[linux-block.git] / drivers / leds / leds-pwm.c

/*
 * linux/drivers/leds-pwm.c
 *
 * simple PWM based LED control
 *
 * Copyright 2009 Luotao Fu @ Pengutronix (l.fu@pengutronix.de)
 *
 * based on leds-gpio.c by Raphael Assenat <raph@8d.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#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>
#include <linux/leds.h>
#include <linux/err.h>
#include <linux/pwm.h>
#include <linux/leds_pwm.h>
#include <linux/slab.h>

struct led_pwm_data {
	struct led_classdev	cdev;
	struct pwm_device	*pwm;
	unsigned int		active_low;
	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)
{
	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;

	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);
	}
}

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 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)
{
	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;
	}

	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);

	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),
	},
};

module_platform_driver(led_pwm_driver);

MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
MODULE_DESCRIPTION("PWM LED driver for PXA");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:leds-pwm");
Commit	Line	Data
41c42ff5 LF	1	/*
	2	* linux/drivers/leds-pwm.c
	3	*
	4	* simple PWM based LED control
	5	*
	6	* Copyright 2009 Luotao Fu @ Pengutronix (l.fu@pengutronix.de)
	7	*
	8	* based on leds-gpio.c by Raphael Assenat <raph@8d.com>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*/
	14
	15	#include <linux/module.h>
	16	#include <linux/kernel.h>
	17	#include <linux/init.h>
	18	#include <linux/platform_device.h>
08541cbc	19	#include <linux/of_platform.h>
41c42ff5 LF	20	#include <linux/fb.h>
	21	#include <linux/leds.h>
	22	#include <linux/err.h>
	23	#include <linux/pwm.h>
	24	#include <linux/leds_pwm.h>
5a0e3ad6	25	#include <linux/slab.h>
41c42ff5 LF	26
	27	struct led_pwm_data {
	28	struct led_classdev cdev;
	29	struct pwm_device *pwm;
dcba9105	30	unsigned int active_low;
41c42ff5	31	unsigned int period;
41c42ff5 LF	32	};
41c42ff5 LF	33
0f86815a PU	34	struct led_pwm_priv {
	35	int num_leds;
	36	struct led_pwm_data leds[0];
	37	};
	38
41c42ff5 LF	39	static void led_pwm_set(struct led_classdev *led_cdev,
	40	enum led_brightness brightness)
	41	{
	42	struct led_pwm_data *led_dat =
	43	container_of(led_cdev, struct led_pwm_data, cdev);
e4590620	44	unsigned int max = led_dat->cdev.max_brightness;
41c42ff5 LF	45	unsigned int period = led_dat->period;
	46
	47	if (brightness == 0) {
	48	pwm_config(led_dat->pwm, 0, period);
	49	pwm_disable(led_dat->pwm);
	50	} else {
	51	pwm_config(led_dat->pwm, brightness * period / max, period);
	52	pwm_enable(led_dat->pwm);
	53	}
	54	}
	55
0f86815a PU	56	static inline size_t sizeof_pwm_leds_priv(int num_leds)
	57	{
	58	return sizeof(struct led_pwm_priv) +
	59	(sizeof(struct led_pwm_data) * num_leds);
	60	}
	61
08541cbc	62	static struct led_pwm_priv led_pwm_create_of(struct platform_device pdev)
41c42ff5	63	{
08541cbc PU	64	struct device_node *node = pdev->dev.of_node;
08541cbc PU	65	struct device_node *child;
0f86815a	66	struct led_pwm_priv *priv;
08541cbc	67	int count, ret;
41c42ff5	68
08541cbc PU	69	/* count LEDs in this device, so we know how much to allocate */
	70	count = of_get_child_count(node);
	71	if (!count)
	72	return NULL;
41c42ff5	73
08541cbc	74	priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count),
0f86815a PU	75	GFP_KERNEL);
0f86815a PU	76	if (!priv)
08541cbc	77	return NULL;
41c42ff5	78
08541cbc PU	79	for_each_child_of_node(node, child) {
08541cbc PU	80	struct led_pwm_data *led_dat = &priv->leds[priv->num_leds];
41c42ff5	81
08541cbc PU	82	led_dat->cdev.name = of_get_property(child, "label",
	83	NULL) ? : child->name;
	84
	85	led_dat->pwm = devm_of_pwm_get(&pdev->dev, child, NULL);
