// 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 void 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);
}

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");