static struct i2c_driver max6875_driver = { + .driver = { + .name = "max6875", + }, + .probe = max6875_probe, + .remove = max6875_remove, + .id_table = max6875_id, +}; + +module_i2c_driver(max6875_driver); + +MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>"); +MODULE_DESCRIPTION("MAX6875 driver"); +MODULE_LICENSE("GPL"); |