drivers/video/backlight/platform_lcd.c

   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
  22 struct 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
  31 static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
  32 {
  33         return lcd_get_data(lcd);
  34 }
  35
  36 static 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
  43 static 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
  57 static 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
  68 static 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
  74 static 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("platform-lcd", 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         return 0;
 105
 106  err_mem:
 107         kfree(plcd);
 108         return err;
 109 }
 110
 111 static int __devexit platform_lcd_remove(struct platform_device *pdev)
 112 {
 113         struct platform_lcd *plcd = platform_get_drvdata(pdev);
 114
 115         lcd_device_unregister(plcd->lcd);
 116         kfree(plcd);
 117
 118         return 0;
 119 }
 120
 121 #ifdef CONFIG_PM
 122 static int platform_lcd_suspend(struct platform_device *pdev, pm_message_t st)
 123 {
 124         struct platform_lcd *plcd = platform_get_drvdata(pdev);
 125
 126         plcd->suspended = 1;
 127         platform_lcd_set_power(plcd->lcd, plcd->power);
 128
 129         return 0;
 130 }
 131
 132 static int platform_lcd_resume(struct platform_device *pdev)
 133 {
 134         struct platform_lcd *plcd = platform_get_drvdata(pdev);
 135
 136         plcd->suspended = 0;
 137         platform_lcd_set_power(plcd->lcd, plcd->power);
 138
 139         return 0;
 140 }
 141 #else
 142 #define platform_lcd_suspend NULL
 143 #define platform_lcd_resume NULL
 144 #endif
 145
 146 static struct platform_driver platform_lcd_driver = {
 147         .driver         = {
 148                 .name   = "platform-lcd",
 149                 .owner  = THIS_MODULE,
 150         },
 151         .probe          = platform_lcd_probe,
 152         .remove         = __devexit_p(platform_lcd_remove),
 153         .suspend        = platform_lcd_suspend,
 154         .resume         = platform_lcd_resume,
 155 };
 156
 157 static int __init platform_lcd_init(void)
 158 {
 159         return platform_driver_register(&platform_lcd_driver);
 160 }
 161
 162 static void __exit platform_lcd_cleanup(void)
 163 {
 164         platform_driver_unregister(&platform_lcd_driver);
 165 }
 166
 167 module_init(platform_lcd_init);
 168 module_exit(platform_lcd_cleanup);
 169
 170 MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
 171 MODULE_LICENSE("GPL v2");
 172 MODULE_ALIAS("platform:platform-lcd");