platform_lcd.c

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/* drivers/video/backlight/platform_lcd.c
 *
 * Copyright 2008 Simtec Electronics
 *  Ben Dooks <[email protected]>
 *
 * Generic platform-device LCD power control interface.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
*/

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/lcd.h>
#include <linux/of.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 == FB_BLANK_POWERDOWN || plcd->suspended)
        lcd_power = 0;

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

    return 0;
}

static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info)
{
    struct platform_lcd *plcd = to_our_lcd(lcd);
    struct plat_lcd_data *pdata = plcd->pdata;

    if (pdata->match_fb)
        return pdata->match_fb(pdata, info);

    return plcd->us->parent == info->device;
}

static struct lcd_ops platform_lcd_ops = {
    .get_power  = platform_lcd_get_power,
    .set_power  = platform_lcd_set_power,
    .check_fb   = platform_lcd_match,
};

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

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

    plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd),
                GFP_KERNEL);
    if (!plcd) {
        dev_err(dev, "no memory for state\n");
        return -ENOMEM;
    }

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

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

    return 0;

 err:
    return err;
}

static int __devexit platform_lcd_remove(struct platform_device *pdev)
{
    struct platform_lcd *plcd = platform_get_drvdata(pdev);

    lcd_device_unregister(plcd->lcd);

    return 0;
}

#ifdef CONFIG_PM
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;
}

static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend,
            platform_lcd_resume);
#endif

#ifdef CONFIG_OF
static const struct of_device_id platform_lcd_of_match[] = {
    { .compatible = "platform-lcd" },
    {},
};
MODULE_DEVICE_TABLE(of, platform_lcd_of_match);
#endif

static struct platform_driver platform_lcd_driver = {
    .driver     = {
        .name   = "platform-lcd",
        .owner  = THIS_MODULE,
#ifdef CONFIG_PM
        .pm = &platform_lcd_pm_ops,
#endif
        .of_match_table = of_match_ptr(platform_lcd_of_match),
    },
    .probe      = platform_lcd_probe,
    .remove     = __devexit_p(platform_lcd_remove),
};

module_platform_driver(platform_lcd_driver);

MODULE_AUTHOR("Ben Dooks <[email protected]>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:platform-lcd");