[linux-2.6-block.git] / drivers / leds / leds-dac124s085.c

/*
 * Copyright 2008
 * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
 *
 * 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/spi/spi.h>

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

	struct mutex		mutex;
};

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 int dac124s085_set_brightness(struct led_classdev *ldev,
				      enum led_brightness brightness)
{
	struct dac124s085_led *led = container_of(ldev, struct dac124s085_led,
						  ldev);
	u16 word;
	int ret;

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

	return ret;
}

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->spi	= spi;
		snprintf(led->name, sizeof(led->name), "dac124s085-%d", i);
		mutex_init(&led->mutex);
		led->ldev.name = led->name;
		led->ldev.brightness = LED_OFF;
		led->ldev.max_brightness = 0xfff;
		led->ldev.brightness_set_blocking = 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);

	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);

	return 0;
}

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

module_spi_driver(dac124s085_driver);

MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
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, <lg@denx.de>
	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>
ac2dd0f1 GL	16	#include <linux/spi/spi.h>
	17
	18	struct dac124s085_led {
	19	struct led_classdev ldev;
	20	struct spi_device *spi;
	21	int id;
ac2dd0f1 GL	22	char name[sizeof("dac124s085-3")];
	23
	24	struct mutex mutex;
ac2dd0f1 GL	25	};
	26
	27	struct dac124s085 {
	28	struct dac124s085_led leds[4];
	29	};
	30
	31	#define REG_WRITE (0 << 12)
	32	#define REG_WRITE_UPDATE (1 << 12)
	33	#define ALL_WRITE_UPDATE (2 << 12)
	34	#define POWER_DOWN_OUTPUT (3 << 12)
	35
8ec108c0 AL	36	static int dac124s085_set_brightness(struct led_classdev *ldev,
8ec108c0 AL	37	enum led_brightness brightness)
ac2dd0f1	38	{
8ec108c0 AL	39	struct dac124s085_led *led = container_of(ldev, struct dac124s085_led,
8ec108c0 AL	40	ldev);
ac2dd0f1	41	u16 word;
8ec108c0	42	int ret;
ac2dd0f1 GL	43
	44	mutex_lock(&led->mutex);
	45	word = cpu_to_le16(((led->id) << 14) \| REG_WRITE_UPDATE \|
8ec108c0 AL	46	(brightness & 0xfff));
8ec108c0 AL	47	ret = spi_write(led->spi, (const u8 *)&word, sizeof(word));
ac2dd0f1	48	mutex_unlock(&led->mutex);
ac2dd0f1	49
8ec108c0	50	return ret;
ac2dd0f1 GL	51	}
	52
	53	static int dac124s085_probe(struct spi_device *spi)
	54	{
	55	struct dac124s085 *dac;
	56	struct dac124s085_led *led;
	57	int i, ret;
	58
e5860312	59	dac = devm_kzalloc(&spi->dev, sizeof(*dac), GFP_KERNEL);
ac2dd0f1 GL	60	if (!dac)
	61	return -ENOMEM;
	62
	63	spi->bits_per_word = 16;
	64
	65	for (i = 0; i < ARRAY_SIZE(dac->leds); i++) {
	66	led = dac->leds + i;
	67	led->id = i;
ac2dd0f1 GL	68	led->spi = spi;
ac2dd0f1 GL	69	snprintf(led->name, sizeof(led->name), "dac124s085-%d", i);
ac2dd0f1 GL	70	mutex_init(&led->mutex);
	71	led->ldev.name = led->name;
	72	led->ldev.brightness = LED_OFF;
	73	led->ldev.max_brightness = 0xfff;
8ec108c0	74	led->ldev.brightness_set_blocking = dac124s085_set_brightness;
ac2dd0f1 GL	75	ret = led_classdev_register(&spi->dev, &led->ldev);
	76	if (ret < 0)
	77	goto eledcr;
	78	}
	79
	80	spi_set_drvdata(spi, dac);
	81
	82	return 0;
	83
	84	eledcr:
	85	while (i--)
	86	led_classdev_unregister(&dac->leds[i].ldev);
	87
ac2dd0f1 GL	88	return ret;
	89	}
	90
	91	static int dac124s085_remove(struct spi_device *spi)
	92	{
	93	struct dac124s085 *dac = spi_get_drvdata(spi);
	94	int i;
	95
8ec108c0	96	for (i = 0; i < ARRAY_SIZE(dac->leds); i++)
ac2dd0f1	97	led_classdev_unregister(&dac->leds[i].ldev);
ac2dd0f1	98
ac2dd0f1 GL	99	return 0;
	100	}
	101
	102	static struct spi_driver dac124s085_driver = {
	103	.probe = dac124s085_probe,
	104	.remove = dac124s085_remove,
	105	.driver = {
	106	.name = "dac124s085",
ac2dd0f1 GL	107	},
	108	};
	109
19b95576	110	module_spi_driver(dac124s085_driver);
ac2dd0f1 GL	111
	112	MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
	113	MODULE_DESCRIPTION("DAC124S085 LED driver");
	114	MODULE_LICENSE("GPL v2");
e0626e38	115	MODULE_ALIAS("spi:dac124s085");