linux-toradex.git/drivers/hwmon, branch master Linux kernel for Apalis and Colibri modules hwmon: (npcm750-pwm-fan): stop fan timer on device detach 2026-07-29T16:21:17+00:00 Hongyan Xu getshell@seu.edu.cn 2026-07-29T10:01:16+00:00 f27f6976ea269219c1259a7c2f8c6dfe782540a3 When a fan tach channel is present, npcm7xx_pwm_fan_probe() starts fan_timer. The timer callback polls tach state and rearms the timer, but the driver has no remove callback or devm cleanup action to stop it. On device detach, the devm-managed driver data and I/O mappings can be released while the timer is still pending or running. Register a devm cleanup action before starting the timer and shut the timer down synchronously from that action. This issue was found by a static analysis tool. Fixes: f1fd4a4db777 ("hwmon: Add NPCM7xx PWM and Fan driver") Cc: stable@vger.kernel.org Signed-off-by: Hongyan Xu <getshell@seu.edu.cn> Link: https://lore.kernel.org/r/20260729100116.790-1-getshell@seu.edu.cn Signed-off-by: Guenter Roeck <linux@roeck-us.net> 
When a fan tach channel is present, npcm7xx_pwm_fan_probe() starts
fan_timer. The timer callback polls tach state and rearms the timer, but
the driver has no remove callback or devm cleanup action to stop it. On
device detach, the devm-managed driver data and I/O mappings can be
released while the timer is still pending or running.

Register a devm cleanup action before starting the timer and shut the
timer down synchronously from that action.

This issue was found by a static analysis tool.

Fixes: f1fd4a4db777 ("hwmon: Add NPCM7xx PWM and Fan driver")
Cc: stable@vger.kernel.org
Signed-off-by: Hongyan Xu <getshell@seu.edu.cn>
Link: https://lore.kernel.org/r/20260729100116.790-1-getshell@seu.edu.cn
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
hwmon: (pmbus) Fix return value from pmbus_update_byte_data() 2026-07-28T16:02:57+00:00 Guenter Roeck linux@roeck-us.net 2026-07-28T15:41:40+00:00 a19038a200f18d9e74ac30081797917d0886e16b pmbus_update_byte_data() is supposed to return a negative error code or 0. However, if no change is made to the register, it actually returns the register value. This can result in problems if the calling code explicitly expects to see an error code or 0. Fix it to return 0 on success or the error code as expected. Fixes: 11c119986f270 ("hwmon: (pmbus) add helpers for byte write and read modify write") Signed-off-by: Guenter Roeck <linux@roeck-us.net> 
pmbus_update_byte_data() is supposed to return a negative error code or 0.
However, if no change is made to the register, it actually returns the
register value. This can result in problems if the calling code explicitly
expects to see an error code or 0.

Fix it to return 0 on success or the error code as expected.

Fixes: 11c119986f270 ("hwmon: (pmbus) add helpers for byte write and read modify write")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
hwmon: (adt7470) Fix PWM auto temp state array and bounds check 2026-07-28T00:58:39+00:00 Luiz Angelo Daros de Luca luizluca@gmail.com 2026-07-28T00:22:24+00:00 92413f439d1ec5e55b73ede8d66a7b971cbd1ced In pwm_auto_temp_store(), the parsed user input was missing bounds checks, allowing values > 0xF to overflow into the adjacent channel's bits. Furthermore, the value was being incorrectly written to the pwm_automatic state array instead of pwm_auto_temp. Fix this by rejecting values > 0xF with -EINVAL, and assigning the value to the correct array only after a successful I2C write. Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/all/20260727034932.0B7C41F000E9@smtp.kernel.org/#t Fixes: 6f9703d0be16 ("hwmon: add support for adt7470") Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com> Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-8-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> 
In pwm_auto_temp_store(), the parsed user input was missing bounds
checks, allowing values > 0xF to overflow into the adjacent channel's
bits. Furthermore, the value was being incorrectly written to the
pwm_automatic state array instead of pwm_auto_temp.

Fix this by rejecting values > 0xF with -EINVAL, and assigning the
value to the correct array only after a successful I2C write.

