firmware/target/arm/ipod/backlight-4g_color.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2002 by Linus Nielsen Feltzing
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include "config.h"
  22 #include <stdlib.h>
  23 #include "cpu.h"
  24 #include "kernel.h"
  25 #include "thread.h"
  26 #include "i2c.h"
  27 #include "debug.h"
  28 #include "rtc.h"
  29 #include "usb.h"
  30 #include "power.h"
  31 #include "system.h"
  32 #include "button.h"
  33 #include "timer.h"
  34 #include "backlight.h"
  35 #include "backlight-target.h"
  36
  37 /* Index 0 is a dummy, 1..31 are used */
  38 static unsigned char log_brightness[32] = {
  39       0,   1,   2,   4,   6,   9,  12,  16,  20,  25,  30,  36,
  40      42,  49,  56,  64,  72,  81,  90, 100, 110, 121, 132, 144,
  41     156, 169, 182, 196, 210, 225, 240, 255
  42 };
  43
  44 static unsigned brightness = 100;   /* 1 to 255 */
  45 static bool enabled = false;
  46
  47 /* Handling B03 in _backlight_on() and _backlight_off() makes backlight go off
  48  * without delay. Not doing that does a short (fixed) fade out. Opt for the
  49  * latter. */
  50
  51 void _backlight_on(void)
  52 {
  53     /* brightness full */
  54     outl(0x80000000 | (brightness << 16), 0x7000a010);
  55     /* GPIO_SET_BITWISE(GPIOB_OUTPUT_VAL, 0x08); */
  56     enabled = true;
  57 }
  58
  59 void _backlight_off(void)
  60 {
  61     outl(0x80000000, 0x7000a010);
  62     /* GPIO_CLEAR_BITWISE(GPIOB_OUTPUT_VAL, 0x08); */
  63     enabled = false;
  64 }
  65
  66 void _backlight_set_brightness(int val)
  67 {
  68     brightness = log_brightness[val];
  69     if (enabled)
  70         outl(0x80000000 | (brightness << 16), 0x7000a010);
  71 }
  72
  73 bool _backlight_init(void)
  74 {
  75     GPIO_SET_BITWISE(GPIOB_ENABLE, 0x0c); /* B02 and B03 enable */
  76     GPIO_SET_BITWISE(GPIOB_OUTPUT_VAL, 0x08); /* B03 = 1 */
  77     GPO32_ENABLE &= ~0x2000000; /* D01 disable, so pwm takes over */
  78     DEV_EN |= DEV_PWM;   /* PWM enable */
  79
  80     _backlight_on();
  81     return true;
  82 }