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