leds: leds-pwm: Add device tree bindings (08541cbc) · Commits · e / devices / android_kernel_fairphone_FP3

Documentation/devicetree/bindings/leds/leds-pwm.txt

0 → 100644

+48 −0

Original line number	Original line	Diff line number	Diff line
			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>;
			};
			};

drivers/leds/leds-pwm.c

+92 −20

Original line number	Original line	Diff line number	Diff line
	@@ -16,6 +16,7 @@
	#include <linux/kernel.h>		#include <linux/kernel.h>
	#include <linux/init.h>		#include <linux/init.h>
	#include <linux/platform_device.h>		#include <linux/platform_device.h>
			#include <linux/of_platform.h>
	#include <linux/fb.h>		#include <linux/fb.h>
	#include <linux/leds.h>		#include <linux/leds.h>
	#include <linux/err.h>		#include <linux/err.h>
	@@ -58,16 +59,74 @@ static inline size_t sizeof_pwm_leds_priv(int num_leds)
	(sizeof(struct led_pwm_data) * num_leds);		(sizeof(struct led_pwm_data) * num_leds);
	}		}

			static struct led_pwm_priv led_pwm_create_of(struct platform_device pdev)
			{
			struct device_node *node = pdev->dev.of_node;
			struct device_node *child;
			struct led_pwm_priv *priv;
			int count, ret;

			/* 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(count),
			GFP_KERNEL);
			if (!priv)
			return NULL;

			for_each_child_of_node(node, child) {
			struct led_pwm_data *led_dat = &priv->leds[priv->num_leds];

			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)) {
			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);

			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.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);
			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)		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 = pdev->dev.platform_data;
	struct led_pwm_priv *priv;		struct led_pwm_priv *priv;
	int i, ret = 0;		int i, ret = 0;

	if (!pdata)		if (pdata && pdata->num_leds) {
	return -EBUSY;		priv = devm_kzalloc(&pdev->dev,
			sizeof_pwm_leds_priv(pdata->num_leds),
	priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(pdata->num_leds),
	GFP_KERNEL);		GFP_KERNEL);
	if (!priv)		if (!priv)
	return -ENOMEM;		return -ENOMEM;
	@@ -79,7 +138,8 @@ static int led_pwm_probe(struct platform_device *pdev)
	led_dat->pwm = devm_pwm_get(&pdev->dev, cur_led->name);		led_dat->pwm = devm_pwm_get(&pdev->dev, cur_led->name);
	if (IS_ERR(led_dat->pwm)) {		if (IS_ERR(led_dat->pwm)) {
	ret = PTR_ERR(led_dat->pwm);		ret = PTR_ERR(led_dat->pwm);
	dev_err(&pdev->dev, "unable to request PWM for %s\n",		dev_err(&pdev->dev,
			"unable to request PWM for %s\n",
	cur_led->name);		cur_led->name);
	goto err;		goto err;
	}		}
	@@ -98,6 +158,11 @@ static int led_pwm_probe(struct platform_device *pdev)
	goto err;		goto err;
	}		}
	priv->num_leds = pdata->num_leds;		priv->num_leds = pdata->num_leds;
			} else {
			priv = led_pwm_create_of(pdev);
			if (!priv)
			return -ENODEV;
			}

	platform_set_drvdata(pdev, priv);		platform_set_drvdata(pdev, priv);

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