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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/rtc/rtc-bq32k.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/rtc/rtc-bq32k.c')
| -rw-r--r-- | drivers/rtc/rtc-bq32k.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-bq32k.c b/drivers/rtc/rtc-bq32k.c new file mode 100644 index 000000000..573231613 --- /dev/null +++ b/drivers/rtc/rtc-bq32k.c @@ -0,0 +1,341 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for TI BQ32000 RTC. + * + * Copyright (C) 2009 Semihalf. + * Copyright (C) 2014 Pavel Machek <pavel@denx.de> + * + * You can get hardware description at + * https://www.ti.com/lit/ds/symlink/bq32000.pdf + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/rtc.h> +#include <linux/init.h> +#include <linux/kstrtox.h> +#include <linux/errno.h> +#include <linux/bcd.h> +#include <linux/delay.h> + +#define BQ32K_SECONDS 0x00 /* Seconds register address */ +#define BQ32K_SECONDS_MASK 0x7F /* Mask over seconds value */ +#define BQ32K_STOP 0x80 /* Oscillator Stop flat */ + +#define BQ32K_MINUTES 0x01 /* Minutes register address */ +#define BQ32K_MINUTES_MASK 0x7F /* Mask over minutes value */ +#define BQ32K_OF 0x80 /* Oscillator Failure flag */ + +#define BQ32K_HOURS_MASK 0x3F /* Mask over hours value */ +#define BQ32K_CENT 0x40 /* Century flag */ +#define BQ32K_CENT_EN 0x80 /* Century flag enable bit */ + +#define BQ32K_CALIBRATION 0x07 /* CAL_CFG1, calibration and control */ +#define BQ32K_TCH2 0x08 /* Trickle charge enable */ +#define BQ32K_CFG2 0x09 /* Trickle charger control */ +#define BQ32K_TCFE BIT(6) /* Trickle charge FET bypass */ + +#define MAX_LEN 10 /* Maximum number of consecutive + * register for this particular RTC. + */ + +struct bq32k_regs { + uint8_t seconds; + uint8_t minutes; + uint8_t cent_hours; + uint8_t day; + uint8_t date; + uint8_t month; + uint8_t years; +}; + +static struct i2c_driver bq32k_driver; + +static int bq32k_read(struct device *dev, void *data, uint8_t off, uint8_t len) +{ + struct i2c_client *client = to_i2c_client(dev); + struct i2c_msg msgs[] = { + { + .addr = client->addr, + .flags = 0, + .len = 1, + .buf = &off, + }, { + .addr = client->addr, + .flags = I2C_M_RD, + .len = len, + .buf = data, + } + }; + + if (i2c_transfer(client->adapter, msgs, 2) == 2) + return 0; + + return -EIO; +} + +static int bq32k_write(struct device *dev, void *data, uint8_t off, uint8_t len) +{ + struct i2c_client *client = to_i2c_client(dev); + uint8_t buffer[MAX_LEN + 1]; + + buffer[0] = off; + memcpy(&buffer[1], data, len); + + if (i2c_master_send(client, buffer, len + 1) == len + 1) + return 0; + + return -EIO; +} + +static int bq32k_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct bq32k_regs regs; + int error; + + /* + * When the device doesn't have the interrupt connected, prevent + * userpace from polling the RTC registers too frequently. + */ + if (client->irq <= 0) + usleep_range(2000, 2500); + + error = bq32k_read(dev, ®s, 0, sizeof(regs)); + if (error) + return error; + + /* + * In case of oscillator failure, the register contents should be + * considered invalid. The flag is cleared the next time the RTC is set. + */ + if (regs.minutes & BQ32K_OF) + return -EINVAL; + + tm->tm_sec = bcd2bin(regs.seconds & BQ32K_SECONDS_MASK); + tm->tm_min = bcd2bin(regs.minutes & BQ32K_MINUTES_MASK); + tm->tm_hour = bcd2bin(regs.cent_hours & BQ32K_HOURS_MASK); + tm->tm_mday = bcd2bin(regs.date); + tm->tm_wday = bcd2bin(regs.day) - 1; + tm->tm_mon = bcd2bin(regs.month) - 1; + tm->tm_year = bcd2bin(regs.years) + + ((regs.cent_hours & BQ32K_CENT) ? 100 : 0); + + return 0; +} + +static int bq32k_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct bq32k_regs regs; + + regs.seconds = bin2bcd(tm->tm_sec); + regs.minutes = bin2bcd(tm->tm_min); + regs.cent_hours = bin2bcd(tm->tm_hour) | BQ32K_CENT_EN; + regs.day = bin2bcd(tm->tm_wday + 1); + regs.date = bin2bcd(tm->tm_mday); + regs.month = bin2bcd(tm->tm_mon + 1); + + if (tm->tm_year >= 100) { + regs.cent_hours |= BQ32K_CENT; + regs.years = bin2bcd(tm->tm_year - 100); + } else + regs.years = bin2bcd(tm->tm_year); + + return bq32k_write(dev, ®s, 0, sizeof(regs)); +} + +static const struct rtc_class_ops bq32k_rtc_ops = { + .read_time = bq32k_rtc_read_time, + .set_time = bq32k_rtc_set_time, +}; + +static int trickle_charger_of_init(struct device *dev, struct device_node *node) +{ + unsigned char reg; + int error; + u32 ohms = 0; + + if (of_property_read_u32(node, "trickle-resistor-ohms" , &ohms)) + return 0; + + switch (ohms) { + case 180+940: + /* + * TCHE[3:0] == 0x05, TCH2 == 1, TCFE == 0 (charging + * over diode and 940ohm resistor) + */ + + if (of_property_read_bool(node, "trickle-diode-disable")) { + dev_err(dev, "diode and resistor mismatch\n"); + return -EINVAL; + } + reg = 0x05; + break; + + case 180+20000: + /* diode disabled */ + + if (!of_property_read_bool(node, "trickle-diode-disable")) { + dev_err(dev, "bq32k: diode and resistor mismatch\n"); + return -EINVAL; + } + reg = 0x45; + break; + + default: + dev_err(dev, "invalid resistor value (%d)\n", ohms); + return -EINVAL; + } + + error = bq32k_write(dev, ®, BQ32K_CFG2, 1); + if (error) + return error; + + reg = 0x20; + error = bq32k_write(dev, ®, BQ32K_TCH2, 1); + if (error) + return error; + + dev_info(dev, "Enabled trickle RTC battery charge.\n"); + return 0; +} + +static ssize_t bq32k_sysfs_show_tricklecharge_bypass(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int reg, error; + + error = bq32k_read(dev, ®, BQ32K_CFG2, 1); + if (error) + return error; + + return sprintf(buf, "%d\n", (reg & BQ32K_TCFE) ? 1 : 0); +} + +static ssize_t bq32k_sysfs_store_tricklecharge_bypass(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int reg, enable, error; + + if (kstrtoint(buf, 0, &enable)) + return -EINVAL; + + error = bq32k_read(dev, ®, BQ32K_CFG2, 1); + if (error) + return error; + + if (enable) { + reg |= BQ32K_TCFE; + error = bq32k_write(dev, ®, BQ32K_CFG2, 1); + if (error) + return error; + + dev_info(dev, "Enabled trickle charge FET bypass.\n"); + } else { + reg &= ~BQ32K_TCFE; + error = bq32k_write(dev, ®, BQ32K_CFG2, 1); + if (error) + return error; + + dev_info(dev, "Disabled trickle charge FET bypass.\n"); + } + + return count; +} + +static DEVICE_ATTR(trickle_charge_bypass, 0644, + bq32k_sysfs_show_tricklecharge_bypass, + bq32k_sysfs_store_tricklecharge_bypass); + +static int bq32k_sysfs_register(struct device *dev) +{ + return device_create_file(dev, &dev_attr_trickle_charge_bypass); +} + +static void bq32k_sysfs_unregister(struct device *dev) +{ + device_remove_file(dev, &dev_attr_trickle_charge_bypass); +} + +static int bq32k_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + struct rtc_device *rtc; + uint8_t reg; + int error; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return -ENODEV; + + /* Check Oscillator Stop flag */ + error = bq32k_read(dev, ®, BQ32K_SECONDS, 1); + if (!error && (reg & BQ32K_STOP)) { + dev_warn(dev, "Oscillator was halted. Restarting...\n"); + reg &= ~BQ32K_STOP; + error = bq32k_write(dev, ®, BQ32K_SECONDS, 1); + } + if (error) + return error; + + /* Check Oscillator Failure flag */ + error = bq32k_read(dev, ®, BQ32K_MINUTES, 1); + if (error) + return error; + if (reg & BQ32K_OF) + dev_warn(dev, "Oscillator Failure. Check RTC battery.\n"); + + if (client->dev.of_node) + trickle_charger_of_init(dev, client->dev.of_node); + + rtc = devm_rtc_device_register(&client->dev, bq32k_driver.driver.name, + &bq32k_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + error = bq32k_sysfs_register(&client->dev); + if (error) { + dev_err(&client->dev, + "Unable to create sysfs entries for rtc bq32000\n"); + return error; + } + + + i2c_set_clientdata(client, rtc); + + return 0; +} + +static void bq32k_remove(struct i2c_client *client) +{ + bq32k_sysfs_unregister(&client->dev); +} + +static const struct i2c_device_id bq32k_id[] = { + { .name = "bq32000" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, bq32k_id); + +static const __maybe_unused struct of_device_id bq32k_of_match[] = { + { .compatible = "ti,bq32000" }, + { } +}; +MODULE_DEVICE_TABLE(of, bq32k_of_match); + +static struct i2c_driver bq32k_driver = { + .driver = { + .name = "bq32k", + .of_match_table = of_match_ptr(bq32k_of_match), + }, + .probe = bq32k_probe, + .remove = bq32k_remove, + .id_table = bq32k_id, +}; + +module_i2c_driver(bq32k_driver); + +MODULE_AUTHOR("Semihalf, Piotr Ziecik <kosmo@semihalf.com>"); +MODULE_DESCRIPTION("TI BQ32000 I2C RTC driver"); +MODULE_LICENSE("GPL"); |
