hwmon: (aquacomputer_d5next) Add fan PWM control for Aquaero

Add the option to control fan PWM on Aquacomputer Aquaero. The Aquaero is
the most complex Aquacomputer device, control is therefore more complicated
then on already supported devices.
Setting PWM requires multiple steps. First, an internal static PWM
controller is set to the desired PWM value. Second, the fan is set to use
that PWM controller. Last, the minimum and maximum accepted PWM values
of the fan are set to allow all possible PWM values.

Signed-off-by: Leonard Anderweit <leonard.anderweit@gmail.com>
Link: https://lore.kernel.org/r/20230214220221.15003-7-leonard.anderweit@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/aquacomputer_d5next.rst

@@ -25,7 +25,8 @@ communicate through proprietary USB HID protocols.
 
 The Aquaero devices expose eight physical, eight virtual and four calculated
 virtual temperature sensors, as well as two flow sensors. The fans expose their
-speed (in RPM), power, voltage and current. Temperature offsets can be controlled.
+speed (in RPM), power, voltage and current. Temperature offsets and fan speeds
+can be controlled.
 
 For the D5 Next pump, available sensors are pump and fan speed, power, voltage
 and current, as well as coolant temperature and eight virtual temp sensors. Also

drivers/hwmon/aquacomputer_d5next.c

@@ -104,6 +104,9 @@ static u8 aquaero_secondary_ctrl_report[] = {
 #define AQUAERO_NUM_CALC_VIRTUAL_SENSORS	4
 #define AQUAERO_NUM_FLOW_SENSORS		2
 #define AQUAERO_CTRL_REPORT_SIZE		0xa93
+#define AQUAERO_CTRL_PRESET_ID			0x5c
+#define AQUAERO_CTRL_PRESET_SIZE		0x02
+#define AQUAERO_CTRL_PRESET_START		0x55c
 
 /* Sensor report offsets for Aquaero fan controllers */
 #define AQUAERO_SENSOR_START			0x65
@@ -118,6 +121,10 @@ static u16 aquaero_sensor_fan_offsets[] = { 0x167, 0x173, 0x17f, 0x18B };
 
 /* Control report offsets for the Aquaero fan controllers */
 #define AQUAERO_TEMP_CTRL_OFFSET	0xdb
+#define AQUAERO_FAN_CTRL_MIN_PWR_OFFSET	0x04
+#define AQUAERO_FAN_CTRL_MAX_PWR_OFFSET	0x06
+#define AQUAERO_FAN_CTRL_SRC_OFFSET	0x10
+static u16 aquaero_ctrl_fan_offsets[] = { 0x20c, 0x220, 0x234, 0x248 };
 
 /* Specs of the D5 Next pump */
 #define D5NEXT_NUM_FANS			2
@@ -857,13 +864,23 @@ static int aqc_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 		*val = priv->power_input[channel];
 		break;
 	case hwmon_pwm:
-		if (priv->fan_ctrl_offsets) {
+		switch (priv->kind) {
+		case aquaero:
+			ret = aqc_get_ctrl_val(priv,
+				AQUAERO_CTRL_PRESET_START + channel * AQUAERO_CTRL_PRESET_SIZE,
+				val, AQC_BE16);
+			if (ret < 0)
+				return ret;
+			*val = aqc_percent_to_pwm(*val);
+			break;
+		default:
 			ret = aqc_get_ctrl_val(priv, priv->fan_ctrl_offsets[channel],
 					       val, AQC_BE16);
 			if (ret < 0)
 				return ret;
 
 			*val = aqc_percent_to_pwm(ret);
+			break;
 		}
 		break;
 	case hwmon_in:
@@ -922,6 +939,10 @@ static int aqc_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 		     long val)
 {
 	int ret, pwm_value;
+	/* Arrays for setting multiple values at once in the control report */
+	int ctrl_values_offsets[4];
+	long ctrl_values[4];
+	int ctrl_values_types[4];
 	struct aqc_data *priv = dev_get_drvdata(dev);
 
 	switch (type) {
@@ -956,15 +977,47 @@ static int aqc_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 	case hwmon_pwm:
 		switch (attr) {
 		case hwmon_pwm_input:
-			if (priv->fan_ctrl_offsets) {
-				pwm_value = aqc_pwm_to_percent(val);
-				if (pwm_value < 0)
-					return pwm_value;
+			pwm_value = aqc_pwm_to_percent(val);
+			if (pwm_value < 0)
+				return pwm_value;
 
+			switch (priv->kind) {
+			case aquaero:
+				/* Write pwm value to preset corresponding to the channel */
+				ctrl_values_offsets[0] = AQUAERO_CTRL_PRESET_START +
+				    channel * AQUAERO_CTRL_PRESET_SIZE;
+				ctrl_values[0] = pwm_value;
+				ctrl_values_types[0] = AQC_BE16;
+
+				/* Write preset number in fan control source */
+				ctrl_values_offsets[1] = priv->fan_ctrl_offsets[channel] +
+				    AQUAERO_FAN_CTRL_SRC_OFFSET;
+				ctrl_values[1] = AQUAERO_CTRL_PRESET_ID + channel;
+				ctrl_values_types[1] = AQC_BE16;
+
+				/* Set minimum power to 0 to allow the fan to turn off */
+				ctrl_values_offsets[2] = priv->fan_ctrl_offsets[channel] +
+				    AQUAERO_FAN_CTRL_MIN_PWR_OFFSET;
+				ctrl_values[2] = 0;
+				ctrl_values_types[2] = AQC_BE16;
+
+				/* Set maximum power to 255 to allow the fan to reach max speed */
+				ctrl_values_offsets[3] = priv->fan_ctrl_offsets[channel] +
+				    AQUAERO_FAN_CTRL_MAX_PWR_OFFSET;
+				ctrl_values[3] = aqc_pwm_to_percent(255);
+				ctrl_values_types[3] = AQC_BE16;
+
+				ret = aqc_set_ctrl_vals(priv, ctrl_values_offsets, ctrl_values,
+							ctrl_values_types, 4);
+				if (ret < 0)
+					return ret;
+				break;
+			default:
 				ret = aqc_set_ctrl_val(priv, priv->fan_ctrl_offsets[channel],
 						       pwm_value, AQC_BE16);
 				if (ret < 0)
 					return ret;
+				break;
 			}
 			break;
 		default:
@@ -1287,6 +1340,7 @@ static int aqc_probe(struct hid_device *hdev, const struct hid_device_id *id)
 
 		priv->num_fans = AQUAERO_NUM_FANS;
 		priv->fan_sensor_offsets = aquaero_sensor_fan_offsets;
+		priv->fan_ctrl_offsets = aquaero_ctrl_fan_offsets;
 
 		priv->num_temp_sensors = AQUAERO_NUM_SENSORS;
 		priv->temp_sensor_start_offset = AQUAERO_SENSOR_START;