[PATCH v3 00/10] platform/x86: alienware-wmi-wmax: HWMON support + DebugFS + Improvements

[PATCH v3 00/10] platform/x86: alienware-wmi-wmax: HWMON support + DebugFS + Improvements

[Kurt Borja]

Hi all,

This set mainly adds hwmon and manual fan control support (patches 7-8)
to the alienware-wmi driver, after some improvements.

Aside from some minor changes Ilpo commented on, I added inline helpers
for most awcc operations to make those calls more compact.

Thank you for your feedback :)

---
Changes since v2:

[02/10]
  - Move BIT(8) flag comment to AWCC_RESOURCE_ID_MASK definition

[03/10]
  - Add awcc_profile_id_to_pprof()
  - Add awcc_op_activate_profile()
  - Dropped Armin's rev-by because the patch changed a bit

[05/10]
  - Dropped __packed attribute from system_description

[07/10]
  - Add awcc_op_get_fan_rpm()
  - Add awcc_op_get_temperature()
  - Use ternary conditional operator on awcc_hwmon_is_visible()
  - Check priv->temp_sensors weight to determine hwmon_temp visibility
  - Replace U8_MAX with priv->temp_sensors_size in find_nth_bit() calls
  - Drop find_nth_bit() failure check due to the visibility change
  - Cc+ Jean Delvare <jdelvare@suse.com>
  - Cc+ linux-hwmon@vger.kernel.org

[08/10]
  - Add a pwm1_enable attribute
  - Add awcc_op_get_fan_boost()
  - Add awcc_op_set_fan_boost()
  - Cc+ Jean Delvare <jdelvare@suse.com>
  - Cc+ linux-hwmon@vger.kernel.org

[10/10]
  - Reword commit title to reflect path

v2: https://lore.kernel.org/r/20250225222500.23535-1-kuurtb@gmail.com

---
Kurt Borja (10):
      platform/x86: alienware-wmi-wmax: Rename thermal related symbols
      platform/x86: alienware-wmi-wmax: Refactor is_awcc_thermal_mode()
      platform/x86: alienware-wmi-wmax: Improve internal AWCC API
      platform/x86: alienware-wmi-wmax: Modify supported_thermal_profiles[]
      platform/x86: alienware-wmi-wmax: Improve platform profile probe
      platform/x86: alienware-wmi-wmax: Add support for the "custom" thermal profile
      platform/x86: alienware-wmi-wmax: Add HWMON support
      platform/x86: alienware-wmi-wmax: Add support for manual fan control
      platform/x86: alienware-wmi-wmax: Add a DebugFS interface
      Documentation: wmi: Improve and update alienware-wmi documentation

 Documentation/wmi/devices/alienware-wmi.rst    |  383 +++-----
 drivers/platform/x86/dell/Kconfig              |    1 +
 drivers/platform/x86/dell/alienware-wmi-wmax.c | 1132 ++++++++++++++++++++----
 3 files changed, 1098 insertions(+), 418 deletions(-)
---
base-commit: 5ad6d62c9b183314ec1c64a95a26636e973e736a
change-id: 20250305-hwm-f7bd91902b57

Best regards,
-- 
  ~ Kurt

[PATCH v3 07/10] platform/x86: alienware-wmi-wmax: Add HWMON support

[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 | 431 +++++++++++++++++++++++++
 2 files changed, 432 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 71fc17e8d103146b8edf53a552ae5ba64414e873..20cf3371ee3c0e1ea038b3ca517e831f3b30dc29 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
@@ -39,6 +43,10 @@
 /* Arbitrary limit based on supported models */
 #define AWCC_MAX_RES_COUNT			16
 
+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);
 MODULE_PARM_DESC(force_platform_profile, "Forces auto-detecting thermal profiles without checking if WMI thermal backend is available");
@@ -48,16 +56,19 @@ 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 +166,18 @@ 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 +200,12 @@ 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,
+	AWCC_TEMP_SENSOR_LAST
+};
+
 enum awcc_thermal_profile {
 	AWCC_PROFILE_USTT_BALANCED,
 	AWCC_PROFILE_USTT_BALANCED_PERFORMANCE,
@@ -216,6 +242,15 @@ struct wmax_u32_args {
 	u8 arg3;
 };
 
+struct awcc_fan_data {
+	unsigned long *related_temps;
+	unsigned long *auto_channels_temp;
+	u32 total_temps;
+	u32 min_rpm;
+	u32 max_rpm;
+	u8 id;
+};
+
 struct awcc_priv {
 	struct wmi_device *wdev;
 	union {
@@ -231,6 +266,11 @@ struct awcc_priv {
 
 	struct device *ppdev;
 	u8 supported_profiles[PLATFORM_PROFILE_LAST];
+
+	struct device *hwdev;
+	struct awcc_fan_data **fan_data;
+	unsigned int temp_sensors_size;
+	unsigned long *temp_sensors;
 };
 
 static const enum platform_profile_option awcc_mode_to_platform_profile[AWCC_PROFILE_LAST] = {
@@ -495,6 +535,19 @@ 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 +605,32 @@ 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 = {
@@ -599,6 +678,345 @@ static int awcc_profile_id_to_pprof(u32 id, enum platform_profile_option *profil
 	return 0;
 }
 
+/*
+ * 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, priv->temp_sensors_size);
+
+		return channel < temp_count ? 0444 : 0;
+	case hwmon_fan:
+		return channel < priv->fan_count ? 0444 : 0;
+	case hwmon_pwm:
+		if (channel >= priv->fan_count)
+			return 0;
+
+		switch (attr) {
+		case hwmon_pwm_enable:
+			return 0644;
+		case hwmon_pwm_auto_channels_temp:
+			return 0444;
+		default:
+			return 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);
+	struct awcc_fan_data *fan;
+	u32 state;
+	int ret;
+	u8 temp;
+
+	switch (type) {
+	case hwmon_temp:
+		temp = find_nth_bit(priv->temp_sensors, priv->temp_sensors_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:
+			bitmap_copy(val, fan->auto_channels_temp, BITS_PER_LONG);
+			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);
+	struct awcc_fan_data *fan;
+	u8 temp;
+
+	switch (type) {
+	case hwmon_temp:
+		temp = find_nth_bit(priv->temp_sensors, priv->temp_sensors_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:
+		fan = priv->fan_data[channel];
+
+		switch (fan->total_temps) {
+		case 0:
+			*str = "Independent Fan";
+			break;
+		case 1:
+			temp = find_first_bit(fan->related_temps, priv->temp_sensors_size);
+
+			switch (temp) {
+			case AWCC_TEMP_SENSOR_CPU:
+				*str = "Processor Fan";
+				break;
+			case AWCC_TEMP_SENSOR_GPU:
+				*str = "Video Fan";
+				break;
+			default:
+				*str = "Unknown Fan";
+				break;
+			}
+
+			break;
+		default:
+			*str = "Shared Fan";
+			break;
+		}
+
+		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 long temp_sensors[BITS_TO_LONGS(U8_MAX)];
+	unsigned int i, max_sensor_id = 0;
+	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;
+
+		id = FIELD_GET(AWCC_RESOURCE_ID_MASK, id);
+		if (id > max_sensor_id)
+			max_sensor_id = id;
+
+		__set_bit(id, temp_sensors);
+	}
+
+	/*
+	 * We prefer to allocate the bitmap dynamically because usually temp IDs
+	 * are small (< 0x30) and only one UL is needed to store it, but there
+	 * may be unknown devices that break this rule
+	 */
+	priv->temp_sensors_size = max_sensor_id + 1;
+	priv->temp_sensors = devm_bitmap_zalloc(&wdev->dev, priv->temp_sensors_size,
+						GFP_KERNEL);
+	if (!priv->temp_sensors)
+		return -ENOMEM;
+
+	bitmap_copy(priv->temp_sensors, temp_sensors, priv->temp_sensors_size);
+
+	return 0;
+}
+
+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 gather[BITS_TO_LONGS(U8_MAX)];
+	struct awcc_fan_data *fan_data;
+	unsigned int i, j;
+	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_data->related_temps = devm_bitmap_zalloc(&wdev->dev,
+							     priv->temp_sensors_size,
+							     GFP_KERNEL);
+		if (!priv->temp_sensors)
+			return -ENOMEM;
+
+		fan_data->auto_channels_temp = devm_bitmap_zalloc(&wdev->dev,
+								  priv->temp_count,
+								  GFP_KERNEL);
+		if (!priv->temp_sensors)
+			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);
+			if (temp_id < priv->temp_sensors_size)
+				__set_bit(temp_id, fan_data->related_temps);
+		}
+
+		fan_data->id = id;
+		fan_data->min_rpm = min_rpm;
+		fan_data->max_rpm = max_rpm;
+		fan_data->total_temps = bitmap_weight(fan_data->related_temps,
+						      priv->temp_sensors_size);
+		bitmap_gather(gather, fan_data->related_temps, priv->temp_sensors,
+			      priv->temp_sensors_size);
+		bitmap_copy(fan_data->auto_channels_temp, gather, priv->temp_count);
+		priv->fan_data[i] = fan_data;
+	}
+
+	return 0;
+}
+
+static int awcc_hwmon_init(struct wmi_device *wdev)
+{
+	struct awcc_priv *priv = dev_get_drvdata(&wdev->dev);
+	int ret;
+
+	priv->fan_data = devm_kcalloc(&wdev->dev, priv->fan_count,
+				      sizeof(*priv->fan_data), GFP_KERNEL);
+	if (!priv->fan_data)
+		return -ENOMEM;
+
+	ret = awcc_hwmon_temps_init(wdev);
+	if (ret)
+		return ret;
+
+	ret = awcc_hwmon_fans_init(wdev);
+	if (ret)
+		return ret;
+
+	priv->hwdev = devm_hwmon_device_register_with_info(&wdev->dev, "alienware_wmi", priv,
+							   &awcc_hwmon_chip_info, NULL);
+
+	return PTR_ERR_OR_ZERO(priv->hwdev);
+}
+
 /*
  * Thermal Profile control
  *  - Provides thermal profile control through the Platform Profile API
@@ -753,6 +1171,12 @@ static int alienware_awcc_setup(struct wmi_device *wdev)
 	priv->wdev = wdev;
 	dev_set_drvdata(&wdev->dev, priv);
 
+	if (awcc->hwmon) {
+		ret = awcc_hwmon_init(wdev);
+		if (ret)
+			return ret;
+	}
+
 	if (awcc->pprof) {
 		ret = awcc_platform_profile_init(wdev);
 		if (ret)
@@ -833,6 +1257,13 @@ int __init alienware_wmax_wmi_init(void)
 	if (id)
 		awcc = id->driver_data;
 
+	if (force_hwmon) {
+		if (!awcc)
+			awcc = &empty_quirks;
+
+		awcc->hwmon = true;
+	}
+
 	if (force_platform_profile) {
 		if (!awcc)
 			awcc = &empty_quirks;

-- 
2.48.1

Re: [PATCH v3 07/10] platform/x86: alienware-wmi-wmax: Add HWMON support

[Armin Wolf]

Am 06.03.25 um 01:56 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 | 431 +++++++++++++++++++++++++
>   2 files changed, 432 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 71fc17e8d103146b8edf53a552ae5ba64414e873..20cf3371ee3c0e1ea038b3ca517e831f3b30dc29 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
> @@ -39,6 +43,10 @@
>   /* Arbitrary limit based on supported models */
>   #define AWCC_MAX_RES_COUNT			16
>
> +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);
>   MODULE_PARM_DESC(force_platform_profile, "Forces auto-detecting thermal profiles without checking if WMI thermal backend is available");
> @@ -48,16 +56,19 @@ 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 +166,18 @@ 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 +200,12 @@ 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,
> +	AWCC_TEMP_SENSOR_LAST
> +};
> +
>   enum awcc_thermal_profile {
>   	AWCC_PROFILE_USTT_BALANCED,
>   	AWCC_PROFILE_USTT_BALANCED_PERFORMANCE,
> @@ -216,6 +242,15 @@ struct wmax_u32_args {
>   	u8 arg3;
>   };
>
> +struct awcc_fan_data {
> +	unsigned long *related_temps;
> +	unsigned long *auto_channels_temp;
> +	u32 total_temps;
> +	u32 min_rpm;
> +	u32 max_rpm;
> +	u8 id;
> +};
> +
>   struct awcc_priv {
>   	struct wmi_device *wdev;
>   	union {
> @@ -231,6 +266,11 @@ struct awcc_priv {
>
>   	struct device *ppdev;
>   	u8 supported_profiles[PLATFORM_PROFILE_LAST];
> +
> +	struct device *hwdev;
> +	struct awcc_fan_data **fan_data;
> +	unsigned int temp_sensors_size;
> +	unsigned long *temp_sensors;
>   };
>
>   static const enum platform_profile_option awcc_mode_to_platform_profile[AWCC_PROFILE_LAST] = {
> @@ -495,6 +535,19 @@ 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 +605,32 @@ 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 = {
> @@ -599,6 +678,345 @@ static int awcc_profile_id_to_pprof(u32 id, enum platform_profile_option *profil
>   	return 0;
>   }
>
> +/*
> + * 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, priv->temp_sensors_size);
> +
> +		return channel < temp_count ? 0444 : 0;
> +	case hwmon_fan:
> +		return channel < priv->fan_count ? 0444 : 0;
> +	case hwmon_pwm:
> +		if (channel >= priv->fan_count)
> +			return 0;
> +
> +		switch (attr) {
> +		case hwmon_pwm_enable:

Please drop pwm_enable here and only introduce it inside the proper patch.

