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         usleep_range(10000, 11000);
  38         outb(KB3886_PWM0_WRITE, KB3886_IO);
  39         usleep_range(10000, 11000);
  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 const struct dmi_system_id kb3886bl_device_table[] __initconst = {
  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_SLEEP
 110 static int kb3886bl_suspend(struct device *dev)
 111 {
 112         struct backlight_device *bd = dev_get_drvdata(dev);
 113
 114         kb3886bl_flags |= KB3886BL_SUSPENDED;
 115         backlight_update_status(bd);
 116         return 0;
 117 }
 118
 119 static int kb3886bl_resume(struct device *dev)
 120 {
 121         struct backlight_device *bd = dev_get_drvdata(dev);
 122
 123         kb3886bl_flags &= ~KB3886BL_SUSPENDED;
 124         backlight_update_status(bd);
 125         return 0;
 126 }
 127 #endif
 128
 129 static SIMPLE_DEV_PM_OPS(kb3886bl_pm_ops, kb3886bl_suspend, kb3886bl_resume);
 130
 131 static int kb3886bl_get_intensity(struct backlight_device *bd)
 132 {
 133         return kb3886bl_intensity;
 134 }
 135
 136 static const struct backlight_ops kb3886bl_ops = {
 137         .get_brightness = kb3886bl_get_intensity,
 138         .update_status  = kb3886bl_send_intensity,
 139 };
 140
 141 static int kb3886bl_probe(struct platform_device *pdev)
 142 {
 143         struct backlight_properties props;
 144         struct kb3886bl_machinfo *machinfo = dev_get_platdata(&pdev->dev);
 145
 146         bl_machinfo = machinfo;
 147         if (!machinfo->limit_mask)
 148                 machinfo->limit_mask = -1;
 149
 150         memset(&props, 0, sizeof(struct backlight_properties));
 151         props.type = BACKLIGHT_RAW;
 152         props.max_brightness = machinfo->max_intensity;
 153         kb3886_backlight_device = devm_backlight_device_register(&pdev->dev,
 154                                                         "kb3886-bl", &pdev->dev,
 155                                                         NULL, &kb3886bl_ops,
 156                                                         &props);
 157         if (IS_ERR(kb3886_backlight_device))
 158                 return PTR_ERR(kb3886_backlight_device);
 159
 160         platform_set_drvdata(pdev, kb3886_backlight_device);
 161
 162         kb3886_backlight_device->props.power = FB_BLANK_UNBLANK;
 163         kb3886_backlight_device->props.brightness = machinfo->default_intensity;
 164         backlight_update_status(kb3886_backlight_device);
 165
 166         return 0;
 167 }
 168
 169 static struct platform_driver kb3886bl_driver = {
 170         .probe          = kb3886bl_probe,
 171         .driver         = {
 172                 .name   = "kb3886-bl",
 173                 .pm     = &kb3886bl_pm_ops,
 174         },
 175 };
 176
 177 static int __init kb3886_init(void)
 178 {
 179         if (!dmi_check_system(kb3886bl_device_table))
 180                 return -ENODEV;
 181
 182         platform_add_devices(devices, ARRAY_SIZE(devices));
 183         return platform_driver_register(&kb3886bl_driver);
 184 }
 185
 186 static void __exit kb3886_exit(void)
 187 {
 188         platform_driver_unregister(&kb3886bl_driver);
 189 }
 190
 191 module_init(kb3886_init);
 192 module_exit(kb3886_exit);
 193
 194 MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>");
 195 MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver");
 196 MODULE_LICENSE("GPL");
 197 MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*");