diff options
| 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/char/ds1620.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/char/ds1620.c')
| -rw-r--r-- | drivers/char/ds1620.c | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/drivers/char/ds1620.c b/drivers/char/ds1620.c new file mode 100644 index 000000000..44a1cdbd4 --- /dev/null +++ b/drivers/char/ds1620.c @@ -0,0 +1,424 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/drivers/char/ds1620.c: Dallas Semiconductors DS1620 + * thermometer driver (as used in the Rebel.com NetWinder) + */ +#include <linux/module.h> +#include <linux/miscdevice.h> +#include <linux/delay.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/capability.h> +#include <linux/init.h> +#include <linux/mutex.h> + +#include <mach/hardware.h> +#include <asm/mach-types.h> +#include <linux/uaccess.h> +#include <asm/therm.h> + +#ifdef CONFIG_PROC_FS +/* define for /proc interface */ +#define THERM_USE_PROC +#endif + +/* Definitions for DS1620 chip */ +#define THERM_START_CONVERT 0xee +#define THERM_RESET 0xaf +#define THERM_READ_CONFIG 0xac +#define THERM_READ_TEMP 0xaa +#define THERM_READ_TL 0xa2 +#define THERM_READ_TH 0xa1 +#define THERM_WRITE_CONFIG 0x0c +#define THERM_WRITE_TL 0x02 +#define THERM_WRITE_TH 0x01 + +#define CFG_CPU 2 +#define CFG_1SHOT 1 + +static DEFINE_MUTEX(ds1620_mutex); +static const char *fan_state[] = { "off", "on", "on (hardwired)" }; + +/* + * Start of NetWinder specifics + * Note! We have to hold the gpio lock with IRQs disabled over the + * whole of our transaction to the Dallas chip, since there is a + * chance that the WaveArtist driver could touch these bits to + * enable or disable the speaker. + */ +extern unsigned int system_rev; + +static inline void netwinder_ds1620_set_clk(int clk) +{ + nw_gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0); +} + +static inline void netwinder_ds1620_set_data(int dat) +{ + nw_gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0); +} + +static inline int netwinder_ds1620_get_data(void) +{ + return nw_gpio_read() & GPIO_DATA; +} + +static inline void netwinder_ds1620_set_data_dir(int dir) +{ + nw_gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0); +} + +static inline void netwinder_ds1620_reset(void) +{ + nw_cpld_modify(CPLD_DS_ENABLE, 0); + nw_cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE); +} + +static inline void netwinder_lock(unsigned long *flags) +{ + raw_spin_lock_irqsave(&nw_gpio_lock, *flags); +} + +static inline void netwinder_unlock(unsigned long *flags) +{ + raw_spin_unlock_irqrestore(&nw_gpio_lock, *flags); +} + +static inline void netwinder_set_fan(int i) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&nw_gpio_lock, flags); + nw_gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0); + raw_spin_unlock_irqrestore(&nw_gpio_lock, flags); +} + +static inline int netwinder_get_fan(void) +{ + if ((system_rev & 0xf000) == 0x4000) + return FAN_ALWAYS_ON; + + return (nw_gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF; +} + +/* + * End of NetWinder specifics + */ + +static void ds1620_send_bits(int nr, int value) +{ + int i; + + for (i = 0; i < nr; i++) { + netwinder_ds1620_set_data(value & 1); + netwinder_ds1620_set_clk(0); + udelay(1); + netwinder_ds1620_set_clk(1); + udelay(1); + + value >>= 1; + } +} + +static unsigned int ds1620_recv_bits(int nr) +{ + unsigned int value = 0, mask = 1; + int i; + + netwinder_ds1620_set_data(0); + + for (i = 0; i < nr; i++) { + netwinder_ds1620_set_clk(0); + udelay(1); + + if (netwinder_ds1620_get_data()) + value |= mask; + + mask <<= 1; + + netwinder_ds1620_set_clk(1); + udelay(1); + } + + return value; +} + +static void ds1620_out(int cmd, int bits, int value) +{ + unsigned long flags; + + netwinder_lock(&flags); + netwinder_ds1620_set_clk(1); + netwinder_ds1620_set_data_dir(0); + netwinder_ds1620_reset(); + + udelay(1); + + ds1620_send_bits(8, cmd); + if (bits) + ds1620_send_bits(bits, value); + + udelay(1); + + netwinder_ds1620_reset(); + netwinder_unlock(&flags); + + msleep(20); +} + +static unsigned int ds1620_in(int cmd, int bits) +{ + unsigned long flags; + unsigned int value; + + netwinder_lock(&flags); + netwinder_ds1620_set_clk(1); + netwinder_ds1620_set_data_dir(0); + netwinder_ds1620_reset(); + + udelay(1); + + ds1620_send_bits(8, cmd); + + netwinder_ds1620_set_data_dir(1); + value = ds1620_recv_bits(bits); + + netwinder_ds1620_reset(); + netwinder_unlock(&flags); + + return value; +} + +static int cvt_9_to_int(unsigned int val) +{ + if (val & 0x100) + val |= 0xfffffe00; + + return val; +} + +static void ds1620_write_state(struct therm *therm) +{ + ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU); + ds1620_out(THERM_WRITE_TL, 