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