> +			return 0644;
> +		case hwmon_pwm_auto_channels_temp:
> +			return 0444;
> +		default:
> +			return 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);
> +	struct awcc_fan_data *fan;
> +	u32 state;
> +	int ret;
> +	u8 temp;
> +
> +	switch (type) {
> +	case hwmon_temp:
> +		temp = find_nth_bit(priv->temp_sensors, priv->temp_sensors_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:
> +			bitmap_copy(val, fan->auto_channels_temp, BITS_PER_LONG);
> +			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);
> +	struct awcc_fan_data *fan;
> +	u8 temp;
> +
> +	switch (type) {
> +	case hwmon_temp:
> +		temp = find_nth_bit(priv->temp_sensors, priv->temp_sensors_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:
> +		fan = priv->fan_data[channel];
> +
> +		switch (fan->total_temps) {
> +		case 0:
> +			*str = "Independent Fan";
> +			break;
> +		case 1:
> +			temp = find_first_bit(fan->related_temps, priv->temp_sensors_size);
> +
> +			switch (temp) {
> +			case AWCC_TEMP_SENSOR_CPU:
> +				*str = "Processor Fan";
> +				break;
> +			case AWCC_TEMP_SENSOR_GPU:
> +				*str = "Video Fan";
> +				break;
> +			default:
> +				*str = "Unknown Fan";
> +				break;
> +			}
> +
> +			break;
> +		default:
> +			*str = "Shared Fan";
> +			break;
> +		}
> +
> +		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
> +			   ),

Since the number of fans and temperature sensors is only known at runtime creating awcc_hwmon_info
would make sense.

> +	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 long temp_sensors[BITS_TO_LONGS(U8_MAX)];
> +	unsigned int i, max_sensor_id = 0;
> +	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;
> +
> +		id = FIELD_GET(AWCC_RESOURCE_ID_MASK, id);
> +		if (id > max_sensor_id)
> +			max_sensor_id = id;
> +
> +		__set_bit(id, temp_sensors);
> +	}
> +
> +	/*
> +	 * We prefer to allocate the bitmap dynamically because usually temp IDs
> +	 * are small (< 0x30) and only one UL is needed to store it, but there
> +	 * may be unknown devices that break this rule
> +	 */

Hi,

as far as i know the memory allocator inside the kernel at least allocates 32 bytes, so you are
not saving any memory with this. I suggest you allocate the bitmaps statically.

> +	priv->temp_sensors_size = max_sensor_id + 1;
> +	priv->temp_sensors = devm_bitmap_zalloc(&wdev->dev, priv->temp_sensors_size,
> +						GFP_KERNEL);
> +	if (!priv->temp_sensors)
> +		return -ENOMEM;
> +
> +	bitmap_copy(priv->temp_sensors, temp_sensors, priv->temp_sensors_size);
> +
> +	return 0;
> +}
> +
> +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 gather[BITS_TO_LONGS(U8_MAX)];
> +	struct awcc_fan_data *fan_data;
> +	unsigned int i, j;
> +	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_data->related_temps = devm_bitmap_zalloc(&wdev->dev,
> +							     priv->temp_sensors_size,
> +							     GFP_KERNEL);

Same as above

> +		if (!priv->temp_sensors)
> +			return -ENOMEM;
> +
> +		fan_data->auto_channels_temp = devm_bitmap_zalloc(&wdev->dev,
> +								  priv->temp_count,
> +								  GFP_KERNEL);

We already know that we only ever use the first sizeof(long) bytes from this bitmap,
please do a static allocation here.

> +		if (!priv->temp_sensors)
> +			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);
> +			if (temp_id < priv->temp_sensors_size)
> +				__set_bit(temp_id, fan_data->related_temps);
> +		}
> +
> +		fan_data->id = id;
> +		fan_data->min_rpm = min_rpm;
> +		fan_data->max_rpm = max_rpm;
> +		fan_data->total_temps = bitmap_weight(fan_data->related_temps,
> +						      priv->temp_sensors_size);
> +		bitmap_gather(gather, fan_data->related_temps, priv->temp_sensors,
> +			      priv->temp_sensors_size);

Since fan_data->related_temps is only used for determining the fan label after this it would
make sense to determine the fan label here and turn fan_data->related_temps into a local
variable on the stack.

Thanks,
Armin Wolf

> +		bitmap_copy(fan_data->auto_channels_temp, gather, priv->temp_count);
> +		priv->fan_data[i] = fan_data;
> +	}
> +
> +	return 0;
> +}
> +
> +static int awcc_hwmon_init(struct wmi_device *wdev)
> +{
> +	struct awcc_priv *priv = dev_get_drvdata(&wdev->dev);
> +	int ret;
> +
> +	priv->fan_data = devm_kcalloc(&wdev->dev, priv->fan_count,
> +				      sizeof(*priv->fan_data), GFP_KERNEL);
> +	if (!priv->fan_data)
> +		return -ENOMEM;
> +
> +	ret = awcc_hwmon_temps_init(wdev);
> +	if (ret)
> +		return ret;
> +
> +	ret = awcc_hwmon_fans_init(wdev);
> +	if (ret)
> +		return ret;
> +
> +	priv->hwdev = devm_hwmon_device_register_with_info(&wdev->dev, "alienware_wmi", priv,
> +							   &awcc_hwmon_chip_info, NULL);
> +
> +	return PTR_ERR_OR_ZERO(priv->hwdev);
> +}
> +
>   /*
>    * Thermal Profile control
>    *  - Provides thermal profile control through the Platform Profile API
> @@ -753,6 +1171,12 @@ static int alienware_awcc_setup(struct wmi_device *wdev)
>   	priv->wdev = wdev;
>   	dev_set_drvdata(&wdev->dev, priv);
>
> +	if (awcc->hwmon) {
> +		ret = awcc_hwmon_init(wdev);
> +		if (ret)
> +			return ret;
> +	}
> +
>   	if (awcc->pprof) {
>   		ret = awcc_platform_profile_init(wdev);
>   		if (ret)
> @@ -833,6 +1257,13 @@ int __init alienware_wmax_wmi_init(void)
>   	if (id)
>   		awcc = id->driver_data;
>
> +	if (force_hwmon) {
> +		if (!awcc)
> +			awcc = &empty_quirks;
> +
> +		awcc->hwmon = true;
> +	}
> +
>   	if (force_platform_profile) {
>   		if (!awcc)
>   			awcc = &empty_quirks;
>

Re: [PATCH v3 07/10] platform/x86: alienware-wmi-wmax: Add HWMON support

[Kurt Borja]

On Thu Mar 6, 2025 at 5:19 PM -05, Armin Wolf wrote:
> Am 06.03.25 um 01:56 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 | 431 +++++++++++++++++++++++++
>>   2 files changed, 432 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 71fc17e8d103146b8edf53a552ae5ba64414e873..20cf3371ee3c0e1ea038b3ca517e831f3b30dc29 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
>> @@ -39,6 +43,10 @@
>>   /* Arbitrary limit based on supported models */
>>   #define AWCC_MAX_RES_COUNT			16
>>
>> +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);
>>   MODULE_PARM_DESC(force_platform_profile, "Forces auto-detecting thermal profiles without checking if WMI thermal backend is available");
>> @@ -48,16 +56,19 @@ 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 +166,18 @@ 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 +200,12 @@ 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,
>> +	AWCC_TEMP_SENSOR_LAST
>> +};
>> +
>>   enum awcc_thermal_profile {
>>   	AWCC_PROFILE_USTT_BALANCED,
>>   	AWCC_PROFILE_USTT_BALANCED_PERFORMANCE,
>> @@ -216,6 +242,15 @@ struct wmax_u32_args {
>>   	u8 arg3;
>>   };
>>
>> +struct awcc_fan_data {
>> +	unsigned long *related_temps;
>> +	unsigned long *auto_channels_temp;
>> +	u32 total_temps;
>> +	u32 min_rpm;
>> +	u32 max_rpm;
>> +	u8 id;
>> +};
>> +
>>   struct awcc_priv {
>>   	struct wmi_device *wdev;
>>   	union {
>> @@ -231,6 +266,11 @@ struct awcc_priv {
>>
>>   	struct device *ppdev;
>>   	u8 supported_profiles[PLATFORM_PROFILE_LAST];
>> +
>> +	struct device *hwdev;
>> +	struct awcc_fan_data **fan_data;
>> +	unsigned int temp_sensors_size;
>> +	unsigned long *temp_sensors;
>>   };
>>
>>   static const enum platform_profile_option awcc_mode_to_platform_profile[AWCC_PROFILE_LAST] = {
>> @@ -495,6 +535,19 @@ 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 +605,32 @@ 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 = {
>> @@ -599,6 +678,345 @@ static int awcc_profile_id_to_pprof(u32 id, enum platform_profile_option *profil
>>   	return 0;
>>   }
>>
>> +/*
>> + * 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, priv->temp_sensors_size);
>> +
>> +		return channel < temp_count ? 0444 : 0;
>> +	case hwmon_fan:
>> +		return channel < priv->fan_count ? 0444 : 0;
>> +	case hwmon_pwm:
>> +		if (channel >= priv->fan_count)
>> +			return 0;
>> +
>> +		switch (attr) {
>> +		case hwmon_pwm_enable:
>
> Please drop pwm_enable here and only introduce it inside the proper patch.

Thanks, mb.

>
>> +			return 0644;
>> +		case hwmon_pwm_auto_channels_temp:
>> +			return 0444;
>> +		default:
>> +			return 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);
>> +	struct awcc_fan_data *fan;
>> +	u32 state;
>> +	int ret;
>> +	u8 temp;
>> +
>> +	switch (type) {
>> +	case hwmon_temp:
>> +		temp = find_nth_bit(priv->temp_sensors, priv->temp_sensors_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:
>> +			bitmap_copy(val, fan->auto_channels_temp, BITS_PER_LONG);
>> +			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);
>> +	struct awcc_fan_data *fan;
>> +	u8 temp;
>> +
>> +	switch (type) {
>> +	case hwmon_temp:
>> +		temp = find_nth_bit(priv->temp_sensors, priv->temp_sensors_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:
>> +		fan = priv->fan_data[channel];
>> +
>> +		switch (fan->total_temps) {
>> +		case 0:
>> +			*str = "Independent Fan";
>> +			break;
>> +		case 1:
>> +			temp = find_first_bit(fan->related_temps, priv->temp_sensors_size);
>> +
>> +			switch (temp) {
>> +			case AWCC_TEMP_SENSOR_CPU:
>> +				*str = "Processor Fan";
>> +				break;
>> +			case AWCC_TEMP_SENSOR_GPU:
>> +				*str = "Video Fan";
>> +				break;
>> +			default:
>> +				*str = "Unknown Fan";
>> +				break;
>> +			}
>> +
>> +			break;
>> +		default:
>> +			*str = "Shared Fan";
>> +			break;
>> +		}
>> +
>> +		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
>> +			   ),
>
> Since the number of fans and temperature sensors is only known at runtime creating awcc_hwmon_info
> would make sense.

IIRC Guenter asked another dev to add more CHANNEL_INFO entries instead
of doing that? I might be wrong tho.

I'm fine either way.

>
>> +	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 long temp_sensors[BITS_TO_LONGS(U8_MAX)];
>> +	unsigned int i, max_sensor_id = 0;
>> +	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;
>> +
>> +		id = FIELD_GET(AWCC_RESOURCE_ID_MASK, id);
>> +		if (id > max_sensor_id)
>> +			max_sensor_id = id;
>> +
>> +		__set_bit(id, temp_sensors);
>> +	}
>> +
>> +	/*
>> +	 * We prefer to allocate the bitmap dynamically because usually temp IDs
>> +	 * are small (< 0x30) and only one UL is needed to store it, but there
>> +	 * may be unknown devices that break this rule
>> +	 */
>
> Hi,
>
> as far as i know the memory allocator inside the kernel at least allocates 32 bytes, so you are

bytes? bits maybe?

> not saving any memory with this. I suggest you allocate the bitmaps statically.

