[PATCH 2/3] hwmon: (cros_ec) Add reading target fan RPM function

[Sung-Chi Li <lschyi@xxxxxxxxxxxx>]

Implement the functionality of reading the target fan RPM setting from
ChromeOS embedded controller under framework.

Signed-off-by: Sung-Chi Li <lschyi@xxxxxxxxxxxx>
---
 drivers/hwmon/cros_ec_hwmon.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c
index b2fec0768301f116f49c57b8dbfb042b98a573e1..73bfcbbaf9531be6b753cfef8045fd5dab5b2ab3 100644
--- a/drivers/hwmon/cros_ec_hwmon.c
+++ b/drivers/hwmon/cros_ec_hwmon.c
@@ -36,6 +36,19 @@ static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index
 	return 0;
 }
 
+static int cros_ec_hwmon_read_fan_target(struct cros_ec_device *cros_ec, u8 index, int32_t *speed)
+{
+	int ret;
+	struct ec_response_pwm_get_fan_rpm r;
+
+	ret = cros_ec_cmd(cros_ec, 0, EC_CMD_PWM_GET_FAN_TARGET_RPM, NULL, 0, &r, sizeof(r));
+	if (ret < 0)
+		return ret;
+
+	*speed = le32_to_cpu(r.rpm);
+	return 0;
+}
+
 static int cros_ec_hwmon_read_temp(struct cros_ec_device *cros_ec, u8 index, u8 *temp)
 {
 	unsigned int offset;
@@ -95,6 +108,7 @@ static int cros_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
 {
 	struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev);
 	int ret = -EOPNOTSUPP;
+	int32_t target_rpm;
 	u16 speed;
 	u8 temp;
 
@@ -111,6 +125,10 @@ static int cros_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
 			ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, channel, &speed);
 			if (ret == 0)
 				*val = cros_ec_hwmon_is_error_fan(speed);
+		} else if (attr == hwmon_fan_target) {
+			ret = cros_ec_hwmon_read_fan_target(priv->cros_ec, channel, &target_rpm);
+			if (ret == 0)
+				*val = target_rpm;
 		}
 	} else if (type == hwmon_temp) {
 		if (attr == hwmon_temp_input) {

-- 
2.49.0.rc0.332.g42c0ae87b1-goog