1 files changed, 230 insertions, 0 deletions

diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c
index 9991c3fa020a..9eddc554ddef 100644
--- a/drivers/hwmon/cros_ec_hwmon.c
+++ b/drivers/hwmon/cros_ec_hwmon.c
@@ -7,6 +7,7 @@
 
 #include <linux/device.h>
 #include <linux/hwmon.h>
+#include <linux/math.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
@@ -17,10 +18,17 @@
 
 #define DRV_NAME	"cros-ec-hwmon"
 
+#define CROS_EC_HWMON_PWM_GET_FAN_DUTY_CMD_VERSION	0
+#define CROS_EC_HWMON_PWM_SET_FAN_DUTY_CMD_VERSION	1
+#define CROS_EC_HWMON_THERMAL_AUTO_FAN_CTRL_CMD_VERSION	2
+
 struct cros_ec_hwmon_priv {
 	struct cros_ec_device *cros_ec;
 	const char *temp_sensor_names[EC_TEMP_SENSOR_ENTRIES + EC_TEMP_SENSOR_B_ENTRIES];
 	u8 usable_fans;
+	bool fan_control_supported;
+	u8 manual_fans; /* bits to indicate whether the fan is set to manual */
+	u8 manual_fan_pwm[EC_FAN_SPEED_ENTRIES];
 };
 
 static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index, u16 *speed)
@@ -36,6 +44,42 @@ static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index
 	return 0;
 }
 
+static int cros_ec_hwmon_read_pwm_value(struct cros_ec_device *cros_ec, u8 index, u8 *pwm_value)
+{
+	struct ec_params_pwm_get_fan_duty req = {
+		.fan_idx = index,
+	};
+	struct ec_response_pwm_get_fan_duty resp;
+	int ret;
+
+	ret = cros_ec_cmd(cros_ec, CROS_EC_HWMON_PWM_GET_FAN_DUTY_CMD_VERSION,
+			  EC_CMD_PWM_GET_FAN_DUTY, &req, sizeof(req), &resp, sizeof(resp));
+	if (ret < 0)
+		return ret;
+
+	*pwm_value = (u8)DIV_ROUND_CLOSEST(le32_to_cpu(resp.percent) * 255, 100);
+	return 0;
+}
+
+static int cros_ec_hwmon_read_pwm_enable(struct cros_ec_device *cros_ec, u8 index,
+					 u8 *control_method)
+{
+	struct ec_params_auto_fan_ctrl_v2 req = {
+		.cmd = EC_AUTO_FAN_CONTROL_CMD_GET,
+		.fan_idx = index,
+	};
+	struct ec_response_auto_fan_control resp;
+	int ret;
+
+	ret = cros_ec_cmd(cros_ec, CROS_EC_HWMON_THERMAL_AUTO_FAN_CTRL_CMD_VERSION,
+			  EC_CMD_THERMAL_AUTO_FAN_CTRL, &req, sizeof(req), &resp, sizeof(resp));
+	if (ret < 0)
+		return ret;
+
+	*control_method = resp.is_auto ? 2 : 1;
+	return 0;
+}
+
 static int cros_ec_hwmon_read_temp(struct cros_ec_device *cros_ec, u8 index, u8 *temp)
 {
 	unsigned int offset;
@@ -75,6 +119,8 @@ 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;
+	u8 control_method;
+	u8 pwm_value;
 	u16 speed;
 	u8 temp;
 
@@ -92,6 +138,17 @@ static int cros_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
 			if (ret == 0)
 				*val = cros_ec_hwmon_is_error_fan(speed);
 		}
+	} else if (type == hwmon_pwm) {
+		if (attr == hwmon_pwm_enable) {
+			ret = cros_ec_hwmon_read_pwm_enable(priv->cros_ec, channel,
+							    &control_method);
+			if (ret == 0)
+				*val = control_method;
+		} else if (attr == hwmon_pwm_input) {
+			ret = cros_ec_hwmon_read_pwm_value(priv->cros_ec, channel, &pwm_value);
+			if (ret == 0)
+				*val = pwm_value;
+		}
 	} else if (type == hwmon_temp) {
 		if (attr == hwmon_temp_input) {
 			ret = cros_ec_hwmon_read_temp(priv->cros_ec, channel, &temp);
@@ -124,6 +181,74 @@ static int cros_ec_hwmon_read_string(struct device *dev, enum hwmon_sensor_types
 	return -EOPNOTSUPP;
 }
 
