[linux-2.6-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>
#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 {
	int num_leds;
	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;

	led_dat->duty = brightness * period / max;

	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)
{
	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;

		led_dat->can_sleep = pwm_can_sleep(led_dat->pwm);
		if (led_dat->can_sleep)
			INIT_WORK(&led_dat->work, led_pwm_work);

		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 = 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;

			led_dat->can_sleep = pwm_can_sleep(led_dat->pwm);
			if (led_dat->can_sleep)
				INIT_WORK(&led_dat->work, led_pwm_work);

			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);
		if (priv->leds[i].can_sleep)
			cancel_work_sync(&priv->leds[i].work);
	}

	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>
c971ff18	26	#include <linux/workqueue.h>
41c42ff5 LF	27
	28	struct led_pwm_data {
	29	struct led_classdev cdev;
	30	struct pwm_device *pwm;
c971ff18	31	struct work_struct work;
dcba9105	32	unsigned int active_low;
41c42ff5	33	unsigned int period;
c971ff18 FV	34	int duty;
c971ff18 FV	35	bool can_sleep;
41c42ff5 LF	36	};
41c42ff5 LF	37
0f86815a PU	38	struct led_pwm_priv {
	39	int num_leds;
	40	struct led_pwm_data leds[0];
	41	};
	42
c971ff18 FV	43	static void __led_pwm_set(struct led_pwm_data *led_dat)
	44	{
	45	int new_duty = led_dat->duty;
	46
	47	pwm_config(led_dat->pwm, new_duty, led_dat->period);
	48
	49	if (new_duty == 0)
	50	pwm_disable(led_dat->pwm);
	51	else
	52	pwm_enable(led_dat->pwm);
	53	}
	54
	55	static void led_pwm_work(struct work_struct *work)
	56	{
	57	struct led_pwm_data *led_dat =
	58	container_of(work, struct led_pwm_data, work);
	59
	60	__led_pwm_set(led_dat);
	61	}
	62
41c42ff5 LF	63	static void led_pwm_set(struct led_classdev *led_cdev,
	64	enum led_brightness brightness)
	65	{
	66	struct led_pwm_data *led_dat =
	67	container_of(led_cdev, struct led_pwm_data, cdev);
e4590620	68	unsigned int max = led_dat->cdev.max_brightness;
41c42ff5 LF	69	unsigned int period = led_dat->period;
41c42ff5 LF	70
c971ff18 FV	71	led_dat->duty = brightness * period / max;
	72
	73	if (led_dat->can_sleep)
	74	schedule_work(&led_dat->work);
	75	else
	76	__led_pwm_set(led_dat);
41c42ff5 LF	77	}
41c42ff5 LF	78
0f86815a PU	79	static inline size_t sizeof_pwm_leds_priv(int num_leds)
	80	{
	81	return sizeof(struct led_pwm_priv) +
	82	(sizeof(struct led_pwm_data) * num_leds);
	83	}
	84
08541cbc	85	static struct led_pwm_priv led_pwm_create_of(struct platform_device pdev)
41c42ff5	86	{
08541cbc PU	87	struct device_node *node = pdev->dev.of_node;
08541cbc PU	88	struct device_node *child;
0f86815a	89	struct led_pwm_priv *priv;
08541cbc	90	int count, ret;
41c42ff5	91
08541cbc PU	92	/* count LEDs in this device, so we know how much to allocate */
	93	count = of_get_child_count(node);
	94	if (!count)
	95	return NULL;
41c42ff5	96
08541cbc	97	priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count),
0f86815a PU	98	GFP_KERNEL);
0f86815a PU	99	if (!priv)
08541cbc	100	return NULL;
41c42ff5	101
08541cbc PU	102	for_each_child_of_node(node, child) {
08541cbc PU	103	struct led_pwm_data *led_dat = &priv->leds[priv->num_leds];
41c42ff5	104
08541cbc PU	105	led_dat->cdev.name = of_get_property(child, "label",
	106	NULL) ? : child->name;
	107
	108	led_dat->pwm = devm_of_pwm_get(&pdev->dev, child, NULL);
41c42ff5	109	if (IS_ERR(led_dat->pwm)) {
9ea6cdac	110	dev_err(&pdev->dev, "unable to request PWM for %s\n",
08541cbc	111	led_dat->cdev.name);
41c42ff5 LF	112	goto err;
41c42ff5 LF	113	}
08541cbc PU	114	/* Get the period from PWM core when n*/
	115	led_dat->period = pwm_get_period(led_dat->pwm);
	116
	117	led_dat->cdev.default_trigger = of_get_property(child,
	118	"linux,default-trigger", NULL);
