// SPDX-License-Identifier: GPL-2.0-only
/*
 * Backlight driver for Dialog Semiconductor DA9030/DA9034
 *
 * Copyright (C) 2008 Compulab, Ltd.
 *      Mike Rapoport <mike@compulab.co.il>
 *
 * Copyright (C) 2006-2008 Marvell International Ltd.
 *      Eric Miao <eric.miao@marvell.com>
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/backlight.h>
#include <linux/mfd/da903x.h>
#include <linux/slab.h>
#include <linux/module.h>

#define DA9030_WLED_CONTROL     0x25
#define DA9030_WLED_CP_EN       (1 << 6)
#define DA9030_WLED_TRIM(x)     ((x) & 0x7)

#define DA9034_WLED_CONTROL1    0x3C
#define DA9034_WLED_CONTROL2    0x3D
#define DA9034_WLED_ISET(x)     ((x) & 0x1f)

#define DA9034_WLED_BOOST_EN    (1 << 5)

#define DA9030_MAX_BRIGHTNESS   7
#define DA9034_MAX_BRIGHTNESS   0x7f

struct da903x_backlight_data {
        struct device *da903x_dev;
        int id;
        int current_brightness;
};

static int da903x_backlight_set(struct backlight_device *bl, int brightness)
{
        struct da903x_backlight_data *data = bl_get_data(bl);
        struct device *dev = data->da903x_dev;
        uint8_t val;
        int ret = 0;

        switch (data->id) {
        case DA9034_ID_WLED:
                ret = da903x_update(dev, DA9034_WLED_CONTROL1,
                                brightness, 0x7f);
                if (ret)
                        return ret;

                if (data->current_brightness && brightness == 0)
                        ret = da903x_clr_bits(dev,
                                        DA9034_WLED_CONTROL2,
                                        DA9034_WLED_BOOST_EN);

                if (data->current_brightness == 0 && brightness)
                        ret = da903x_set_bits(dev,
                                        DA9034_WLED_CONTROL2,
                                        DA9034_WLED_BOOST_EN);
                break;
        case DA9030_ID_WLED:
                val = DA9030_WLED_TRIM(brightness);
                val |= brightness ? DA9030_WLED_CP_EN : 0;
                ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
                break;
        }

        if (ret)
                return ret;

        data->current_brightness = brightness;
        return 0;
}

static int da903x_backlight_update_status(struct backlight_device *bl)
{
        return da903x_backlight_set(bl, backlight_get_brightness(bl));
}

static int da903x_backlight_get_brightness(struct backlight_device *bl)
{
        struct da903x_backlight_data *data = bl_get_data(bl);

        return data->current_brightness;
}

static const struct backlight_ops da903x_backlight_ops = {
        .options        = BL_CORE_SUSPENDRESUME,
        .update_status  = da903x_backlight_update_status,
        .get_brightness = da903x_backlight_get_brightness,
};

static int da903x_backlight_probe(struct platform_device *pdev)
{
        struct da9034_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
        struct da903x_backlight_data *data;
        struct backlight_device *bl;
        struct backlight_properties props;
        int max_brightness;

        data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
        if (data == NULL)
                return -ENOMEM;

        switch (pdev->id) {
        case DA9030_ID_WLED:
                max_brightness = DA9030_MAX_BRIGHTNESS;
                break;
        case DA9034_ID_WLED:
                max_brightness = DA9034_MAX_BRIGHTNESS;
                break;
        default:
                dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
                                pdev->id);
                return -EINVAL;
        }

        data->id = pdev->id;
        data->da903x_dev = pdev->dev.parent;
        data->current_brightness = 0;

        /* adjust the WLED output current */
        if (pdata)
                da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2,
                                DA9034_WLED_ISET(pdata->output_current));

        memset(&props, 0, sizeof(props));
        props.type = BACKLIGHT_RAW;
        props.max_brightness = max_brightness;
        bl = devm_backlight_device_register(&pdev->dev, pdev->name,
                                        data->da903x_dev, data,
                                        &da903x_backlight_ops, &props);
        if (IS_ERR(bl)) {
                dev_err(&pdev->dev, "failed to register backlight\n");
                return PTR_ERR(bl);
        }

        bl->props.brightness = max_brightness;

        platform_set_drvdata(pdev, bl);
        backlight_update_status(bl);
        return 0;
}

static struct platform_driver da903x_backlight_driver = {
        .driver         = {
                .name   = "da903x-backlight",
        },
        .probe          = da903x_backlight_probe,
};

module_platform_driver(da903x_backlight_driver);

MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da903x-backlight");