From ac2dd0f110d5ab0359de7786e88e9971954ac7ee Mon Sep 17 00:00:00 2001 From: Guennadi Liakhovetski Date: Sat, 10 Jan 2009 18:58:28 +0000 Subject: 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: Guennadi Liakhovetski Signed-off-by: Randy Dunlap Signed-off-by: Richard Purdie --- drivers/leds/leds-dac124s085.c | 150 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 drivers/leds/leds-dac124s085.c (limited to 'drivers/leds/leds-dac124s085.c') diff --git a/drivers/leds/leds-dac124s085.c b/drivers/leds/leds-dac124s085.c new file mode 100644 index 00000000000..098d9aae725 --- /dev/null +++ b/drivers/leds/leds-dac124s085.c @@ -0,0 +1,150 @@ +/* + * Copyright 2008 + * Guennadi Liakhovetski, DENX Software Engineering, + * + * 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 +#include +#include +#include +#include +#include +#include +#include + +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 "); +MODULE_DESCRIPTION("DAC124S085 LED driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3