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 DEFINE_MUTEX(bl_mutex);
  26 static struct backlight_properties corgibl_data;
  27 static struct backlight_device *corgi_backlight_device;
  28 static struct corgibl_machinfo *bl_machinfo;
  29
  30 static unsigned long corgibl_flags;
  31 #define CORGIBL_SUSPENDED     0x01
  32 #define CORGIBL_BATTLOW       0x02
  33
  34 static int corgibl_send_intensity(struct backlight_device *bd)
  35 {
  36         void (*corgi_kick_batt)(void);
  37         int intensity = bd->props->brightness;
  38
  39         if (bd->props->power != FB_BLANK_UNBLANK)
  40                 intensity = 0;
  41         if (bd->props->fb_blank != FB_BLANK_UNBLANK)
  42                 intensity = 0;
  43         if (corgibl_flags & CORGIBL_SUSPENDED)
  44                 intensity = 0;
  45         if (corgibl_flags & CORGIBL_BATTLOW)
  46                 intensity &= bl_machinfo->limit_mask;
  47
  48         mutex_lock(&bl_mutex);
  49         bl_machinfo->set_bl_intensity(intensity);
  50         mutex_unlock(&bl_mutex);
  51
  52         corgibl_intensity = intensity;
  53
  54         corgi_kick_batt = symbol_get(sharpsl_battery_kick);
  55         if (corgi_kick_batt) {
  56                 corgi_kick_batt();
  57                 symbol_put(sharpsl_battery_kick);
  58         }
  59
  60         return 0;
  61 }
  62
  63 #ifdef CONFIG_PM
  64 static int corgibl_suspend(struct platform_device *dev, pm_message_t state)
  65 {
  66         corgibl_flags |= CORGIBL_SUSPENDED;
  67         corgibl_send_intensity(corgi_backlight_device);
  68         return 0;
  69 }
  70
  71 static int corgibl_resume(struct platform_device *dev)
  72 {
  73         corgibl_flags &= ~CORGIBL_SUSPENDED;
  74         corgibl_send_intensity(corgi_backlight_device);
  75         return 0;
  76 }
  77 #else
  78 #define corgibl_suspend NULL
  79 #define corgibl_resume  NULL
  80 #endif
  81
  82 static int corgibl_get_intensity(struct backlight_device *bd)
  83 {
  84         return corgibl_intensity;
  85 }
  86
  87 static int corgibl_set_intensity(struct backlight_device *bd)
  88 {
  89         corgibl_send_intensity(corgi_backlight_device);
  90         return 0;
  91 }
  92
  93 /*
  94  * Called when the battery is low to limit the backlight intensity.
  95  * If limit==0 clear any limit, otherwise limit the intensity
  96  */
  97 void corgibl_limit_intensity(int limit)
  98 {
  99         if (limit)
 100                 corgibl_flags |= CORGIBL_BATTLOW;
 101         else
 102                 corgibl_flags &= ~CORGIBL_BATTLOW;
 103         corgibl_send_intensity(corgi_backlight_device);
 104 }
 105 EXPORT_SYMBOL(corgibl_limit_intensity);
 106
 107
 108 static struct backlight_properties corgibl_data = {
 109         .owner          = THIS_MODULE,
 110         .get_brightness = corgibl_get_intensity,
 111         .update_status  = corgibl_set_intensity,
 112 };
 113
 114 static int __init corgibl_probe(struct platform_device *pdev)
 115 {
 116         struct corgibl_machinfo *machinfo = pdev->dev.platform_data;
 117
 118         bl_machinfo = machinfo;
 119         corgibl_data.max_brightness = machinfo->max_intensity;
 120         if (!machinfo->limit_mask)
 121                 machinfo->limit_mask = -1;
 122
 123         corgi_backlight_device = backlight_device_register ("corgi-bl",
 124                 NULL, &corgibl_data);
 125         if (IS_ERR (corgi_backlight_device))
 126                 return PTR_ERR (corgi_backlight_device);
 127
 128         corgibl_data.power = FB_BLANK_UNBLANK;
 129         corgibl_data.brightness = machinfo->default_intensity;
 130         corgibl_send_intensity(corgi_backlight_device);
 131
 132         printk("Corgi Backlight Driver Initialized.\n");
 133         return 0;
 134 }
 135
 136 static int corgibl_remove(struct platform_device *dev)
 137 {
 138         backlight_device_unregister(corgi_backlight_device);
 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   = "corgi-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("GPLv2");