[PATCH v5 0/7] leds: leds-pwm: Device tree support

@@ -30,6 +30,11 @@ struct led_pwm_data {
 	unsigned int		period;
 };
 
+struct led_pwm_priv {
+	int num_leds;
+	struct led_pwm_data leds[0];
+};
+
 static void led_pwm_set(struct led_classdev *led_cdev,
 	enum led_brightness brightness)
 {

@@ -47,25 +52,29 @@ static void led_pwm_set(struct led_classdev *led_cdev,
 	}
 }
 
+static inline size_t sizeof_pwm_leds_priv(int num_leds)
+{
+	return sizeof(struct led_pwm_priv) +
+		      (sizeof(struct led_pwm_data) * num_leds);
+}
+
 static int led_pwm_probe(struct platform_device *pdev)
 {
 	struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
-	struct led_pwm *cur_led;
-	struct led_pwm_data *leds_data, *led_dat;
+	struct led_pwm_priv *priv;
 	int i, ret = 0;
 
 	if (!pdata)
 		return -EBUSY;
 
-	leds_data = devm_kzalloc(&pdev->dev,
-			sizeof(struct led_pwm_data) * pdata->num_leds,
-				GFP_KERNEL);
-	if (!leds_data)
+	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++) {
-		cur_led = &pdata->leds[i];
-		led_dat = &leds_data[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)) {

@@ -88,15 +97,16 @@ static int led_pwm_probe(struct platform_device *pdev)
 		if (ret < 0)
 			goto err;
 	}
+	priv->num_leds = pdata->num_leds;
 
-	platform_set_drvdata(pdev, leds_data);
+	platform_set_drvdata(pdev, priv);
 
 	return 0;
 
 err:
 	if (i > 0) {
 		for (i = i - 1; i >= 0; i--)
-			led_classdev_unregister(&leds_data[i].cdev);
+			led_classdev_unregister(&priv->leds[i].cdev);
 	}
 
 	return ret;

@@ -104,14 +114,11 @@ err:
 
 static int led_pwm_remove(struct platform_device *pdev)
 {
+	struct led_pwm_priv *priv = platform_get_drvdata(pdev);
 	int i;
-	struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
-	struct led_pwm_data *leds_data;
-
-	leds_data = platform_get_drvdata(pdev);
 
-	for (i = 0; i < pdata->num_leds; i++)
-		led_classdev_unregister(&leds_data[i].cdev);
+	for (i = 0; i < priv->num_leds; i++)
+		led_classdev_unregister(&priv->leds[i].cdev);
 
 	return 0;
 }

@@ -67,12 +67,11 @@ static int led_pwm_probe(struct platform_device *pdev)
 		cur_led = &pdata->leds[i];
 		led_dat = &leds_data[i];
 
-		led_dat->pwm = pwm_request(cur_led->pwm_id,
-				cur_led->name);
+		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 %d\n",
-					cur_led->pwm_id);
+			dev_err(&pdev->dev, "unable to request PWM for %s\n",
+				cur_led->name);
 			goto err;
 		}
 

@@ -86,10 +85,8 @@ static int led_pwm_probe(struct platform_device *pdev)
 		led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 
 		ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
-		if (ret < 0) {
-			pwm_free(led_dat->pwm);
+		if (ret < 0)
 			goto err;
-		}
 	}
 
 	platform_set_drvdata(pdev, leds_data);

@@ -98,10 +95,8 @@ static int led_pwm_probe(struct platform_device *pdev)
 
 err:
 	if (i > 0) {
-		for (i = i - 1; i >= 0; i--) {
+		for (i = i - 1; i >= 0; i--)
 			led_classdev_unregister(&leds_data[i].cdev);
-			pwm_free(leds_data[i].pwm);
-		}
 	}
 
 	return ret;

@@ -115,10 +110,8 @@ static int led_pwm_remove(struct platform_device *pdev)
 
 	leds_data = platform_get_drvdata(pdev);
 
-	for (i = 0; i < pdata->num_leds; i++) {
+	for (i = 0; i < pdata->num_leds; i++)
 		led_classdev_unregister(&leds_data[i].cdev);
-		pwm_free(leds_data[i].pwm);
-	}
 
 	return 0;
 }

@@ -7,7 +7,7 @@
 struct led_pwm {
 	const char	*name;
 	const char	*default_trigger;
-	unsigned	pwm_id;
+	unsigned	pwm_id __deprecated;
 	u8 		active_low;
 	unsigned 	max_brightness;
 	unsigned	pwm_period_ns;