Reported-by: sashiko-bot@kernel.org
Closes: https://lore.kernel.org/all/20260727034932.0B7C41F000E9@smtp.kernel.org/#t
Fixes: 6f9703d0be16 ("hwmon: add support for adt7470")
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-8-598e38a46ba6@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
hwmon: (adt7470) Fix divide-by-zero TOCTOU crash in fan speed read 2026-07-28T00:58:05+00:00 Luiz Angelo Daros de Luca luizluca@gmail.com 2026-07-28T00:22:23+00:00 1b46fe9dc8f8de59310f37e6c5e5c0e05ded46c3 If the fan data becomes 0 between the FAN_DATA_VALID() check and the FAN_PERIOD_TO_RPM() conversion, it will result in a divide-by-zero crash due to a race with a concurrent update of the cached fan value. Fix a TOCTOU issue by reading fan data once. Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/r/20260727034929.E29B71F000E9@smtp.kernel.org/ Fixes: fc958a61ff6d ("hwmon: (adt7470) Convert to devm_hwmon_device_register_with_info API") Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com> Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-7-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> 
If the fan data becomes 0 between the FAN_DATA_VALID() check and the
FAN_PERIOD_TO_RPM() conversion, it will result in a divide-by-zero crash
due to a race with a concurrent update of the cached fan value.

Fix a TOCTOU issue by reading fan data once.

Reported-by: sashiko-bot@kernel.org
Closes: https://lore.kernel.org/r/20260727034929.E29B71F000E9@smtp.kernel.org/
Fixes: fc958a61ff6d ("hwmon: (adt7470) Convert to devm_hwmon_device_register_with_info API")
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-7-598e38a46ba6@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
hwmon: (adt7470) Use cached PWM frequency value 2026-07-28T00:57:22+00:00 Luiz Angelo Daros de Luca luizluca@gmail.com 2026-07-28T00:22:22+00:00 60677cd4c28f44d5b307d3029dccece38fcce90f adt7470_pwm_read() currently ignores failures returned by pwm1_freq_get(). If the register read fails, the negative error code is returned through *val while the function itself reports success, potentially exposing a negative PWM frequency through sysfs. Fix this by using the cached PWM frequency maintained by the driver, eliminating the register access from the read path. Apart from the corrected error propagation and using the cached value, no functional change is intended. Fixes: ef67959c4253 ("hwmon: (adt7470) Convert to use regmap") Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com> Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-6-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> 
adt7470_pwm_read() currently ignores failures returned by
pwm1_freq_get(). If the register read fails, the negative error code is
returned through *val while the function itself reports success,
potentially exposing a negative PWM frequency through sysfs.

Fix this by using the cached PWM frequency maintained by the driver,
eliminating the register access from the read path.

Apart from the corrected error propagation and using the cached value,
no functional change is intended.

Fixes: ef67959c4253 ("hwmon: (adt7470) Convert to use regmap")
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-6-598e38a46ba6@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
hwmon: (adt7470) Fix swapped PWM3 and PWM4 auto mode masks 2026-07-28T00:56:50+00:00 Luiz Angelo Daros de Luca luizluca@gmail.com 2026-07-28T00:22:20+00:00 a3850231521b06bbbb18c8ebea100320c14a08be The ADT7470_PWM3_AUTO_MASK and ADT7470_PWM4_AUTO_MASK macros are currently defined with swapped bit values. According to Table 22 of the ADT7470 datasheet, the Fan Control Mode Configuration for register 0x69 follows the exact same bit position layout as register 0x68: - 0x68 Bit[7] corresponds to BHVR1 (PWM1) -> 0x80 - 0x68 Bit[6] corresponds to BHVR2 (PWM2) -> 0x40 - 0x69 Bit[7] corresponds to BHVR3 (PWM3) -> 0x80 - 0x69 Bit[6] corresponds to BHVR4 (PWM4) -> 0x40 Consequently, PWM3 should use mask 0x80 and PWM4 should use 0x40. This typo did not cause any functional bugs because these specific macros are never referenced in the driver code. Instead, the driver correctly applies the configuration by relying on the modulo parity of the channel index (e.g., `channel % 2`) to selectively apply either ADT7470_PWM1_AUTO_MASK (0x80) or ADT7470_PWM2_AUTO_MASK (0x40). Since the bit layout is identical between the two configuration registers, the hardware is currently configured correctly. Fix the macro definitions to reflect the datasheet accurately and prevent future bugs or confusion during code review and refactoring. As this is a purely cosmetic fix with no functional impact, a backport to stable kernels is not necessary. Fixes: 6f9703d0be16 ("hwmon: add support for adt7470") Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com> Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-4-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> 
The ADT7470_PWM3_AUTO_MASK and ADT7470_PWM4_AUTO_MASK macros are
currently defined with swapped bit values.

