diff options
Diffstat (limited to 'drivers/leds/leds-dac124s085.c')
-rw-r--r-- | drivers/leds/leds-dac124s085.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/drivers/leds/leds-dac124s085.c b/drivers/leds/leds-dac124s085.c new file mode 100644 index 000000000..20dc9b9d7 --- /dev/null +++ b/drivers/leds/leds-dac124s085.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2008 + * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de> + * + * 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"); |