The thing is - We don't know before hand how big an ID can be.

Technically the upper limit is U8_MAX which would require 4 ULs to
store, which is a lot. However I haven't seen temp IDs bigger than 0x6,
so this way only one UL is allocated for most devices.

I would be very grateful if Dell could help us on this one :')

>
>> +	priv->temp_sensors_size = max_sensor_id + 1;
>> +	priv->temp_sensors = devm_bitmap_zalloc(&wdev->dev, priv->temp_sensors_size,
>> +						GFP_KERNEL);
>> +	if (!priv->temp_sensors)
>> +		return -ENOMEM;
>> +
>> +	bitmap_copy(priv->temp_sensors, temp_sensors, priv->temp_sensors_size);
>> +
>> +	return 0;
>> +}
>> +
>> +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 gather[BITS_TO_LONGS(U8_MAX)];
>> +	struct awcc_fan_data *fan_data;
>> +	unsigned int i, j;
>> +	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_data->related_temps = devm_bitmap_zalloc(&wdev->dev,
>> +							     priv->temp_sensors_size,
>> +							     GFP_KERNEL);
>
> Same as above
>
>> +		if (!priv->temp_sensors)
>> +			return -ENOMEM;
>> +
>> +		fan_data->auto_channels_temp = devm_bitmap_zalloc(&wdev->dev,
>> +								  priv->temp_count,
>> +								  GFP_KERNEL);
>
> We already know that we only ever use the first sizeof(long) bytes from this bitmap,
> please do a static allocation here.

Right, ofc! I forgot about the limit I imposed.

>
>> +		if (!priv->temp_sensors)
>> +			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);
>> +			if (temp_id < priv->temp_sensors_size)
>> +				__set_bit(temp_id, fan_data->related_temps);
>> +		}
>> +
>> +		fan_data->id = id;
>> +		fan_data->min_rpm = min_rpm;
>> +		fan_data->max_rpm = max_rpm;
>> +		fan_data->total_temps = bitmap_weight(fan_data->related_temps,
>> +						      priv->temp_sensors_size);
>> +		bitmap_gather(gather, fan_data->related_temps, priv->temp_sensors,
>> +			      priv->temp_sensors_size);
>
> Since fan_data->related_temps is only used for determining the fan label after this it would
> make sense to determine the fan label here and turn fan_data->related_temps into a local
> variable on the stack.

Ack.

>
> Thanks,
> Armin Wolf

Thank you very much! Very helpful feedback :)

>
>> +		bitmap_copy(fan_data->auto_channels_temp, gather, priv->temp_count);
>> +		priv->fan_data[i] = fan_data;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int awcc_hwmon_init(struct wmi_device *wdev)
>> +{
>> +	struct awcc_priv *priv = dev_get_drvdata(&wdev->dev);
>> +	int ret;
>> +
>> +	priv->fan_data = devm_kcalloc(&wdev->dev, priv->fan_count,
>> +				      sizeof(*priv->fan_data), GFP_KERNEL);
>> +	if (!priv->fan_data)
>> +		return -ENOMEM;
>> +
>> +	ret = awcc_hwmon_temps_init(wdev);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = awcc_hwmon_fans_init(wdev);
>> +	if (ret)
>> +		return ret;
>> +
>> +	priv->hwdev = devm_hwmon_device_register_with_info(&wdev->dev, "alienware_wmi", priv,
>> +							   &awcc_hwmon_chip_info, NULL);
>> +
>> +	return PTR_ERR_OR_ZERO(priv->hwdev);
>> +}
>> +
>>   /*
>>    * Thermal Profile control
>>    *  - Provides thermal profile control through the Platform Profile API
>> @@ -753,6 +1171,12 @@ static int alienware_awcc_setup(struct wmi_device *wdev)
>>   	priv->wdev = wdev;
>>   	dev_set_drvdata(&wdev->dev, priv);
>>
>> +	if (awcc->hwmon) {
>> +		ret = awcc_hwmon_init(wdev);
>> +		if (ret)
>> +			return ret;
>> +	}
>> +
>>   	if (awcc->pprof) {
>>   		ret = awcc_platform_profile_init(wdev);
>>   		if (ret)
>> @@ -833,6 +1257,13 @@ int __init alienware_wmax_wmi_init(void)
>>   	if (id)
>>   		awcc = id->driver_data;
>>
>> +	if (force_hwmon) {
>> +		if (!awcc)
>> +			awcc = &empty_quirks;
>> +
>> +		awcc->hwmon = true;
>> +	}
>> +
>>   	if (force_platform_profile) {
>>   		if (!awcc)
>>   			awcc = &empty_quirks;
>>


-- 
 ~ Kurt

Re: [PATCH v3 07/10] platform/x86: alienware-wmi-wmax: Add HWMON support

[Armin Wolf]

Am 07.03.25 um 01:35 schrieb Kurt Borja:

> On Thu Mar 6, 2025 at 5:19 PM -05, Armin Wolf wrote:
>> Am 06.03.25 um 01:56 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 | 431 +++++++++++++++++++++++++
>>>    2 files changed, 432 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 71fc17e8d103146b8edf53a552ae5ba64414e873..20cf3371ee3c0e1ea038b3ca517e831f3b30dc29 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
>>> @@ -39,6 +43,10 @@
>>>    /* Arbitrary limit based on supported models */
>>>    #define AWCC_MAX_RES_COUNT			16
>>>
>>> +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);
>>>    MODULE_PARM_DESC(force_platform_profile, "Forces auto-detecting thermal profiles without checking if WMI thermal backend is available");
>>> @@ -48,16 +56,19 @@ 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 +166,18 @@ 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 +200,12 @@ 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,
>>> +	AWCC_TEMP_SENSOR_LAST
>>> +};
>>> +
>>>    enum awcc_thermal_profile {
>>>    	AWCC_PROFILE_USTT_BALANCED,
>>>    	AWCC_PROFILE_USTT_BALANCED_PERFORMANCE,
>>> @@ -216,6 +242,15 @@ struct wmax_u32_args {
>>>    	u8 arg3;
>>>    };
>>>
>>> +struct awcc_fan_data {
>>> +	unsigned long *related_temps;
>>> +	unsigned long *auto_channels_temp;
>>> +	u32 total_temps;
>>> +	u32 min_rpm;
>>> +	u32 max_rpm;
>>> +	u8 id;
>>> +};
>>> +
>>>    struct awcc_priv {
>>>    	struct wmi_device *wdev;
>>>    	union {
>>> @@ -231,6 +266,11 @@ struct awcc_priv {
>>>
>>>    	struct device *ppdev;
>>>    	u8 supported_profiles[PLATFORM_PROFILE_LAST];
>>> +
>>> +	struct device *hwdev;
>>> +	struct awcc_fan_data **fan_data;
>>> +	unsigned int temp_sensors_size;
>>> +	unsigned long *temp_sensors;
>>>    };
>>>
>>>    static const enum platform_profile_option awcc_mode_to_platform_profile[AWCC_PROFILE_LAST] = {
>>> @@ -495,6 +535,19 @@ 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 +605,32 @@ 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 = {
>>> @@ -599,6 +678,345 @@ static int awcc_profile_id_to_pprof(u32 id, enum platform_profile_option *profil
>>>    	return 0;
>>>    }
>>>
>>> +/*
>>> + * 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, priv->temp_sensors_size);
>>> +
>>> +		return channel < temp_count ? 0444 : 0;
>>> +	case hwmon_fan:
>>> +		return channel < priv->fan_count ? 0444 : 0;
>>> +	case hwmon_pwm:
>>> +		if (channel >= priv->fan_count)
>>> +			return 0;
>>> +
>>> +		switch (attr) {
>>> +		case hwmon_pwm_enable:
>> Please drop pwm_enable here and only introduce it inside the proper patch.
> Thanks, mb.
>
>>> +			return 0644;
>>> +		case hwmon_pwm_auto_channels_temp:
>>> +			return 0444;
>>> +		default:
>>> +			return 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);
>>> +	struct awcc_fan_data *fan;
>>> +	u32 state;
>>> +	int ret;
>>> +	u8 temp;
>>> +
>>> +	switch (type) {
>>> +	case hwmon_temp:
>>> +		temp = find_nth_bit(priv->temp_sensors, priv->temp_sensors_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:
>>> +			bitmap_copy(val, fan->auto_channels_temp, BITS_PER_LONG);
>>> +			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);
>>> +	struct awcc_fan_data *fan;
>>> +	u8 temp;
>>> +
>>> +	switch (type) {
>>> +	case hwmon_temp:
>>> +		temp = find_nth_bit(priv->temp_sensors, priv->temp_sensors_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:
>>> +		fan = priv->fan_data[channel];
>>> +
>>> +		switch (fan->total_temps) {
>>> +		case 0:
>>> +			*str = "Independent Fan";
>>> +			break;
>>> +		case 1:
>>> +			temp = find_first_bit(fan->related_temps, priv->temp_sensors_size);
>>> +
>>> +			switch (temp) {
>>> +			case AWCC_TEMP_SENSOR_CPU:
>>> +				*str = "Processor Fan";
>>> +				break;
>>> +			case AWCC_TEMP_SENSOR_GPU:
>>> +				*str = "Video Fan";
>>> +				break;
>>> +			default:
>>> +				*str = "Unknown Fan";
>>> +				break;
>>> +			}
>>> +
>>> +			break;
>>> +		default:
>>> +			*str = "Shared Fan";
>>> +			break;
>>> +		}
>>> +
>>> +		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
>>> +			   ),
>> Since the number of fans and temperature sensors is only known at runtime creating awcc_hwmon_info
>> would make sense.
> IIRC Guenter asked another dev to add more CHANNEL_INFO entries instead
> of doing that? I might be wrong tho.
>
> I'm fine either way.
>
If Guenter is fine with your current approach then you can keep it.

>>> +	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 long temp_sensors[BITS_TO_LONGS(U8_MAX)];
>>> +	unsigned int i, max_sensor_id = 0;
>>> +	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;
>>> +
>>> +		id = FIELD_GET(AWCC_RESOURCE_ID_MASK, id);
>>> +		if (id > max_sensor_id)
>>> +			max_sensor_id = id;
>>> +
>>> +		__set_bit(id, temp_sensors);
>>> +	}
>>> +
>>> +	/*
>>> +	 * We prefer to allocate the bitmap dynamically because usually temp IDs
>>> +	 * are small (< 0x30) and only one UL is needed to store it, but there
>>> +	 * may be unknown devices that break this rule
>>> +	 */
>> Hi,
>>
>> as far as i know the memory allocator inside the kernel at least allocates 32 bytes, so you are
> bytes? bits maybe?

I am sure it is bytes.

>> not saving any memory with this. I suggest you allocate the bitmaps statically.
> The thing is - We don't know before hand how big an ID can be.
>
> Technically the upper limit is U8_MAX which would require 4 ULs to
> store, which is a lot. However I haven't seen temp IDs bigger than 0x6,
> so this way only one UL is allocated for most devices.
>
> I would be very grateful if Dell could help us on this one :')
>
I think wasting 3 * 8 = 24 bytes is OK, especially if you allocate at least 32 bytes
for a dynamic bitmap either way.