According to Table 22 of the ADT7470 datasheet, the Fan Control Mode
Configuration for register 0x69 follows the exact same bit position
layout as register 0x68:
- 0x68 Bit[7] corresponds to BHVR1 (PWM1) -> 0x80
- 0x68 Bit[6] corresponds to BHVR2 (PWM2) -> 0x40
- 0x69 Bit[7] corresponds to BHVR3 (PWM3) -> 0x80
- 0x69 Bit[6] corresponds to BHVR4 (PWM4) -> 0x40

Consequently, PWM3 should use mask 0x80 and PWM4 should use 0x40.

This typo did not cause any functional bugs because these specific
macros are never referenced in the driver code. Instead, the driver
correctly applies the configuration by relying on the modulo parity of
the channel index (e.g., `channel % 2`) to selectively apply either
ADT7470_PWM1_AUTO_MASK (0x80) or ADT7470_PWM2_AUTO_MASK (0x40).
Since the bit layout is identical between the two configuration
registers, the hardware is currently configured correctly.

Fix the macro definitions to reflect the datasheet accurately and
prevent future bugs or confusion during code review and refactoring.
As this is a purely cosmetic fix with no functional impact, a backport
to stable kernels is not necessary.

Fixes: 6f9703d0be16 ("hwmon: add support for adt7470")
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-4-598e38a46ba6@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
hwmon: (adt7470) Fix temperature alarm logic in hwmon_temp_read() 2026-07-28T00:55:44+00:00 Luiz Angelo Daros de Luca luizluca@gmail.com 2026-07-28T00:22:21+00:00 1a18c79c4bc44cc5349c60e16b0b744dc6ec5f77 During the conversion the alarm callback started interpreting the channel index as an alarm bitmask, resulting in incorrect alarm reporting. Compute the proper alarm bit instead. Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/r/20260717211224.B9E291F000E9@smtp.kernel.org Fixes: fc958a61ff6d ("hwmon: (adt7470) Convert to devm_hwmon_device_register_with_info API") Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com> Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-5-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> 
During the conversion the alarm callback started interpreting the
channel index as an alarm bitmask, resulting in incorrect alarm
reporting. Compute the proper alarm bit instead.

Reported-by: sashiko-bot@kernel.org
Closes: https://lore.kernel.org/r/20260717211224.B9E291F000E9@smtp.kernel.org
Fixes: fc958a61ff6d ("hwmon: (adt7470) Convert to devm_hwmon_device_register_with_info API")
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-5-598e38a46ba6@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
hwmon: (adt7470) Fix busy-loop and I2C flooding in update thread 2026-07-28T00:55:07+00:00 Luiz Angelo Daros de Luca luizluca@gmail.com 2026-07-28T00:22:19+00:00 cb0b7f9c43b0abbd422a7e4c2c85e91db429207c When userspace configures 'auto_update_interval' to 0 via sysfs, the background kthread executes schedule_timeout_interruptible(0), which returns immediately. If 'num_temp_sensors' is concurrently or previously set to 0, the msleep_interruptible() delay inside adt7470_read_temperatures() also becomes 0. This combination forces the background thread into a tight, unbounded busy-loop, hogging the CPU and flooding the I2C bus with a continuous stream of transactions. Fix this vulnerability by raising the lower limit of the clamp_val in auto_update_interval_store() from 0 to 500 milliseconds. This guarantees a reasonable minimum sleep window between sensor updates, protecting the system from intentional or accidental I2C bus denial of service. Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/r/20260716213252.EACA71F000E9@smtp.kernel.org Fixes: 89fac11cb3e7 ("adt7470: make automatic fan control really work") Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com> Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-3-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> 
When userspace configures 'auto_update_interval' to 0 via sysfs, the
background kthread executes schedule_timeout_interruptible(0), which
returns immediately.