@@ -174,10 +174,10 @@ struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
 struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc,
 		const struct of_phandle_args *args);
 
-struct pwm_device *pwm_get(struct device *dev, const char *consumer);
+struct pwm_device *pwm_get(struct device *dev, const char *con_id);
 void pwm_put(struct pwm_device *pwm);
 
-struct pwm_device *devm_pwm_get(struct device *dev, const char *consumer);
+struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id);
 void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
 #else
 static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)

@@ -471,7 +471,7 @@ static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
 }
 
 /**
- * of_pwm_request() - request a PWM via the PWM framework
+ * of_pwm_get() - request a PWM via the PWM framework
  * @np: device node to get the PWM from
  * @con_id: consumer name
  *

@@ -486,8 +486,7 @@ static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
  * becomes mandatory for devices that look up the PWM device via the con_id
  * parameter.
  */
-static struct pwm_device *of_pwm_request(struct device_node *np,
-					 const char *con_id)
+struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
 {
 	struct pwm_device *pwm = NULL;
 	struct of_phandle_args args;

@@ -545,6 +544,7 @@ put:
 
 	return pwm;
 }
+EXPORT_SYMBOL_GPL(of_pwm_get);
 
 /**
  * pwm_add_table() - register PWM device consumers

@@ -587,7 +587,7 @@ struct pwm_device *pwm_get(struct device *dev, const char *con_id)
 
 	/* look up via DT first */
 	if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
-		return of_pwm_request(dev->of_node, con_id);
+		return of_pwm_get(dev->of_node, con_id);
 
 	/*
 	 * We look up the provider in the static table typically provided by

@@ -175,6 +175,7 @@ struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc,
 		const struct of_phandle_args *args);
 
 struct pwm_device *pwm_get(struct device *dev, const char *con_id);
+struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id);
 void pwm_put(struct pwm_device *pwm);
 
 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id);

@@ -213,6 +214,12 @@ static inline struct pwm_device *pwm_get(struct device *dev,
 	return ERR_PTR(-ENODEV);
 }
 
+static inline struct pwm_device *of_pwm_get(struct device_node *np,
+					    const char *con_id)
+{
+	return ERR_PTR(-ENODEV);
+}
+
 static inline void pwm_put(struct pwm_device *pwm)
 {
 }

@@ -708,6 +708,36 @@ struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
 }
 EXPORT_SYMBOL_GPL(devm_pwm_get);
 
+/**
+ * devm_of_pwm_get() - resource managed of_pwm_get()
+ * @dev: device for PWM consumer
+ * @np: device node to get the PWM from
+ * @con_id: consumer name
+ *
+ * This function performs like of_pwm_get() but the acquired PWM device will
+ * automatically be released on driver detach.
+ */
+struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
+				   const char *con_id)
+{
+	struct pwm_device **ptr, *pwm;
+
+	ptr = devres_alloc(devm_pwm_release, sizeof(**ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	pwm = of_pwm_get(np, con_id);
+	if (!IS_ERR(pwm)) {
+		*ptr = pwm;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return pwm;
+}
+EXPORT_SYMBOL_GPL(devm_of_pwm_get);
+
 static int devm_pwm_match(struct device *dev, void *res, void *data)
 {
 	struct pwm_device **p = res;

@@ -179,6 +179,8 @@ struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id);
 void pwm_put(struct pwm_device *pwm);
 
 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id);
+struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
+				   const char *con_id);
 void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
 #else
 static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)

@@ -230,6 +232,13 @@ static inline struct pwm_device *devm_pwm_get(struct device *dev,
 	return ERR_PTR(-ENODEV);
 }
 
+static inline struct pwm_device *devm_of_pwm_get(struct device *dev,
+						 struct device_node *np,
+						 const char *con_id)
+{
+	return ERR_PTR(-ENODEV);
+}
+
 static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
 {
 }

@@ -104,10 +104,8 @@ static int led_pwm_probe(struct platform_device *pdev)
 	return 0;
 
 err:
-	if (i > 0) {
-		for (i = i - 1; i >= 0; i--)
-			led_classdev_unregister(&priv->leds[i].cdev);
-	}
+	while (i--)
+		led_classdev_unregister(&priv->leds[i].cdev);
 
