Re: [PATCH v4 07/12] platform/x86: alienware-wmi-wmax: Add HWMON support

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

On Tue Mar 11, 2025 at 1:55 PM -05, Armin Wolf wrote:
> Am 08.03.25 um 21:23 schrieb Kurt Borja:
>
>> All models with the "AWCC" WMAX device support monitoring fan speed and
>> temperature sensors. Expose this feature through the HWMON interface.
>>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Cc: Jean Delvare <jdelvare@suse.com>
>> Cc: linux-hwmon@vger.kernel.org
>> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
>> ---
>>   drivers/platform/x86/dell/Kconfig              |   1 +
>>   drivers/platform/x86/dell/alienware-wmi-wmax.c | 396 +++++++++++++++++++++++++
>>   2 files changed, 397 insertions(+)
>>
>> diff --git a/drivers/platform/x86/dell/Kconfig b/drivers/platform/x86/dell/Kconfig
>> index f8a0dffcaab7c3b423472c5b9093011334a698c8..85a57c01aaada5d899cd8252e77ed6043da5cbdf 100644
>> --- a/drivers/platform/x86/dell/Kconfig
>> +++ b/drivers/platform/x86/dell/Kconfig
>> @@ -43,6 +43,7 @@ config ALIENWARE_WMI_WMAX
>>   	bool "Alienware WMAX WMI device driver"
>>   	default y
>>   	depends on ALIENWARE_WMI
>> +	depends on HWMON
>>   	select ACPI_PLATFORM_PROFILE
>>   	help
>>   	 Alienware WMI driver with AlienFX LED, HDMI, amplifier, deep sleep and
>> diff --git a/drivers/platform/x86/dell/alienware-wmi-wmax.c b/drivers/platform/x86/dell/alienware-wmi-wmax.c
>> index 3b37e4456482bc284b8e867c1c5b6255fc6c8ef2..f1f20db206d47f644e8cd58a6d169c850606e75b 100644
>> --- a/drivers/platform/x86/dell/alienware-wmi-wmax.c
>> +++ b/drivers/platform/x86/dell/alienware-wmi-wmax.c
>> @@ -9,10 +9,13 @@
>>   #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>>
>>   #include <linux/bitfield.h>
>> +#include <linux/bitmap.h>
>>   #include <linux/bits.h>
>>   #include <linux/dmi.h>
>> +#include <linux/hwmon.h>
>>   #include <linux/moduleparam.h>
>>   #include <linux/platform_profile.h>
>> +#include <linux/units.h>
>>   #include <linux/wmi.h>
>>   #include "alienware-wmi.h"
>>
>> @@ -25,6 +28,7 @@
>>   #define WMAX_METHOD_BRIGHTNESS			0x3
>>   #define WMAX_METHOD_ZONE_CONTROL		0x4
>>
>> +#define AWCC_METHOD_GET_FAN_SENSORS		0x13
>>   #define AWCC_METHOD_THERMAL_INFORMATION		0x14
>>   #define AWCC_METHOD_THERMAL_CONTROL		0x15
>>   #define AWCC_METHOD_GAME_SHIFT_STATUS		0x25
>> @@ -38,6 +42,12 @@
>>
>>   /* Arbitrary limit based on supported models */
>>   #define AWCC_MAX_RES_COUNT			16
>> +#define AWCC_ID_BITMAP_SIZE			(U8_MAX + 1)
>> +#define AWCC_ID_BITMAP_LONGS			BITS_TO_LONGS(AWCC_ID_BITMAP_SIZE)
>> +
>> +static bool force_hwmon;
>> +module_param_unsafe(force_hwmon, bool, 0);
>> +MODULE_PARM_DESC(force_hwmon, "Force probing for HWMON support without checking if the WMI backend is available");
>>
>>   static bool force_platform_profile;
>>   module_param_unsafe(force_platform_profile, bool, 0);
>> @@ -48,16 +58,19 @@ module_param_unsafe(force_gmode, bool, 0);
>>   MODULE_PARM_DESC(force_gmode, "Forces G-Mode when performance profile is selected");
>>
>>   struct awcc_quirks {
>> +	bool hwmon;
>>   	bool pprof;
>>   	bool gmode;
>>   };
>>
