Re: [RFC PATCH 2/3] platform/x86: acer-wmi: Add fan control support

["Kurt Borja" <kuurtb@gmail.com>]

On Fri Feb 14, 2025 at 5:13 PM -05, Armin Wolf wrote:
> Add support for controlling the fan speed using the
> SetGamingFanSpeed() and GetGamingFanSpeed() WMI methods.
>
> This feature is only enabled if the machine has ACER_CAP_PWM enabled
> and depend on ACER_CAP_HWMON for detecting the number of available
> fans.
>
> Signed-off-by: Armin Wolf <W_Armin@gmx.de>
> ---
>  drivers/platform/x86/acer-wmi.c | 222 +++++++++++++++++++++++++++++++-
>  1 file changed, 220 insertions(+), 2 deletions(-)
>
> --
> 2.39.5
>
> diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
> index f20a882e3650..e24f5a323f95 100644
> --- a/drivers/platform/x86/acer-wmi.c
> +++ b/drivers/platform/x86/acer-wmi.c
> @@ -12,10 +12,12 @@
>  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>
>  #include <linux/kernel.h>
> +#include <linux/minmax.h>
>  #include <linux/module.h>
>  #include <linux/init.h>
>  #include <linux/types.h>
>  #include <linux/dmi.h>
> +#include <linux/fixp-arith.h>

I didn't know about this, thanks!

>  #include <linux/backlight.h>
>  #include <linux/leds.h>
>  #include <linux/platform_device.h>
> @@ -30,6 +32,7 @@
>  #include <linux/input/sparse-keymap.h>
>  #include <acpi/video.h>
>  #include <linux/hwmon.h>
> +#include <linux/unaligned.h>

Duplicated include.

>  #include <linux/units.h>
>  #include <linux/unaligned.h>
>  #include <linux/bitfield.h>
...
> @@ -2867,8 +2978,10 @@ static int acer_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
>  			       u32 attr, int channel, long *val)
>  {
>  	u64 command = ACER_WMID_CMD_GET_PREDATOR_V4_SENSOR_READING;
> +	u8 fan, speed, mode_bitmap;
> +	u16 fan_bitmap;
> +	int mode, ret;
>  	u64 result;
> -	int ret;
>
>  	switch (type) {
>  	case hwmon_temp:
> @@ -2892,6 +3005,106 @@ static int acer_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
>
>  		*val = FIELD_GET(ACER_PREDATOR_V4_SENSOR_READING_BIT_MASK, result);
>  		return 0;
> +	case hwmon_pwm:
> +		switch (attr) {
> +		case hwmon_pwm_input:
> +			fan = acer_wmi_fan_channel_to_fan_id[channel];
> +			ret = WMID_gaming_get_gaming_fan_speed(fan, &speed);
> +			if (ret < 0)
> +				return ret;
> +
> +			*val = fixp_linear_interpolate(0, 0, 100, U8_MAX, speed);
> +			return 0;
> +		case hwmon_pwm_enable:
> +			fan_bitmap = acer_wmi_fan_channel_to_fan_bitmap[channel];
> +			ret = WMID_gaming_get_fan_behavior(fan_bitmap, &mode_bitmap);
> +			if (ret < 0)
> +				return ret;
> +
> +			switch (channel) {
> +			case 0:
> +				mode = FIELD_GET(ACER_GAMING_FAN_BEHAVIOR_CPU_MODE_MASK,
> +						 mode_bitmap);
> +				break;
> +			case 1:
> +				mode = FIELD_GET(ACER_GAMING_FAN_BEHAVIOR_GPU_MODE_MASK,
> +						 mode_bitmap);
> +				break;
> +			default:
> +				return -EINVAL;
> +			}
> +
> +			switch (mode) {
> +			case ACER_WMID_FAN_MODE_AUTO:
> +				*val = 2;
> +				return 0;
> +			case ACER_WMID_FAN_MODE_TURBO:
> +				*val = 0;
> +				return 0;
> +			case ACER_WMID_FAN_MODE_CUSTOM:
> +				*val = 1;
> +				return 0;
> +			default:
> +				return -ENXIO;
> +			}
> +		default:
> +			return -EOPNOTSUPP;
> +		}
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static int acer_wmi_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
> +				u32 attr, int channel, long val)
> +{
> +	u8 fan, speed, mode_bitmap;
> +	u16 fan_bitmap;
> +	int mode;
> +
> +	switch (type) {
> +	case hwmon_pwm:
> +		switch (attr) {
> +		case hwmon_pwm_input:
> +			fan = acer_wmi_fan_channel_to_fan_id[channel];
> +			speed = fixp_linear_interpolate(0, 0, U8_MAX, 100,
> +							clamp_val(val, 0, U8_MAX));
> +
> +			return WMID_gaming_set_gaming_fan_speed(fan, speed);
> +		case hwmon_pwm_mode:

hwmon_pwm_enable?

Other than that:

Reviewed-by: Kurt Borja <kuurtb@gmail.com>

> <snip>