LXR linux/drivers/video/backlight/hp680

   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 const 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_properties props;
 109        struct backlight_device *bd;
 110
 111        memset(&props, 0, sizeof(struct backlight_properties));
 112        props.type = BACKLIGHT_RAW;
 113        props.max_brightness = HP680_MAX_INTENSITY;
 114        bd = backlight_device_register("hp680-bl", &pdev->dev, NULL,
 115                                       &hp680bl_ops, &props);
 116        if (IS_ERR(bd))
 117                return PTR_ERR(bd);
 118
 119        platform_set_drvdata(pdev, bd);
 120
 121        bd->props.brightness = HP680_DEFAULT_INTENSITY;
 122        hp680bl_send_intensity(bd);
 123
 124        return 0;
 125}
 126
 127static int hp680bl_remove(struct platform_device *pdev)
 128{
 129        struct backlight_device *bd = platform_get_drvdata(pdev);
 130
 131        bd->props.brightness = 0;
 132        bd->props.power = 0;
 133        hp680bl_send_intensity(bd);
 134
 135        backlight_device_unregister(bd);
 136
 137        return 0;
 138}
 139
 140static struct platform_driver hp680bl_driver = {
 141        .probe          = hp680bl_probe,
 142        .remove         = hp680bl_remove,
 143        .suspend        = hp680bl_suspend,
 144        .resume         = hp680bl_resume,
 145        .driver         = {
 146                .name   = "hp680-bl",
 147        },
 148};
 149
 150static struct platform_device *hp680bl_device;
 151
 152static int __init hp680bl_init(void)
 153{
 154        int ret;
 155
 156        ret = platform_driver_register(&hp680bl_driver);
 157        if (ret)
 158                return ret;
 159        hp680bl_device = platform_device_register_simple("hp680-bl", -1,
 160                                                        NULL, 0);
 161        if (IS_ERR(hp680bl_device)) {
 162                platform_driver_unregister(&hp680bl_driver);
 163                return PTR_ERR(hp680bl_device);
 164        }
 165        return 0;
 166}
 167
 168static void __exit hp680bl_exit(void)
 169{
 170        platform_device_unregister(hp680bl_device);
 171        platform_driver_unregister(&hp680bl_driver);
 172}
 173
 174module_init(hp680bl_init);
 175module_exit(hp680bl_exit);
 176
 177MODULE_AUTHOR("Andriy Skulysh <askulysh@gmail.com>");
 178MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver");
 179MODULE_LICENSE("GPL");
 180