Thanks,
Armin Wolf

>>> +	priv->temp_sensors_size = max_sensor_id + 1;
>>> +	priv->temp_sensors = devm_bitmap_zalloc(&wdev->dev, priv->temp_sensors_size,
>>> +						GFP_KERNEL);
>>> +	if (!priv->temp_sensors)
>>> +		return -ENOMEM;
>>> +
>>> +	bitmap_copy(priv->temp_sensors, temp_sensors, priv->temp_sensors_size);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +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 gather[BITS_TO_LONGS(U8_MAX)];
>>> +	struct awcc_fan_data *fan_data;
>>> +	unsigned int i, j;
>>> +	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_data->related_temps = devm_bitmap_zalloc(&wdev->dev,
>>> +							     priv->temp_sensors_size,
>>> +							     GFP_KERNEL);
>> Same as above
>>
>>> +		if (!priv->temp_sensors)
>>> +			return -ENOMEM;
>>> +
>>> +		fan_data->auto_channels_temp = devm_bitmap_zalloc(&wdev->dev,
>>> +								  priv->temp_count,
>>> +								  GFP_KERNEL);
>> We already know that we only ever use the first sizeof(long) bytes from this bitmap,
>> please do a static allocation here.
> Right, ofc! I forgot about the limit I imposed.
>
>>> +		if (!priv->temp_sensors)
>>> +			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);
>>> +			if (temp_id < priv->temp_sensors_size)
>>> +				__set_bit(temp_id, fan_data->related_temps);
>>> +		}
>>> +
>>> +		fan_data->id = id;
>>> +		fan_data->min_rpm = min_rpm;
>>> +		fan_data->max_rpm = max_rpm;
>>> +		fan_data->total_temps = bitmap_weight(fan_data->related_temps,
>>> +						      priv->temp_sensors_size);
>>> +		bitmap_gather(gather, fan_data->related_temps, priv->temp_sensors,
>>> +			      priv->temp_sensors_size);
>> Since fan_data->related_temps is only used for determining the fan label after this it would
>> make sense to determine the fan label here and turn fan_data->related_temps into a local
>> variable on the stack.
> Ack.
>
>> Thanks,
>> Armin Wolf
> Thank you very much! Very helpful feedback :)
>
>>> +		bitmap_copy(fan_data->auto_channels_temp, gather, priv->temp_count);
>>> +		priv->fan_data[i] = fan_data;
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int awcc_hwmon_init(struct wmi_device *wdev)
>>> +{
>>> +	struct awcc_priv *priv = dev_get_drvdata(&wdev->dev);
>>> +	int ret;
>>> +
>>> +	priv->fan_data = devm_kcalloc(&wdev->dev, priv->fan_count,
>>> +				      sizeof(*priv->fan_data), GFP_KERNEL);
>>> +	if (!priv->fan_data)
>>> +		return -ENOMEM;
>>> +
>>> +	ret = awcc_hwmon_temps_init(wdev);
>>> +	if (ret)
>>> +		return ret;
>>> +
>>> +	ret = awcc_hwmon_fans_init(wdev);
>>> +	if (ret)
>>> +		return ret;
>>> +
>>> +	priv->hwdev = devm_hwmon_device_register_with_info(&wdev->dev, "alienware_wmi", priv,
>>> +							   &awcc_hwmon_chip_info, NULL);
>>> +
>>> +	return PTR_ERR_OR_ZERO(priv->hwdev);
>>> +}
>>> +
>>>    /*
>>>     * Thermal Profile control
>>>     *  - Provides thermal profile control through the Platform Profile API
>>> @@ -753,6 +1171,12 @@ static int alienware_awcc_setup(struct wmi_device *wdev)
>>>    	priv->wdev = wdev;
>>>    	dev_set_drvdata(&wdev->dev, priv);
>>>
>>> +	if (awcc->hwmon) {
>>> +		ret = awcc_hwmon_init(wdev);
>>> +		if (ret)
>>> +			return ret;
>>> +	}
>>> +
>>>    	if (awcc->pprof) {
>>>    		ret = awcc_platform_profile_init(wdev);
>>>    		if (ret)
>>> @@ -833,6 +1257,13 @@ int __init alienware_wmax_wmi_init(void)
>>>    	if (id)
>>>    		awcc = id->driver_data;
>>>
>>> +	if (force_hwmon) {
>>> +		if (!awcc)
>>> +			awcc = &empty_quirks;
>>> +
>>> +		awcc->hwmon = true;
>>> +	}
>>> +
>>>    	if (force_platform_profile) {
>>>    		if (!awcc)
>>>    			awcc = &empty_quirks;
>>>
>

Re: [PATCH v3 07/10] platform/x86: alienware-wmi-wmax: Add HWMON support

[Guenter Roeck]

On 3/7/25 13:09, Armin Wolf wrote:
> Am 07.03.25 um 01:35 schrieb Kurt Borja:
...
>>>> +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
>>>> +               ),
>>> Since the number of fans and temperature sensors is only known at runtime creating awcc_hwmon_info
>>> would make sense.
>> IIRC Guenter asked another dev to add more CHANNEL_INFO entries instead
>> of doing that? I might be wrong tho.
>>
>> I'm fine either way.
>>
> If Guenter is fine with your current approach then you can keep it.
> 

In drivers/hwmon, I prefer static descriptions such as the above and using
the is_visible() function to determine if sensor attributes should actually
be created. However, as I have mentioned several times, I do not comment on style
questions like this (or, for that matter, non-standard sysfs attributes) outside
drivers/hwmon, so you can do or request whatever you like.

Guenter

Re: [PATCH v3 07/10] platform/x86: alienware-wmi-wmax: Add HWMON support

[Kurt Borja]

On Fri Mar 7, 2025 at 6:59 PM -05, Guenter Roeck wrote:
> On 3/7/25 13:09, Armin Wolf wrote:
>> Am 07.03.25 um 01:35 schrieb Kurt Borja:
> ...
>>>>> +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
>>>>> +               ),
>>>> Since the number of fans and temperature sensors is only known at runtime creating awcc_hwmon_info
>>>> would make sense.
>>> IIRC Guenter asked another dev to add more CHANNEL_INFO entries instead
>>> of doing that? I might be wrong tho.
>>>
>>> I'm fine either way.
>>>
>> If Guenter is fine with your current approach then you can keep it.
>> 
>
> In drivers/hwmon, I prefer static descriptions such as the above and using
> the is_visible() function to determine if sensor attributes should actually
> be created. However, as I have mentioned several times, I do not comment on style
> questions like this (or, for that matter, non-standard sysfs attributes) outside
> drivers/hwmon, so you can do or request whatever you like.
>
> Guenter

Thank you for clarifying!

If there are no objections, then I prefer to keep it this way. With the
few extra HWMON_CHANNEL_INFO entries.

-- 
 ~ Kurt

[PATCH v3 08/10] platform/x86: alienware-wmi-wmax: Add support for manual fan control

[Kurt Borja]

All models with the "AWCC" WMAX device support a way of manually
controlling fans.

The PWM duty cycle of a fan can't be controlled directly. Instead the
AWCC interface let's us tune a PWM `boost` value, which has the
following empirically discovered, aproximate behavior over the PWM
value:

	pwm = pwm_base + (pwm_boost / 255) * (pwm_max - pwm_base)

Where the pwm_base is the locked PWM value controlled by the FW and
pwm_boost is a value between 0 and 255.

Expose this pwm_boost knob as a custom HWMON attribute.

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/alienware-wmi-wmax.c | 223 ++++++++++++++++++++++++-
 1 file changed, 220 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/dell/alienware-wmi-wmax.c b/drivers/platform/x86/dell/alienware-wmi-wmax.c
index 20cf3371ee3c0e1ea038b3ca517e831f3b30dc29..de4e8f177aadc9552b05cc732e41ee458b761143 100644
--- a/drivers/platform/x86/dell/alienware-wmi-wmax.c
+++ b/drivers/platform/x86/dell/alienware-wmi-wmax.c
@@ -13,8 +13,11 @@
 #include <linux/bits.h>
 #include <linux/dmi.h>
 #include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/minmax.h>
 #include <linux/moduleparam.h>
 #include <linux/platform_profile.h>
+#include <linux/pm.h>
 #include <linux/units.h>
 #include <linux/wmi.h>
 #include "alienware-wmi.h"
@@ -179,10 +182,12 @@ enum AWCC_THERMAL_INFORMATION_OPERATIONS {
 	AWCC_OP_GET_FAN_MIN_RPM			= 0x08,
 	AWCC_OP_GET_FAN_MAX_RPM			= 0x09,
 	AWCC_OP_GET_CURRENT_PROFILE		= 0x0B,
+	AWCC_OP_GET_FAN_BOOST			= 0x0C,
 };
 
 enum AWCC_THERMAL_CONTROL_OPERATIONS {
 	AWCC_OP_ACTIVATE_PROFILE		= 0x01,
+	AWCC_OP_SET_FAN_BOOST			= 0x02,
 };
 
 enum AWCC_GAME_SHIFT_STATUS_OPERATIONS {
@@ -248,6 +253,7 @@ struct awcc_fan_data {
 	u32 total_temps;
 	u32 min_rpm;
 	u32 max_rpm;
+	u8 suspend_cache;
 	u8 id;
 };
 
@@ -627,6 +633,17 @@ static inline int awcc_op_get_temperature(struct wmi_device *wdev, u8 temp_id, u
 		.arg3 = 0,
 	};
 
+	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out);
+}
+
+static inline int awcc_op_get_fan_boost(struct wmi_device *wdev, u8 fan_id, u32 *out)
+{
+	struct wmax_u32_args args = {
+		.operation = AWCC_OP_GET_FAN_BOOST,
+		.arg1 = fan_id,
+		.arg2 = 0,
+		.arg3 = 0,
+	};
 
 	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out);
 }
@@ -656,6 +673,19 @@ static inline int awcc_op_activate_profile(struct wmi_device *wdev, u8 profile)
 	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_CONTROL, &args, &out);
 }
 
+static int awcc_op_set_fan_boost(struct wmi_device *wdev, u8 fan_id, u8 boost)
+{
+	struct wmax_u32_args args = {
+		.operation = AWCC_OP_SET_FAN_BOOST,
+		.arg1 = fan_id,
+		.arg2 = boost,
+		.arg3 = 0,
+	};
+	u32 out;
+
+	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_CONTROL, &args, &out);
+}
+
 static int awcc_profile_id_to_pprof(u32 id, enum platform_profile_option *profile)
 {
 	switch (id) {
@@ -717,6 +747,7 @@ 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);
+	enum platform_profile_option profile;
 	struct awcc_fan_data *fan;
 	u32 state;
 	int ret;
@@ -765,6 +796,28 @@ static int awcc_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
 		fan = priv->fan_data[channel];
 
 		switch (attr) {
+		case hwmon_pwm_enable:
+			ret = awcc_op_get_current_profile(priv->wdev, &state);
+			if (ret)
+				return ret;
+
+			ret = awcc_profile_id_to_pprof(state, &profile);
+			if (ret)
+				return ret;
+
+			switch (profile) {
+			case PLATFORM_PROFILE_PERFORMANCE:
+				*val = 0;
+				break;
+			case PLATFORM_PROFILE_CUSTOM:
+				*val = 1;
+				break;
+			default:
+				*val = 2;
+				break;
+			}
+
+			break;
 		case hwmon_pwm_auto_channels_temp:
 			bitmap_copy(val, fan->auto_channels_temp, BITS_PER_LONG);
 			break;
@@ -840,10 +893,48 @@ static int awcc_hwmon_read_string(struct device *dev, enum hwmon_sensor_types ty
 	return 0;
 }
 
+
+static int awcc_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
+			    u32 attr, int channel, long val)
+{
+	struct awcc_priv *priv = dev_get_drvdata(dev);
+	int ret;
+
+	switch (type) {
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_enable:
+			/*
+			 * We don't want to duplicate platform profile logic, so
+			 * we only allow enabling manual fan control
+			 */
+			if (val != 1)
+				return -EINVAL;
+
+			ret = awcc_op_activate_profile(priv->wdev, AWCC_SPECIAL_PROFILE_CUSTOM);
+			if (ret)
+				return ret;
+
+			if (priv->ppdev)
+				platform_profile_notify(priv->ppdev);
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+
+		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,
+	.write = awcc_hwmon_write,
 };
 
 static const struct hwmon_channel_info * const awcc_hwmon_info[] = {
@@ -864,7 +955,7 @@ static const struct hwmon_channel_info * const awcc_hwmon_info[] = {
 			   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_ENABLE,
 			   HWMON_PWM_AUTO_CHANNELS_TEMP,
 			   HWMON_PWM_AUTO_CHANNELS_TEMP,
 			   HWMON_PWM_AUTO_CHANNELS_TEMP,
@@ -879,6 +970,75 @@ static const struct hwmon_chip_info awcc_hwmon_chip_info = {
 	.info = awcc_hwmon_info,
 };
 
+static ssize_t pwm_boost_show(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	int ret, index = to_sensor_dev_attr(attr)->index;
+	struct awcc_priv *priv = dev_get_drvdata(dev);
+	struct awcc_fan_data *fan = priv->fan_data[index];
+	u32 boost;
+
+	ret = awcc_op_get_fan_boost(priv->wdev, fan->id, &boost);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%u\n", boost);
+}
+
+static ssize_t pwm_boost_store(struct device *dev, struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	int ret, index = to_sensor_dev_attr(attr)->index;
+	struct awcc_priv *priv = dev_get_drvdata(dev);
+	struct awcc_fan_data *fan = priv->fan_data[index];
+	unsigned long val;
+
+	ret = kstrtoul(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	ret = awcc_op_set_fan_boost(priv->wdev, fan->id, clamp_val(val, 0, 255));
+
+	return ret ? ret : count;
+}
+
+static SENSOR_DEVICE_ATTR_RW(pwm1_boost, pwm_boost, 0);
+static SENSOR_DEVICE_ATTR_RW(pwm2_boost, pwm_boost, 1);
+static SENSOR_DEVICE_ATTR_RW(pwm3_boost, pwm_boost, 2);
+static SENSOR_DEVICE_ATTR_RW(pwm4_boost, pwm_boost, 3);
+
+static umode_t pwm_boost_attr_visible(struct kobject *kobj, struct attribute *attr, int n)
+{
+	struct awcc_priv *priv = dev_get_drvdata(kobj_to_dev(kobj));
+
+	return n < priv->fan_count ? attr->mode : 0;
+}
+
+static bool pwm_boost_group_visible(struct kobject *kobj)
+{
+	return true;
+}
+
+DEFINE_SYSFS_GROUP_VISIBLE(pwm_boost);
+
+static struct attribute *fan_boost_attrs[] = {
+	&sensor_dev_attr_pwm1_boost.dev_attr.attr,
+	&sensor_dev_attr_pwm2_boost.dev_attr.attr,
+	&sensor_dev_attr_pwm3_boost.dev_attr.attr,
+	&sensor_dev_attr_pwm4_boost.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group pwm_boost_group = {
+	.attrs = fan_boost_attrs,
+	.is_visible = SYSFS_GROUP_VISIBLE(pwm_boost),
+};
+
+static const struct attribute_group *awcc_hwmon_groups[] = {
+	&pwm_boost_group,
+	NULL
+};
+
 static int awcc_hwmon_temps_init(struct wmi_device *wdev)
 {
 	struct awcc_priv *priv = dev_get_drvdata(&wdev->dev);
@@ -1011,12 +1171,50 @@ static int awcc_hwmon_init(struct wmi_device *wdev)
 	if (ret)
 		return ret;
 
