Re: [PATCH v3 08/10] platform/x86: alienware-wmi-wmax: Add support for manual fan control
From: Armin Wolf
Date: Thu Mar 06 2025 - 17:36:18 EST
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@xxxxxxxxxxxx>
Cc: Jean Delvare <jdelvare@xxxxxxxx>
Cc: linux-hwmon@xxxxxxxxxxxxxxx
Signed-off-by: Kurt Borja <kuurtb@xxxxxxxxx>
---
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,