// SPDX-License-Identifier: GPL-2.0-only
/* drivers/video/backlight/platform_lcd.c
 *
 * Copyright 2008 Simtec Electronics
 *      Ben Dooks <ben@simtec.co.uk>
 *
 * Generic platform-device LCD power control interface.
*/

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/lcd.h>
#include <linux/slab.h>

#include <video/platform_lcd.h>

struct platform_lcd {
        struct device           *us;
        struct lcd_device       *lcd;
        struct plat_lcd_data    *pdata;

        unsigned int             power;
        unsigned int             suspended:1;
};

static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
{
        return lcd_get_data(lcd);
}

static int platform_lcd_get_power(struct lcd_device *lcd)
{
        struct platform_lcd *plcd = to_our_lcd(lcd);

        return plcd->power;
}

static int platform_lcd_set_power(struct lcd_device *lcd, int power)
{
        struct platform_lcd *plcd = to_our_lcd(lcd);
        int lcd_power = 1;

        if (power == LCD_POWER_OFF || plcd->suspended)
                lcd_power = 0;

        plcd->pdata->set_power(plcd->pdata, lcd_power);
        plcd->power = power;

        return 0;
}

static bool platform_lcd_controls_device(struct lcd_device *lcd, struct device *display_device)
{
        struct platform_lcd *plcd = to_our_lcd(lcd);

        return plcd->us->parent == display_device;
}

static const struct lcd_ops platform_lcd_ops = {
        .get_power              = platform_lcd_get_power,
        .set_power              = platform_lcd_set_power,
        .controls_device        = platform_lcd_controls_device,
};

static int platform_lcd_probe(struct platform_device *pdev)
{
        struct plat_lcd_data *pdata;
        struct platform_lcd *plcd;
        struct device *dev = &pdev->dev;
        int err;

        pdata = dev_get_platdata(&pdev->dev);
        if (!pdata) {
                dev_err(dev, "no platform data supplied\n");
                return -EINVAL;
        }

        if (pdata->probe) {
                err = pdata->probe(pdata);
                if (err)
                        return err;
        }

        plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd),
                            GFP_KERNEL);
        if (!plcd)
                return -ENOMEM;

        plcd->us = dev;
        plcd->pdata = pdata;
        plcd->lcd = devm_lcd_device_register(&pdev->dev, dev_name(dev), dev,
                                                plcd, &platform_lcd_ops);
        if (IS_ERR(plcd->lcd)) {
                dev_err(dev, "cannot register lcd device\n");
                return PTR_ERR(plcd->lcd);
        }

        platform_set_drvdata(pdev, plcd);
        platform_lcd_set_power(plcd->lcd, LCD_POWER_REDUCED);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int platform_lcd_suspend(struct device *dev)
{
        struct platform_lcd *plcd = dev_get_drvdata(dev);

        plcd->suspended = 1;
        platform_lcd_set_power(plcd->lcd, plcd->power);

        return 0;
}

static int platform_lcd_resume(struct device *dev)
{
        struct platform_lcd *plcd = dev_get_drvdata(dev);

        plcd->suspended = 0;
        platform_lcd_set_power(plcd->lcd, plcd->power);

        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend,
                        platform_lcd_resume);

static struct platform_driver platform_lcd_driver = {
        .driver         = {
                .name   = "platform-lcd",
                .pm     = &platform_lcd_pm_ops,
        },
        .probe          = platform_lcd_probe,
};

module_platform_driver(platform_lcd_driver);

MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
MODULE_DESCRIPTION("Generic platform-device LCD power control interface");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:platform-lcd");