If 'num_temp_sensors' is concurrently or previously set to 0, the
msleep_interruptible() delay inside adt7470_read_temperatures() also
becomes 0. This combination forces the background thread into a tight,
unbounded busy-loop, hogging the CPU and flooding the I2C bus with a
continuous stream of transactions.

Fix this vulnerability by raising the lower limit of the clamp_val in
auto_update_interval_store() from 0 to 500 milliseconds. This guarantees
a reasonable minimum sleep window between sensor updates, protecting the
system from intentional or accidental I2C bus denial of service.

Reported-by: sashiko-bot@kernel.org
Closes: https://lore.kernel.org/r/20260716213252.EACA71F000E9@smtp.kernel.org
Fixes: 89fac11cb3e7 ("adt7470: make automatic fan control really work")
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-3-598e38a46ba6@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
hwmon: (adt7470) Fix cache updated before hardware write on I2C error 2026-07-28T00:54:08+00:00 Luiz Angelo Daros de Luca luizluca@gmail.com 2026-07-28T00:22:18+00:00 05270bd38d9bf88a2f4c212246a8fa29f4032078 adt7470_temp_write() and adt7470_pwm_write() update the driver's cached values (temp_min, temp_max, pwm_input, pwm_enable) before issuing the corresponding regmap_write(), and never check whether the write succeeded before committing that update. If the I2C transaction fails, the function correctly propagates the error to the caller, but the cache silently keeps the new value, which was never actually applied to the hardware. Subsequent reads then report a value that does not match the device state. Reorder both write paths to update the cache only after a successful regmap_write(), so the cache always reflects what was actually written to the hardware. Fixes: ef67959c4253 ("hwmon: (adt7470) Convert to use regmap") Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com> Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-2-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> 
adt7470_temp_write() and adt7470_pwm_write() update the driver's
cached values (temp_min, temp_max, pwm_input, pwm_enable) before issuing
the corresponding regmap_write(), and never check whether the write
succeeded before committing that update. If the I2C transaction fails,
the function correctly propagates the error to the caller, but the cache
silently keeps the new value, which was never actually applied to the
hardware. Subsequent reads then report a value that does not match the
device state.

Reorder both write paths to update the cache only after a successful
regmap_write(), so the cache always reflects what was actually
written to the hardware.

Fixes: ef67959c4253 ("hwmon: (adt7470) Convert to use regmap")
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-2-598e38a46ba6@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
hwmon: (adt7470) Fix fans stuck in manual mode on I2C errors 2026-07-28T00:53:28+00:00 Luiz Angelo Daros de Luca luizluca@gmail.com 2026-07-28T00:22:17+00:00 625a2c02a1c04571232a746fe188b4d9a8d63edd During adt7470_read_temperatures(), the driver temporarily switches the PWM channels to manual mode, performs the temperature collection, and then restores the original configuration registers. However, if an I2C transaction fails at any point after entering manual mode, the function aborts and returns immediately. This leaves the configuration registers un-restored, permanently trapping the fans in manual mode. Introduce a recovery path to ensure that the original PWM configuration registers are always restored, even when intermediate I2C operations fail. Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/r/20260716213252.EACA71F000E9@smtp.kernel.org Fixes: ef67959c4253 ("hwmon: (adt7470) Convert to use regmap") Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com> Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-1-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> 
During adt7470_read_temperatures(), the driver temporarily switches
the PWM channels to manual mode, performs the temperature collection,
and then restores the original configuration registers.

However, if an I2C transaction fails at any point after entering manual
mode, the function aborts and returns immediately. This leaves the
configuration registers un-restored, permanently trapping the fans in
manual mode.

Introduce a recovery path to ensure that the original PWM configuration
registers are always restored, even when intermediate I2C operations
fail.

Reported-by: sashiko-bot@kernel.org
Closes: https://lore.kernel.org/r/20260716213252.EACA71F000E9@smtp.kernel.org
Fixes: ef67959c4253 ("hwmon: (adt7470) Convert to use regmap")
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-1-598e38a46ba6@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>