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 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 EC and
pwm_boost is a value between 0 and 255.
This pwm_boost knob is exposed as a standard `pwm` attribute.
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Kurt Borja <kuurtb@xxxxxxxxx>
---
.../platform/x86/dell/alienware-wmi-wmax.c | 55 +++++++++++++++++--
1 file changed, 49 insertions(+), 6 deletions(-)
diff --git a/drivers/platform/x86/dell/alienware-wmi-wmax.c b/drivers/platform/x86/dell/alienware-wmi-wmax.c
index 5f02da7ff25f..06d6f88ea54b 100644
--- a/drivers/platform/x86/dell/alienware-wmi-wmax.c
+++ b/drivers/platform/x86/dell/alienware-wmi-wmax.c
@@ -13,6 +13,7 @@
#include <linux/dmi.h>
#include <linux/hwmon.h>
#include <linux/jiffies.h>
+#include <linux/minmax.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <linux/overflow.h>
@@ -176,10 +177,12 @@ enum AWCC_THERMAL_INFORMATION_OPERATIONS {
AWCC_OP_GET_MIN_RPM = 0x08,
AWCC_OP_GET_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 {
@@ -563,12 +566,13 @@ static inline int awcc_thermal_information(struct wmi_device *wdev, u8 operation
return __awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out);
}
-static inline int awcc_thermal_control(struct wmi_device *wdev, u8 profile)
+static inline int awcc_thermal_control(struct wmi_device *wdev, u8 operation,
+ u8 arg1, u8 arg2)
{
struct wmax_u32_args args = {
- .operation = AWCC_OP_ACTIVATE_PROFILE,
- .arg1 = profile,
- .arg2 = 0,
+ .operation = operation,
+ .arg1 = arg1,
+ .arg2 = arg2,
.arg3 = 0,
};
u32 out;
@@ -684,6 +688,11 @@ static umode_t awcc_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_type
if (channel < priv->fan_count)
return 0444;
+ break;
+ case hwmon_pwm:
+ if (channel < priv->fan_count)
+ return 0644;
+
break;
default:
break;
@@ -698,6 +707,7 @@ static int awcc_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
struct awcc_priv *priv = dev_get_drvdata(dev);
struct awcc_temp_channel_data *temp;
struct awcc_fan_channel_data *fan;
+ u32 fan_boost;
int ret;
switch (type) {
@@ -742,6 +752,16 @@ static int awcc_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
return -EOPNOTSUPP;
}
+ break;
+ case hwmon_pwm:
+ fan = &priv->fan_data[channel];
+
+ ret = awcc_thermal_information(priv->wdev, AWCC_OP_GET_FAN_BOOST,
+ fan->id, &fan_boost);
+ if (ret)
+ return ret;
+
+ *val = fan_boost;
break;
default:
return -EOPNOTSUPP;
@@ -796,10 +816,27 @@ 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);
+ u8 fan_id = priv->fan_data[channel].id;
+
+ switch (type) {
+ case hwmon_pwm:
+ return awcc_thermal_control(priv->wdev, AWCC_OP_SET_FAN_BOOST,
+ fan_id, (u8)clamp_val(val, 0, 255));
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
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[] = {
@@ -814,6 +851,12 @@ static const struct hwmon_channel_info * const awcc_hwmon_info[] = {
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_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT
+ ),
NULL
};
@@ -954,8 +997,8 @@ static int awcc_platform_profile_set(struct device *dev,
}
}
- return awcc_thermal_control(priv->wdev,
- priv->supported_profiles[profile]);
+ return awcc_thermal_control(priv->wdev, AWCC_OP_ACTIVATE_PROFILE,
+ priv->supported_profiles[profile], 0);
}
static int awcc_platform_profile_probe(void *drvdata, unsigned long *choices)
--
2.48.1
