Re: [PATCH v2 07/10] platform/x86: alienware-wmi-wmax: Add HWMON support

Kurt Borja
2025-03-04T16:27:44Z

On Tue Mar 4, 2025 at 10:53 AM -05, Ilpo Järvinen wrote:
> On Tue, 25 Feb 2025, Kurt Borja wrote:
>
>> All models with the "AWCC" WMAX device support monitoring fan speed and
>> temperature sensors. Expose this feature through the HWMON interface.
>>
>> Sensor readings are cached for 1 second before refreshing them to
>> mitigate the performance cost of calling WMI methods.
>>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
>> ---
>> drivers/platform/x86/dell/Kconfig | 1 +
>> .../platform/x86/dell/alienware-wmi-wmax.c | 403 ++++++++++++++++++
>> 2 files changed, 404 insertions(+)
>>
>> diff --git a/drivers/platform/x86/dell/Kconfig b/drivers/platform/x86/dell/Kconfig
>> index f8a0dffcaab7..85a57c01aaad 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 bbe87f91fcb6..818023a5b205 100644
>> --- a/drivers/platform/x86/dell/alienware-wmi-wmax.c
>> +++ b/drivers/platform/x86/dell/alienware-wmi-wmax.c
>> @@ -9,10 +9,13 @@
>> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>>
>> #include <linux/bitfield.h>
>> +#include <linux/bitmap.h>
>> #include <linux/bits.h>
>> #include <linux/dmi.h>
>> +#include <linux/hwmon.h>
>> #include <linux/moduleparam.h>
>> #include <linux/platform_profile.h>
>> +#include <linux/units.h>
>> #include <linux/wmi.h>
>> #include "alienware-wmi.h"
>>
>> @@ -25,6 +28,7 @@
>> #define WMAX_METHOD_BRIGHTNESS 0x3
>> #define WMAX_METHOD_ZONE_CONTROL 0x4
>>
>> +#define AWCC_METHOD_GET_FAN_SENSORS 0x13
>> #define AWCC_METHOD_THERMAL_INFORMATION 0x14
>> #define AWCC_METHOD_THERMAL_CONTROL 0x15
>> #define AWCC_METHOD_GAME_SHIFT_STATUS 0x25
>> @@ -38,6 +42,10 @@
>> /* 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");
>> @@ -47,16 +55,19 @@ 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,
>> };
>> @@ -154,9 +165,18 @@ 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,
>> };
>>
>> @@ -179,6 +199,12 @@ 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,
>> @@ -215,6 +241,15 @@ struct wmax_u32_args {
>> u8 arg3;
>> } __packed;
>>
>> +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 {
>> @@ -230,6 +265,11 @@ 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] = {
>> @@ -494,6 +534,19 @@ static int __awcc_wmi_command(struct wmi_device *wdev, u32 method_id,
>> return 0;
>> }
>>
>> +static inline int awcc_get_fan_sensors(struct wmi_device *wdev, u8 operation,
>> + u8 fan_id, u8 index, u32 *out)
>> +{
>> + struct wmax_u32_args args = {
>> + .operation = operation,
>> + .arg1 = fan_id,
>> + .arg2 = index,
>> + .arg3 = 0,
>> + };
>> +
>> + return __awcc_wmi_command(wdev, AWCC_METHOD_GET_FAN_SENSORS, &args, out);
>> +}
>> +
>> static inline int awcc_thermal_information(struct wmi_device *wdev, u8 operation,
>> u8 arg, u32 *out)
>> {
>> @@ -564,6 +617,343 @@ 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);
>> }
>>
>> +/*
>> + * 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;
>> +
>> + switch (type) {
>> + case hwmon_temp:
>> + if (channel < priv->temp_count)
>> + return 0444;
>> +
>> + break;
>
> IMO, these could be written as:
> return channel < priv->temp_count ? 0444 : 0;

Ack.

>
>> + case hwmon_fan:
>> + if (channel < priv->fan_count)
>> + return 0444;
>> +
>> + break;
>> + case hwmon_pwm:
>> + if (channel < priv->fan_count)
>> + return 0444;
>> +
>> + break;
>> + default:
>> + break;
>> + }
>> +
>> + 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, U8_MAX, channel);
>> + if (temp >= U8_MAX)
>
> It cannot be larger than as its type is u8??

Thanks, I forgot to change this! U8_MAX should be replaced with
priv->temp_sensors_size.

Thank you for reviewing this set! :)

--
~ Kurt

>
>> + return -ENXIO;
>> +
>> + switch (attr) {
>> + case hwmon_temp_input:
>> + ret = awcc_thermal_information(priv->wdev, AWCC_OP_GET_TEMPERATURE,
>> + 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_thermal_information(priv->wdev, AWCC_OP_GET_FAN_RPM,
>> + 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];
>> +
>> + bitmap_copy(val, fan->auto_channels_temp, BITS_PER_LONG);
>> + 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, U8_MAX, channel);
>> + if (temp >= U8_MAX)
>> + return -ENXIO;
>> +
>> + 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, U8_MAX);
>> +
>> + 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;
>> +
>> + ret = __test_and_set_bit(id, temp_sensors);
>> + if (ret)
>> + dev_warn(&wdev->dev, "Sensor ID at index %u is duplicated\n", i);
>> + }
>> +
>> + /*
>> + * 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, total_fan_temps, 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, &total_fan_temps);
>> + if (ret)
>> + return ret;
>> +
>> + for (j = 0; j < total_fan_temps; 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 = total_fan_temps;
>> + 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
>> @@ -735,6 +1125,12 @@ 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)
>> @@ -815,6 +1211,13 @@ 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;
>>