>>   static struct awcc_quirks g_series_quirks = {
>> +	.hwmon = true,
>>   	.pprof = true,
>>   	.gmode = true,
>>   };
>>
>>   static struct awcc_quirks generic_quirks = {
>> +	.hwmon = true,
>>   	.pprof = true,
>>   	.gmode = false,
>>   };
>> @@ -155,9 +168,18 @@ static const struct dmi_system_id awcc_dmi_table[] __initconst = {
>>   	},
>>   };
>>
>> +enum AWCC_GET_FAN_SENSORS_OPERATIONS {
>> +	AWCC_OP_GET_TOTAL_FAN_TEMPS		= 0x01,
>> +	AWCC_OP_GET_FAN_TEMP_ID			= 0x02,
>> +};
>> +
>>   enum AWCC_THERMAL_INFORMATION_OPERATIONS {
>>   	AWCC_OP_GET_SYSTEM_DESCRIPTION		= 0x02,
>>   	AWCC_OP_GET_RESOURCE_ID			= 0x03,
>> +	AWCC_OP_GET_TEMPERATURE			= 0x04,
>> +	AWCC_OP_GET_FAN_RPM			= 0x05,
>> +	AWCC_OP_GET_FAN_MIN_RPM			= 0x08,
>> +	AWCC_OP_GET_FAN_MAX_RPM			= 0x09,
>>   	AWCC_OP_GET_CURRENT_PROFILE		= 0x0B,
>>   };
>>
>> @@ -180,6 +202,11 @@ enum AWCC_SPECIAL_THERMAL_CODES {
>>   	AWCC_SPECIAL_PROFILE_GMODE		= 0xAB,
>>   };
>>
>> +enum AWCC_TEMP_SENSOR_TYPES {
>> +	AWCC_TEMP_SENSOR_CPU			= 0x01,
>> +	AWCC_TEMP_SENSOR_GPU			= 0x06,
>> +};
>> +
>>   enum awcc_thermal_profile {
>>   	AWCC_PROFILE_USTT_BALANCED,
>>   	AWCC_PROFILE_USTT_BALANCED_PERFORMANCE,
>> @@ -216,6 +243,14 @@ struct wmax_u32_args {
>>   	u8 arg3;
>>   };
>>
>> +struct awcc_fan_data {
>> +	unsigned long auto_channels_temp;
>> +	const char *label;
>> +	u32 min_rpm;
>> +	u32 max_rpm;
>> +	u8 id;
>> +};
>> +
>>   struct awcc_priv {
>>   	struct wmi_device *wdev;
>>   	union {
>> @@ -231,6 +266,10 @@ struct awcc_priv {
>>
>>   	struct device *ppdev;
>>   	u8 supported_profiles[PLATFORM_PROFILE_LAST];
>> +
>> +	struct device *hwdev;
>> +	struct awcc_fan_data **fan_data;
>> +	unsigned long temp_sensors[AWCC_ID_BITMAP_LONGS];
>>   };
>>
>>   static const enum platform_profile_option awcc_mode_to_platform_profile[AWCC_PROFILE_LAST] = {
>> @@ -495,6 +534,19 @@ static int __awcc_wmi_command(struct wmi_device *wdev, u32 method_id,
>>   	return 0;
>>   }
>>
>> +static inline int awcc_get_fan_sensors(struct wmi_device *wdev, u8 operation,
>> +				       u8 fan_id, u8 index, u32 *out)
>> +{
>> +	struct wmax_u32_args args = {
>> +		.operation = operation,
>> +		.arg1 = fan_id,
>> +		.arg2 = index,
>> +		.arg3 = 0,
>> +	};
>> +
>> +	return __awcc_wmi_command(wdev, AWCC_METHOD_GET_FAN_SENSORS, &args, out);
>> +}
>> +
>>   static inline int awcc_thermal_information(struct wmi_device *wdev, u8 operation,
>>   					   u8 arg, u32 *out)
>>   {
>> @@ -552,6 +604,30 @@ static inline int awcc_op_get_resource_id(struct wmi_device *wdev, u8 index, u32
>>   	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out);
>>   }
>>
>> +static inline int awcc_op_get_fan_rpm(struct wmi_device *wdev, u8 fan_id, u32 *out)
>> +{
>> +	struct wmax_u32_args args = {
>> +		.operation = AWCC_OP_GET_FAN_RPM,
>> +		.arg1 = fan_id,
>> +		.arg2 = 0,
>> +		.arg3 = 0,
>> +	};
>> +
>> +	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out);
>> +}
>> +
>> +static inline int awcc_op_get_temperature(struct wmi_device *wdev, u8 temp_id, u32 *out)
>> +{
>> +	struct wmax_u32_args args = {
>> +		.operation = AWCC_OP_GET_TEMPERATURE,
>> +		.arg1 = temp_id,
