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Commit ac2dd0f1 authored by Guennadi Liakhovetski's avatar Guennadi Liakhovetski Committed by Richard Purdie
Browse files

leds: Add dac124s085 driver 



Add an LED driver using the DAC124S085 DAC from NatSemi

[randy.dunlap@oracle.com: use header files for interfaces]
Signed-off-by: default avatarGuennadi Liakhovetski <lg@denx.de>
Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: default avatarRichard Purdie <rpurdie@linux.intel.com>
parent 1bd465e6

drivers/leds/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -190,6 +190,13 @@ config LEDS_DA903X 
	  This option enables support for on-chip LED drivers found

	  on Dialog Semiconductor DA9030/DA9034 PMICs.



config LEDS_DAC124S085

	tristate "LED Support for DAC124S085 SPI DAC"

	depends on LEDS_CLASS && SPI

	help

	  This option enables support for DAC124S085 SPI DAC from NatSemi,

	  which can be used to control up to four LEDs.



comment "LED Triggers"



config LEDS_TRIGGERS

drivers/leds/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -25,6 +25,9 @@ obj-$(CONFIG_LEDS_PCA955X) += leds-pca955x.o 
obj-$(CONFIG_LEDS_DA903X)		+= leds-da903x.o

obj-$(CONFIG_LEDS_WM8350)		+= leds-wm8350.o



# LED SPI Drivers

obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o



# LED Triggers

obj-$(CONFIG_LEDS_TRIGGER_TIMER)	+= ledtrig-timer.o

obj-$(CONFIG_LEDS_TRIGGER_IDE_DISK)	+= ledtrig-ide-disk.o

drivers/leds/leds-dac124s085.c

0 → 100644
+150 −0
Original line number Diff line number Diff line 
/*

 * 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");