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 *pdev, pm_message_t state)
  65 {
  66         struct backlight_device *bd = platform_get_drvdata(pdev);
  67
  68         corgibl_flags |= CORGIBL_SUSPENDED;
  69         corgibl_send_intensity(bd);
  70         return 0;
  71 }
  72
  73 static int corgibl_resume(struct platform_device *pdev)
  74 {
  75         struct backlight_device *bd = platform_get_drvdata(pdev);
  76
  77         corgibl_flags &= ~CORGIBL_SUSPENDED;
  78         corgibl_send_intensity(bd);
  79         return 0;
  80 }
  81 #else
  82 #define corgibl_suspend NULL
  83 #define corgibl_resume  NULL
  84 #endif
  85
  86 static int corgibl_get_intensity(struct backlight_device *bd)
  87 {
  88         return corgibl_intensity;
  89 }
  90
  91 /*
  92  * Called when the battery is low to limit the backlight intensity.
  93  * If limit==0 clear any limit, otherwise limit the intensity
  94  */
  95 void corgibl_limit_intensity(int limit)
  96 {
  97         if (limit)
  98                 corgibl_flags |= CORGIBL_BATTLOW;
  99         else
 100                 corgibl_flags &= ~CORGIBL_BATTLOW;
 101         corgibl_send_intensity(corgi_backlight_device);
 102 }
 103 EXPORT_SYMBOL(corgibl_limit_intensity);
 104
 105
 106 static struct backlight_ops corgibl_ops = {
 107         .get_brightness = corgibl_get_intensity,
 108         .update_status  = corgibl_send_intensity,
 109 };
 110
 111 static int corgibl_probe(struct platform_device *pdev)
 112 {
 113         struct corgibl_machinfo *machinfo = pdev->dev.platform_data;
 114
 115         bl_machinfo = machinfo;
 116         if (!machinfo->limit_mask)
 117                 machinfo->limit_mask = -1;
 118
 119         corgi_backlight_device = backlight_device_register ("corgi-bl",
 120                 &pdev->dev, NULL, &corgibl_ops);
 121         if (IS_ERR (corgi_backlight_device))
 122                 return PTR_ERR (corgi_backlight_device);
 123
 124         platform_set_drvdata(pdev, corgi_backlight_device);
 125
 126         corgi_backlight_device->props.max_brightness = machinfo->max_intensity;
 127         corgi_backlight_device->props.power = FB_BLANK_UNBLANK;
 128         corgi_backlight_device->props.brightness = machinfo->default_intensity;
 129         corgibl_send_intensity(corgi_backlight_device);
 130
 131         printk("Corgi Backlight Driver Initialized.\n");
 132         return 0;
 133 }
 134
 135 static int corgibl_remove(struct platform_device *pdev)
 136 {
 137         struct backlight_device *bd = platform_get_drvdata(pdev);
 138
 139         corgibl_data.power = 0;
 140         corgibl_data.brightness = 0;
 141         corgibl_send_intensity(bd);
 142
 143         backlight_device_unregister(bd);
 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("GPL");