1 files changed, 136 insertions, 101 deletions

diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
index a1ea5f6a8d3..d672bb4480f 100644
--- a/drivers/leds/leds-pwm.c
+++ b/drivers/leds/leds-pwm.c
@@ -14,7 +14,6 @@
 
 #include <linux/module.h>
 #include <linux/kernel.h>
-#include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/of_platform.h>
 #include <linux/fb.h>
@@ -23,12 +22,16 @@
 #include <linux/pwm.h>
 #include <linux/leds_pwm.h>
 #include <linux/slab.h>
+#include <linux/workqueue.h>
 
 struct led_pwm_data {
 	struct led_classdev	cdev;
 	struct pwm_device	*pwm;
+	struct work_struct	work;
 	unsigned int		active_low;
 	unsigned int		period;
+	int			duty;
+	bool			can_sleep;
 };
 
 struct led_pwm_priv {
@@ -36,21 +39,46 @@ struct led_pwm_priv {
 	struct led_pwm_data leds[0];
 };
 
+static void __led_pwm_set(struct led_pwm_data *led_dat)
+{
+	int new_duty = led_dat->duty;
+
+	pwm_config(led_dat->pwm, new_duty, led_dat->period);
+
+	if (new_duty == 0)
+		pwm_disable(led_dat->pwm);
+	else
+		pwm_enable(led_dat->pwm);
+}
+
+static void led_pwm_work(struct work_struct *work)
+{
+	struct led_pwm_data *led_dat =
+		container_of(work, struct led_pwm_data, work);
+
+	__led_pwm_set(led_dat);
+}
+
 static void led_pwm_set(struct led_classdev *led_cdev,
 	enum led_brightness brightness)
 {
 	struct led_pwm_data *led_dat =
 		container_of(led_cdev, struct led_pwm_data, cdev);
 	unsigned int max = led_dat->cdev.max_brightness;
-	unsigned int period =  led_dat->period;
+	unsigned long long duty =  led_dat->period;
 
-	if (brightness == 0) {
-		pwm_config(led_dat->pwm, 0, period);
-		pwm_disable(led_dat->pwm);
-	} else {
-		pwm_config(led_dat->pwm, brightness * period / max, period);
-		pwm_enable(led_dat->pwm);
-	}
+	duty *= brightness;
+	do_div(duty, max);
+
+	if (led_dat->active_low)
+		duty = led_dat->period - duty;
+
+	led_dat->duty = duty;
+
+	if (led_dat->can_sleep)
+		schedule_work(&led_dat->work);
+	else
+		__led_pwm_set(led_dat);
 }
 
 static inline size_t sizeof_pwm_leds_priv(int num_leds)
@@ -59,129 +87,136 @@ static inline size_t sizeof_pwm_leds_priv(int num_leds)
 		      (sizeof(struct led_pwm_data) * num_leds);
 }
 
-static struct led_pwm_priv *led_pwm_create_of(struct platform_device *pdev)
+static void led_pwm_cleanup(struct led_pwm_priv *priv)
 {
-	struct device_node *node = pdev->dev.of_node;
-	struct device_node *child;
-	struct led_pwm_priv *priv;
-	int count, ret;
+	while (priv->num_leds--) {
+		led_classdev_unregister(&priv->leds[priv->num_leds].cdev);
+		if (priv->leds[priv->num_leds].can_sleep)
+			cancel_work_sync(&priv->leds[priv->num_leds].work);
+	}
+}
 
-	/* count LEDs in this device, so we know how much to allocate */
-	count = of_get_child_count(node);
-	if (!count)
-		return NULL;
+static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
+		       struct led_pwm *led, struct device_node *child)
+{
+	struct led_pwm_data *led_data = &priv->leds[priv->num_leds];
+	int ret;
+
+	led_data->active_low = led->active_low;
+	led_data->cdev.name = led->name;
+	led_data->cdev.default_trigger = led->default_trigger;
+	led_data->cdev.brightness_set = led_pwm_set;
+	led_data->cdev.brightness = LED_OFF;
+	led_data->cdev.max_brightness = led->max_brightness;
+	led_data->cdev.flags = LED_CORE_SUSPENDRESUME;
+
+	if (child)
+		led_data->pwm = devm_of_pwm_get(dev, child, NULL);
+	else
+		led_data->pwm = devm_pwm_get(dev, led->name);
+	if (IS_ERR(led_data->pwm)) {
+		ret = PTR_ERR(led_data->pwm);
+		dev_err(dev, "unable to request PWM for %s: %d\n",
+			led->name, ret);
+		return ret;
+	}
 
-	priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count),
-			    GFP_KERNEL);
-	if (!priv)
-		return NULL;
+	if (child)
+		led_data->period = pwm_get_period(led_data->pwm);
 
-	for_each_child_of_node(node, child) {
-		struct led_pwm_data *led_dat = &priv->leds[priv->num_leds];
+	led_data->can_sleep = pwm_can_sleep(led_data->pwm);
+	if (led_data->can_sleep)
+		INIT_WORK(&led_data->work, led_pwm_work);
 
-		led_dat->cdev.name = of_get_property(child, "label",
-						     NULL) ? : child->name;
+	led_data->period = pwm_get_period(led_data->pwm);
+	if (!led_data->period && (led->pwm_period_ns > 0))
+		led_data->period = led->pwm_period_ns;
 