>> +		.arg2 = 0,
>> +		.arg3 = 0,
>> +	};
>> +
>> +	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out);
>> +}
>> +
>>   static inline int awcc_op_get_current_profile(struct wmi_device *wdev, u32 *out)
>>   {
>>   	struct wmax_u32_args args = {
>> @@ -577,6 +653,313 @@ static inline int awcc_op_activate_profile(struct wmi_device *wdev, u8 profile)
>>   	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_CONTROL, &args, &out);
>>   }
>>
>> +/*
>> + * HWMON
>> + *  - Provides temperature and fan speed monitoring as well as manual fan
>> + *    control
>> + */
>> +static umode_t awcc_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
>> +				     u32 attr, int channel)
>> +{
>> +	const struct awcc_priv *priv = drvdata;
>> +	unsigned int temp_count;
>> +
>> +	switch (type) {
>> +	case hwmon_temp:
>> +		temp_count = bitmap_weight(priv->temp_sensors, AWCC_ID_BITMAP_SIZE);
>> +
>> +		return channel < temp_count ? 0444 : 0;
>> +	case hwmon_fan:
>> +		return channel < priv->fan_count ? 0444 : 0;
>> +	case hwmon_pwm:
>> +		return channel < priv->fan_count ? 0444 : 0;
>> +	default:
>> +		return 0;
>> +	}
>> +}
>> +
>> +static int awcc_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
>> +			   u32 attr, int channel, long *val)
>> +{
>> +	struct awcc_priv *priv = dev_get_drvdata(dev);
>> +	const struct awcc_fan_data *fan;
>> +	u32 state;
>> +	int ret;
>> +	u8 temp;
>> +
>> +	switch (type) {
>> +	case hwmon_temp:
>> +		temp = find_nth_bit(priv->temp_sensors, AWCC_ID_BITMAP_SIZE, channel);
>> +
>> +		switch (attr) {
>> +		case hwmon_temp_input:
>> +			ret = awcc_op_get_temperature(priv->wdev, temp, &state);
>> +			if (ret)
>> +				return ret;
>> +
>> +			*val = state * MILLIDEGREE_PER_DEGREE;
>> +			break;
>> +		default:
>> +			return -EOPNOTSUPP;
>> +		}
>> +
>> +		break;
>> +	case hwmon_fan:
>> +		fan = priv->fan_data[channel];
>> +
>> +		switch (attr) {
>> +		case hwmon_fan_input:
>> +			ret = awcc_op_get_fan_rpm(priv->wdev, fan->id, &state);
>> +			if (ret)
>> +				return ret;
>> +
>> +			*val = state;
>> +			break;
>> +		case hwmon_fan_min:
>> +			*val = fan->min_rpm;
>> +			break;
>> +		case hwmon_fan_max:
>> +			*val = fan->max_rpm;
>> +			break;
>> +		default:
>> +			return -EOPNOTSUPP;
>> +		}
>> +
>> +		break;
>> +	case hwmon_pwm:
>> +		fan = priv->fan_data[channel];
>> +
>> +		switch (attr) {
>> +		case hwmon_pwm_auto_channels_temp:
>> +			*val = fan->auto_channels_temp;
>> +			break;
>> +		default:
>> +			return -EOPNOTSUPP;
>> +		}
>> +
>> +		break;
>> +	default:
>> +		return -EOPNOTSUPP;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int awcc_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
>> +				  u32 attr, int channel, const char **str)
>> +{
>> +	struct awcc_priv *priv = dev_get_drvdata(dev);
>> +	u8 temp;
>> +
>> +	switch (type) {
>> +	case hwmon_temp:
>> +		temp = find_nth_bit(priv->temp_sensors, AWCC_ID_BITMAP_SIZE, channel);
>> +
>> +		switch (temp) {
>> +		case AWCC_TEMP_SENSOR_CPU:
>> +			*str = "CPU";
>> +			break;
>> +		case AWCC_TEMP_SENSOR_GPU:
>> +			*str = "GPU";
>> +			break;
>> +		default:
>> +			*str = "Unknown";
>> +			break;
