linux/drivers/video/backlight/hp680_bl.c
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   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 <cpu/dac.h>
  22#include <mach/hp6xx.h>
  23#include <asm/hd64461.h>
  24
  25#define HP680_MAX_INTENSITY 255
  26#define HP680_DEFAULT_INTENSITY 10
  27
  28static int hp680bl_suspended;
  29static int current_intensity = 0;
  30static DEFINE_SPINLOCK(bl_lock);
  31
  32static void hp680bl_send_intensity(struct backlight_device *bd)
  33{
  34        unsigned long flags;
  35        u16 v;
  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 (hp680bl_suspended)
  43                intensity = 0;
  44
  45        spin_lock_irqsave(&bl_lock, flags);
  46        if (intensity && current_intensity == 0) {
  47                sh_dac_enable(DAC_LCD_BRIGHTNESS);
  48                v = inw(HD64461_GPBDR);
  49                v &= ~HD64461_GPBDR_LCDOFF;
  50                outw(v, HD64461_GPBDR);
  51                sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
  52        } else if (intensity == 0 && current_intensity != 0) {
  53                sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
  54                sh_dac_disable(DAC_LCD_BRIGHTNESS);
  55                v = inw(HD64461_GPBDR);
  56                v |= HD64461_GPBDR_LCDOFF;
  57                outw(v, HD64461_GPBDR);
  58        } else if (intensity) {
  59                sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
  60        }
  61        spin_unlock_irqrestore(&bl_lock, flags);
  62
  63        current_intensity = intensity;
  64}
  65
  66
  67#ifdef CONFIG_PM
  68static int hp680bl_suspend(struct platform_device *pdev, pm_message_t state)
  69{
  70        struct backlight_device *bd = platform_get_drvdata(pdev);
  71
  72        hp680bl_suspended = 1;
  73        hp680bl_send_intensity(bd);
  74        return 0;
  75}
  76
  77static int hp680bl_resume(struct platform_device *pdev)
  78{
  79        struct backlight_device *bd = platform_get_drvdata(pdev);
  80
  81        hp680bl_suspended = 0;
  82        hp680bl_send_intensity(bd);
  83        return 0;
  84}
  85#else
  86#define hp680bl_suspend NULL
  87#define hp680bl_resume  NULL
  88#endif
  89
  90static int hp680bl_set_intensity(struct backlight_device *bd)
  91{
  92        hp680bl_send_intensity(bd);
  93        return 0;
  94}
  95
  96static int hp680bl_get_intensity(struct backlight_device *bd)
  97{
  98        return current_intensity;
  99}
 100
 101static struct backlight_ops hp680bl_ops = {
 102        .get_brightness = hp680bl_get_intensity,
 103        .update_status  = hp680bl_set_intensity,
 104};
 105
 106static int __devinit hp680bl_probe(struct platform_device *pdev)
 107{
 108        struct backlight_device *bd;
 109
 110        bd = backlight_device_register ("hp680-bl", &pdev->dev, NULL,
 111                    &hp680bl_ops);
 112        if (IS_ERR(bd))
 113                return PTR_ERR(bd);
 114
 115        platform_set_drvdata(pdev, bd);
 116
 117        bd->props.max_brightness = HP680_MAX_INTENSITY;
 118        bd->props.brightness = HP680_DEFAULT_INTENSITY;
 119        hp680bl_send_intensity(bd);
 120
 121        return 0;
 122}
 123
 124static int hp680bl_remove(struct platform_device *pdev)
 125{
 126        struct backlight_device *bd = platform_get_drvdata(pdev);
 127
 128        bd->props.brightness = 0;
 129        bd->props.power = 0;
 130        hp680bl_send_intensity(bd);
 131
 132        backlight_device_unregister(bd);
 133
 134        return 0;
 135}
 136
 137static struct platform_driver hp680bl_driver = {
 138        .probe          = hp680bl_probe,
 139        .remove         = hp680bl_remove,
 140        .suspend        = hp680bl_suspend,
 141        .resume         = hp680bl_resume,
 142        .driver         = {
 143                .name   = "hp680-bl",
 144        },
 145};
 146
 147static struct platform_device *hp680bl_device;
 148
 149static int __init hp680bl_init(void)
 150{
 151        int ret;
 152
 153        ret = platform_driver_register(&hp680bl_driver);
 154        if (ret)
 155                return ret;
 156        hp680bl_device = platform_device_register_simple("hp680-bl", -1,
 157                                                        NULL, 0);
 158        if (IS_ERR(hp680bl_device)) {
 159                platform_driver_unregister(&hp680bl_driver);
 160                return PTR_ERR(hp680bl_device);
 161        }
 162        return 0;
 163}
 164
 165static void __exit hp680bl_exit(void)
 166{
 167        platform_device_unregister(hp680bl_device);
 168        platform_driver_unregister(&hp680bl_driver);
 169}
 170
 171module_init(hp680bl_init);
 172module_exit(hp680bl_exit);
 173
 174MODULE_AUTHOR("Andriy Skulysh <askulysh@gmail.com>");
 175MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver");
 176MODULE_LICENSE("GPL");
 177