9, therm->lo); + ds1620_out(THERM_WRITE_TH, 9, therm->hi); + ds1620_out(THERM_START_CONVERT, 0, 0); +} + +static void ds1620_read_state(struct therm *therm) +{ + therm->lo = cvt_9_to_int(ds1620_in(THERM_READ_TL, 9)); + therm->hi = cvt_9_to_int(ds1620_in(THERM_READ_TH, 9)); +} + +static int ds1620_open(struct inode *inode, struct file *file) +{ + return stream_open(inode, file); +} + +static ssize_t +ds1620_read(struct file *file, char __user *buf, size_t count, loff_t *ptr) +{ + signed int cur_temp; + signed char cur_temp_degF; + + cur_temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)) >> 1; + + /* convert to Fahrenheit, as per wdt.c */ + cur_temp_degF = (cur_temp * 9) / 5 + 32; + + if (copy_to_user(buf, &cur_temp_degF, 1)) + return -EFAULT; + + return 1; +} + +static int +ds1620_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct therm therm; + union { + struct therm __user *therm; + int __user *i; + } uarg; + int i; + + uarg.i = (int __user *)arg; + + switch(cmd) { + case CMD_SET_THERMOSTATE: + case CMD_SET_THERMOSTATE2: + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (cmd == CMD_SET_THERMOSTATE) { + if (get_user(therm.hi, uarg.i)) + return -EFAULT; + therm.lo = therm.hi - 3; + } else { + if (copy_from_user(&therm, uarg.therm, sizeof(therm))) + return -EFAULT; + } + + therm.lo <<= 1; + therm.hi <<= 1; + + ds1620_write_state(&therm); + break; + + case CMD_GET_THERMOSTATE: + case CMD_GET_THERMOSTATE2: + ds1620_read_state(&therm); + + therm.lo >>= 1; + therm.hi >>= 1; + + if (cmd == CMD_GET_THERMOSTATE) { + if (put_user(therm.hi, uarg.i)) + return -EFAULT; + } else { + if (copy_to_user(uarg.therm, &therm, sizeof(therm))) + return -EFAULT; + } + break; + + case CMD_GET_TEMPERATURE: + case CMD_GET_TEMPERATURE2: + i = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); + + if (cmd == CMD_GET_TEMPERATURE) + i >>= 1; + + return put_user(i, uarg.i) ? -EFAULT : 0; + + case CMD_GET_STATUS: + i = ds1620_in(THERM_READ_CONFIG, 8) & 0xe3; + + return put_user(i, uarg.i) ? -EFAULT : 0; + + case CMD_GET_FAN: + i = netwinder_get_fan(); + + return put_user(i, uarg.i) ? -EFAULT : 0; + + case CMD_SET_FAN: + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (get_user(i, uarg.i)) + return -EFAULT; + + netwinder_set_fan(i); + break; + + default: + return -ENOIOCTLCMD; + } + + return 0; +} + +static long +ds1620_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + int ret; + + mutex_lock(&ds1620_mutex); + ret = ds1620_ioctl(file, cmd, arg); + mutex_unlock(&ds1620_mutex); + + return ret; +} + +#ifdef THERM_USE_PROC +static int ds1620_proc_therm_show(struct seq_file *m, void *v) +{ + struct therm th; + int temp; + + ds1620_read_state(&th); + temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); + + seq_printf(m, "Thermostat: HI %i.%i, LOW %i.%i; temperature: %i.%i C, fan %s\n", + th.hi >> 1, th.hi & 1 ? 5 : 0, + th.lo >> 1, th.lo & 1 ? 5 : 0, + temp >> 1, temp & 1 ? 5 : 0, + fan_state[netwinder_get_fan()]); + return 0; +} +#endif + +static const struct file_operations ds1620_fops = { + .owner = THIS_MODULE, + .open = ds1620_open, + .read = ds1620_read, + .unlocked_ioctl = ds1620_unlocked_ioctl, +}; + +static struct miscdevice ds1620_miscdev = { + TEMP_MINOR, + "temp", + &ds1620_fops +}; + +static int __init ds1620_init(void) +{ + int ret; + struct therm th, th_start; + + if (!machine_is_netwinder()) + return -ENODEV; + + ds1620_out(THERM_RESET, 0, 0); + ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU); + ds1620_out(THERM_START_CONVERT, 0, 0); + + /* + * Trigger the fan to start by setting + * temperature high point low. This kicks + * the fan into action. + */ + ds1620_read_state(&th); + th_start.lo = 0; + th_start.hi = 1; + ds1620_write_state(&th_start); + + msleep(2000); + + ds1620_write_state(&th); + + ret = misc_register(&ds1620_miscdev); + if (ret < 0) + return ret; + +#ifdef THERM_USE_PROC + if (!proc_create_single("therm", 0, NULL, ds1620_proc_therm_show)) + printk(KERN_ERR "therm: unable to register /proc/therm\n"); +#endif + + ds1620_read_state(&th); + ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); + + printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, " + "current %i.%i C, fan %s.\n", + th.hi >> 1, th.hi & 1 ? 5 : 0, + th.lo >> 1, th.lo & 1 ? 5 : 0, + ret >> 1, ret & 1 ? 5 : 0, + fan_state[netwinder_get_fan()]); + + return 0; +} + +static void __exit ds1620_exit(void) +{ +#ifdef THERM_USE_PROC + remove_proc_entry("therm", NULL); +#endif + misc_deregister(&ds1620_miscdev); +} + +module_init(ds1620_init); +module_exit(ds1620_exit); + +MODULE_DESCRIPTION("Dallas Semiconductor DS1620 thermometer driver"); +MODULE_LICENSE("GPL"); |
