drivers/video/backlight/hp680_bl.c

   1 /*
   2  *  Backlight Driver for HP Jornada 680
   3  *
   4  *  Copyright (c) 2005 Andriy Skulysh
   5  *
   6  *  Based on Sharp's Corgi Backlight Driver
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file "COPYING" in the main directory of this archive
  10  * for more details.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/fb.h>
  19 #include <linux/backlight.h>
  20
  21 #include <asm/cpu/dac.h>
  22 #include <asm/hp6xx.h>
  23 #include <asm/hd64461.h>
  24
  25 #define HP680_MAX_INTENSITY 255
  26 #define HP680_DEFAULT_INTENSITY 10
  27
  28 static int hp680bl_suspended;
  29 static int current_intensity = 0;
  30 static DEFINE_SPINLOCK(bl_lock);
  31 static struct backlight_device *hp680_backlight_device;
  32
  33 static void hp680bl_send_intensity(struct backlight_device *bd)
  34 {
  35         unsigned long flags;
  36         u16 v;
  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 (hp680bl_suspended)
  44                 intensity = 0;
  45
  46         spin_lock_irqsave(&bl_lock, flags);
  47         if (intensity && current_intensity == 0) {
  48                 sh_dac_enable(DAC_LCD_BRIGHTNESS);
  49                 v = inw(HD64461_GPBDR);
  50                 v &= ~HD64461_GPBDR_LCDOFF;
  51                 outw(v, HD64461_GPBDR);
  52                 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
  53         } else if (intensity == 0 && current_intensity != 0) {
  54                 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
  55                 sh_dac_disable(DAC_LCD_BRIGHTNESS);
  56                 v = inw(HD64461_GPBDR);
  57                 v |= HD64461_GPBDR_LCDOFF;
  58                 outw(v, HD64461_GPBDR);
  59         } else if (intensity) {
  60                 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
  61         }
  62         spin_unlock_irqrestore(&bl_lock, flags);
  63
  64         current_intensity = intensity;
  65 }
  66
  67
  68 #ifdef CONFIG_PM
  69 static int hp680bl_suspend(struct platform_device *dev, pm_message_t state)
  70 {
  71         hp680bl_suspended = 1;
  72         hp680bl_send_intensity(hp680_backlight_device);
  73         return 0;
  74 }
  75
  76 static int hp680bl_resume(struct platform_device *dev)
  77 {
  78         hp680bl_suspended = 0;
  79         hp680bl_send_intensity(hp680_backlight_device);
  80         return 0;
  81 }
  82 #else
  83 #define hp680bl_suspend NULL
  84 #define hp680bl_resume  NULL
  85 #endif
  86
  87 static int hp680bl_set_intensity(struct backlight_device *bd)
  88 {
  89         hp680bl_send_intensity(bd);
  90         return 0;
  91 }
  92
  93 static int hp680bl_get_intensity(struct backlight_device *bd)
  94 {
  95         return current_intensity;
  96 }
  97
  98 static struct backlight_properties hp680bl_data = {
  99         .max_brightness = HP680_MAX_INTENSITY,
 100         .get_brightness = hp680bl_get_intensity,
 101         .update_status  = hp680bl_set_intensity,
 102 };
 103
 104 static int __init hp680bl_probe(struct platform_device *dev)
 105 {
 106         hp680_backlight_device = backlight_device_register ("hp680-bl",
 107                 &dev->dev, NULL, &hp680bl_data);
 108         if (IS_ERR (hp680_backlight_device))
 109                 return PTR_ERR (hp680_backlight_device);
 110
 111         hp680_backlight_device->props->brightness = HP680_DEFAULT_INTENSITY;
 112         hp680bl_send_intensity(hp680_backlight_device);
 113
 114         return 0;
 115 }
 116
 117 static int hp680bl_remove(struct platform_device *dev)
 118 {
 119         hp680bl_data.brightness = 0;
 120         hp680bl_data.power = 0;
 121         hp680bl_send_intensity(hp680_backlight_device);
 122
 123         backlight_device_unregister(hp680_backlight_device);
 124
 125         return 0;
 126 }
 127
 128 static struct platform_driver hp680bl_driver = {
 129         .probe          = hp680bl_probe,
 130         .remove         = hp680bl_remove,
 131         .suspend        = hp680bl_suspend,
 132         .resume         = hp680bl_resume,
 133         .driver         = {
 134                 .name   = "hp680-bl",
 135         },
 136 };
 137
 138 static struct platform_device *hp680bl_device;
 139
 140 static int __init hp680bl_init(void)
 141 {
 142         int ret;
 143
 144         ret = platform_driver_register(&hp680bl_driver);
 145         if (!ret) {
 146                 hp680bl_device = platform_device_alloc("hp680-bl", -1);
 147                 if (!hp680bl_device)
 148                         return -ENOMEM;
 149
 150                 ret = platform_device_add(hp680bl_device);
 151
 152                 if (ret) {
 153                         platform_device_put(hp680bl_device);
 154                         platform_driver_unregister(&hp680bl_driver);
 155                 }
 156         }
 157         return ret;
 158 }
 159
 160 static void __exit hp680bl_exit(void)
 161 {
 162         platform_device_unregister(hp680bl_device);
 163         platform_driver_unregister(&hp680bl_driver);
 164 }
 165
 166 module_init(hp680bl_init);
 167 module_exit(hp680bl_exit);
 168
 169 MODULE_AUTHOR("Andriy Skulysh <askulysh@gmail.com>");
 170 MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver");
 171 MODULE_LICENSE("GPL");