>> +		}
>> +
>> +		break;
>> +	case hwmon_fan:
>> +		*str = priv->fan_data[channel]->label;
>> +		break;
>> +	default:
>> +		return -EOPNOTSUPP;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct hwmon_ops awcc_hwmon_ops = {
>> +	.is_visible = awcc_hwmon_is_visible,
>> +	.read = awcc_hwmon_read,
>> +	.read_string = awcc_hwmon_read_string,
>> +};
>> +
>> +static const struct hwmon_channel_info * const awcc_hwmon_info[] = {
>> +	HWMON_CHANNEL_INFO(temp,
>> +			   HWMON_T_LABEL | HWMON_T_INPUT,
>> +			   HWMON_T_LABEL | HWMON_T_INPUT,
>> +			   HWMON_T_LABEL | HWMON_T_INPUT,
>> +			   HWMON_T_LABEL | HWMON_T_INPUT,
>> +			   HWMON_T_LABEL | HWMON_T_INPUT,
>> +			   HWMON_T_LABEL | HWMON_T_INPUT
>> +			   ),
>> +	HWMON_CHANNEL_INFO(fan,
>> +			   HWMON_F_LABEL | HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX,
>> +			   HWMON_F_LABEL | HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX,
>> +			   HWMON_F_LABEL | HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX,
>> +			   HWMON_F_LABEL | HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX,
>> +			   HWMON_F_LABEL | HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX,
>> +			   HWMON_F_LABEL | HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX
>> +			   ),
>> +	HWMON_CHANNEL_INFO(pwm,
>> +			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>> +			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>> +			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>> +			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>> +			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>> +			   HWMON_PWM_AUTO_CHANNELS_TEMP
>> +			   ),
>> +	NULL
>> +};
>> +
>> +static const struct hwmon_chip_info awcc_hwmon_chip_info = {
>> +	.ops = &awcc_hwmon_ops,
>> +	.info = awcc_hwmon_info,
>> +};
>> +
>> +static int awcc_hwmon_temps_init(struct wmi_device *wdev)
>> +{
>> +	struct awcc_priv *priv = dev_get_drvdata(&wdev->dev);
>> +	unsigned int i;
>> +	int ret;
>> +	u32 id;
>> +
>> +	for (i = 0; i < priv->temp_count; i++) {
>> +		/*
>> +		 * Temperature sensors IDs are listed after the fan IDs at
>> +		 * offset `fan_count`
>> +		 */
>> +		ret = awcc_op_get_resource_id(wdev, i + priv->fan_count, &id);
>> +		if (ret)
>> +			return ret;
>> +
>> +		__set_bit(FIELD_GET(AWCC_RESOURCE_ID_MASK, id), priv->temp_sensors);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static char *awcc_alloc_fan_label(struct device *dev, u32 temp_count, u8 temp_id)
>> +{
>> +	char *label;
>> +
>> +	switch (temp_count) {
>> +	case 0:
>> +		label = devm_kstrdup(dev, "Independent Fan", GFP_KERNEL);
>> +		break;
>> +	case 1:
>> +		switch (temp_id) {
>> +		case AWCC_TEMP_SENSOR_CPU:
>> +			label = devm_kstrdup(dev, "Processor Fan", GFP_KERNEL);
>> +			break;
>> +		case AWCC_TEMP_SENSOR_GPU:
>> +			label = devm_kstrdup(dev, "Video Fan", GFP_KERNEL);
>> +			break;
>> +		default:
>> +			label = devm_kstrdup(dev, "Unknown Fan", GFP_KERNEL);
>> +			break;
>> +		}
>> +
>> +		break;
>> +	default:
>> +		label = devm_kstrdup(dev, "Shared Fan", GFP_KERNEL);
>
> All of those strings are static, please drop the usage of devm_kstrdup() here.