+static int cros_ec_hwmon_set_fan_pwm_val(struct cros_ec_device *cros_ec, u8 index, u8 val)
+{
+	struct ec_params_pwm_set_fan_duty_v1 req = {
+		.fan_idx = index,
+		.percent = DIV_ROUND_CLOSEST((uint32_t)val * 100, 255),
+	};
+	int ret;
+
+	ret = cros_ec_cmd(cros_ec, CROS_EC_HWMON_PWM_SET_FAN_DUTY_CMD_VERSION,
+			  EC_CMD_PWM_SET_FAN_DUTY, &req, sizeof(req), NULL, 0);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+static int cros_ec_hwmon_write_pwm_input(struct cros_ec_device *cros_ec, u8 index, u8 val)
+{
+	u8 control_method;
+	int ret;
+
+	ret = cros_ec_hwmon_read_pwm_enable(cros_ec, index, &control_method);
+	if (ret)
+		return ret;
+	if (control_method != 1)
+		return -EOPNOTSUPP;
+
+	return cros_ec_hwmon_set_fan_pwm_val(cros_ec, index, val);
+}
+
+static int cros_ec_hwmon_write_pwm_enable(struct cros_ec_device *cros_ec, u8 index, u8 val)
+{
+	struct ec_params_auto_fan_ctrl_v2 req = {
+		.fan_idx = index,
+		.cmd = EC_AUTO_FAN_CONTROL_CMD_SET,
+	};
+	int ret;
+
+	/* No CrOS EC supports no fan speed control */
+	if (val == 0)
+		return -EOPNOTSUPP;
+
+	req.set_auto = (val != 1) ? true : false;
+	ret = cros_ec_cmd(cros_ec, CROS_EC_HWMON_THERMAL_AUTO_FAN_CTRL_CMD_VERSION,
+			  EC_CMD_THERMAL_AUTO_FAN_CTRL, &req, sizeof(req), NULL, 0);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+static int cros_ec_hwmon_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+			       int channel, long val)
+{
+	struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev);
+
+	if (type == hwmon_pwm) {
+		switch (attr) {
+		case hwmon_pwm_input:
+			return cros_ec_hwmon_write_pwm_input(priv->cros_ec, channel, val);
+		case hwmon_pwm_enable:
+			return cros_ec_hwmon_write_pwm_enable(priv->cros_ec, channel, val);
+		default:
+			return -EOPNOTSUPP;
+		}
+	}
+
+	return -EOPNOTSUPP;
+}
+
 static umode_t cros_ec_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
 					u32 attr, int channel)
 {
@@ -132,6 +257,9 @@ static umode_t cros_ec_hwmon_is_visible(const void *data, enum hwmon_sensor_type
 	if (type == hwmon_fan) {
 		if (priv->usable_fans & BIT(channel))
 			return 0444;
+	} else if (type == hwmon_pwm) {
+		if (priv->fan_control_supported && priv->usable_fans & BIT(channel))
+			return 0644;
 	} else if (type == hwmon_temp) {
 		if (priv->temp_sensor_names[channel])
 			return 0444;
@@ -147,6 +275,11 @@ static const struct hwmon_channel_info * const cros_ec_hwmon_info[] = {
 			   HWMON_F_INPUT | HWMON_F_FAULT,
 			   HWMON_F_INPUT | HWMON_F_FAULT,
 			   HWMON_F_INPUT | HWMON_F_FAULT),
+	HWMON_CHANNEL_INFO(pwm,
+			   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(temp,
 			   HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,
 			   HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,
@@ -178,6 +311,7 @@ static const struct hwmon_channel_info * const cros_ec_hwmon_info[] = {
 static const struct hwmon_ops cros_ec_hwmon_ops = {
 	.read = cros_ec_hwmon_read,
 	.read_string = cros_ec_hwmon_read_string,
+	.write = cros_ec_hwmon_write,
 	.is_visible = cros_ec_hwmon_is_visible,
 };
 
@@ -233,6 +367,25 @@ static void cros_ec_hwmon_probe_fans(struct cros_ec_hwmon_priv *priv)
 	}
 }
 
