1 files changed, 163 insertions, 21 deletions

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 1991d9032c38..2d9a712699ff 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -24,55 +24,78 @@
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/sysfs.h>
+#include <linux/thermal.h>
 
 #define MAX_PWM 255
 
 struct pwm_fan_ctx {
 	struct mutex lock;
 	struct pwm_device *pwm;
-	unsigned char pwm_value;
+	unsigned int pwm_value;
+	unsigned int pwm_fan_state;
+	unsigned int pwm_fan_max_state;
+	unsigned int *pwm_fan_cooling_levels;
+	struct thermal_cooling_device *cdev;
 };
 
-static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
-		       const char *buf, size_t count)
+static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
 {
-	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
-	unsigned long pwm, duty;
-	ssize_t ret;
-
-	if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM)
-		return -EINVAL;
+	unsigned long duty;
+	int ret = 0;
 
 	mutex_lock(&ctx->lock);
-
 	if (ctx->pwm_value == pwm)
-		goto exit_set_pwm_no_change;
-
-	if (pwm == 0) {
-		pwm_disable(ctx->pwm);
-		goto exit_set_pwm;
-	}
+		goto exit_set_pwm_err;
 
 	duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM);
 	ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
 	if (ret)
 		goto exit_set_pwm_err;
 
+	if (pwm == 0)
+		pwm_disable(ctx->pwm);
+
 	if (ctx->pwm_value == 0) {
 		ret = pwm_enable(ctx->pwm);
 		if (ret)
 			goto exit_set_pwm_err;
 	}
 
-exit_set_pwm:
 	ctx->pwm_value = pwm;
-exit_set_pwm_no_change:
-	ret = count;
 exit_set_pwm_err:
 	mutex_unlock(&ctx->lock);
 	return ret;
 }
 
+static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
+{
+	int i;
+
+	for (i = 0; i < ctx->pwm_fan_max_state; ++i)
+		if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
+			break;
+
+	ctx->pwm_fan_state = i;
+}
+
+static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
+		       const char *buf, size_t count)
+{
+	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
+	unsigned long pwm;
+	int ret;
+
+	if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM)
+		return -EINVAL;
+
+	ret = __set_pwm(ctx, pwm);
+	if (ret)
+		return ret;
+
+	pwm_fan_update_state(ctx, pwm);
+	return count;
+}
+
 static ssize_t show_pwm(struct device *dev,
 			struct device_attribute *attr, char *buf)
 {
@@ -91,10 +114,108 @@ static struct attribute *pwm_fan_attrs[] = {
 
 ATTRIBUTE_GROUPS(pwm_fan);
 
+/* thermal cooling device callbacks */
+static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
+				 unsigned long *state)
+{
+	struct pwm_fan_ctx *ctx = cdev->devdata;
+
+	if (!ctx)
+		return -EINVAL;
+
+	*state = ctx->pwm_fan_max_state;
+
+	return 0;
+}
+
+static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
+				 unsigned long *state)
+{
+	struct pwm_fan_ctx *ctx = cdev->devdata;
+
+	if (!ctx)
+		return -EINVAL;
+
+	*state = ctx->pwm_fan_state;
+
+	return 0;
+}
+
+static int
+pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
+{
+	struct pwm_fan_ctx *ctx = cdev->devdata;
+	int ret;
+
+	if (!ctx || (state > ctx->pwm_fan_max_state))
+		return -EINVAL;
+
+	if (state == ctx->pwm_fan_state)
+		return 0;
+
+	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
+	if (ret) {
+		dev_err(&cdev->device, "Cannot set pwm!\n");
+		return ret;
+	}
+
+	ctx->pwm_fan_state = state;
+
+	return ret;
+}
+
+static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
+	.get_max_state = pwm_fan_get_max_state,
+	.get_cur_state = pwm_fan_get_cur_state,
+	.set_cur_state = pwm_fan_set_cur_state,
+};
+
+static int pwm_fan_of_get_cooling_data(struct device *dev,
+				       struct pwm_fan_ctx *ctx)
+{
+	struct device_node *np = dev->of_node;
+	int num, i, ret;
+
+	if (!of_find_property(np, "cooling-levels", NULL))
+		return 0;
+
+	ret = of_property_count_u32_elems(np, "cooling-levels");
+	if (ret <= 0) {
+		dev_err(dev, "Wrong data!\n");
+		return ret ? : -EINVAL;
+	}
+
+	num = ret;
+	ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32),
+						   GFP_KERNEL);
+	if (!ctx->pwm_fan_cooling_levels)
+		return -ENOMEM;
+
+	ret = of_property_read_u32_array(np, "cooling-levels",
+					 ctx->pwm_fan_cooling_levels, num);
+	if (ret) {
+		dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
+		return ret;
+	}
+
+	for (i = 0; i < num; i++) {
+		if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
+			dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
+				ctx->pwm_fan_cooling_levels[i], MAX_PWM);
+			return -EINVAL;
+		}
+	}
+
+	ctx->pwm_fan_max_state = num - 1;
+
+	return 0;
+}
+
 static int pwm_fan_probe(struct platform_device *pdev)
 {
-	struct device *hwmon;
+	struct thermal_cooling_device *cdev;
 	struct pwm_fan_ctx *ctx;
+	struct device *hwmon;
 	int duty_cycle;
 	int ret;
 
@@ -136,6 +257,26 @@ static int pwm_fan_probe(struct platform_device *pdev)
 		pwm_disable(ctx->pwm);
 		return PTR_ERR(hwmon);
 	}
+
+	ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx);
+	if (ret)
+		return ret;
+
+	ctx->pwm_fan_state = ctx->pwm_fan_max_state;
+	if (IS_ENABLED(CONFIG_THERMAL)) {
+		cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
+							  "pwm-fan", ctx,
+							  &pwm_fan_cooling_ops);
+		if (IS_ERR(cdev)) {
+			dev_err(&pdev->dev,
+				"Failed to register pwm-fan as cooling device");
+			pwm_disable(ctx->pwm);
+			return PTR_ERR(cdev);
+		}
+		ctx->cdev = cdev;
+		thermal_cdev_update(cdev);
+	}
+
 	return 0;
 }
 
@@ -143,6 +284,7 @@ static int pwm_fan_remove(struct platform_device *pdev)
 {
 	struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
 
+	thermal_cooling_device_unregister(ctx->cdev);
 	if (ctx->pwm_value)
 		pwm_disable(ctx->pwm);
 	return 0;
@@ -177,7 +319,7 @@ static int pwm_fan_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
 
-static struct of_device_id of_pwm_fan_match[] = {
+static const struct of_device_id of_pwm_fan_match[] = {
 	{ .compatible = "pwm-fan", },
 	{},
 };