drivers/video/backlight/generic_bl.c

   1 /*
   2  *  Generic Backlight Driver
   3  *
   4  *  Copyright (c) 2004-2008 Richard Purdie
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License version 2 as
   8  *  published by the Free Software Foundation.
   9  *
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/mutex.h>
  17 #include <linux/fb.h>
  18 #include <linux/backlight.h>
  19
  20 static int genericbl_intensity;
  21 static struct backlight_device *generic_backlight_device;
  22 static struct generic_bl_info *bl_machinfo;
  23
  24 static int genericbl_send_intensity(struct backlight_device *bd)
  25 {
  26         int intensity = bd->props.brightness;
  27
  28         if (bd->props.power != FB_BLANK_UNBLANK)
  29                 intensity = 0;
  30         if (bd->props.state & BL_CORE_FBBLANK)
  31                 intensity = 0;
  32         if (bd->props.state & BL_CORE_SUSPENDED)
  33                 intensity = 0;
  34
  35         bl_machinfo->set_bl_intensity(intensity);
  36
  37         genericbl_intensity = intensity;
  38
  39         if (bl_machinfo->kick_battery)
  40                 bl_machinfo->kick_battery();
  41
  42         return 0;
  43 }
  44
  45 static int genericbl_get_intensity(struct backlight_device *bd)
  46 {
  47         return genericbl_intensity;
  48 }
  49
  50 static const struct backlight_ops genericbl_ops = {
  51         .options = BL_CORE_SUSPENDRESUME,
  52         .get_brightness = genericbl_get_intensity,
  53         .update_status  = genericbl_send_intensity,
  54 };
  55
  56 static int genericbl_probe(struct platform_device *pdev)
  57 {
  58         struct backlight_properties props;
  59         struct generic_bl_info *machinfo = dev_get_platdata(&pdev->dev);
  60         const char *name = "generic-bl";
  61         struct backlight_device *bd;
  62
  63         bl_machinfo = machinfo;
  64         if (!machinfo->limit_mask)
  65                 machinfo->limit_mask = -1;
  66
  67         if (machinfo->name)
  68                 name = machinfo->name;
  69
  70         memset(&props, 0, sizeof(struct backlight_properties));
  71         props.type = BACKLIGHT_RAW;
  72         props.max_brightness = machinfo->max_intensity;
  73         bd = devm_backlight_device_register(&pdev->dev, name, &pdev->dev,
  74                                         NULL, &genericbl_ops, &props);
  75         if (IS_ERR(bd))
  76                 return PTR_ERR(bd);
  77
  78         platform_set_drvdata(pdev, bd);
  79
  80         bd->props.power = FB_BLANK_UNBLANK;
  81         bd->props.brightness = machinfo->default_intensity;
  82         backlight_update_status(bd);
  83
  84         generic_backlight_device = bd;
  85
  86         dev_info(&pdev->dev, "Generic Backlight Driver Initialized.\n");
  87         return 0;
  88 }
  89
  90 static int genericbl_remove(struct platform_device *pdev)
  91 {
  92         struct backlight_device *bd = platform_get_drvdata(pdev);
  93
  94         bd->props.power = 0;
  95         bd->props.brightness = 0;
  96         backlight_update_status(bd);
  97
  98         dev_info(&pdev->dev, "Generic Backlight Driver Unloaded\n");
  99         return 0;
 100 }
 101
 102 static struct platform_driver genericbl_driver = {
 103         .probe          = genericbl_probe,
 104         .remove         = genericbl_remove,
 105         .driver         = {
 106                 .name   = "generic-bl",
 107         },
 108 };
 109
 110 module_platform_driver(genericbl_driver);
 111
 112 MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
 113 MODULE_DESCRIPTION("Generic Backlight Driver");
 114 MODULE_LICENSE("GPL");