[PATCH v6 11/14] platform/x86: oxpec: Adhere to sysfs-class-hwmon and enable pwm on 2

Antheas Kapenekakis
2025-03-19T17:55:49Z

Currently, the driver does not adhere to the sysfs-class-hwmon
specification: 0 is used for auto fan control and 1 is used for manual
control. However, it is expected that 0 sets the fan to full speed,
1 sets the fan to manual, and then 2 is used for automatic control.

Therefore, change the sysfs API to reflect this and enable pwm on 2.

As we are breaking the ABI for this driver, rename oxpec to oxp_ec,
reflecting the naming convention used by other drivers, to allow for
a smooth migration in current userspace programs.

Closes: https://lore.kernel.org/linux-hwmon/20241027174836.8588-1-derekjohn.clark@gmail.com/
Reviewed-by: Derek J. Clark <derekjohn.clark@gmail.com>
Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
---
drivers/platform/x86/oxpec.c | 35 ++++++++++++++++++++++++++++++++---
1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/oxpec.c b/drivers/platform/x86/oxpec.c
index e84afc5f53379..680fa537babf6 100644
--- a/drivers/platform/x86/oxpec.c
+++ b/drivers/platform/x86/oxpec.c
@@ -731,7 +731,27 @@ static int oxp_platform_read(struct device *dev, enum hwmon_sensor_types type,
case hwmon_pwm_input:
return oxp_pwm_input_read(val);
case hwmon_pwm_enable:
- return oxp_pwm_read(val);
+ ret = oxp_pwm_read(val);
+ if (ret)
+ return ret;
+
+ /* Check for auto and return 2 */
+ if (!*val) {
+ *val = 2;
+ return 0;
+ }
+
+ /* Return 0 if at full fan speed, 1 otherwise */
+ ret = oxp_pwm_fan_speed(val);
+ if (ret)
+ return ret;
+
+ if (*val == 255)
+ *val = 0;
+ else
+ *val = 1;
+
+ return 0;
default:
break;
}
@@ -745,15 +765,24 @@ static int oxp_platform_read(struct device *dev, enum hwmon_sensor_types type,
static int oxp_platform_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long val)
{
+ int ret;
+
switch (type) {
case hwmon_pwm:
switch (attr) {
case hwmon_pwm_enable:
if (val == 1)
return oxp_pwm_enable();
- else if (val == 0)
+ else if (val == 2)
return oxp_pwm_disable();
- return -EINVAL;
+ else if (val != 0)
+ return -EINVAL;
+
+ /* Enable PWM and set to max speed */
+ ret = oxp_pwm_enable();
+ if (ret)
+ return ret;
+ return oxp_pwm_input_write(255);
case hwmon_pwm_input:
return oxp_pwm_input_write(val);
default:
--
2.48.1