LXR linux/drivers/leds/leds-dac124s085.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright 2008
   4 * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
   5 *
   6 * LED driver for the DAC124S085 SPI DAC
   7 */
   8
   9#include <linux/leds.h>
  10#include <linux/module.h>
  11#include <linux/mutex.h>
  12#include <linux/slab.h>
  13#include <linux/spi/spi.h>
  14
  15struct dac124s085_led {
  16        struct led_classdev     ldev;
  17        struct spi_device       *spi;
  18        int                     id;
  19        char                    name[sizeof("dac124s085-3")];
  20
  21        struct mutex            mutex;
  22};
  23
  24struct dac124s085 {
  25        struct dac124s085_led leds[4];
  26};
  27
  28#define REG_WRITE               (0 << 12)
  29#define REG_WRITE_UPDATE        (1 << 12)
  30#define ALL_WRITE_UPDATE        (2 << 12)
  31#define POWER_DOWN_OUTPUT       (3 << 12)
  32
  33static int dac124s085_set_brightness(struct led_classdev *ldev,
  34                                      enum led_brightness brightness)
  35{
  36        struct dac124s085_led *led = container_of(ldev, struct dac124s085_led,
  37                                                  ldev);
  38        u16 word;
  39        int ret;
  40
  41        mutex_lock(&led->mutex);
  42        word = cpu_to_le16(((led->id) << 14) | REG_WRITE_UPDATE |
  43                           (brightness & 0xfff));
  44        ret = spi_write(led->spi, (const u8 *)&word, sizeof(word));
  45        mutex_unlock(&led->mutex);
  46
  47        return ret;
  48}
  49
  50static int dac124s085_probe(struct spi_device *spi)
  51{
  52        struct dac124s085       *dac;
  53        struct dac124s085_led   *led;
  54        int i, ret;
  55
  56        dac = devm_kzalloc(&spi->dev, sizeof(*dac), GFP_KERNEL);
  57        if (!dac)
  58                return -ENOMEM;
  59
  60        spi->bits_per_word = 16;
  61
  62        for (i = 0; i < ARRAY_SIZE(dac->leds); i++) {
  63                led             = dac->leds + i;
  64                led->id         = i;
  65                led->spi        = spi;
  66                snprintf(led->name, sizeof(led->name), "dac124s085-%d", i);
  67                mutex_init(&led->mutex);
  68                led->ldev.name = led->name;
  69                led->ldev.brightness = LED_OFF;
  70                led->ldev.max_brightness = 0xfff;
  71                led->ldev.brightness_set_blocking = dac124s085_set_brightness;
  72                ret = led_classdev_register(&spi->dev, &led->ldev);
  73                if (ret < 0)
  74                        goto eledcr;
  75        }
  76
  77        spi_set_drvdata(spi, dac);
  78
  79        return 0;
  80
  81eledcr:
  82        while (i--)
  83                led_classdev_unregister(&dac->leds[i].ldev);
  84
  85        return ret;
  86}
  87
  88static int dac124s085_remove(struct spi_device *spi)
  89{
  90        struct dac124s085       *dac = spi_get_drvdata(spi);
  91        int i;
  92
  93        for (i = 0; i < ARRAY_SIZE(dac->leds); i++)
  94                led_classdev_unregister(&dac->leds[i].ldev);
  95
  96        return 0;
  97}
  98
  99static struct spi_driver dac124s085_driver = {
 100        .probe          = dac124s085_probe,
 101        .remove         = dac124s085_remove,
 102        .driver = {
 103                .name   = "dac124s085",
 104        },
 105};
 106
 107module_spi_driver(dac124s085_driver);
 108
 109MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
 110MODULE_DESCRIPTION("DAC124S085 LED driver");
 111MODULE_LICENSE("GPL v2");
 112MODULE_ALIAS("spi:dac124s085");
 113