drivers/video/backlight/corgi_bl.c

   1 /*
   2  *  Backlight Driver for Sharp Zaurus Handhelds (various models)
   3  *
   4  *  Copyright (c) 2004-2006 Richard Purdie
   5  *
   6  *  Based on Sharp's 2.4 Backlight Driver
   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/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/mutex.h>
  19 #include <linux/fb.h>
  20 #include <linux/backlight.h>
  21
  22 static int corgibl_intensity;
  23 static struct backlight_properties corgibl_data;
  24 static struct backlight_device *corgi_backlight_device;
  25 static struct generic_bl_info *bl_machinfo;
  26
  27 static unsigned long corgibl_flags;
  28 #define CORGIBL_SUSPENDED     0x01
  29 #define CORGIBL_BATTLOW       0x02
  30
  31 static int corgibl_send_intensity(struct backlight_device *bd)
  32 {
  33         int intensity = bd->props.brightness;
  34
  35         if (bd->props.power != FB_BLANK_UNBLANK)
  36                 intensity = 0;
  37         if (bd->props.fb_blank != FB_BLANK_UNBLANK)
  38                 intensity = 0;
  39         if (corgibl_flags & CORGIBL_SUSPENDED)
  40                 intensity = 0;
  41         if (corgibl_flags & CORGIBL_BATTLOW)
  42                 intensity &= bl_machinfo->limit_mask;
  43
  44         bl_machinfo->set_bl_intensity(intensity);
  45
  46         corgibl_intensity = intensity;
  47
  48         if (bl_machinfo->kick_battery)
  49                 bl_machinfo->kick_battery();
  50
  51         return 0;
  52 }
  53
  54 #ifdef CONFIG_PM
  55 static int corgibl_suspend(struct platform_device *pdev, pm_message_t state)
  56 {
  57         struct backlight_device *bd = platform_get_drvdata(pdev);
  58
  59         corgibl_flags |= CORGIBL_SUSPENDED;
  60         backlight_update_status(bd);
  61         return 0;
  62 }
  63
  64 static int corgibl_resume(struct platform_device *pdev)
  65 {
  66         struct backlight_device *bd = platform_get_drvdata(pdev);
  67
  68         corgibl_flags &= ~CORGIBL_SUSPENDED;
  69         backlight_update_status(bd);
  70         return 0;
  71 }
  72 #else
  73 #define corgibl_suspend NULL
  74 #define corgibl_resume  NULL
  75 #endif
  76
  77 static int corgibl_get_intensity(struct backlight_device *bd)
  78 {
  79         return corgibl_intensity;
  80 }
  81
  82 /*
  83  * Called when the battery is low to limit the backlight intensity.
  84  * If limit==0 clear any limit, otherwise limit the intensity
  85  */
  86 void corgibl_limit_intensity(int limit)
  87 {
  88         if (limit)
  89                 corgibl_flags |= CORGIBL_BATTLOW;
  90         else
  91                 corgibl_flags &= ~CORGIBL_BATTLOW;
  92         backlight_update_status(corgi_backlight_device);
  93 }
  94 EXPORT_SYMBOL(corgibl_limit_intensity);
  95
  96
  97 static struct backlight_ops corgibl_ops = {
  98         .get_brightness = corgibl_get_intensity,
  99         .update_status  = corgibl_send_intensity,
 100 };
 101
 102 static int corgibl_probe(struct platform_device *pdev)
 103 {
 104         struct generic_bl_info *machinfo = pdev->dev.platform_data;
 105         const char *name = "generic-bl";
 106
 107         bl_machinfo = machinfo;
 108         if (!machinfo->limit_mask)
 109                 machinfo->limit_mask = -1;
 110
 111         if (machinfo->name)
 112                 name = machinfo->name;
 113
 114         corgi_backlight_device = backlight_device_register (name,
 115                 &pdev->dev, NULL, &corgibl_ops);
 116         if (IS_ERR (corgi_backlight_device))
 117                 return PTR_ERR (corgi_backlight_device);
 118
 119         platform_set_drvdata(pdev, corgi_backlight_device);
 120
 121         corgi_backlight_device->props.max_brightness = machinfo->max_intensity;
 122         corgi_backlight_device->props.power = FB_BLANK_UNBLANK;
 123         corgi_backlight_device->props.brightness = machinfo->default_intensity;
 124         backlight_update_status(corgi_backlight_device);
 125
 126         printk("Corgi Backlight Driver Initialized.\n");
 127         return 0;
 128 }
 129
 130 static int corgibl_remove(struct platform_device *pdev)
 131 {
 132         struct backlight_device *bd = platform_get_drvdata(pdev);
 133
 134         corgibl_data.power = 0;
 135         corgibl_data.brightness = 0;
 136         backlight_update_status(bd);
 137
 138         backlight_device_unregister(bd);
 139
 140         printk("Corgi Backlight Driver Unloaded\n");
 141         return 0;
 142 }
 143
 144 static struct platform_driver corgibl_driver = {
 145         .probe          = corgibl_probe,
 146         .remove         = corgibl_remove,
 147         .suspend        = corgibl_suspend,
 148         .resume         = corgibl_resume,
 149         .driver         = {
 150                 .name   = "generic-bl",
 151         },
 152 };
 153
 154 static int __init corgibl_init(void)
 155 {
 156         return platform_driver_register(&corgibl_driver);
 157 }
 158
 159 static void __exit corgibl_exit(void)
 160 {
 161         platform_driver_unregister(&corgibl_driver);
 162 }
 163
 164 module_init(corgibl_init);
 165 module_exit(corgibl_exit);
 166
 167 MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
 168 MODULE_DESCRIPTION("Corgi Backlight Driver");
 169 MODULE_LICENSE("GPL");