linux/drivers/video/backlight/platform_lcd.c
<<
>>
Prefs
   1/* drivers/video/backlight/platform_lcd.c
   2 *
   3 * Copyright 2008 Simtec Electronics
   4 *      Ben Dooks <ben@simtec.co.uk>
   5 *
   6 * Generic platform-device LCD power control interface.
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 *
  12*/
  13
  14#include <linux/module.h>
  15#include <linux/platform_device.h>
  16#include <linux/fb.h>
  17#include <linux/backlight.h>
  18#include <linux/lcd.h>
  19
  20#include <video/platform_lcd.h>
  21
  22struct platform_lcd {
  23        struct device           *us;
  24        struct lcd_device       *lcd;
  25        struct plat_lcd_data    *pdata;
  26
  27        unsigned int             power;
  28        unsigned int             suspended : 1;
  29};
  30
  31static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
  32{
  33        return lcd_get_data(lcd);
  34}
  35
  36static int platform_lcd_get_power(struct lcd_device *lcd)
  37{
  38        struct platform_lcd *plcd = to_our_lcd(lcd);
  39
  40        return plcd->power;
  41}
  42
  43static int platform_lcd_set_power(struct lcd_device *lcd, int power)
  44{
  45        struct platform_lcd *plcd = to_our_lcd(lcd);
  46        int lcd_power = 1;
  47
  48        if (power == FB_BLANK_POWERDOWN || plcd->suspended)
  49                lcd_power = 0;
  50
  51        plcd->pdata->set_power(plcd->pdata, lcd_power);
  52        plcd->power = power;
  53
  54        return 0;
  55}
  56
  57static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info)
  58{
  59        struct platform_lcd *plcd = to_our_lcd(lcd);
  60        struct plat_lcd_data *pdata = plcd->pdata;
  61
  62        if (pdata->match_fb)
  63                return pdata->match_fb(pdata, info);
  64
  65        return plcd->us->parent == info->device;
  66}
  67
  68static struct lcd_ops platform_lcd_ops = {
  69        .get_power      = platform_lcd_get_power,
  70        .set_power      = platform_lcd_set_power,
  71        .check_fb       = platform_lcd_match,
  72};
  73
  74static int __devinit platform_lcd_probe(struct platform_device *pdev)
  75{
  76        struct plat_lcd_data *pdata;
  77        struct platform_lcd *plcd;
  78        struct device *dev = &pdev->dev;
  79        int err;
  80
  81        pdata = pdev->dev.platform_data;
  82        if (!pdata) {
  83                dev_err(dev, "no platform data supplied\n");
  84                return -EINVAL;
  85        }
  86
  87        plcd = kzalloc(sizeof(struct platform_lcd), GFP_KERNEL);
  88        if (!plcd) {
  89                dev_err(dev, "no memory for state\n");
  90                return -ENOMEM;
  91        }
  92
  93        plcd->us = dev;
  94        plcd->pdata = pdata;
  95        plcd->lcd = lcd_device_register(dev_name(dev), dev,
  96                                        plcd, &platform_lcd_ops);
  97        if (IS_ERR(plcd->lcd)) {
  98                dev_err(dev, "cannot register lcd device\n");
  99                err = PTR_ERR(plcd->lcd);
 100                goto err_mem;
 101        }
 102
 103        platform_set_drvdata(pdev, plcd);
 104        platform_lcd_set_power(plcd->lcd, FB_BLANK_NORMAL);
 105
 106        return 0;
 107
 108 err_mem:
 109        kfree(plcd);
 110        return err;
 111}
 112
 113static int __devexit platform_lcd_remove(struct platform_device *pdev)
 114{
 115        struct platform_lcd *plcd = platform_get_drvdata(pdev);
 116
 117        lcd_device_unregister(plcd->lcd);
 118        kfree(plcd);
 119
 120        return 0;
 121}
 122
 123#ifdef CONFIG_PM
 124static int platform_lcd_suspend(struct platform_device *pdev, pm_message_t st)
 125{
 126        struct platform_lcd *plcd = platform_get_drvdata(pdev);
 127
 128        plcd->suspended = 1;
 129        platform_lcd_set_power(plcd->lcd, plcd->power);
 130
 131        return 0;
 132}
 133
 134static int platform_lcd_resume(struct platform_device *pdev)
 135{
 136        struct platform_lcd *plcd = platform_get_drvdata(pdev);
 137
 138        plcd->suspended = 0;
 139        platform_lcd_set_power(plcd->lcd, plcd->power);
 140
 141        return 0;
 142}
 143#else
 144#define platform_lcd_suspend NULL
 145#define platform_lcd_resume NULL
 146#endif
 147
 148static struct platform_driver platform_lcd_driver = {
 149        .driver         = {
 150                .name   = "platform-lcd",
 151                .owner  = THIS_MODULE,
 152        },
 153        .probe          = platform_lcd_probe,
 154        .remove         = __devexit_p(platform_lcd_remove),
 155        .suspend        = platform_lcd_suspend,
 156        .resume         = platform_lcd_resume,
 157};
 158
 159static int __init platform_lcd_init(void)
 160{
 161        return platform_driver_register(&platform_lcd_driver);
 162}
 163
 164static void __exit platform_lcd_cleanup(void)
 165{
 166        platform_driver_unregister(&platform_lcd_driver);
 167}
 168
 169module_init(platform_lcd_init);
 170module_exit(platform_lcd_cleanup);
 171
 172MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
 173MODULE_LICENSE("GPL v2");
 174MODULE_ALIAS("platform:platform-lcd");
 175