[linux.git] / drivers / leds / leds-dac124s085.c

/*
 * Copyright 2008
 * Guennadi Liakhovetski, DENX Software Engineering, <[email protected]>
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * LED driver for the DAC124S085 SPI DAC
 */

#include <linux/leds.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/spi/spi.h>

struct dac124s085_led {
	struct led_classdev	ldev;
	struct spi_device	*spi;
	int			id;
	int			brightness;
	char			name[sizeof("dac124s085-3")];

	struct mutex		mutex;
	struct work_struct	work;
	spinlock_t		lock;
};

struct dac124s085 {
	struct dac124s085_led leds[4];
};

#define REG_WRITE		(0 << 12)
#define REG_WRITE_UPDATE	(1 << 12)
#define ALL_WRITE_UPDATE	(2 << 12)
#define POWER_DOWN_OUTPUT	(3 << 12)

static void dac124s085_led_work(struct work_struct *work)
{
	struct dac124s085_led *led = container_of(work, struct dac124s085_led,
						  work);
	u16 word;

	mutex_lock(&led->mutex);
	word = cpu_to_le16(((led->id) << 14) | REG_WRITE_UPDATE |
			   (led->brightness & 0xfff));
	spi_write(led->spi, (const u8 *)&word, sizeof(word));
	mutex_unlock(&led->mutex);
}

static void dac124s085_set_brightness(struct led_classdev *ldev,
				      enum led_brightness brightness)
{
	struct dac124s085_led *led = container_of(ldev, struct dac124s085_led,
						  ldev);

	spin_lock(&led->lock);
	led->brightness = brightness;
	schedule_work(&led->work);
	spin_unlock(&led->lock);
}

static int dac124s085_probe(struct spi_device *spi)
{
	struct dac124s085	*dac;
	struct dac124s085_led	*led;
	int i, ret;

	dac = devm_kzalloc(&spi->dev, sizeof(*dac), GFP_KERNEL);
	if (!dac)
		return -ENOMEM;

	spi->bits_per_word = 16;

	for (i = 0; i < ARRAY_SIZE(dac->leds); i++) {
		led		= dac->leds + i;
		led->id		= i;
		led->brightness	= LED_OFF;
		led->spi	= spi;
		snprintf(led->name, sizeof(led->name), "dac124s085-%d", i);
		spin_lock_init(&led->lock);
		INIT_WORK(&led->work, dac124s085_led_work);
		mutex_init(&led->mutex);
		led->ldev.name = led->name;
		led->ldev.brightness = LED_OFF;
		led->ldev.max_brightness = 0xfff;
		led->ldev.brightness_set = dac124s085_set_brightness;
		ret = led_classdev_register(&spi->dev, &led->ldev);
		if (ret < 0)
			goto eledcr;
	}

	spi_set_drvdata(spi, dac);

	return 0;

eledcr:
	while (i--)
		led_classdev_unregister(&dac->leds[i].ldev);

	spi_set_drvdata(spi, NULL);
	return ret;
}

static int dac124s085_remove(struct spi_device *spi)
{
	struct dac124s085	*dac = spi_get_drvdata(spi);
	int i;

	for (i = 0; i < ARRAY_SIZE(dac->leds); i++) {
		led_classdev_unregister(&dac->leds[i].ldev);
		cancel_work_sync(&dac->leds[i].work);
	}

	spi_set_drvdata(spi, NULL);

	return 0;
}

static struct spi_driver dac124s085_driver = {
	.probe		= dac124s085_probe,
	.remove		= dac124s085_remove,
	.driver = {
		.name	= "dac124s085",
		.owner	= THIS_MODULE,
	},
};

module_spi_driver(dac124s085_driver);

