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         if (pdata->probe) {
  90                 err = pdata->probe(pdata);
  91                 if (err)
  92                         return err;
  93         }
  94
  95         plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd),
  96                             GFP_KERNEL);
  97         if (!plcd) {
  98                 dev_err(dev, "no memory for state\n");
  99                 return -ENOMEM;
 100         }
 101
 102         plcd->us = dev;
 103         plcd->pdata = pdata;
 104         plcd->lcd = lcd_device_register(dev_name(dev), dev,
 105                                         plcd, &platform_lcd_ops);
 106         if (IS_ERR(plcd->lcd)) {
 107                 dev_err(dev, "cannot register lcd device\n");
 108                 err = PTR_ERR(plcd->lcd);
 109                 goto err;
 110         }
 111
 112         platform_set_drvdata(pdev, plcd);
 113         platform_lcd_set_power(plcd->lcd, FB_BLANK_NORMAL);
 114
 115         return 0;
 116
 117  err:
 118         return err;
 119 }
 120
 121 static int platform_lcd_remove(struct platform_device *pdev)
 122 {
 123         struct platform_lcd *plcd = platform_get_drvdata(pdev);
 124
 125         lcd_device_unregister(plcd->lcd);
 126
 127         return 0;
 128 }
 129
 130 #ifdef CONFIG_PM_SLEEP
 131 static int platform_lcd_suspend(struct device *dev)
 132 {
 133         struct platform_lcd *plcd = dev_get_drvdata(dev);
 134
 135         plcd->suspended = 1;
 136         platform_lcd_set_power(plcd->lcd, plcd->power);
 137
 138         return 0;
 139 }
 140
 141 static int platform_lcd_resume(struct device *dev)
 142 {
 143         struct platform_lcd *plcd = dev_get_drvdata(dev);
 144
 145         plcd->suspended = 0;
 146         platform_lcd_set_power(plcd->lcd, plcd->power);
 147
 148         return 0;
 149 }
 150 #endif
 151
 152 static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend,
 153                         platform_lcd_resume);
 154
 155 #ifdef CONFIG_OF
 156 static const struct of_device_id platform_lcd_of_match[] = {
 157         { .compatible = "platform-lcd" },
 158         {},
 159 };
 160 MODULE_DEVICE_TABLE(of, platform_lcd_of_match);
 161 #endif
 162
 163 static struct platform_driver platform_lcd_driver = {
 164         .driver         = {
 165                 .name   = "platform-lcd",
 166                 .owner  = THIS_MODULE,
 167                 .pm     = &platform_lcd_pm_ops,
 168                 .of_match_table = of_match_ptr(platform_lcd_of_match),
 169         },
 170         .probe          = platform_lcd_probe,
 171         .remove         = platform_lcd_remove,
 172 };
 173
 174 module_platform_driver(platform_lcd_driver);
 175
 176 MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
 177 MODULE_LICENSE("GPL v2");
 178 MODULE_ALIAS("platform:platform-lcd");