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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright 20084 * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>5 *6 * LED driver for the DAC124S085 SPI DAC7 */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 void 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 97static struct spi_driver dac124s085_driver = {98 .probe = dac124s085_probe,99 .remove = dac124s085_remove,100 .driver = {101 .name = "dac124s085",102 },103};104 105module_spi_driver(dac124s085_driver);106 107MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");108MODULE_DESCRIPTION("DAC124S085 LED driver");109MODULE_LICENSE("GPL v2");110MODULE_ALIAS("spi:dac124s085");111