Re: [PATCH v2 2/6] platform/x86: ayaneo-ec: Add hwmon support

[Armin Wolf <W_Armin@gmx.de>]

Am 15.10.25 um 10:44 schrieb Antheas Kapenekakis:

> Add hwmon single fan sensor reads and control for Ayaneo devices.
> The register and method of access is the same for all devices.
>
> Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
> ---
>   drivers/platform/x86/Kconfig     |   2 +
>   drivers/platform/x86/ayaneo-ec.c | 134 +++++++++++++++++++++++++++++++
>   2 files changed, 136 insertions(+)
>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index ff2678927696..f132a87fcee9 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -319,6 +319,8 @@ config ASUS_TF103C_DOCK
>   config AYANEO_EC
>   	tristate "Ayaneo EC platform control"
>   	depends on X86
> +	depends on ACPI_EC
> +	depends on HWMON
>   	help
>   	  Enables support for the platform EC of Ayaneo devices. This
>   	  includes fan control, fan speed, charge limit, magic
> diff --git a/drivers/platform/x86/ayaneo-ec.c b/drivers/platform/x86/ayaneo-ec.c
> index 90b86527ab0d..9884eed0cc84 100644
> --- a/drivers/platform/x86/ayaneo-ec.c
> +++ b/drivers/platform/x86/ayaneo-ec.c
> @@ -7,13 +7,23 @@
>    * Copyright (C) 2025 Antheas Kapenekakis <lkml@antheas.dev>
>    */
>   
> +#include <linux/acpi.h>
>   #include <linux/dmi.h>
> +#include <linux/hwmon.h>
>   #include <linux/init.h>
>   #include <linux/kernel.h>
>   #include <linux/module.h>
>   #include <linux/platform_device.h>
>   
> +#define AYANEO_PWM_ENABLE_REG	 0x4A
> +#define AYANEO_PWM_REG		 0x4B
> +#define AYANEO_PWM_MODE_AUTO	 0x00
> +#define AYANEO_PWM_MODE_MANUAL	 0x01
> +
> +#define AYANEO_FAN_REG		 0x76
> +
>   struct ayaneo_ec_quirk {
> +	bool has_fan_control;
>   };
>   
>   struct ayaneo_ec_platform_data {
> @@ -22,6 +32,7 @@ struct ayaneo_ec_platform_data {
>   };
>   
>   static const struct ayaneo_ec_quirk ayaneo3 = {
> +	.has_fan_control = true,
>   };
>   
>   static const struct dmi_system_id dmi_table[] = {
> @@ -35,10 +46,126 @@ static const struct dmi_system_id dmi_table[] = {
>   	{},
>   };
>   
> +/* Callbacks for hwmon interface */
> +static umode_t ayaneo_ec_hwmon_is_visible(const void *drvdata,
> +				       enum hwmon_sensor_types type, u32 attr,
> +				       int channel)
> +{
> +	switch (type) {
> +	case hwmon_fan:
> +		return 0444;
> +	case hwmon_pwm:
> +		return 0644;
> +	default:
> +		return 0;
> +	}
> +}
> +
> +static int ayaneo_ec_read(struct device *dev, enum hwmon_sensor_types type,
> +			     u32 attr, int channel, long *val)
> +{
> +	u8 tmp;
> +	int ret;
> +
> +	switch (type) {
> +	case hwmon_fan:
> +		switch (attr) {
> +		case hwmon_fan_input:
> +			ret = ec_read(AYANEO_FAN_REG, &tmp);
> +			if (ret)
> +				return ret;
> +			*val = tmp << 8;
> +			ret = ec_read(AYANEO_FAN_REG + 1, &tmp);
> +			if (ret)
> +				return ret;
> +			*val += tmp;
> +			return 0;
> +		default:
> +			break;
> +		}
> +		break;
> +	case hwmon_pwm:
> +		switch (attr) {
> +		case hwmon_pwm_input:
> +			ret = ec_read(AYANEO_PWM_REG, &tmp);
> +			if (ret)
> +				return ret;
> +			*val = (255 * tmp) / 100;
> +			if (*val < 0 || *val > 255)
> +				return -EINVAL;

I think it would make more sense to first check if tmp has a value between 0 and 100 and
then performing the calculation. Also please return -EIO instead of -EINVAL.

> +			return 0;
> +		case hwmon_pwm_enable:
> +			ret = ec_read(AYANEO_PWM_ENABLE_REG, &tmp);
> +			if (ret)
> +				return ret;
> +			if (tmp == AYANEO_PWM_MODE_MANUAL)
> +				*val = 1;
> +			else
> +				*val = 2;

Please check for AYANEO_PWM_MODE_MANUAL as well and return -EIO if the EC
returned an unknown value.

> +			return 0;
> +		default:
> +			break;
> +		}
> +		break;
> +	default:
> +		break;
> +	}
> +	return -EOPNOTSUPP;
> +}
> +
> +static int ayaneo_ec_write(struct device *dev, enum hwmon_sensor_types type,
> +			      u32 attr, int channel, long val)
> +{
> +	switch (type) {
> +	case hwmon_pwm:
> +		switch (attr) {
> +		case hwmon_pwm_enable:
> +			switch (val) {
> +			case 1:
> +				return ec_write(AYANEO_PWM_ENABLE_REG,
> +						AYANEO_PWM_MODE_MANUAL);
> +			case 2:
> +				return ec_write(AYANEO_PWM_ENABLE_REG,
> +						AYANEO_PWM_MODE_AUTO);
> +			default:
> +				return -EINVAL;
> +			}
> +		case hwmon_pwm_input:
> +			if (val < 0 || val > 255)
> +				return -EINVAL;
> +			return ec_write(AYANEO_PWM_REG, (val * 100) / 255);
> +		default:
> +			break;
> +		}
> +		break;
> +	default:
> +		break;
> +	}
> +	return -EOPNOTSUPP;
> +}
> +
> +static const struct hwmon_ops ayaneo_ec_hwmon_ops = {
> +	.is_visible = ayaneo_ec_hwmon_is_visible,
> +	.read = ayaneo_ec_read,
> +	.write = ayaneo_ec_write,
> +};
> +
> +static const struct hwmon_channel_info *const ayaneo_ec_sensors[] = {
> +	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
> +	HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
> +	NULL,
> +};
> +
> +static const struct hwmon_chip_info ayaneo_ec_chip_info = {
> +	.ops = &ayaneo_ec_hwmon_ops,
> +	.info = ayaneo_ec_sensors,
> +};
> +
>   static int ayaneo_ec_probe(struct platform_device *pdev)
>   {
>   	const struct dmi_system_id *dmi_entry;
>   	struct ayaneo_ec_platform_data *data;
> +	struct device *hwdev;
>   
>   	dmi_entry = dmi_first_match(dmi_table);
>   	if (!dmi_entry)
> @@ -52,6 +179,13 @@ static int ayaneo_ec_probe(struct platform_device *pdev)
>   	data->quirks = dmi_entry->driver_data;
>   	platform_set_drvdata(pdev, data);
>   
> +	if (data->quirks->has_fan_control) {
> +		hwdev = devm_hwmon_device_register_with_info(
> +			&pdev->dev, "ayaneo_ec", NULL, &ayaneo_ec_chip_info, NULL);

Please run "./scripts/checkpatch.pl --strict" on this file and fix any issues.

Thanks,
Armin Wolf

> +		if (IS_ERR(hwdev))
> +			return PTR_ERR(hwdev);
> +	}
> +
>   	return 0;
>   }
>