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 <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
  28 static int hp680bl_suspended;
  29 static int current_intensity;
  30 static DEFINE_SPINLOCK(bl_lock);
  31
  32 static void hp680bl_send_intensity(struct backlight_device *bd)
  33 {
  34         unsigned long flags;
  35         u16 v;
  36         int intensity = backlight_get_brightness(bd);
  37
  38         if (hp680bl_suspended)
  39                 intensity = 0;
  40
  41         spin_lock_irqsave(&bl_lock, flags);
  42         if (intensity && current_intensity == 0) {
  43                 sh_dac_enable(DAC_LCD_BRIGHTNESS);
  44                 v = inw(HD64461_GPBDR);
  45                 v &= ~HD64461_GPBDR_LCDOFF;
  46                 outw(v, HD64461_GPBDR);
  47                 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
  48         } else if (intensity == 0 && current_intensity != 0) {
  49                 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
  50                 sh_dac_disable(DAC_LCD_BRIGHTNESS);
  51                 v = inw(HD64461_GPBDR);
  52                 v |= HD64461_GPBDR_LCDOFF;
  53                 outw(v, HD64461_GPBDR);
  54         } else if (intensity) {
  55                 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
  56         }
  57         spin_unlock_irqrestore(&bl_lock, flags);
  58
  59         current_intensity = intensity;
  60 }
  61
  62
  63 #ifdef CONFIG_PM_SLEEP
  64 static int hp680bl_suspend(struct device *dev)
  65 {
  66         struct backlight_device *bd = dev_get_drvdata(dev);
  67
  68         hp680bl_suspended = 1;
  69         hp680bl_send_intensity(bd);
  70         return 0;
  71 }
  72
  73 static int hp680bl_resume(struct device *dev)
  74 {
  75         struct backlight_device *bd = dev_get_drvdata(dev);
  76
  77         hp680bl_suspended = 0;
  78         hp680bl_send_intensity(bd);
  79         return 0;
  80 }
  81 #endif
  82
  83 static SIMPLE_DEV_PM_OPS(hp680bl_pm_ops, hp680bl_suspend, hp680bl_resume);
  84
  85 static int hp680bl_set_intensity(struct backlight_device *bd)
  86 {
  87         hp680bl_send_intensity(bd);
  88         return 0;
  89 }
  90
  91 static int hp680bl_get_intensity(struct backlight_device *bd)
  92 {
  93         return current_intensity;
  94 }
  95
  96 static const struct backlight_ops hp680bl_ops = {
  97         .get_brightness = hp680bl_get_intensity,
  98         .update_status  = hp680bl_set_intensity,
  99 };
 100
 101 static int hp680bl_probe(struct platform_device *pdev)
 102 {
 103         struct backlight_properties props;
 104         struct backlight_device *bd;
 105
 106         memset(&props, 0, sizeof(struct backlight_properties));
 107         props.type = BACKLIGHT_RAW;
 108         props.max_brightness = HP680_MAX_INTENSITY;
 109         bd = devm_backlight_device_register(&pdev->dev, "hp680-bl", &pdev->dev,
 110                                         NULL, &hp680bl_ops, &props);
 111         if (IS_ERR(bd))
 112                 return PTR_ERR(bd);
 113
 114         platform_set_drvdata(pdev, bd);
 115
 116         bd->props.brightness = HP680_DEFAULT_INTENSITY;
 117         hp680bl_send_intensity(bd);
 118
 119         return 0;
 120 }
 121
 122 static void hp680bl_remove(struct platform_device *pdev)
 123 {
 124         struct backlight_device *bd = platform_get_drvdata(pdev);
 125
 126         bd->props.brightness = 0;
 127         bd->props.power = 0;
 128         hp680bl_send_intensity(bd);
 129 }
 130
 131 static struct platform_driver hp680bl_driver = {
 132         .probe          = hp680bl_probe,
 133         .remove         = hp680bl_remove,
 134         .driver         = {
 135                 .name   = "hp680-bl",
 136                 .pm     = &hp680bl_pm_ops,
 137         },
 138 };
 139
 140 static struct platform_device *hp680bl_device;
 141
 142 static int __init hp680bl_init(void)
 143 {
 144         int ret;
 145
 146         ret = platform_driver_register(&hp680bl_driver);
 147         if (ret)
 148                 return ret;
 149         hp680bl_device = platform_device_register_simple("hp680-bl", -1,
 150                                                         NULL, 0);
 151         if (IS_ERR(hp680bl_device)) {
 152                 platform_driver_unregister(&hp680bl_driver);
 153                 return PTR_ERR(hp680bl_device);
 154         }
 155         return 0;
 156 }
 157
 158 static void __exit hp680bl_exit(void)
 159 {
 160         platform_device_unregister(hp680bl_device);
 161         platform_driver_unregister(&hp680bl_driver);
 162 }
 163
 164 module_init(hp680bl_init);
 165 module_exit(hp680bl_exit);
 166
 167 MODULE_AUTHOR("Andriy Skulysh <askulysh@gmail.com>");
 168 MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver");
 169 MODULE_LICENSE("GPL");