mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-15 23:14:31 +08:00
b4f31ad618
Driver core sets driver data to NULL upon failure or remove. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Cc: Guennadi Liakhovetski <lg@denx.de> Signed-off-by: Bryan Wu <cooloney@gmail.com>
135 lines
3.1 KiB
C
135 lines
3.1 KiB
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/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);
|
|
|
|
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);
|
|
}
|
|
|
|
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 <lg@denx.de>");
|
|
MODULE_DESCRIPTION("DAC124S085 LED driver");
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_ALIAS("spi:dac124s085");
|