-	priv->hwdev = devm_hwmon_device_register_with_info(&wdev->dev, "alienware_wmi", priv,
-							   &awcc_hwmon_chip_info, NULL);
+	priv->hwdev = devm_hwmon_device_register_with_info(&wdev->dev, "alienware_wmi",
+							   priv, &awcc_hwmon_chip_info,
+							   awcc_hwmon_groups);
 
 	return PTR_ERR_OR_ZERO(priv->hwdev);
 }
 
+static void awcc_hwmon_suspend(struct device *dev)
+{
+	struct awcc_priv *priv = dev_get_drvdata(dev);
+	struct awcc_fan_data *fan;
+	unsigned int i;
+	u32 boost;
+	int ret;
+
+	for (i = 0; i < priv->fan_count; i++) {
+		fan = priv->fan_data[i];
+
+		ret = awcc_thermal_information(priv->wdev, AWCC_OP_GET_FAN_BOOST,
+					       fan->id, &boost);
+		if (ret)
+			fan->suspend_cache = 0;
+		else
+			fan->suspend_cache = clamp_val(boost, 0, 255);
+
+		awcc_op_set_fan_boost(priv->wdev, fan->id, 0);
+	}
+}
+
+static void awcc_hwmon_resume(struct device *dev)
+{
+
+	struct awcc_priv *priv = dev_get_drvdata(dev);
+	struct awcc_fan_data *fan;
+	unsigned int i;
+
+	for (i = 0; i < priv->fan_count; i++) {
+		fan = priv->fan_data[i];
+
+		if (fan->suspend_cache)
+			awcc_op_set_fan_boost(priv->wdev, fan->id, fan->suspend_cache);
+	}
+}
+
 /*
  * Thermal Profile control
  *  - Provides thermal profile control through the Platform Profile API
@@ -1233,6 +1431,24 @@ static int wmax_wmi_probe(struct wmi_device *wdev, const void *context)
 	return ret;
 }
 
+static int wmax_wmi_suspend(struct device *dev)
+{
+	if (awcc->hwmon)
+		awcc_hwmon_suspend(dev);
+
+	return 0;
+}
+
+static int wmax_wmi_resume(struct device *dev)
+{
+	if (awcc->hwmon)
+		awcc_hwmon_resume(dev);
+
+	return 0;
+}
+
+DEFINE_SIMPLE_DEV_PM_OPS(wmax_wmi_pm_ops, wmax_wmi_suspend, wmax_wmi_resume);
+
 static const struct wmi_device_id alienware_wmax_device_id_table[] = {
 	{ WMAX_CONTROL_GUID, NULL },
 	{ },
@@ -1243,6 +1459,7 @@ static struct wmi_driver alienware_wmax_wmi_driver = {
 	.driver = {
 		.name = "alienware-wmi-wmax",
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.pm = pm_sleep_ptr(&wmax_wmi_pm_ops),
 	},
 	.id_table = alienware_wmax_device_id_table,
 	.probe = wmax_wmi_probe,

-- 
2.48.1

Re: [PATCH v3 08/10] platform/x86: alienware-wmi-wmax: Add support for manual fan control

[Armin Wolf]

Am 06.03.25 um 01:56 schrieb Kurt Borja:

> All models with the "AWCC" WMAX device support a way of manually
> controlling fans.
>
> The PWM duty cycle of a fan can't be controlled directly. Instead the
> AWCC interface let's us tune a PWM `boost` value, which has the
> following empirically discovered, aproximate behavior over the PWM
> value:
>
> 	pwm = pwm_base + (pwm_boost / 255) * (pwm_max - pwm_base)
>
> Where the pwm_base is the locked PWM value controlled by the FW and
> pwm_boost is a value between 0 and 255.
>
> Expose this pwm_boost knob as a custom HWMON attribute.
>
> 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/alienware-wmi-wmax.c | 223 ++++++++++++++++++++++++-
>   1 file changed, 220 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/platform/x86/dell/alienware-wmi-wmax.c b/drivers/platform/x86/dell/alienware-wmi-wmax.c
> index 20cf3371ee3c0e1ea038b3ca517e831f3b30dc29..de4e8f177aadc9552b05cc732e41ee458b761143 100644
> --- a/drivers/platform/x86/dell/alienware-wmi-wmax.c
> +++ b/drivers/platform/x86/dell/alienware-wmi-wmax.c
> @@ -13,8 +13,11 @@
>   #include <linux/bits.h>
>   #include <linux/dmi.h>
>   #include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/minmax.h>
>   #include <linux/moduleparam.h>
>   #include <linux/platform_profile.h>
> +#include <linux/pm.h>
>   #include <linux/units.h>
>   #include <linux/wmi.h>
>   #include "alienware-wmi.h"
> @@ -179,10 +182,12 @@ enum AWCC_THERMAL_INFORMATION_OPERATIONS {
>   	AWCC_OP_GET_FAN_MIN_RPM			= 0x08,
>   	AWCC_OP_GET_FAN_MAX_RPM			= 0x09,
>   	AWCC_OP_GET_CURRENT_PROFILE		= 0x0B,
> +	AWCC_OP_GET_FAN_BOOST			= 0x0C,
>   };
>
>   enum AWCC_THERMAL_CONTROL_OPERATIONS {
>   	AWCC_OP_ACTIVATE_PROFILE		= 0x01,
> +	AWCC_OP_SET_FAN_BOOST			= 0x02,
>   };
>
>   enum AWCC_GAME_SHIFT_STATUS_OPERATIONS {
> @@ -248,6 +253,7 @@ struct awcc_fan_data {
>   	u32 total_temps;
>   	u32 min_rpm;
>   	u32 max_rpm;
> +	u8 suspend_cache;
>   	u8 id;
>   };
>
> @@ -627,6 +633,17 @@ static inline int awcc_op_get_temperature(struct wmi_device *wdev, u8 temp_id, u
>   		.arg3 = 0,
>   	};
>
> +	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out);
> +}
> +
> +static inline int awcc_op_get_fan_boost(struct wmi_device *wdev, u8 fan_id, u32 *out)
> +{
> +	struct wmax_u32_args args = {
> +		.operation = AWCC_OP_GET_FAN_BOOST,
> +		.arg1 = fan_id,
> +		.arg2 = 0,
> +		.arg3 = 0,
> +	};
>
>   	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out);
>   }
> @@ -656,6 +673,19 @@ static inline int awcc_op_activate_profile(struct wmi_device *wdev, u8 profile)
>   	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_CONTROL, &args, &out);
>   }
>
> +static int awcc_op_set_fan_boost(struct wmi_device *wdev, u8 fan_id, u8 boost)
> +{
> +	struct wmax_u32_args args = {
> +		.operation = AWCC_OP_SET_FAN_BOOST,
> +		.arg1 = fan_id,
> +		.arg2 = boost,
> +		.arg3 = 0,
> +	};
> +	u32 out;
> +
> +	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_CONTROL, &args, &out);
> +}
> +
>   static int awcc_profile_id_to_pprof(u32 id, enum platform_profile_option *profile)
>   {
>   	switch (id) {
> @@ -717,6 +747,7 @@ 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);
> +	enum platform_profile_option profile;
>   	struct awcc_fan_data *fan;
>   	u32 state;
>   	int ret;
> @@ -765,6 +796,28 @@ static int awcc_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
>   		fan = priv->fan_data[channel];
>
>   		switch (attr) {
> +		case hwmon_pwm_enable:
> +			ret = awcc_op_get_current_profile(priv->wdev, &state);
> +			if (ret)
> +				return ret;
> +
> +			ret = awcc_profile_id_to_pprof(state, &profile);
> +			if (ret)
> +				return ret;
> +
> +			switch (profile) {
> +			case PLATFORM_PROFILE_PERFORMANCE:

The hwmon sysfs docs say that 0 means that the fan is spinning at maximum speed. Does PLATFORM_PROFILE_PERFORMANCE
guarantee that all fans are always spinning at maximum speed?

If no then i suggest to drop support for 0.

> +				*val = 0;
> +				break;
> +			case PLATFORM_PROFILE_CUSTOM:
> +				*val = 1;
> +				break;
> +			default:
> +				*val = 2;
> +				break;
> +			}
> +
> +			break;
>   		case hwmon_pwm_auto_channels_temp:
>   			bitmap_copy(val, fan->auto_channels_temp, BITS_PER_LONG);
>   			break;
> @@ -840,10 +893,48 @@ static int awcc_hwmon_read_string(struct device *dev, enum hwmon_sensor_types ty
>   	return 0;
>   }
>
> +
> +static int awcc_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
> +			    u32 attr, int channel, long val)
> +{
> +	struct awcc_priv *priv = dev_get_drvdata(dev);
> +	int ret;
> +
> +	switch (type) {
> +	case hwmon_pwm:
> +		switch (attr) {
> +		case hwmon_pwm_enable:
> +			/*
> +			 * We don't want to duplicate platform profile logic, so
> +			 * we only allow enabling manual fan control
> +			 */

I do not think that having pwm1_enable brings any benefit, as the pwmX_boost attributes
behave differently than pwmX attributes. I think it would be enough to document that
pwmX_boost settings will only reliably work when the custom platform profile is selected.

> +			if (val != 1)
> +				return -EINVAL;
> +
> +			ret = awcc_op_activate_profile(priv->wdev, AWCC_SPECIAL_PROFILE_CUSTOM);
> +			if (ret)
> +				return ret;
> +
> +			if (priv->ppdev)
> +				platform_profile_notify(priv->ppdev);
> +			break;
> +		default:
> +			return -EOPNOTSUPP;
> +		}
> +
> +		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,
> +	.write = awcc_hwmon_write,
>   };
>
>   static const struct hwmon_channel_info * const awcc_hwmon_info[] = {
> @@ -864,7 +955,7 @@ static const struct hwmon_channel_info * const awcc_hwmon_info[] = {
>   			   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_ENABLE,
>   			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>   			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>   			   HWMON_PWM_AUTO_CHANNELS_TEMP,
> @@ -879,6 +970,75 @@ static const struct hwmon_chip_info awcc_hwmon_chip_info = {
>   	.info = awcc_hwmon_info,
>   };
>
> +static ssize_t pwm_boost_show(struct device *dev, struct device_attribute *attr,
> +			      char *buf)
> +{
> +	int ret, index = to_sensor_dev_attr(attr)->index;

Please initialize "index" on a separate line, can remember the reverse xmas-tree order for variables.

> +	struct awcc_priv *priv = dev_get_drvdata(dev);
> +	struct awcc_fan_data *fan = priv->fan_data[index];
> +	u32 boost;
> +
> +	ret = awcc_op_get_fan_boost(priv->wdev, fan->id, &boost);
> +	if (ret)
> +		return ret;
> +
> +	return sysfs_emit(buf, "%u\n", boost);
> +}
> +
> +static ssize_t pwm_boost_store(struct device *dev, struct device_attribute *attr,
> +			       const char *buf, size_t count)
> +{
> +	int ret, index = to_sensor_dev_attr(attr)->index;
> +	struct awcc_priv *priv = dev_get_drvdata(dev);
> +	struct awcc_fan_data *fan = priv->fan_data[index];
> +	unsigned long val;
> +
> +	ret = kstrtoul(buf, 0, &val);
> +	if (ret)
> +		return ret;
> +
> +	ret = awcc_op_set_fan_boost(priv->wdev, fan->id, clamp_val(val, 0, 255));
> +
> +	return ret ? ret : count;
> +}
> +
> +static SENSOR_DEVICE_ATTR_RW(pwm1_boost, pwm_boost, 0);
> +static SENSOR_DEVICE_ATTR_RW(pwm2_boost, pwm_boost, 1);
> +static SENSOR_DEVICE_ATTR_RW(pwm3_boost, pwm_boost, 2);
> +static SENSOR_DEVICE_ATTR_RW(pwm4_boost, pwm_boost, 3);

Since those attributes are working differently than the standard pwm attributes, i suggest to
instead name them fanX_boost.