	119	of_property_read_u32(child, "max-brightness",
	120	&led_dat->cdev.max_brightness);
41c42ff5	121
41c42ff5 LF	122	led_dat->cdev.brightness_set = led_pwm_set;
	123	led_dat->cdev.brightness = LED_OFF;
	124	led_dat->cdev.flags \|= LED_CORE_SUSPENDRESUME;
	125
c971ff18 FV	126	led_dat->can_sleep = pwm_can_sleep(led_dat->pwm);
	127	if (led_dat->can_sleep)
	128	INIT_WORK(&led_dat->work, led_pwm_work);
	129
41c42ff5	130	ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
08541cbc PU	131	if (ret < 0) {
	132	dev_err(&pdev->dev, "failed to register for %s\n",
	133	led_dat->cdev.name);
	134	of_node_put(child);
41c42ff5	135	goto err;
08541cbc PU	136	}
	137	priv->num_leds++;
	138	}
	139
	140	return priv;
	141	err:
	142	while (priv->num_leds--)
	143	led_classdev_unregister(&priv->leds[priv->num_leds].cdev);
	144
	145	return NULL;
	146	}
	147
	148	static int led_pwm_probe(struct platform_device *pdev)
	149	{
87aae1ea	150	struct led_pwm_platform_data *pdata = dev_get_platdata(&pdev->dev);
08541cbc PU	151	struct led_pwm_priv *priv;
	152	int i, ret = 0;
	153
	154	if (pdata && pdata->num_leds) {
	155	priv = devm_kzalloc(&pdev->dev,
	156	sizeof_pwm_leds_priv(pdata->num_leds),
	157	GFP_KERNEL);
	158	if (!priv)
	159	return -ENOMEM;
	160
	161	for (i = 0; i < pdata->num_leds; i++) {
	162	struct led_pwm *cur_led = &pdata->leds[i];
	163	struct led_pwm_data *led_dat = &priv->leds[i];
	164
	165	led_dat->pwm = devm_pwm_get(&pdev->dev, cur_led->name);
	166	if (IS_ERR(led_dat->pwm)) {
	167	ret = PTR_ERR(led_dat->pwm);
	168	dev_err(&pdev->dev,
	169	"unable to request PWM for %s\n",
	170	cur_led->name);
	171	goto err;
	172	}
	173
	174	led_dat->cdev.name = cur_led->name;
	175	led_dat->cdev.default_trigger = cur_led->default_trigger;
	176	led_dat->active_low = cur_led->active_low;
	177	led_dat->period = cur_led->pwm_period_ns;
	178	led_dat->cdev.brightness_set = led_pwm_set;
	179	led_dat->cdev.brightness = LED_OFF;
	180	led_dat->cdev.max_brightness = cur_led->max_brightness;
	181	led_dat->cdev.flags \|= LED_CORE_SUSPENDRESUME;
	182
c971ff18 FV	183	led_dat->can_sleep = pwm_can_sleep(led_dat->pwm);
	184	if (led_dat->can_sleep)
	185	INIT_WORK(&led_dat->work, led_pwm_work);
	186
08541cbc PU	187	ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
	188	if (ret < 0)
	189	goto err;
	190	}
	191	priv->num_leds = pdata->num_leds;
	192	} else {
	193	priv = led_pwm_create_of(pdev);
	194	if (!priv)
	195	return -ENODEV;
41c42ff5 LF	196	}
41c42ff5 LF	197
0f86815a	198	platform_set_drvdata(pdev, priv);
41c42ff5 LF	199
	200	return 0;
	201
	202	err:
8a66a579 PU	203	while (i--)
8a66a579 PU	204	led_classdev_unregister(&priv->leds[i].cdev);
41c42ff5	205
41c42ff5 LF	206	return ret;
	207	}
	208
678e8a6b	209	static int led_pwm_remove(struct platform_device *pdev)
41c42ff5	210	{
0f86815a	211	struct led_pwm_priv *priv = platform_get_drvdata(pdev);
41c42ff5	212	int i;
41c42ff5	213
c971ff18	214	for (i = 0; i < priv->num_leds; i++) {
0f86815a	215	led_classdev_unregister(&priv->leds[i].cdev);
c971ff18 FV	216	if (priv->leds[i].can_sleep)
	217	cancel_work_sync(&priv->leds[i].work);
	218	}
41c42ff5	219
41c42ff5 LF	220	return 0;
	221	}
	222
08541cbc PU	223	static const struct of_device_id of_pwm_leds_match[] = {
	224	{ .compatible = "pwm-leds", },
	225	{},
	226	};
	227	MODULE_DEVICE_TABLE(of, of_pwm_leds_match);
	228
41c42ff5 LF	229	static struct platform_driver led_pwm_driver = {
41c42ff5 LF	230	.probe = led_pwm_probe,
df07cf81	231	.remove = led_pwm_remove,
41c42ff5 LF	232	.driver = {
	233	.name = "leds_pwm",
	234	.owner = THIS_MODULE,
08541cbc	235	.of_match_table = of_match_ptr(of_pwm_leds_match),
41c42ff5 LF	236	},
	237	};
	238
892a8843	239	module_platform_driver(led_pwm_driver);
41c42ff5 LF	240
	241	MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
	242	MODULE_DESCRIPTION("PWM LED driver for PXA");
	243	MODULE_LICENSE("GPL");
	244	MODULE_ALIAS("platform:leds-pwm");