drivers/video/backlight/kb3886_bl.c

   1 /*
   2  *  Backlight Driver for the KB3886 Backlight
   3  *
   4  *  Copyright (c) 2007-2008 Claudio Nieder
   5  *
   6  *  Based on corgi_bl.c by Richard Purdie and kb3886 driver by Robert Woerle
   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 <linux/delay.h>
  22 #include <linux/dmi.h>
  23
  24 #define KB3886_PARENT 0x64
  25 #define KB3886_IO 0x60
  26 #define KB3886_ADC_DAC_PWM 0xC4
  27 #define KB3886_PWM0_WRITE 0x81
  28 #define KB3886_PWM0_READ 0x41
  29
  30 static DEFINE_MUTEX(bl_mutex);
  31
  32 static void kb3886_bl_set_intensity(int intensity)
  33 {
  34         mutex_lock(&bl_mutex);
  35         intensity = intensity&0xff;
  36         outb(KB3886_ADC_DAC_PWM, KB3886_PARENT);
  37         msleep(10);
  38         outb(KB3886_PWM0_WRITE, KB3886_IO);
  39         msleep(10);
  40         outb(intensity, KB3886_IO);
  41         mutex_unlock(&bl_mutex);
  42 }
  43
  44 struct kb3886bl_machinfo {
  45         int max_intensity;
  46         int default_intensity;
  47         int limit_mask;
  48         void (*set_bl_intensity)(int intensity);
  49 };
  50
  51 static struct kb3886bl_machinfo kb3886_bl_machinfo = {
  52         .max_intensity = 0xff,
  53         .default_intensity = 0xa0,
  54         .limit_mask = 0x7f,
  55         .set_bl_intensity = kb3886_bl_set_intensity,
  56 };
  57
  58 static struct platform_device kb3886bl_device = {
  59         .name           = "kb3886-bl",
  60         .dev            = {
  61                 .platform_data  = &kb3886_bl_machinfo,
  62         },
  63         .id             = -1,
  64 };
  65
  66 static struct platform_device *devices[] __initdata = {
  67         &kb3886bl_device,
  68 };
  69
  70 /*
  71  * Back to driver
  72  */
  73
  74 static int kb3886bl_intensity;
  75 static struct backlight_device *kb3886_backlight_device;
  76 static struct kb3886bl_machinfo *bl_machinfo;
  77
  78 static unsigned long kb3886bl_flags;
  79 #define KB3886BL_SUSPENDED     0x01
  80
  81 static struct dmi_system_id __initdata kb3886bl_device_table[] = {
  82         {
  83                 .ident = "Sahara Touch-iT",
  84                 .matches = {
  85                         DMI_MATCH(DMI_SYS_VENDOR, "SDV"),
  86                         DMI_MATCH(DMI_PRODUCT_NAME, "iTouch T201"),
  87                 },
  88         },
  89         { }
  90 };
  91
  92 static int kb3886bl_send_intensity(struct backlight_device *bd)
  93 {
  94         int intensity = bd->props.brightness;
  95
  96         if (bd->props.power != FB_BLANK_UNBLANK)
  97                 intensity = 0;
  98         if (bd->props.fb_blank != FB_BLANK_UNBLANK)
  99                 intensity = 0;
 100         if (kb3886bl_flags & KB3886BL_SUSPENDED)
 101                 intensity = 0;
 102
 103         bl_machinfo->set_bl_intensity(intensity);
 104
 105         kb3886bl_intensity = intensity;
 106         return 0;
 107 }
 108
 109 #ifdef CONFIG_PM
 110 static int kb3886bl_suspend(struct platform_device *pdev, pm_message_t state)
 111 {
 112         struct backlight_device *bd = platform_get_drvdata(pdev);
 113
 114         kb3886bl_flags |= KB3886BL_SUSPENDED;
 115         backlight_update_status(bd);
 116         return 0;
 117 }
 118
 119 static int kb3886bl_resume(struct platform_device *pdev)
 120 {
 121         struct backlight_device *bd = platform_get_drvdata(pdev);
 122
 123         kb3886bl_flags &= ~KB3886BL_SUSPENDED;
 124         backlight_update_status(bd);
 125         return 0;
 126 }
 127 #else
 128 #define kb3886bl_suspend        NULL
 129 #define kb3886bl_resume         NULL
 130 #endif
 131
 132 static int kb3886bl_get_intensity(struct backlight_device *bd)
 133 {
 134         return kb3886bl_intensity;
 135 }
 136
 137 static const struct backlight_ops kb3886bl_ops = {
 138         .get_brightness = kb3886bl_get_intensity,
 139         .update_status  = kb3886bl_send_intensity,
 140 };
 141
 142 static int kb3886bl_probe(struct platform_device *pdev)
 143 {
 144         struct kb3886bl_machinfo *machinfo = pdev->dev.platform_data;
 145
 146         bl_machinfo = machinfo;
 147         if (!machinfo->limit_mask)
 148                 machinfo->limit_mask = -1;
 149
 150         kb3886_backlight_device = backlight_device_register("kb3886-bl",
 151                 &pdev->dev, NULL, &kb3886bl_ops);
 152         if (IS_ERR(kb3886_backlight_device))
 153                 return PTR_ERR(kb3886_backlight_device);
 154
 155         platform_set_drvdata(pdev, kb3886_backlight_device);
 156
 157         kb3886_backlight_device->props.max_brightness = machinfo->max_intensity;
 158         kb3886_backlight_device->props.power = FB_BLANK_UNBLANK;
 159         kb3886_backlight_device->props.brightness = machinfo->default_intensity;
 160         backlight_update_status(kb3886_backlight_device);
 161
 162         return 0;
 163 }
 164
 165 static int kb3886bl_remove(struct platform_device *pdev)
 166 {
 167         struct backlight_device *bd = platform_get_drvdata(pdev);
 168
 169         backlight_device_unregister(bd);
 170
 171         return 0;
 172 }
 173
 174 static struct platform_driver kb3886bl_driver = {
 175         .probe          = kb3886bl_probe,
 176         .remove         = kb3886bl_remove,
 177         .suspend        = kb3886bl_suspend,
 178         .resume         = kb3886bl_resume,
 179         .driver         = {
 180                 .name   = "kb3886-bl",
 181         },
 182 };
 183
 184 static int __init kb3886_init(void)
 185 {
 186         if (!dmi_check_system(kb3886bl_device_table))
 187                 return -ENODEV;
 188
 189         platform_add_devices(devices, ARRAY_SIZE(devices));
 190         return platform_driver_register(&kb3886bl_driver);
 191 }
 192
 193 static void __exit kb3886_exit(void)
 194 {
 195         platform_driver_unregister(&kb3886bl_driver);
 196 }
 197
 198 module_init(kb3886_init);
 199 module_exit(kb3886_exit);
 200
 201 MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>");
 202 MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver");
 203 MODULE_LICENSE("GPL");
 204 MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*");