> +
> +static umode_t pwm_boost_attr_visible(struct kobject *kobj, struct attribute *attr, int n)
> +{
> +	struct awcc_priv *priv = dev_get_drvdata(kobj_to_dev(kobj));
> +
> +	return n < priv->fan_count ? attr->mode : 0;
> +}
> +
> +static bool pwm_boost_group_visible(struct kobject *kobj)
> +{
> +	return true;
> +}
> +
> +DEFINE_SYSFS_GROUP_VISIBLE(pwm_boost);
> +
> +static struct attribute *fan_boost_attrs[] = {
> +	&sensor_dev_attr_pwm1_boost.dev_attr.attr,
> +	&sensor_dev_attr_pwm2_boost.dev_attr.attr,
> +	&sensor_dev_attr_pwm3_boost.dev_attr.attr,
> +	&sensor_dev_attr_pwm4_boost.dev_attr.attr,
> +	NULL
> +};
> +
> +static const struct attribute_group pwm_boost_group = {
> +	.attrs = fan_boost_attrs,
> +	.is_visible = SYSFS_GROUP_VISIBLE(pwm_boost),
> +};
> +
> +static const struct attribute_group *awcc_hwmon_groups[] = {
> +	&pwm_boost_group,
> +	NULL
> +};
> +
>   static int awcc_hwmon_temps_init(struct wmi_device *wdev)
>   {
>   	struct awcc_priv *priv = dev_get_drvdata(&wdev->dev);
> @@ -1011,12 +1171,50 @@ static int awcc_hwmon_init(struct wmi_device *wdev)
>   	if (ret)
>   		return ret;
>
> -	priv->hwdev = devm_hwmon_device_register_with_info(&wdev->dev, "alienware_wmi", priv,
> -							   &awcc_hwmon_chip_info, NULL);
> +	priv->hwdev = devm_hwmon_device_register_with_info(&wdev->dev, "alienware_wmi",
> +							   priv, &awcc_hwmon_chip_info,
> +							   awcc_hwmon_groups);
>
>   	return PTR_ERR_OR_ZERO(priv->hwdev);
>   }
>
> +static void awcc_hwmon_suspend(struct device *dev)
> +{
> +	struct awcc_priv *priv = dev_get_drvdata(dev);
> +	struct awcc_fan_data *fan;
> +	unsigned int i;
> +	u32 boost;
> +	int ret;
> +
> +	for (i = 0; i < priv->fan_count; i++) {
> +		fan = priv->fan_data[i];
> +
> +		ret = awcc_thermal_information(priv->wdev, AWCC_OP_GET_FAN_BOOST,
> +					       fan->id, &boost);
> +		if (ret)
> +			fan->suspend_cache = 0;

Please at least log a warning here that the fan boost value can not be restored properly.

> +		else
> +			fan->suspend_cache = clamp_val(boost, 0, 255);
> +
> +		awcc_op_set_fan_boost(priv->wdev, fan->id, 0);
> +	}
> +}
> +
> +static void awcc_hwmon_resume(struct device *dev)
> +{
> +
> +	struct awcc_priv *priv = dev_get_drvdata(dev);
> +	struct awcc_fan_data *fan;
> +	unsigned int i;
> +
> +	for (i = 0; i < priv->fan_count; i++) {
> +		fan = priv->fan_data[i];
> +
> +		if (fan->suspend_cache)

How does the driver restore fan boost settings with a value of 0?

Thanks,
Armin Wolf

> +			awcc_op_set_fan_boost(priv->wdev, fan->id, fan->suspend_cache);
> +	}
> +}
> +
>   /*
>    * Thermal Profile control
>    *  - Provides thermal profile control through the Platform Profile API
> @@ -1233,6 +1431,24 @@ static int wmax_wmi_probe(struct wmi_device *wdev, const void *context)
>   	return ret;
>   }
>
> +static int wmax_wmi_suspend(struct device *dev)
> +{
> +	if (awcc->hwmon)
> +		awcc_hwmon_suspend(dev);
> +
> +	return 0;
> +}
> +
> +static int wmax_wmi_resume(struct device *dev)
> +{
> +	if (awcc->hwmon)
> +		awcc_hwmon_resume(dev);
> +
> +	return 0;
> +}
> +
> +DEFINE_SIMPLE_DEV_PM_OPS(wmax_wmi_pm_ops, wmax_wmi_suspend, wmax_wmi_resume);
> +
>   static const struct wmi_device_id alienware_wmax_device_id_table[] = {
>   	{ WMAX_CONTROL_GUID, NULL },
>   	{ },
> @@ -1243,6 +1459,7 @@ static struct wmi_driver alienware_wmax_wmi_driver = {
>   	.driver = {
>   		.name = "alienware-wmi-wmax",
>   		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
> +		.pm = pm_sleep_ptr(&wmax_wmi_pm_ops),
>   	},
>   	.id_table = alienware_wmax_device_id_table,
>   	.probe = wmax_wmi_probe,
>

Re: [PATCH v3 08/10] platform/x86: alienware-wmi-wmax: Add support for manual fan control

[Kurt Borja]

Hi Armin,

On Thu Mar 6, 2025 at 5:35 PM -05, Armin Wolf wrote:
> Am 06.03.25 um 01:56 schrieb Kurt Borja:
>
>> All models with the "AWCC" WMAX device support a way of manually
>> controlling fans.
>>
>> The PWM duty cycle of a fan can't be controlled directly. Instead the
>> AWCC interface let's us tune a PWM `boost` value, which has the
>> following empirically discovered, aproximate behavior over the PWM
>> value:
>>
>> 	pwm = pwm_base + (pwm_boost / 255) * (pwm_max - pwm_base)
>>
>> Where the pwm_base is the locked PWM value controlled by the FW and
>> pwm_boost is a value between 0 and 255.
>>
>> Expose this pwm_boost knob as a custom HWMON attribute.
>>
>> 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/alienware-wmi-wmax.c | 223 ++++++++++++++++++++++++-
>>   1 file changed, 220 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/platform/x86/dell/alienware-wmi-wmax.c b/drivers/platform/x86/dell/alienware-wmi-wmax.c
>> index 20cf3371ee3c0e1ea038b3ca517e831f3b30dc29..de4e8f177aadc9552b05cc732e41ee458b761143 100644
>> --- a/drivers/platform/x86/dell/alienware-wmi-wmax.c
>> +++ b/drivers/platform/x86/dell/alienware-wmi-wmax.c
>> @@ -13,8 +13,11 @@
>>   #include <linux/bits.h>
>>   #include <linux/dmi.h>
>>   #include <linux/hwmon.h>
>> +#include <linux/hwmon-sysfs.h>
>> +#include <linux/minmax.h>
>>   #include <linux/moduleparam.h>
>>   #include <linux/platform_profile.h>
>> +#include <linux/pm.h>
>>   #include <linux/units.h>
>>   #include <linux/wmi.h>
>>   #include "alienware-wmi.h"
>> @@ -179,10 +182,12 @@ enum AWCC_THERMAL_INFORMATION_OPERATIONS {
>>   	AWCC_OP_GET_FAN_MIN_RPM			= 0x08,
>>   	AWCC_OP_GET_FAN_MAX_RPM			= 0x09,
>>   	AWCC_OP_GET_CURRENT_PROFILE		= 0x0B,
>> +	AWCC_OP_GET_FAN_BOOST			= 0x0C,
>>   };
>>
>>   enum AWCC_THERMAL_CONTROL_OPERATIONS {
>>   	AWCC_OP_ACTIVATE_PROFILE		= 0x01,
>> +	AWCC_OP_SET_FAN_BOOST			= 0x02,
>>   };
>>
>>   enum AWCC_GAME_SHIFT_STATUS_OPERATIONS {
>> @@ -248,6 +253,7 @@ struct awcc_fan_data {
>>   	u32 total_temps;
>>   	u32 min_rpm;
>>   	u32 max_rpm;
>> +	u8 suspend_cache;
>>   	u8 id;
>>   };
>>
>> @@ -627,6 +633,17 @@ static inline int awcc_op_get_temperature(struct wmi_device *wdev, u8 temp_id, u
>>   		.arg3 = 0,
>>   	};
>>
>> +	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out);
>> +}
>> +
>> +static inline int awcc_op_get_fan_boost(struct wmi_device *wdev, u8 fan_id, u32 *out)
>> +{
>> +	struct wmax_u32_args args = {
>> +		.operation = AWCC_OP_GET_FAN_BOOST,
>> +		.arg1 = fan_id,
>> +		.arg2 = 0,
>> +		.arg3 = 0,
>> +	};
>>
>>   	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out);
>>   }
>> @@ -656,6 +673,19 @@ static inline int awcc_op_activate_profile(struct wmi_device *wdev, u8 profile)
>>   	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_CONTROL, &args, &out);
>>   }
>>
>> +static int awcc_op_set_fan_boost(struct wmi_device *wdev, u8 fan_id, u8 boost)
>> +{
>> +	struct wmax_u32_args args = {
>> +		.operation = AWCC_OP_SET_FAN_BOOST,
>> +		.arg1 = fan_id,
>> +		.arg2 = boost,
>> +		.arg3 = 0,
>> +	};
>> +	u32 out;
>> +
>> +	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_CONTROL, &args, &out);
>> +}
>> +
>>   static int awcc_profile_id_to_pprof(u32 id, enum platform_profile_option *profile)
>>   {
>>   	switch (id) {
>> @@ -717,6 +747,7 @@ 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);
>> +	enum platform_profile_option profile;
>>   	struct awcc_fan_data *fan;
>>   	u32 state;
>>   	int ret;
>> @@ -765,6 +796,28 @@ static int awcc_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
>>   		fan = priv->fan_data[channel];
>>
>>   		switch (attr) {
>> +		case hwmon_pwm_enable:
>> +			ret = awcc_op_get_current_profile(priv->wdev, &state);
>> +			if (ret)
>> +				return ret;
>> +
>> +			ret = awcc_profile_id_to_pprof(state, &profile);
>> +			if (ret)
>> +				return ret;
>> +
>> +			switch (profile) {
>> +			case PLATFORM_PROFILE_PERFORMANCE:
>
> The hwmon sysfs docs say that 0 means that the fan is spinning at maximum speed. Does PLATFORM_PROFILE_PERFORMANCE
> guarantee that all fans are always spinning at maximum speed?

Yes PERFORMANCE is full-speed for all devices I know. Manual fan control
is completely disabled for that profile too.

In fact I'm thinking about adding a module parameter to suppress this
behavior. Not everyone may like that. That's outside the scope of these
series tho.

>
> If no then i suggest to drop support for 0.
>
>> +				*val = 0;
>> +				break;
>> +			case PLATFORM_PROFILE_CUSTOM:
>> +				*val = 1;
>> +				break;
>> +			default:
>> +				*val = 2;
>> +				break;
>> +			}
>> +
>> +			break;
>>   		case hwmon_pwm_auto_channels_temp:
>>   			bitmap_copy(val, fan->auto_channels_temp, BITS_PER_LONG);
>>   			break;
>> @@ -840,10 +893,48 @@ static int awcc_hwmon_read_string(struct device *dev, enum hwmon_sensor_types ty
>>   	return 0;
>>   }
>>
>> +
>> +static int awcc_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
>> +			    u32 attr, int channel, long val)
>> +{
>> +	struct awcc_priv *priv = dev_get_drvdata(dev);
>> +	int ret;
>> +
>> +	switch (type) {
>> +	case hwmon_pwm:
>> +		switch (attr) {
>> +		case hwmon_pwm_enable:
>> +			/*
>> +			 * We don't want to duplicate platform profile logic, so
>> +			 * we only allow enabling manual fan control
>> +			 */
>
> I do not think that having pwm1_enable brings any benefit, as the pwmX_boost attributes
> behave differently than pwmX attributes. I think it would be enough to document that
> pwmX_boost settings will only reliably work when the custom platform profile is selected.

Now I realise I completely forgot about the admin-guide documentation!
I'll include it in the next revision. Is this path ok?

	Documentation/admin-guide/laptops/alienware-wmi.rst

Or should I add driver specific ABI documentation? (or both ofc)

I don't want to name the file alienware-laptop because this driver is
compatible with Dell G-Series too.