41c42ff5	86	if (IS_ERR(led_dat->pwm)) {
9ea6cdac	87	dev_err(&pdev->dev, "unable to request PWM for %s\n",
08541cbc	88	led_dat->cdev.name);
41c42ff5 LF	89	goto err;
41c42ff5 LF	90	}
08541cbc PU	91	/* Get the period from PWM core when n*/
	92	led_dat->period = pwm_get_period(led_dat->pwm);
	93
	94	led_dat->cdev.default_trigger = of_get_property(child,
	95	"linux,default-trigger", NULL);
	96	of_property_read_u32(child, "max-brightness",
	97	&led_dat->cdev.max_brightness);
41c42ff5	98
41c42ff5 LF	99	led_dat->cdev.brightness_set = led_pwm_set;
	100	led_dat->cdev.brightness = LED_OFF;
	101	led_dat->cdev.flags \|= LED_CORE_SUSPENDRESUME;
	102
	103	ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
08541cbc PU	104	if (ret < 0) {
	105	dev_err(&pdev->dev, "failed to register for %s\n",
	106	led_dat->cdev.name);
	107	of_node_put(child);
41c42ff5	108	goto err;
08541cbc PU	109	}
	110	priv->num_leds++;
	111	}
	112
	113	return priv;
	114	err:
	115	while (priv->num_leds--)
	116	led_classdev_unregister(&priv->leds[priv->num_leds].cdev);
	117
	118	return NULL;
	119	}
	120
	121	static int led_pwm_probe(struct platform_device *pdev)
	122	{
	123	struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
	124	struct led_pwm_priv *priv;
	125	int i, ret = 0;
	126
	127	if (pdata && pdata->num_leds) {
	128	priv = devm_kzalloc(&pdev->dev,
	129	sizeof_pwm_leds_priv(pdata->num_leds),
	130	GFP_KERNEL);
	131	if (!priv)
	132	return -ENOMEM;
	133
	134	for (i = 0; i < pdata->num_leds; i++) {
	135	struct led_pwm *cur_led = &pdata->leds[i];
	136	struct led_pwm_data *led_dat = &priv->leds[i];
	137
	138	led_dat->pwm = devm_pwm_get(&pdev->dev, cur_led->name);
	139	if (IS_ERR(led_dat->pwm)) {
	140	ret = PTR_ERR(led_dat->pwm);
	141	dev_err(&pdev->dev,
	142	"unable to request PWM for %s\n",
	143	cur_led->name);
	144	goto err;
	145	}
	146
	147	led_dat->cdev.name = cur_led->name;
	148	led_dat->cdev.default_trigger = cur_led->default_trigger;
	149	led_dat->active_low = cur_led->active_low;
	150	led_dat->period = cur_led->pwm_period_ns;
	151	led_dat->cdev.brightness_set = led_pwm_set;
	152	led_dat->cdev.brightness = LED_OFF;
	153	led_dat->cdev.max_brightness = cur_led->max_brightness;
	154	led_dat->cdev.flags \|= LED_CORE_SUSPENDRESUME;
	155
	156	ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
	157	if (ret < 0)
	158	goto err;
	159	}
	160	priv->num_leds = pdata->num_leds;
	161	} else {
	162	priv = led_pwm_create_of(pdev);
	163	if (!priv)
	164	return -ENODEV;
41c42ff5 LF	165	}
41c42ff5 LF	166
0f86815a	167	platform_set_drvdata(pdev, priv);
41c42ff5 LF	168
	169	return 0;
	170
	171	err:
8a66a579 PU	172	while (i--)
8a66a579 PU	173	led_classdev_unregister(&priv->leds[i].cdev);
41c42ff5	174
41c42ff5 LF	175	return ret;
	176	}
	177
678e8a6b	178	static int led_pwm_remove(struct platform_device *pdev)
41c42ff5	179	{
0f86815a	180	struct led_pwm_priv *priv = platform_get_drvdata(pdev);
41c42ff5	181	int i;
41c42ff5	182
0f86815a PU	183	for (i = 0; i < priv->num_leds; i++)
0f86815a PU	184	led_classdev_unregister(&priv->leds[i].cdev);
41c42ff5	185
41c42ff5 LF	186	return 0;
	187	}
	188
08541cbc PU	189	static const struct of_device_id of_pwm_leds_match[] = {
	190	{ .compatible = "pwm-leds", },
	191	{},
	192	};
	193	MODULE_DEVICE_TABLE(of, of_pwm_leds_match);
	194
41c42ff5 LF	195	static struct platform_driver led_pwm_driver = {
41c42ff5 LF	196	.probe = led_pwm_probe,
df07cf81	197	.remove = led_pwm_remove,
41c42ff5 LF	198	.driver = {
	199	.name = "leds_pwm",
	200	.owner = THIS_MODULE,
08541cbc	201	.of_match_table = of_match_ptr(of_pwm_leds_match),
41c42ff5 LF	202	},
	203	};
	204
892a8843	205	module_platform_driver(led_pwm_driver);
41c42ff5 LF	206
	207	MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
	208	MODULE_DESCRIPTION("PWM LED driver for PXA");
	209	MODULE_LICENSE("GPL");
	210	MODULE_ALIAS("platform:leds-pwm");