-		led_dat->pwm = devm_of_pwm_get(&pdev->dev, child, NULL);
-		if (IS_ERR(led_dat->pwm)) {
-			dev_err(&pdev->dev, "unable to request PWM for %s\n",
-				led_dat->cdev.name);
-			goto err;
-		}
-		/* Get the period from PWM core when n*/
-		led_dat->period = pwm_get_period(led_dat->pwm);
+	ret = led_classdev_register(dev, &led_data->cdev);
+	if (ret == 0) {
+		priv->num_leds++;
+	} else {
+		dev_err(dev, "failed to register PWM led for %s: %d\n",
+			led->name, ret);
+	}
 
-		led_dat->cdev.default_trigger = of_get_property(child,
+	return ret;
+}
+
+static int led_pwm_create_of(struct device *dev, struct led_pwm_priv *priv)
+{
+	struct device_node *child;
+	struct led_pwm led;
+	int ret = 0;
+
+	memset(&led, 0, sizeof(led));
+
+	for_each_child_of_node(dev->of_node, child) {
+		led.name = of_get_property(child, "label", NULL) ? :
+			   child->name;
+
+		led.default_trigger = of_get_property(child,
 						"linux,default-trigger", NULL);
+		led.active_low = of_property_read_bool(child, "active-low");
 		of_property_read_u32(child, "max-brightness",
-				     &led_dat->cdev.max_brightness);
+				     &led.max_brightness);
 
-		led_dat->cdev.brightness_set = led_pwm_set;
-		led_dat->cdev.brightness = LED_OFF;
-		led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
-
-		ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
-		if (ret < 0) {
-			dev_err(&pdev->dev, "failed to register for %s\n",
-				led_dat->cdev.name);
+		ret = led_pwm_add(dev, priv, &led, child);
+		if (ret) {
 			of_node_put(child);
-			goto err;
+			break;
 		}
-		priv->num_leds++;
 	}
 
-	return priv;
-err:
-	while (priv->num_leds--)
-		led_classdev_unregister(&priv->leds[priv->num_leds].cdev);
-
-	return NULL;
+	return ret;
 }
 
 static int led_pwm_probe(struct platform_device *pdev)
 {
-	struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
+	struct led_pwm_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct led_pwm_priv *priv;
-	int i, ret = 0;
-
-	if (pdata && pdata->num_leds) {
-		priv = devm_kzalloc(&pdev->dev,
-				    sizeof_pwm_leds_priv(pdata->num_leds),
-				    GFP_KERNEL);
-		if (!priv)
-			return -ENOMEM;
-
-		for (i = 0; i < pdata->num_leds; i++) {
-			struct led_pwm *cur_led = &pdata->leds[i];
-			struct led_pwm_data *led_dat = &priv->leds[i];
-
-			led_dat->pwm = devm_pwm_get(&pdev->dev, cur_led->name);
-			if (IS_ERR(led_dat->pwm)) {
-				ret = PTR_ERR(led_dat->pwm);
-				dev_err(&pdev->dev,
-					"unable to request PWM for %s\n",
-					cur_led->name);
-				goto err;
-			}
-
-			led_dat->cdev.name = cur_led->name;
-			led_dat->cdev.default_trigger = cur_led->default_trigger;
-			led_dat->active_low = cur_led->active_low;
-			led_dat->period = cur_led->pwm_period_ns;
-			led_dat->cdev.brightness_set = led_pwm_set;
-			led_dat->cdev.brightness = LED_OFF;
-			led_dat->cdev.max_brightness = cur_led->max_brightness;
-			led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
-
-			ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
-			if (ret < 0)
-				goto err;
+	int count, i;
+	int ret = 0;
+
+	if (pdata)
+		count = pdata->num_leds;
+	else
+		count = of_get_child_count(pdev->dev.of_node);
+
+	if (!count)
+		return -EINVAL;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count),
+			    GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	if (pdata) {
+		for (i = 0; i < count; i++) {
+			ret = led_pwm_add(&pdev->dev, priv, &pdata->leds[i],
+					  NULL);
+			if (ret)
+				break;
 		}
-		priv->num_leds = pdata->num_leds;
 	} else {
-		priv = led_pwm_create_of(pdev);
-		if (!priv)
-			return -ENODEV;
+		ret = led_pwm_create_of(&pdev->dev, priv);
+	}
+
+	if (ret) {
+		led_pwm_cleanup(priv);
+		return ret;
 	}
 
 	platform_set_drvdata(pdev, priv);
 
 	return 0;
-
-err:
-	while (i--)
-		led_classdev_unregister(&priv->leds[i].cdev);
-
-	return ret;
 }
 
 static int led_pwm_remove(struct platform_device *pdev)
 {
 	struct led_pwm_priv *priv = platform_get_drvdata(pdev);
-	int i;
 
-	for (i = 0; i < priv->num_leds; i++)
-		led_classdev_unregister(&priv->leds[i].cdev);
+	led_pwm_cleanup(priv);
 
 	return 0;
 }
@@ -198,7 +233,7 @@ static struct platform_driver led_pwm_driver = {
 	.driver		= {
 		.name	= "leds_pwm",
 		.owner	= THIS_MODULE,
-		.of_match_table = of_match_ptr(of_pwm_leds_match),
+		.of_match_table = of_pwm_leds_match,
 	},
 };