>
>> +			if (val != 1)
>> +				return -EINVAL;
>> +
>> +			ret = awcc_op_activate_profile(priv->wdev, AWCC_SPECIAL_PROFILE_CUSTOM);
>> +			if (ret)
>> +				return ret;
>> +
>> +			if (priv->ppdev)
>> +				platform_profile_notify(priv->ppdev);
>> +			break;
>> +		default:
>> +			return -EOPNOTSUPP;
>> +		}
>> +
>> +		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,
>> +	.write = awcc_hwmon_write,
>>   };
>>
>>   static const struct hwmon_channel_info * const awcc_hwmon_info[] = {
>> @@ -864,7 +955,7 @@ static const struct hwmon_channel_info * const awcc_hwmon_info[] = {
>>   			   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_ENABLE,
>>   			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>>   			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>>   			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>> @@ -879,6 +970,75 @@ static const struct hwmon_chip_info awcc_hwmon_chip_info = {
>>   	.info = awcc_hwmon_info,
>>   };
>>
>> +static ssize_t pwm_boost_show(struct device *dev, struct device_attribute *attr,
>> +			      char *buf)
>> +{
>> +	int ret, index = to_sensor_dev_attr(attr)->index;
>
> Please initialize "index" on a separate line, can remember the reverse xmas-tree order for variables.

Ack.

>
>> +	struct awcc_priv *priv = dev_get_drvdata(dev);
>> +	struct awcc_fan_data *fan = priv->fan_data[index];
>> +	u32 boost;
>> +
>> +	ret = awcc_op_get_fan_boost(priv->wdev, fan->id, &boost);
>> +	if (ret)
>> +		return ret;
>> +
>> +	return sysfs_emit(buf, "%u\n", boost);
>> +}
>> +
>> +static ssize_t pwm_boost_store(struct device *dev, struct device_attribute *attr,
>> +			       const char *buf, size_t count)
>> +{
>> +	int ret, index = to_sensor_dev_attr(attr)->index;
>> +	struct awcc_priv *priv = dev_get_drvdata(dev);
>> +	struct awcc_fan_data *fan = priv->fan_data[index];
>> +	unsigned long val;
>> +
>> +	ret = kstrtoul(buf, 0, &val);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = awcc_op_set_fan_boost(priv->wdev, fan->id, clamp_val(val, 0, 255));
>> +
>> +	return ret ? ret : count;
>> +}
>> +
>> +static SENSOR_DEVICE_ATTR_RW(pwm1_boost, pwm_boost, 0);
>> +static SENSOR_DEVICE_ATTR_RW(pwm2_boost, pwm_boost, 1);
>> +static SENSOR_DEVICE_ATTR_RW(pwm3_boost, pwm_boost, 2);
>> +static SENSOR_DEVICE_ATTR_RW(pwm4_boost, pwm_boost, 3);
>
> Since those attributes are working differently than the standard pwm attributes, i suggest to
> instead name them fanX_boost.

I went for pwm*_boost because we also export pwm*_auto_channels_temp,
but I'm ok with fan*_boost too.

>
>> +
>> +static umode_t pwm_boost_attr_visible(struct kobject *kobj, struct attribute *attr, int n)
>> +{
>> +	struct awcc_priv *priv = dev_get_drvdata(kobj_to_dev(kobj));
>> +
>> +	return n < priv->fan_count ? attr->mode : 0;
>> +}
>> +
>> +static bool pwm_boost_group_visible(struct kobject *kobj)
>> +{
>> +	return true;
>> +}
>> +
>> +DEFINE_SYSFS_GROUP_VISIBLE(pwm_boost);
>> +
>> +static struct attribute *fan_boost_attrs[] = {
>> +	&sensor_dev_attr_pwm1_boost.dev_attr.attr,
>> +	&sensor_dev_attr_pwm2_boost.dev_attr.attr,
>> +	&sensor_dev_attr_pwm3_boost.dev_attr.attr,
>> +	&sensor_dev_attr_pwm4_boost.dev_attr.attr,
>> +	NULL
>> +};
>> +
>> +static const struct attribute_group pwm_boost_group = {
>> +	.attrs = fan_boost_attrs,
>> +	.is_visible = SYSFS_GROUP_VISIBLE(pwm_boost),
>> +};
>> +
>> +static const struct attribute_group *awcc_hwmon_groups[] = {
>> +	&pwm_boost_group,
>> +	NULL
>> +};
>> +
>>   static int awcc_hwmon_temps_init(struct wmi_device *wdev)
>>   {
>>   	struct awcc_priv *priv = dev_get_drvdata(&wdev->dev);
>> @@ -1011,12 +1171,50 @@ static int awcc_hwmon_init(struct wmi_device *wdev)
>>   	if (ret)
>>   		return ret;
>>
>> -	priv->hwdev = devm_hwmon_device_register_with_info(&wdev->dev, "alienware_wmi", priv,
>> -							   &awcc_hwmon_chip_info, NULL);
>> +	priv->hwdev = devm_hwmon_device_register_with_info(&wdev->dev, "alienware_wmi",
>> +							   priv, &awcc_hwmon_chip_info,
>> +							   awcc_hwmon_groups);
>>
>>   	return PTR_ERR_OR_ZERO(priv->hwdev);
>>   }
>>
>> +static void awcc_hwmon_suspend(struct device *dev)
>> +{
>> +	struct awcc_priv *priv = dev_get_drvdata(dev);
>> +	struct awcc_fan_data *fan;
>> +	unsigned int i;
>> +	u32 boost;
>> +	int ret;
>> +
>> +	for (i = 0; i < priv->fan_count; i++) {
>> +		fan = priv->fan_data[i];
>> +
>> +		ret = awcc_thermal_information(priv->wdev, AWCC_OP_GET_FAN_BOOST,
>> +					       fan->id, &boost);
>> +		if (ret)
>> +			fan->suspend_cache = 0;
>
> Please at least log a warning here that the fan boost value can not be restored properly.

Ack.

Is not propagating errors a good approach here? My idea was to try to
turn off fans no matter what.

>
>> +		else
>> +			fan->suspend_cache = clamp_val(boost, 0, 255);
>> +
>> +		awcc_op_set_fan_boost(priv->wdev, fan->id, 0);
>> +	}
>> +}
>> +
>> +static void awcc_hwmon_resume(struct device *dev)
>> +{
>> +
>> +	struct awcc_priv *priv = dev_get_drvdata(dev);
>> +	struct awcc_fan_data *fan;
>> +	unsigned int i;
>> +
>> +	for (i = 0; i < priv->fan_count; i++) {
>> +		fan = priv->fan_data[i];
>> +
>> +		if (fan->suspend_cache)
>
> How does the driver restore fan boost settings with a value of 0?

We set to 0 when suspending so I don't think it's necessary to restore
to 0 again when resuming.

>
> Thanks,
> Armin Wolf
>
>> +			awcc_op_set_fan_boost(priv->wdev, fan->id, fan->suspend_cache);
>> +	}
>> +}
>> +
>>   /*
>>    * Thermal Profile control
>>    *  - Provides thermal profile control through the Platform Profile API
>> @@ -1233,6 +1431,24 @@ static int wmax_wmi_probe(struct wmi_device *wdev, const void *context)
>>   	return ret;
>>   }
>>
>> +static int wmax_wmi_suspend(struct device *dev)
>> +{
>> +	if (awcc->hwmon)
>> +		awcc_hwmon_suspend(dev);
>> +
>> +	return 0;
>> +}
>> +
>> +static int wmax_wmi_resume(struct device *dev)
>> +{
>> +	if (awcc->hwmon)
>> +		awcc_hwmon_resume(dev);
>> +
>> +	return 0;
>> +}
>> +
>> +DEFINE_SIMPLE_DEV_PM_OPS(wmax_wmi_pm_ops, wmax_wmi_suspend, wmax_wmi_resume);
>> +
>>   static const struct wmi_device_id alienware_wmax_device_id_table[] = {
>>   	{ WMAX_CONTROL_GUID, NULL },
>>   	{ },
>> @@ -1243,6 +1459,7 @@ static struct wmi_driver alienware_wmax_wmi_driver = {
>>   	.driver = {
>>   		.name = "alienware-wmi-wmax",
>>   		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
>> +		.pm = pm_sleep_ptr(&wmax_wmi_pm_ops),
>>   	},
>>   	.id_table = alienware_wmax_device_id_table,
>>   	.probe = wmax_wmi_probe,
>>


-- 
 ~ Kurt

Re: [PATCH v3 08/10] platform/x86: alienware-wmi-wmax: Add support for manual fan control

[Armin Wolf]

Am 07.03.25 um 01:16 schrieb Kurt Borja:

> Hi Armin,
>
> On Thu Mar 6, 2025 at 5:35 PM -05, Armin Wolf wrote:
>> Am 06.03.25 um 01:56 schrieb Kurt Borja:
>>
>>> All models with the "AWCC" WMAX device support a way of manually
>>> controlling fans.
>>>
>>> The PWM duty cycle of a fan can't be controlled directly. Instead the
>>> AWCC interface let's us tune a PWM `boost` value, which has the
>>> following empirically discovered, aproximate behavior over the PWM
>>> value:
>>>
>>> 	pwm = pwm_base + (pwm_boost / 255) * (pwm_max - pwm_base)
>>>
>>> Where the pwm_base is the locked PWM value controlled by the FW and
>>> pwm_boost is a value between 0 and 255.
>>>
>>> Expose this pwm_boost knob as a custom HWMON attribute.
>>>
>>> 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/alienware-wmi-wmax.c | 223 ++++++++++++++++++++++++-
>>>    1 file changed, 220 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/platform/x86/dell/alienware-wmi-wmax.c b/drivers/platform/x86/dell/alienware-wmi-wmax.c
>>> index 20cf3371ee3c0e1ea038b3ca517e831f3b30dc29..de4e8f177aadc9552b05cc732e41ee458b761143 100644
>>> --- a/drivers/platform/x86/dell/alienware-wmi-wmax.c
>>> +++ b/drivers/platform/x86/dell/alienware-wmi-wmax.c
>>> @@ -13,8 +13,11 @@
>>>    #include <linux/bits.h>
>>>    #include <linux/dmi.h>
>>>    #include <linux/hwmon.h>
>>> +#include <linux/hwmon-sysfs.h>
>>> +#include <linux/minmax.h>
>>>    #include <linux/moduleparam.h>
>>>    #include <linux/platform_profile.h>
>>> +#include <linux/pm.h>
>>>    #include <linux/units.h>
>>>    #include <linux/wmi.h>
>>>    #include "alienware-wmi.h"
>>> @@ -179,10 +182,12 @@ enum AWCC_THERMAL_INFORMATION_OPERATIONS {
>>>    	AWCC_OP_GET_FAN_MIN_RPM			= 0x08,
>>>    	AWCC_OP_GET_FAN_MAX_RPM			= 0x09,
>>>    	AWCC_OP_GET_CURRENT_PROFILE		= 0x0B,
>>> +	AWCC_OP_GET_FAN_BOOST			= 0x0C,
>>>    };
>>>
>>>    enum AWCC_THERMAL_CONTROL_OPERATIONS {
>>>    	AWCC_OP_ACTIVATE_PROFILE		= 0x01,
>>> +	AWCC_OP_SET_FAN_BOOST			= 0x02,
>>>    };
>>>
>>>    enum AWCC_GAME_SHIFT_STATUS_OPERATIONS {
>>> @@ -248,6 +253,7 @@ struct awcc_fan_data {
>>>    	u32 total_temps;
>>>    	u32 min_rpm;
>>>    	u32 max_rpm;
>>> +	u8 suspend_cache;
>>>    	u8 id;
>>>    };
>>>
>>> @@ -627,6 +633,17 @@ static inline int awcc_op_get_temperature(struct wmi_device *wdev, u8 temp_id, u
>>>    		.arg3 = 0,
>>>    	};
>>>
>>> +	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out);
>>> +}
>>> +
>>> +static inline int awcc_op_get_fan_boost(struct wmi_device *wdev, u8 fan_id, u32 *out)
>>> +{
>>> +	struct wmax_u32_args args = {
>>> +		.operation = AWCC_OP_GET_FAN_BOOST,
>>> +		.arg1 = fan_id,
>>> +		.arg2 = 0,
>>> +		.arg3 = 0,
>>> +	};
>>>
>>>    	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out);
>>>    }
>>> @@ -656,6 +673,19 @@ static inline int awcc_op_activate_profile(struct wmi_device *wdev, u8 profile)
>>>    	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_CONTROL, &args, &out);
>>>    }
>>>
>>> +static int awcc_op_set_fan_boost(struct wmi_device *wdev, u8 fan_id, u8 boost)
>>> +{
>>> +	struct wmax_u32_args args = {
>>> +		.operation = AWCC_OP_SET_FAN_BOOST,
>>> +		.arg1 = fan_id,
>>> +		.arg2 = boost,
>>> +		.arg3 = 0,
>>> +	};
>>> +	u32 out;
>>> +
>>> +	return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_CONTROL, &args, &out);
>>> +}
>>> +
>>>    static int awcc_profile_id_to_pprof(u32 id, enum platform_profile_option *profile)
>>>    {
>>>    	switch (id) {
>>> @@ -717,6 +747,7 @@ 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);
>>> +	enum platform_profile_option profile;
>>>    	struct awcc_fan_data *fan;
>>>    	u32 state;
>>>    	int ret;
>>> @@ -765,6 +796,28 @@ static int awcc_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
>>>    		fan = priv->fan_data[channel];
>>>
>>>    		switch (attr) {
>>> +		case hwmon_pwm_enable:
>>> +			ret = awcc_op_get_current_profile(priv->wdev, &state);
>>> +			if (ret)
>>> +				return ret;
>>> +
>>> +			ret = awcc_profile_id_to_pprof(state, &profile);
>>> +			if (ret)
>>> +				return ret;
>>> +
>>> +			switch (profile) {
>>> +			case PLATFORM_PROFILE_PERFORMANCE:
>> The hwmon sysfs docs say that 0 means that the fan is spinning at maximum speed. Does PLATFORM_PROFILE_PERFORMANCE
>> guarantee that all fans are always spinning at maximum speed?
> Yes PERFORMANCE is full-speed for all devices I know. Manual fan control
> is completely disabled for that profile too.
>
> In fact I'm thinking about adding a module parameter to suppress this
> behavior. Not everyone may like that. That's outside the scope of these
> series tho.