Right! They are string literals.

>
> With those issues being addressed:
> Reviewed-by: Armin Wolf <W_Armin@gmx.de>
>
>> +		break;
>> +	}
>> +
>> +	return label;
>> +}
>> +
>> +static int awcc_hwmon_fans_init(struct wmi_device *wdev)
>> +{
>> +	struct awcc_priv *priv = dev_get_drvdata(&wdev->dev);
>> +	u32 id, min_rpm, max_rpm, temp_count, temp_id;
>> +	unsigned long fan_temps[AWCC_ID_BITMAP_LONGS];
>> +	unsigned long gather[AWCC_ID_BITMAP_LONGS];
>> +	struct awcc_fan_data *fan_data;
>> +	unsigned int i, j;
>> +	char *label;
>> +	int ret;
>> +
>> +	for (i = 0; i < priv->fan_count; i++) {
>> +		fan_data = devm_kzalloc(&wdev->dev, sizeof(*fan_data), GFP_KERNEL);
>> +		if (!fan_data)
>> +			return -ENOMEM;
>> +
>> +		/*
>> +		 * Fan IDs are listed first at offset 0
>> +		 */
>> +		ret = awcc_op_get_resource_id(wdev, i, &id);
>> +		if (ret)
>> +			return ret;
>> +		id = FIELD_GET(AWCC_RESOURCE_ID_MASK, id);
>> +
>> +		ret = awcc_thermal_information(wdev, AWCC_OP_GET_FAN_MIN_RPM, id,
>> +					       &min_rpm);
>> +		if (ret)
>> +			return ret;
>> +
>> +		ret = awcc_thermal_information(wdev, AWCC_OP_GET_FAN_MAX_RPM, id,
>> +					       &max_rpm);
>> +		if (ret)
>> +			return ret;
>> +
>> +		ret = awcc_get_fan_sensors(wdev, AWCC_OP_GET_TOTAL_FAN_TEMPS, id,
>> +					   0, &temp_count);
>> +		if (ret)
>> +			return ret;
>> +
>> +		for (j = 0; j < temp_count; j++) {
>> +			ret = awcc_get_fan_sensors(wdev, AWCC_OP_GET_FAN_TEMP_ID,
>> +						   id, j, &temp_id);
>> +			if (ret)
>> +				break;
>> +
>> +			temp_id = FIELD_GET(AWCC_RESOURCE_ID_MASK, temp_id);
>> +			__set_bit(temp_id, fan_temps);
>> +		}
>> +
>> +		label = awcc_alloc_fan_label(&wdev->dev, temp_count, temp_id);
>> +		if (!label)
>> +			return -ENOMEM;
>> +
>> +		fan_data->id = id;
>> +		fan_data->min_rpm = min_rpm;
>> +		fan_data->max_rpm = max_rpm;
>> +		fan_data->label = label;
>> +		bitmap_gather(gather, fan_temps, priv->temp_sensors, AWCC_ID_BITMAP_SIZE);
>> +		bitmap_copy(&fan_data->auto_channels_temp, gather, priv->temp_count);
>
> Please check that the bitmap can fit into the long variable before using bitmap_copy().

priv->temp_count is bounded by AWCC_MAX_RES_COUNT which is 16.

I don't think it will ever be bigger than 64, but I will replace it with
BITS_PER_LONG just to be extra careful.

Thank you very much for reviewing the whole series!

-- 
 ~ Kurt