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@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?
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