I see no problem in exposing PLATFORM_PROFILE_PERFORMANCE as a normal platform profile,
if a user does not want to use it then they can simply not select it.

>> If no then i suggest to drop support for 0.
>>
>>> +				*val = 0;
>>> +				break;
>>> +			case PLATFORM_PROFILE_CUSTOM:
>>> +				*val = 1;
>>> +				break;
>>> +			default:
>>> +				*val = 2;
>>> +				break;
>>> +			}
>>> +
>>> +			break;
>>>    		case hwmon_pwm_auto_channels_temp:
>>>    			bitmap_copy(val, fan->auto_channels_temp, BITS_PER_LONG);
>>>    			break;
>>> @@ -840,10 +893,48 @@ static int awcc_hwmon_read_string(struct device *dev, enum hwmon_sensor_types ty
>>>    	return 0;
>>>    }
>>>
>>> +
>>> +static int awcc_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
>>> +			    u32 attr, int channel, long val)
>>> +{
>>> +	struct awcc_priv *priv = dev_get_drvdata(dev);
>>> +	int ret;
>>> +
>>> +	switch (type) {
>>> +	case hwmon_pwm:
>>> +		switch (attr) {
>>> +		case hwmon_pwm_enable:
>>> +			/*
>>> +			 * We don't want to duplicate platform profile logic, so
>>> +			 * we only allow enabling manual fan control
>>> +			 */
>> I do not think that having pwm1_enable brings any benefit, as the pwmX_boost attributes
>> behave differently than pwmX attributes. I think it would be enough to document that
>> pwmX_boost settings will only reliably work when the custom platform profile is selected.
> Now I realise I completely forgot about the admin-guide documentation!
> I'll include it in the next revision. Is this path ok?
>
> 	Documentation/admin-guide/laptops/alienware-wmi.rst
>
> Or should I add driver specific ABI documentation? (or both ofc)
>
> I don't want to name the file alienware-laptop because this driver is
> compatible with Dell G-Series too.

The name "alienware-wmi.rst" is OK. I suggest that you create driver specific ABI documentation for
the boost attributes and reference them inside the laptop documentation.

>>> +			if (val != 1)
>>> +				return -EINVAL;
>>> +
>>> +			ret = awcc_op_activate_profile(priv->wdev, AWCC_SPECIAL_PROFILE_CUSTOM);
>>> +			if (ret)
>>> +				return ret;
>>> +
>>> +			if (priv->ppdev)
>>> +				platform_profile_notify(priv->ppdev);
>>> +			break;
>>> +		default:
>>> +			return -EOPNOTSUPP;
>>> +		}
>>> +
>>> +		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,
>>> +	.write = awcc_hwmon_write,
>>>    };
>>>
>>>    static const struct hwmon_channel_info * const awcc_hwmon_info[] = {
>>> @@ -864,7 +955,7 @@ static const struct hwmon_channel_info * const awcc_hwmon_info[] = {
>>>    			   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_ENABLE,
>>>    			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>>>    			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>>>    			   HWMON_PWM_AUTO_CHANNELS_TEMP,
>>> @@ -879,6 +970,75 @@ static const struct hwmon_chip_info awcc_hwmon_chip_info = {
>>>    	.info = awcc_hwmon_info,
>>>    };
>>>
>>> +static ssize_t pwm_boost_show(struct device *dev, struct device_attribute *attr,
>>> +			      char *buf)
>>> +{
>>> +	int ret, index = to_sensor_dev_attr(attr)->index;
>> Please initialize "index" on a separate line, can remember the reverse xmas-tree order for variables.
> Ack.
>
>>> +	struct awcc_priv *priv = dev_get_drvdata(dev);
>>> +	struct awcc_fan_data *fan = priv->fan_data[index];
>>> +	u32 boost;
>>> +
>>> +	ret = awcc_op_get_fan_boost(priv->wdev, fan->id, &boost);
>>> +	if (ret)
>>> +		return ret;
>>> +
>>> +	return sysfs_emit(buf, "%u\n", boost);
>>> +}
>>> +
>>> +static ssize_t pwm_boost_store(struct device *dev, struct device_attribute *attr,
>>> +			       const char *buf, size_t count)
>>> +{
>>> +	int ret, index = to_sensor_dev_attr(attr)->index;
>>> +	struct awcc_priv *priv = dev_get_drvdata(dev);
>>> +	struct awcc_fan_data *fan = priv->fan_data[index];
>>> +	unsigned long val;
>>> +
>>> +	ret = kstrtoul(buf, 0, &val);
>>> +	if (ret)
>>> +		return ret;
>>> +
>>> +	ret = awcc_op_set_fan_boost(priv->wdev, fan->id, clamp_val(val, 0, 255));
>>> +
>>> +	return ret ? ret : count;
>>> +}
>>> +
>>> +static SENSOR_DEVICE_ATTR_RW(pwm1_boost, pwm_boost, 0);
>>> +static SENSOR_DEVICE_ATTR_RW(pwm2_boost, pwm_boost, 1);
>>> +static SENSOR_DEVICE_ATTR_RW(pwm3_boost, pwm_boost, 2);
>>> +static SENSOR_DEVICE_ATTR_RW(pwm4_boost, pwm_boost, 3);
>> Since those attributes are working differently than the standard pwm attributes, i suggest to
>> instead name them fanX_boost.
> I went for pwm*_boost because we also export pwm*_auto_channels_temp,
> but I'm ok with fan*_boost too.
>
Having pwmX_auto_channels_temp as the only pwm attribute is fine, the fsteutates driver does
something similar. Naming the attributes fanX_boost would better fir inside the fan-centric
hwmon API of this driver.

>>> +
>>> +static umode_t pwm_boost_attr_visible(struct kobject *kobj, struct attribute *attr, int n)
>>> +{
>>> +	struct awcc_priv *priv = dev_get_drvdata(kobj_to_dev(kobj));
>>> +
>>> +	return n < priv->fan_count ? attr->mode : 0;
>>> +}
>>> +
>>> +static bool pwm_boost_group_visible(struct kobject *kobj)
>>> +{
>>> +	return true;
>>> +}
>>> +
>>> +DEFINE_SYSFS_GROUP_VISIBLE(pwm_boost);
>>> +
>>> +static struct attribute *fan_boost_attrs[] = {
>>> +	&sensor_dev_attr_pwm1_boost.dev_attr.attr,
>>> +	&sensor_dev_attr_pwm2_boost.dev_attr.attr,
>>> +	&sensor_dev_attr_pwm3_boost.dev_attr.attr,
>>> +	&sensor_dev_attr_pwm4_boost.dev_attr.attr,
>>> +	NULL
>>> +};
>>> +
>>> +static const struct attribute_group pwm_boost_group = {
>>> +	.attrs = fan_boost_attrs,
>>> +	.is_visible = SYSFS_GROUP_VISIBLE(pwm_boost),
>>> +};
>>> +
>>> +static const struct attribute_group *awcc_hwmon_groups[] = {
>>> +	&pwm_boost_group,
>>> +	NULL
>>> +};
>>> +
>>>    static int awcc_hwmon_temps_init(struct wmi_device *wdev)
>>>    {
>>>    	struct awcc_priv *priv = dev_get_drvdata(&wdev->dev);
>>> @@ -1011,12 +1171,50 @@ static int awcc_hwmon_init(struct wmi_device *wdev)
>>>    	if (ret)
>>>    		return ret;
>>>
>>> -	priv->hwdev = devm_hwmon_device_register_with_info(&wdev->dev, "alienware_wmi", priv,
>>> -							   &awcc_hwmon_chip_info, NULL);
>>> +	priv->hwdev = devm_hwmon_device_register_with_info(&wdev->dev, "alienware_wmi",
>>> +							   priv, &awcc_hwmon_chip_info,
>>> +							   awcc_hwmon_groups);
>>>
>>>    	return PTR_ERR_OR_ZERO(priv->hwdev);
>>>    }
>>>
>>> +static void awcc_hwmon_suspend(struct device *dev)
>>> +{
>>> +	struct awcc_priv *priv = dev_get_drvdata(dev);
>>> +	struct awcc_fan_data *fan;
>>> +	unsigned int i;
>>> +	u32 boost;
>>> +	int ret;
>>> +
>>> +	for (i = 0; i < priv->fan_count; i++) {
>>> +		fan = priv->fan_data[i];
>>> +
>>> +		ret = awcc_thermal_information(priv->wdev, AWCC_OP_GET_FAN_BOOST,
>>> +					       fan->id, &boost);
>>> +		if (ret)
>>> +			fan->suspend_cache = 0;
>> Please at least log a warning here that the fan boost value can not be restored properly.
> Ack.
>
> Is not propagating errors a good approach here? My idea was to try to
> turn off fans no matter what.

In this case it should be OK, failing to restore the fan boost value is not critical.

>>> +		else
>>> +			fan->suspend_cache = clamp_val(boost, 0, 255);
>>> +
>>> +		awcc_op_set_fan_boost(priv->wdev, fan->id, 0);
>>> +	}
>>> +}
>>> +
>>> +static void awcc_hwmon_resume(struct device *dev)
>>> +{
>>> +
>>> +	struct awcc_priv *priv = dev_get_drvdata(dev);
>>> +	struct awcc_fan_data *fan;
>>> +	unsigned int i;
>>> +
>>> +	for (i = 0; i < priv->fan_count; i++) {
>>> +		fan = priv->fan_data[i];
>>> +
>>> +		if (fan->suspend_cache)
>> How does the driver restore fan boost settings with a value of 0?
> We set to 0 when suspending so I don't think it's necessary to restore
> to 0 again when resuming.
>
I understand, in this case everything should be fine.

Thanks,
Armin Wolf

>> Thanks,
>> Armin Wolf
>>
>>> +			awcc_op_set_fan_boost(priv->wdev, fan->id, fan->suspend_cache);
>>> +	}
>>> +}
>>> +
>>>    /*
>>>     * Thermal Profile control
>>>     *  - Provides thermal profile control through the Platform Profile API
>>> @@ -1233,6 +1431,24 @@ static int wmax_wmi_probe(struct wmi_device *wdev, const void *context)
>>>    	return ret;
>>>    }
>>>
>>> +static int wmax_wmi_suspend(struct device *dev)
>>> +{
>>> +	if (awcc->hwmon)
>>> +		awcc_hwmon_suspend(dev);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int wmax_wmi_resume(struct device *dev)
>>> +{
>>> +	if (awcc->hwmon)
>>> +		awcc_hwmon_resume(dev);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +DEFINE_SIMPLE_DEV_PM_OPS(wmax_wmi_pm_ops, wmax_wmi_suspend, wmax_wmi_resume);
>>> +
>>>    static const struct wmi_device_id alienware_wmax_device_id_table[] = {
>>>    	{ WMAX_CONTROL_GUID, NULL },
>>>    	{ },
>>> @@ -1243,6 +1459,7 @@ static struct wmi_driver alienware_wmax_wmi_driver = {
>>>    	.driver = {
>>>    		.name = "alienware-wmi-wmax",
>>>    		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
>>> +		.pm = pm_sleep_ptr(&wmax_wmi_pm_ops),
>>>    	},
>>>    	.id_table = alienware_wmax_device_id_table,
>>>    	.probe = wmax_wmi_probe,
>>>
>