// SPDX-License-Identifier: GPL-2.0-only
/*
 * ROHM Semiconductor BD6107 LED Driver
 *
 * Copyright (C) 2013 Ideas on board SPRL
 *
 * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 */

#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/platform_data/bd6107.h>
#include <linux/slab.h>

#define BD6107_PSCNT1                           0x00
#define BD6107_PSCNT1_PSCNTREG2                 (1 << 2)
#define BD6107_PSCNT1_PSCNTREG1                 (1 << 0)
#define BD6107_REGVSET                          0x02
#define BD6107_REGVSET_REG1VSET_2_85V           (1 << 2)
#define BD6107_REGVSET_REG1VSET_2_80V           (0 << 2)
#define BD6107_LEDCNT1                          0x03
#define BD6107_LEDCNT1_LEDONOFF2                (1 << 1)
#define BD6107_LEDCNT1_LEDONOFF1                (1 << 0)
#define BD6107_PORTSEL                          0x04
#define BD6107_PORTSEL_LEDM(n)                  (1 << (n))
#define BD6107_RGB1CNT1                         0x05
#define BD6107_RGB1CNT2                         0x06
#define BD6107_RGB1CNT3                         0x07
#define BD6107_RGB1CNT4                         0x08
#define BD6107_RGB1CNT5                         0x09
#define BD6107_RGB1FLM                          0x0a
#define BD6107_RGB2CNT1                         0x0b
#define BD6107_RGB2CNT2                         0x0c
#define BD6107_RGB2CNT3                         0x0d
#define BD6107_RGB2CNT4                         0x0e
#define BD6107_RGB2CNT5                         0x0f
#define BD6107_RGB2FLM                          0x10
#define BD6107_PSCONT3                          0x11
#define BD6107_SMMONCNT                         0x12
#define BD6107_DCDCCNT                          0x13
#define BD6107_IOSEL                            0x14
#define BD6107_OUT1                             0x15
#define BD6107_OUT2                             0x16
#define BD6107_MASK1                            0x17
#define BD6107_MASK2                            0x18
#define BD6107_FACTOR1                          0x19
#define BD6107_FACTOR2                          0x1a
#define BD6107_CLRFACT1                         0x1b
#define BD6107_CLRFACT2                         0x1c
#define BD6107_STATE1                           0x1d
#define BD6107_LSIVER                           0x1e
#define BD6107_GRPSEL                           0x1f
#define BD6107_LEDCNT2                          0x20
#define BD6107_LEDCNT3                          0x21
#define BD6107_MCURRENT                         0x22
#define BD6107_MAINCNT1                         0x23
#define BD6107_MAINCNT2                         0x24
#define BD6107_SLOPECNT                         0x25
#define BD6107_MSLOPE                           0x26
#define BD6107_RGBSLOPE                         0x27
#define BD6107_TEST                             0x29
#define BD6107_SFTRST                           0x2a
#define BD6107_SFTRSTGD                         0x2b

struct bd6107 {
        struct i2c_client *client;
        struct backlight_device *backlight;
        struct bd6107_platform_data *pdata;
        struct gpio_desc *reset;
};

static int bd6107_write(struct bd6107 *bd, u8 reg, u8 data)
{
        return i2c_smbus_write_byte_data(bd->client, reg, data);
}

static int bd6107_backlight_update_status(struct backlight_device *backlight)
{
        struct bd6107 *bd = bl_get_data(backlight);
        int brightness = backlight_get_brightness(backlight);

        if (brightness) {
                bd6107_write(bd, BD6107_PORTSEL, BD6107_PORTSEL_LEDM(2) |
                             BD6107_PORTSEL_LEDM(1) | BD6107_PORTSEL_LEDM(0));
                bd6107_write(bd, BD6107_MAINCNT1, brightness);
                bd6107_write(bd, BD6107_LEDCNT1, BD6107_LEDCNT1_LEDONOFF1);
        } else {
                /* Assert the reset line (gpiolib will handle active low) */
                gpiod_set_value(bd->reset, 1);
                msleep(24);
                gpiod_set_value(bd->reset, 0);
        }

        return 0;
}

static bool bd6107_backlight_controls_device(struct backlight_device *backlight,
                                             struct device *display_dev)
{
        struct bd6107 *bd = bl_get_data(backlight);

        return !bd->pdata->dev || bd->pdata->dev == display_dev;
}

static const struct backlight_ops bd6107_backlight_ops = {
        .options         = BL_CORE_SUSPENDRESUME,
        .update_status   = bd6107_backlight_update_status,
        .controls_device = bd6107_backlight_controls_device,
};

static int bd6107_probe(struct i2c_client *client)
{
        struct bd6107_platform_data *pdata = dev_get_platdata(&client->dev);
        struct backlight_device *backlight;
        struct backlight_properties props;
        struct bd6107 *bd;

        if (pdata == NULL) {
                dev_err(&client->dev, "No platform data\n");
                return -EINVAL;
        }

        if (!i2c_check_functionality(client->adapter,
                                     I2C_FUNC_SMBUS_BYTE_DATA)) {
                dev_warn(&client->dev,
                         "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
                return -EIO;
        }

        bd = devm_kzalloc(&client->dev, sizeof(*bd), GFP_KERNEL);
        if (!bd)
                return -ENOMEM;

        bd->client = client;
        bd->pdata = pdata;

        /*
         * Request the reset GPIO line with GPIOD_OUT_HIGH meaning asserted,
         * so in the machine descriptor table (or other hardware description),
         * the line should be flagged as active low so this will assert
         * the reset.
         */
        bd->reset = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_HIGH);
        if (IS_ERR(bd->reset))
                return dev_err_probe(&client->dev, PTR_ERR(bd->reset),
                                     "unable to request reset GPIO\n");

        memset(&props, 0, sizeof(props));
        props.type = BACKLIGHT_RAW;
        props.max_brightness = 128;
        props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
                                   props.max_brightness);

        backlight = devm_backlight_device_register(&client->dev,
                                              dev_name(&client->dev),
                                              &bd->client->dev, bd,
                                              &bd6107_backlight_ops, &props);
        if (IS_ERR(backlight)) {
                dev_err(&client->dev, "failed to register backlight\n");
                return PTR_ERR(backlight);
        }

        backlight_update_status(backlight);
        i2c_set_clientdata(client, backlight);

        return 0;
}

static void bd6107_remove(struct i2c_client *client)
{
        struct backlight_device *backlight = i2c_get_clientdata(client);

        backlight->props.brightness = 0;
        backlight_update_status(backlight);
}

static const struct i2c_device_id bd6107_ids[] = {
        { "bd6107" },
        { }
};
MODULE_DEVICE_TABLE(i2c, bd6107_ids);

static struct i2c_driver bd6107_driver = {
        .driver = {
                .name = "bd6107",
        },
        .probe = bd6107_probe,
        .remove = bd6107_remove,
        .id_table = bd6107_ids,
};

module_i2c_driver(bd6107_driver);

MODULE_DESCRIPTION("Rohm BD6107 Backlight Driver");
MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
MODULE_LICENSE("GPL");