 	return ret;
 }

@@ -0,0 +1,48 @@
+LED connected to PWM
+
+Required properties:
+- compatible : should be "pwm-leds".
+
+Each LED is represented as a sub-node of the pwm-leds device.  Each
+node's name represents the name of the corresponding LED.
+
+LED sub-node properties:
+- pwms : PWM property to point to the PWM device (phandle)/port (id) and to
+  specify the period time to be used: <&phandle id period_ns>;
+- pwm-names : (optional) Name to be used by the PWM subsystem for the PWM device
+  For the pwms and pwm-names property please refer to:
+  Documentation/devicetree/bindings/pwm/pwm.txt
+- max-brightness : Maximum brightness possible for the LED
+- label :  (optional)
+  see Documentation/devicetree/bindings/leds/common.txt
+- linux,default-trigger :  (optional)
+  see Documentation/devicetree/bindings/leds/common.txt
+
+Example:
+
+twl_pwm: pwm {
+	/* provides two PWMs (id 0, 1 for PWM1 and PWM2) */
+	compatible = "ti,twl6030-pwm";
+	#pwm-cells = <2>;
+};
+
+twl_pwmled: pwmled {
+	/* provides one PWM (id 0 for Charing indicator LED) */
+	compatible = "ti,twl6030-pwmled";
+	#pwm-cells = <2>;
+};
+
+pwmleds {
+	compatible = "pwm-leds";
+	kpad {
+		label = "omap4::keypad";
+		pwms = <&twl_pwm 0 7812500>;
+		max-brightness = <127>;
+	};
+
+	charging {
+		label = "omap4:green:chrg";
+		pwms = <&twl_pwmled 0 7812500>;
+		max-brightness = <255>;
+	};
+};

@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
+#include <linux/of_platform.h>
 #include <linux/fb.h>
 #include <linux/leds.h>
 #include <linux/err.h>

@@ -58,46 +59,110 @@ static inline size_t sizeof_pwm_leds_priv(int num_leds)
 		      (sizeof(struct led_pwm_data) * num_leds);
 }
 
-static int led_pwm_probe(struct platform_device *pdev)
+static struct led_pwm_priv *led_pwm_create_of(struct platform_device *pdev)
 {
-	struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
+	struct device_node *node = pdev->dev.of_node;
+	struct device_node *child;
 	struct led_pwm_priv *priv;
-	int i, ret = 0;
+	int count, ret;
 
-	if (!pdata)
-		return -EBUSY;
+	/* count LEDs in this device, so we know how much to allocate */
+	count = of_get_child_count(node);
+	if (!count)
+		return NULL;
 
-	priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(pdata->num_leds),
+	priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count),
 			    GFP_KERNEL);
 	if (!priv)
-		return -ENOMEM;
+		return NULL;
 
-	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];
+	for_each_child_of_node(node, child) {
+		struct led_pwm_data *led_dat = &priv->leds[priv->num_leds];
 
-		led_dat->pwm = devm_pwm_get(&pdev->dev, cur_led->name);
+		led_dat->cdev.name = of_get_property(child, "label",
+						     NULL) ? : child->name;
+
+		led_dat->pwm = devm_of_pwm_get(&pdev->dev, child, NULL);
 		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);
+				led_dat->cdev.name);
 			goto err;
 		}
+		/* Get the period from PWM core when n*/
+		led_dat->period = pwm_get_period(led_dat->pwm);
+
+		led_dat->cdev.default_trigger = of_get_property(child,
+						"linux,default-trigger", NULL);
+		of_property_read_u32(child, "max-brightness",
+				     &led_dat->cdev.max_brightness);
 
-		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)
+		if (ret < 0) {
+			dev_err(&pdev->dev, "failed to register for %s\n",
+				led_dat->cdev.name);
+			of_node_put(child);
 			goto err;
+		}
+		priv->num_leds++;
+	}
+
+	return priv;
+err:
+	while (priv->num_leds--)
+		led_classdev_unregister(&priv->leds[priv->num_leds].cdev);
+
+	return NULL;
+}
+
+static int led_pwm_probe(struct platform_device *pdev)
+{
+	struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
+	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;
+		}
+		priv->num_leds = pdata->num_leds;
+	} else {
+		priv = led_pwm_create_of(pdev);
+		if (!priv)
+			return -ENODEV;
 	}
-	priv->num_leds = pdata->num_leds;
 
 	platform_set_drvdata(pdev, priv);
 

@@ -121,12 +186,19 @@ static int led_pwm_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct of_device_id of_pwm_leds_match[] = {
+	{ .compatible = "pwm-leds", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_pwm_leds_match);
+
 static struct platform_driver led_pwm_driver = {
 	.probe		= led_pwm_probe,
 	.remove		= led_pwm_remove,
 	.driver		= {
 		.name	= "leds_pwm",
 		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(of_pwm_leds_match),
 	},
 };