linux/drivers/video/backlight/kb3886_bl.c
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   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
  30static DEFINE_MUTEX(bl_mutex);
  31
  32static 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
  44struct kb3886bl_machinfo {
  45        int max_intensity;
  46        int default_intensity;
  47        int limit_mask;
  48        void (*set_bl_intensity)(int intensity);
  49};
  50
  51static 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
  58static struct platform_device kb3886bl_device = {
  59        .name           = "kb3886-bl",
  60        .dev            = {
  61                .platform_data  = &kb3886_bl_machinfo,
  62        },
  63        .id             = -1,
  64};
  65
  66static struct platform_device *devices[] __initdata = {
  67        &kb3886bl_device,
  68};
  69
  70/*
  71 * Back to driver
  72 */
  73
  74static int kb3886bl_intensity;
  75static struct backlight_device *kb3886_backlight_device;
  76static struct kb3886bl_machinfo *bl_machinfo;
  77
  78static unsigned long kb3886bl_flags;
  79#define KB3886BL_SUSPENDED     0x01
  80
  81static struct dmi_system_id kb3886bl_device_table[] __initdata = {
  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
  92static 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
 110static 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
 119static 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
 129static SIMPLE_DEV_PM_OPS(kb3886bl_pm_ops, kb3886bl_suspend, kb3886bl_resume);
 130
 131static int kb3886bl_get_intensity(struct backlight_device *bd)
 132{
 133        return kb3886bl_intensity;
 134}
 135
 136static const struct backlight_ops kb3886bl_ops = {
 137        .get_brightness = kb3886bl_get_intensity,
 138        .update_status  = kb3886bl_send_intensity,
 139};
 140
 141static 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
 169static struct platform_driver kb3886bl_driver = {
 170        .probe          = kb3886bl_probe,
 171        .driver         = {
 172                .name   = "kb3886-bl",
 173                .pm     = &kb3886bl_pm_ops,
 174        },
 175};
 176
 177static 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
 186static void __exit kb3886_exit(void)
 187{
 188        platform_driver_unregister(&kb3886bl_driver);
 189}
 190
 191module_init(kb3886_init);
 192module_exit(kb3886_exit);
 193
 194MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>");
 195MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver");
 196MODULE_LICENSE("GPL");
 197MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*");
 198