+static inline bool is_cros_ec_cmd_available(struct cros_ec_device *cros_ec,
+					    u16 cmd, u8 version)
+{
+	int ret;
+
+	ret = cros_ec_get_cmd_versions(cros_ec, cmd);
+	return ret >= 0 && (ret & EC_VER_MASK(version));
+}
+
+static bool cros_ec_hwmon_probe_fan_control_supported(struct cros_ec_device *cros_ec)
+{
+	return is_cros_ec_cmd_available(cros_ec, EC_CMD_PWM_GET_FAN_DUTY,
+					CROS_EC_HWMON_PWM_GET_FAN_DUTY_CMD_VERSION) &&
+	       is_cros_ec_cmd_available(cros_ec, EC_CMD_PWM_SET_FAN_DUTY,
+					CROS_EC_HWMON_PWM_SET_FAN_DUTY_CMD_VERSION) &&
+	       is_cros_ec_cmd_available(cros_ec, EC_CMD_THERMAL_AUTO_FAN_CTRL,
+					CROS_EC_HWMON_THERMAL_AUTO_FAN_CTRL_CMD_VERSION);
+}
+
 static int cros_ec_hwmon_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -259,13 +412,88 @@ static int cros_ec_hwmon_probe(struct platform_device *pdev)
 
 	cros_ec_hwmon_probe_temp_sensors(dev, priv, thermal_version);
 	cros_ec_hwmon_probe_fans(priv);
+	priv->fan_control_supported = cros_ec_hwmon_probe_fan_control_supported(priv->cros_ec);
 
 	hwmon_dev = devm_hwmon_device_register_with_info(dev, "cros_ec", priv,
 							 &cros_ec_hwmon_chip_info, NULL);
+	platform_set_drvdata(pdev, priv);
 
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }
 
+static int cros_ec_hwmon_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct cros_ec_hwmon_priv *priv = platform_get_drvdata(pdev);
+	u8 control_method;
+	size_t i;
+	int ret;
+
+	if (!priv->fan_control_supported)
+		return 0;
+
+	/* EC sets fan control to auto after suspended, store settings before suspending. */
+	for (i = 0; i < EC_FAN_SPEED_ENTRIES; i++) {
+		if (!(priv->usable_fans & BIT(i)))
+			continue;
+
+		ret = cros_ec_hwmon_read_pwm_enable(priv->cros_ec, i, &control_method);
+		if (ret) {
+			dev_warn(&pdev->dev, "failed to get mode setting for fan %zu: %d\n", i,
+				 ret);
+			continue;
+		}
+
+		if (control_method != 1) {
+			priv->manual_fans &= ~BIT(i);
+			continue;
+		} else {
+			priv->manual_fans |= BIT(i);
+		}
+
+		ret = cros_ec_hwmon_read_pwm_value(priv->cros_ec, i, &priv->manual_fan_pwm[i]);
+		/*
+		 * If storing the value failed, invalidate the stored mode value by setting it
+		 * to auto control. EC will automatically switch to auto mode for that fan after
+		 * suspended.
+		 */
+		if (ret) {
+			dev_warn(&pdev->dev, "failed to get PWM setting for fan %zu: %pe\n", i,
+				 ERR_PTR(ret));
+			priv->manual_fans &= ~BIT(i);
+			continue;
+		}
+	}
+
+	return 0;
+}
+
+static int cros_ec_hwmon_resume(struct platform_device *pdev)
+{
+	const struct cros_ec_hwmon_priv *priv = platform_get_drvdata(pdev);
+	size_t i;
+	int ret;
+
+	if (!priv->fan_control_supported)
+		return 0;
+
+	/* EC sets fan control to auto after suspend, restore to settings before suspend. */
+	for (i = 0; i < EC_FAN_SPEED_ENTRIES; i++) {
+		if (!(priv->manual_fans & BIT(i)))
+			continue;
+
+		/*
+		 * Setting fan PWM value to EC will change the mode to manual for that fan in EC as
+		 * well, so we do not need to issue a separate fan mode to manual call.
+		 */
+		ret = cros_ec_hwmon_set_fan_pwm_val(priv->cros_ec, i, priv->manual_fan_pwm[i]);
+		if (ret)
+			dev_warn(&pdev->dev, "failed to restore settings for fan %zu: %pe\n", i,
+				 ERR_PTR(ret));
+	}
+
+	return 0;
+}
+
 static const struct platform_device_id cros_ec_hwmon_id[] = {
 	{ DRV_NAME, 0 },
 	{}
@@ -274,6 +502,8 @@ static const struct platform_device_id cros_ec_hwmon_id[] = {
 static struct platform_driver cros_ec_hwmon_driver = {
 	.driver.name	= DRV_NAME,
 	.probe		= cros_ec_hwmon_probe,
+	.suspend	= pm_ptr(cros_ec_hwmon_suspend),
+	.resume		= pm_ptr(cros_ec_hwmon_resume),
 	.id_table	= cros_ec_hwmon_id,
 };
 module_platform_driver(cros_ec_hwmon_driver);