Kernel patch to support (rudimentary) fan control in the FTS Teutates kernel driver

ftsteutates-support-pwm.patch

diff --git a/drivers/hwmon/ftsteutates.c b/drivers/hwmon/ftsteutates.c
index a3a0766..49a7cd5 100644
--- a/drivers/hwmon/ftsteutates.c
+++ b/drivers/hwmon/ftsteutates.c
@@ -79,6 +79,7 @@ struct fts_data {
 	u8 fan_present;
 	u8 fan_input[FTS_NO_FAN_SENSORS]; /* in rps */
 	u8 fan_source[FTS_NO_FAN_SENSORS];
+	u8 pwm_input[FTS_NO_FAN_SENSORS];
 	u8 fan_alarm;
 };
 
@@ -86,6 +87,8 @@ struct fts_data {
 #define FTS_REG_FAN_SOURCE(idx) ((idx) + 0x30)
 #define FTS_REG_FAN_CONTROL(idx) (((idx) << 16) + 0x4881)
 
+#define FTS_REG_FAN_PWM(idx) (((idx) << 8) + 0x4886)
+
 #define FTS_REG_TEMP_INPUT(idx) ((idx) + 0x40)
 #define FTS_REG_TEMP_CONTROL(idx) (((idx) << 16) + 0x0681)
 
@@ -184,9 +187,15 @@ static int fts_update_device(struct fts_data *data)
 			if (err < 0)
 				goto exit;
 			data->fan_source[i] = err;
+
+			err = fts_read_byte(data->client, FTS_REG_FAN_PWM(i));
+			if (err < 0)
+				goto exit;
+			data->pwm_input[i] = err;
 		} else {
 			data->fan_input[i] = 0;
 			data->fan_source[i] = FTS_FAN_SOURCE_INVALID;
+			data->pwm_input[i] = 0;
 		}
 	}
 
@@ -365,6 +374,14 @@ static umode_t fts_is_visible(const void *devdata, enum hwmon_sensor_types type,
 		}
 		break;
 	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_enable:
+		case hwmon_pwm_input:
+			return 0644;
+		default:
+			break;
+		}
+		break;
 	case hwmon_in:
 		return 0444;
 	default:
@@ -423,6 +440,12 @@ static int fts_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 		break;
 	case hwmon_pwm:
 		switch (attr) {
+		case hwmon_pwm_input:
+			*val = data->pwm_input[channel];
+			return 0;
+		case hwmon_pwm_enable:
+			*val = 1;
+			return 0;
 		case hwmon_pwm_auto_channels_temp:
 			if (data->fan_source[channel] == FTS_FAN_SOURCE_INVALID)
 				*val = 0;
@@ -484,6 +507,29 @@ static int fts_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 			break;
 		}
 		break;
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			if (val < 0 || val > 255)
+				return -EINVAL;
+
+			mutex_lock(&data->update_lock);
+			ret = fts_write_byte(data->client, FTS_REG_FAN_PWM(channel), val);
+			if (ret >= 0)
+				data->valid = false;
+
+			mutex_unlock(&data->update_lock);
+
+			if (ret < 0)
+				return ret;
+
+			return 0;
+		case hwmon_pwm_enable:
+			return 0;
+		default:
+			break;
+		}
+		break;
 	case hwmon_fan:
 		switch (attr) {
 		case hwmon_fan_alarm:
@@ -551,14 +597,14 @@ static const struct hwmon_channel_info * const fts_info[] = {
 			   HWMON_F_INPUT | HWMON_F_ALARM | HWMON_F_FAULT
 			   ),
 	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,
-			   HWMON_PWM_AUTO_CHANNELS_TEMP,
-			   HWMON_PWM_AUTO_CHANNELS_TEMP
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE
 			   ),
 	HWMON_CHANNEL_INFO(in,
 			   HWMON_I_INPUT,