[deliverable/linux.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/gfp.h>
#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 = kzalloc(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);
	kfree(dac);
	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);
	kfree(dac);

	return 0;
}

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

static int __init dac124s085_leds_init(void)
{
	return spi_register_driver(&dac124s085_driver);
}

static void __exit dac124s085_leds_exit(void)
{
	spi_unregister_driver(&dac124s085_driver);
}

module_init(dac124s085_leds_init);
module_exit(dac124s085_leds_exit);

MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
MODULE_DESCRIPTION("DAC124S085 LED driver");
MODULE_LICENSE("GPL v2");
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
	12	#include <linux/gfp.h>
	13	#include <linux/leds.h>
	14	#include <linux/module.h>
	15	#include <linux/mutex.h>
	16	#include <linux/slab.h>
	17	#include <linux/spinlock.h>
	18	#include <linux/workqueue.h>
	19	#include <linux/spi/spi.h>
	20
	21	struct dac124s085_led {
	22	struct led_classdev ldev;
	23	struct spi_device *spi;
	24	int id;
	25	int brightness;
	26	char name[sizeof("dac124s085-3")];
	27
	28	struct mutex mutex;
	29	struct work_struct work;
	30	spinlock_t lock;
	31	};
	32
	33	struct dac124s085 {
	34	struct dac124s085_led leds[4];
	35	};
	36
	37	#define REG_WRITE (0 << 12)
	38	#define REG_WRITE_UPDATE (1 << 12)
	39	#define ALL_WRITE_UPDATE (2 << 12)
	40	#define POWER_DOWN_OUTPUT (3 << 12)
	41
	42	static void dac124s085_led_work(struct work_struct *work)
	43	{
	44	struct dac124s085_led *led = container_of(work, struct dac124s085_led,
	45	work);
	46	u16 word;
	47
	48	mutex_lock(&led->mutex);
	49	word = cpu_to_le16(((led->id) << 14) \| REG_WRITE_UPDATE \|
	50	(led->brightness & 0xfff));
	51	spi_write(led->spi, (const u8 *)&word, sizeof(word));
	52	mutex_unlock(&led->mutex);
	53	}
	54
	55	static void dac124s085_set_brightness(struct led_classdev *ldev,
	56	enum led_brightness brightness)
	57	{
	58	struct dac124s085_led *led = container_of(ldev, struct dac124s085_led,
	59	ldev);
	60
	61	spin_lock(&led->lock);
	62	led->brightness = brightness;
	63	schedule_work(&led->work);
	64	spin_unlock(&led->lock);
65	}
66
67	static int dac124s085_probe(struct spi_device *spi)
68	{
69	struct dac124s085 *dac;
70	struct dac124s085_led *led;
71	int i, ret;
72
73	dac = kzalloc(sizeof(*dac), GFP_KERNEL);
74	if (!dac)
75	return -ENOMEM;
76
77	spi->bits_per_word = 16;
78
79	for (i = 0; i < ARRAY_SIZE(dac->leds); i++) {
80	led = dac->leds + i;
81	led->id = i;
82	led->brightness = LED_OFF;
83	led->spi = spi;
84	snprintf(led->name, sizeof(led->name), "dac124s085-%d", i);
85	spin_lock_init(&led->lock);
86	INIT_WORK(&led->work, dac124s085_led_work);
87	mutex_init(&led->mutex);
88	led->ldev.name = led->name;
89	led->ldev.brightness = LED_OFF;
90	led->ldev.max_brightness = 0xfff;
91	led->ldev.brightness_set = dac124s085_set_brightness;
92	ret = led_classdev_register(&spi->dev, &led->ldev);
93	if (ret < 0)
94	goto eledcr;
95	}
96
97	spi_set_drvdata(spi, dac);
98
99	return 0;
100
101	eledcr:
102	while (i--)
103	led_classdev_unregister(&dac->leds[i].ldev);
104
105	spi_set_drvdata(spi, NULL);
106	kfree(dac);
107	return ret;
108	}
109
110	static int dac124s085_remove(struct spi_device *spi)
111	{
112	struct dac124s085 *dac = spi_get_drvdata(spi);
113	int i;
114
115	for (i = 0; i < ARRAY_SIZE(dac->leds); i++) {
116	led_classdev_unregister(&dac->leds[i].ldev);
117	cancel_work_sync(&dac->leds[i].work);
118	}
119
120	spi_set_drvdata(spi, NULL);
121	kfree(dac);
122
123	return 0;
124	}
125
126	static struct spi_driver dac124s085_driver = {
127	.probe = dac124s085_probe,
128	.remove = dac124s085_remove,
129	.driver = {
130	.name = "dac124s085",
131	.owner = THIS_MODULE,
132	},
133	};
134
135	static int __init dac124s085_leds_init(void)
136	{
137	return spi_register_driver(&dac124s085_driver);
138	}
139
140	static void __exit dac124s085_leds_exit(void)
141	{
142	spi_unregister_driver(&dac124s085_driver);
143	}
144
145	module_init(dac124s085_leds_init);
146	module_exit(dac124s085_leds_exit);
147
148	MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
149	MODULE_DESCRIPTION("DAC124S085 LED driver");
150	MODULE_LICENSE("GPL v2");