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