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

Kurt Borja
2025-03-12T05:06:05Z

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

Right! They are string literals.

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

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

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

Thank you very much for reviewing the whole series!

--
~ Kurt