git.oblomov.eu Git - linux-2.6/blob - drivers/video/backlight/corgi_bl.c

   1 /*
   2  *  Backlight Driver for Sharp Corgi
   3  *
   4  *  Copyright (c) 2004-2005 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/spinlock.h>
  19 #include <linux/fb.h>
  20 #include <linux/backlight.h>
  21
  22 #include <asm/arch/sharpsl.h>
  23 #include <asm/hardware/sharpsl_pm.h>
  24
  25 #define CORGI_DEFAULT_INTENSITY         0x1f
  26 #define CORGI_LIMIT_MASK                0x0b
  27
  28 static int corgibl_intensity;
  29 static void (*corgibl_mach_set_intensity)(int intensity);
  30 static spinlock_t bl_lock = SPIN_LOCK_UNLOCKED;
  31 static struct backlight_properties corgibl_data;
  32 static struct backlight_device *corgi_backlight_device;
  33
  34 static unsigned long corgibl_flags;
  35 #define CORGIBL_SUSPENDED     0x01
  36 #define CORGIBL_BATTLOW       0x02
  37
  38 static int corgibl_send_intensity(struct backlight_device *bd)
  39 {
  40         unsigned long flags;
  41         void (*corgi_kick_batt)(void);
  42         int intensity = bd->props->brightness;
  43
  44         if (bd->props->power != FB_BLANK_UNBLANK)
  45                 intensity = 0;
  46         if (bd->props->fb_blank != FB_BLANK_UNBLANK)
  47                 intensity = 0;
  48         if (corgibl_flags & CORGIBL_SUSPENDED)
  49                 intensity = 0;
  50         if (corgibl_flags & CORGIBL_BATTLOW)
  51                 intensity &= CORGI_LIMIT_MASK;
  52
  53         spin_lock_irqsave(&bl_lock, flags);
  54
  55         corgibl_mach_set_intensity(intensity);
  56
  57         spin_unlock_irqrestore(&bl_lock, flags);
  58
  59         corgibl_intensity = intensity;
  60
  61         corgi_kick_batt = symbol_get(sharpsl_battery_kick);
  62         if (corgi_kick_batt) {
  63                 corgi_kick_batt();
  64                 symbol_put(sharpsl_battery_kick);
  65         }
  66
  67         return 0;
  68 }
  69
  70 #ifdef CONFIG_PM
  71 static int corgibl_suspend(struct platform_device *dev, pm_message_t state)
  72 {
  73         corgibl_flags |= CORGIBL_SUSPENDED;
  74         corgibl_send_intensity(corgi_backlight_device);
  75         return 0;
  76 }
  77
  78 static int corgibl_resume(struct platform_device *dev)
  79 {
  80         corgibl_flags &= ~CORGIBL_SUSPENDED;
  81         corgibl_send_intensity(corgi_backlight_device);
  82         return 0;
  83 }
  84 #else
  85 #define corgibl_suspend NULL
  86 #define corgibl_resume  NULL
  87 #endif
  88
  89 static int corgibl_get_intensity(struct backlight_device *bd)
  90 {
  91         return corgibl_intensity;
  92 }
  93
  94 static int corgibl_set_intensity(struct backlight_device *bd)
  95 {
  96         corgibl_send_intensity(corgi_backlight_device);
  97         return 0;
  98 }
  99
 100 /*
 101  * Called when the battery is low to limit the backlight intensity.
 102  * If limit==0 clear any limit, otherwise limit the intensity
 103  */
 104 void corgibl_limit_intensity(int limit)
 105 {
 106         if (limit)
 107                 corgibl_flags |= CORGIBL_BATTLOW;
 108         else
 109                 corgibl_flags &= ~CORGIBL_BATTLOW;
 110         corgibl_send_intensity(corgi_backlight_device);
 111 }
 112 EXPORT_SYMBOL(corgibl_limit_intensity);
 113
 114
 115 static struct backlight_properties corgibl_data = {
 116         .owner          = THIS_MODULE,
 117         .get_brightness = corgibl_get_intensity,
 118         .update_status  = corgibl_set_intensity,
 119 };
 120
 121 static int __init corgibl_probe(struct platform_device *pdev)
 122 {
 123         struct corgibl_machinfo *machinfo = pdev->dev.platform_data;
 124
 125         corgibl_data.max_brightness = machinfo->max_intensity;
 126         corgibl_mach_set_intensity = machinfo->set_bl_intensity;
 127
 128         corgi_backlight_device = backlight_device_register ("corgi-bl",
 129                 NULL, &corgibl_data);
 130         if (IS_ERR (corgi_backlight_device))
 131                 return PTR_ERR (corgi_backlight_device);
 132
 133         corgibl_data.power = FB_BLANK_UNBLANK;
 134         corgibl_data.brightness = CORGI_DEFAULT_INTENSITY;
 135         corgibl_send_intensity(corgi_backlight_device);
 136
 137         printk("Corgi Backlight Driver Initialized.\n");
 138         return 0;
 139 }
 140
 141 static int corgibl_remove(struct platform_device *dev)
 142 {
 143         backlight_device_unregister(corgi_backlight_device);
 144
 145         printk("Corgi Backlight Driver Unloaded\n");
 146         return 0;
 147 }
 148
 149 static struct platform_driver corgibl_driver = {
 150         .probe          = corgibl_probe,
 151         .remove         = corgibl_remove,
 152         .suspend        = corgibl_suspend,
 153         .resume         = corgibl_resume,
 154         .driver         = {
 155                 .name   = "corgi-bl",
 156         },
 157 };
 158
 159 static int __init corgibl_init(void)
 160 {
 161         return platform_driver_register(&corgibl_driver);
 162 }
 163
 164 static void __exit corgibl_exit(void)
 165 {
 166         platform_driver_unregister(&corgibl_driver);
 167 }
 168
 169 module_init(corgibl_init);
 170 module_exit(corgibl_exit);
 171
 172 MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
 173 MODULE_DESCRIPTION("Corgi Backlight Driver");
 174 MODULE_LICENSE("GPLv2");