// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/drivers/video/backlight/aat2870_bl.c
 *
 * Copyright (c) 2011, NVIDIA Corporation.
 * Author: Jin Park <jinyoungp@nvidia.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/backlight.h>
#include <linux/mfd/aat2870.h>

struct aat2870_bl_driver_data {
        struct platform_device *pdev;
        struct backlight_device *bd;

        int channels;
        int max_current;
        int brightness; /* current brightness */
};

static inline int aat2870_brightness(struct aat2870_bl_driver_data *aat2870_bl,
                                     int brightness)
{
        struct backlight_device *bd = aat2870_bl->bd;
        int val;

        val = brightness * (aat2870_bl->max_current - 1);
        val /= bd->props.max_brightness;

        return val;
}

static inline int aat2870_bl_enable(struct aat2870_bl_driver_data *aat2870_bl)
{
        struct aat2870_data *aat2870
                        = dev_get_drvdata(aat2870_bl->pdev->dev.parent);

        return aat2870->write(aat2870, AAT2870_BL_CH_EN,
                              (u8)aat2870_bl->channels);
}

static inline int aat2870_bl_disable(struct aat2870_bl_driver_data *aat2870_bl)
{
        struct aat2870_data *aat2870
                        = dev_get_drvdata(aat2870_bl->pdev->dev.parent);

        return aat2870->write(aat2870, AAT2870_BL_CH_EN, 0x0);
}

static int aat2870_bl_update_status(struct backlight_device *bd)
{
        struct aat2870_bl_driver_data *aat2870_bl = bl_get_data(bd);
        struct aat2870_data *aat2870 =
                        dev_get_drvdata(aat2870_bl->pdev->dev.parent);
        int brightness = backlight_get_brightness(bd);
        int ret;

        if ((brightness < 0) || (bd->props.max_brightness < brightness)) {
                dev_err(&bd->dev, "invalid brightness, %d\n", brightness);
                return -EINVAL;
        }

        dev_dbg(&bd->dev, "brightness=%d, power=%d, state=%d\n",
                 bd->props.brightness, bd->props.power, bd->props.state);

        ret = aat2870->write(aat2870, AAT2870_BLM,
                             (u8)aat2870_brightness(aat2870_bl, brightness));
        if (ret < 0)
                return ret;

        if (brightness == 0) {
                ret = aat2870_bl_disable(aat2870_bl);
                if (ret < 0)
                        return ret;
        } else if (aat2870_bl->brightness == 0) {
                ret = aat2870_bl_enable(aat2870_bl);
                if (ret < 0)
                        return ret;
        }

        aat2870_bl->brightness = brightness;

        return 0;
}

static const struct backlight_ops aat2870_bl_ops = {
        .options = BL_CORE_SUSPENDRESUME,
        .update_status = aat2870_bl_update_status,
};

static int aat2870_bl_probe(struct platform_device *pdev)
{
        struct aat2870_bl_platform_data *pdata = dev_get_platdata(&pdev->dev);
        struct aat2870_bl_driver_data *aat2870_bl;
        struct backlight_device *bd;
        struct backlight_properties props;
        int ret = 0;

        if (!pdata) {
                dev_err(&pdev->dev, "No platform data\n");
                ret = -ENXIO;
                goto out;
        }

        if (pdev->id != AAT2870_ID_BL) {
                dev_err(&pdev->dev, "Invalid device ID, %d\n", pdev->id);
                ret = -EINVAL;
                goto out;
        }

        aat2870_bl = devm_kzalloc(&pdev->dev,
                                  sizeof(struct aat2870_bl_driver_data),
                                  GFP_KERNEL);
        if (!aat2870_bl) {
                ret = -ENOMEM;
                goto out;
        }

        memset(&props, 0, sizeof(struct backlight_properties));

        props.type = BACKLIGHT_RAW;
        bd = devm_backlight_device_register(&pdev->dev, "aat2870-backlight",
                                        &pdev->dev, aat2870_bl, &aat2870_bl_ops,
                                        &props);
        if (IS_ERR(bd)) {
                dev_err(&pdev->dev,
                        "Failed allocate memory for backlight device\n");
                ret = PTR_ERR(bd);
                goto out;
        }

        aat2870_bl->pdev = pdev;
        platform_set_drvdata(pdev, aat2870_bl);

        aat2870_bl->bd = bd;

        if (pdata->channels > 0)
                aat2870_bl->channels = pdata->channels;
        else
                aat2870_bl->channels = AAT2870_BL_CH_ALL;

        if (pdata->max_current > 0)
                aat2870_bl->max_current = pdata->max_current;
        else
                aat2870_bl->max_current = AAT2870_CURRENT_27_9;

        if (pdata->max_brightness > 0)
                bd->props.max_brightness = pdata->max_brightness;
        else
                bd->props.max_brightness = 255;

        aat2870_bl->brightness = 0;
        bd->props.power = BACKLIGHT_POWER_ON;
        bd->props.brightness = bd->props.max_brightness;

        ret = aat2870_bl_update_status(bd);
        if (ret < 0) {
                dev_err(&pdev->dev, "Failed to initialize\n");
                return ret;
        }

        return 0;

out:
        return ret;
}

static void aat2870_bl_remove(struct platform_device *pdev)
{
        struct aat2870_bl_driver_data *aat2870_bl = platform_get_drvdata(pdev);
        struct backlight_device *bd = aat2870_bl->bd;

        bd->props.power = BACKLIGHT_POWER_OFF;
        bd->props.brightness = 0;
        backlight_update_status(bd);
}

static struct platform_driver aat2870_bl_driver = {
        .driver = {
                .name   = "aat2870-backlight",
        },
        .probe          = aat2870_bl_probe,
        .remove         = aat2870_bl_remove,
};

static int __init aat2870_bl_init(void)
{
        return platform_driver_register(&aat2870_bl_driver);
}
subsys_initcall(aat2870_bl_init);

static void __exit aat2870_bl_exit(void)
{
        platform_driver_unregister(&aat2870_bl_driver);
}
module_exit(aat2870_bl_exit);

MODULE_DESCRIPTION("AnalogicTech AAT2870 Backlight");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jin Park <jinyoungp@nvidia.com>");