MODULE_AUTHOR("Guennadi Liakhovetski <[email protected]>");
MODULE_DESCRIPTION("DAC124S085 LED driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("spi:dac124s085");
Commit	Line	Data
ac2dd0f1 GL	1	/*
	2	* Copyright 2008
	3	* Guennadi Liakhovetski, DENX Software Engineering, <[email protected]>
	4	*
	5	* This file is subject to the terms and conditions of version 2 of
	6	* the GNU General Public License. See the file COPYING in the main
	7	* directory of this archive for more details.
	8	*
	9	* LED driver for the DAC124S085 SPI DAC
	10	*/
	11
ac2dd0f1 GL	12	#include <linux/leds.h>
	13	#include <linux/module.h>
	14	#include <linux/mutex.h>
	15	#include <linux/slab.h>
	16	#include <linux/spinlock.h>
	17	#include <linux/workqueue.h>
	18	#include <linux/spi/spi.h>
	19
	20	struct dac124s085_led {
	21	struct led_classdev ldev;
	22	struct spi_device *spi;
	23	int id;
	24	int brightness;
	25	char name[sizeof("dac124s085-3")];
	26
	27	struct mutex mutex;
	28	struct work_struct work;
	29	spinlock_t lock;
	30	};
	31
	32	struct dac124s085 {
	33	struct dac124s085_led leds[4];
	34	};
	35
	36	#define REG_WRITE (0 << 12)
	37	#define REG_WRITE_UPDATE (1 << 12)
	38	#define ALL_WRITE_UPDATE (2 << 12)
	39	#define POWER_DOWN_OUTPUT (3 << 12)
	40
	41	static void dac124s085_led_work(struct work_struct *work)
	42	{
	43	struct dac124s085_led *led = container_of(work, struct dac124s085_led,
	44	work);
	45	u16 word;
	46
	47	mutex_lock(&led->mutex);
	48	word = cpu_to_le16(((led->id) << 14) \| REG_WRITE_UPDATE \|
	49	(led->brightness & 0xfff));
	50	spi_write(led->spi, (const u8 *)&word, sizeof(word));
	51	mutex_unlock(&led->mutex);
	52	}
	53
	54	static void dac124s085_set_brightness(struct led_classdev *ldev,
	55	enum led_brightness brightness)
	56	{
	57	struct dac124s085_led *led = container_of(ldev, struct dac124s085_led,
	58	ldev);
	59
	60	spin_lock(&led->lock);
	61	led->brightness = brightness;
	62	schedule_work(&led->work);
	63	spin_unlock(&led->lock);
	64	}
	65
	66	static int dac124s085_probe(struct spi_device *spi)
	67	{
	68	struct dac124s085 *dac;
	69	struct dac124s085_led *led;
	70	int i, ret;
	71
e5860312	72	dac = devm_kzalloc(&spi->dev, sizeof(*dac), GFP_KERNEL);
ac2dd0f1 GL	73	if (!dac)
	74	return -ENOMEM;
	75
	76	spi->bits_per_word = 16;
	77
	78	for (i = 0; i < ARRAY_SIZE(dac->leds); i++) {
	79	led = dac->leds + i;
	80	led->id = i;
	81	led->brightness = LED_OFF;
	82	led->spi = spi;
	83	snprintf(led->name, sizeof(led->name), "dac124s085-%d", i);
	84	spin_lock_init(&led->lock);
	85	INIT_WORK(&led->work, dac124s085_led_work);
	86	mutex_init(&led->mutex);
	87	led->ldev.name = led->name;
	88	led->ldev.brightness = LED_OFF;
	89	led->ldev.max_brightness = 0xfff;
	90	led->ldev.brightness_set = dac124s085_set_brightness;
	91	ret = led_classdev_register(&spi->dev, &led->ldev);
	92	if (ret < 0)
	93	goto eledcr;
	94	}
	95
	96	spi_set_drvdata(spi, dac);
	97
	98	return 0;
	99
	100	eledcr:
	101	while (i--)
	102	led_classdev_unregister(&dac->leds[i].ldev);
	103
	104	spi_set_drvdata(spi, NULL);
ac2dd0f1 GL	105	return ret;
	106	}
	107
	108	static int dac124s085_remove(struct spi_device *spi)
	109	{
	110	struct dac124s085 *dac = spi_get_drvdata(spi);
	111	int i;
	112
	113	for (i = 0; i < ARRAY_SIZE(dac->leds); i++) {
	114	led_classdev_unregister(&dac->leds[i].ldev);
	115	cancel_work_sync(&dac->leds[i].work);
	116	}
	117
	118	spi_set_drvdata(spi, NULL);
ac2dd0f1 GL	119
	120	return 0;
	121	}
	122
	123	static struct spi_driver dac124s085_driver = {
	124	.probe = dac124s085_probe,
	125	.remove = dac124s085_remove,
	126	.driver = {
	127	.name = "dac124s085",
	128	.owner = THIS_MODULE,
	129	},
	130	};
	131
19b95576	132	module_spi_driver(dac124s085_driver);
ac2dd0f1 GL	133
	134	MODULE_AUTHOR("Guennadi Liakhovetski <[email protected]>");
	135	MODULE_DESCRIPTION("DAC124S085 LED driver");
	136	MODULE_LICENSE("GPL v2");
e0626e38	137	MODULE_ALIAS("spi:dac124s085");