firmware/target/arm/as3525/sansa-clip/button-clip.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2009 Bertrik Sikken
  11  * Copyright (C) 2008 François Dinel
  12  * Copyright (C) 2008 Rafaël Carré
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
  16  * as published by the Free Software Foundation; either version 2
  17  * of the License, or (at your option) any later version.
  18  *
  19  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  20  * KIND, either express or implied.
  21  *
  22  ****************************************************************************/
  23 #include "system.h"
  24 #include "button-target.h"
  25 #include "as3525.h"
  26 #ifndef BOOTLOADER
  27 #include "backlight.h"
  28 #endif
  29
  30 /*  The Sansa Clip uses a button matrix that is scanned by selecting one of
  31     three rows and reading back the button states from the columns.
  32
  33     In this driver, the row is changed at each call (i.e. once per tick).
  34     In one tick, column data from one row is read back and then the next row
  35     is selected for the following tick. This mechanism ensures that there is
  36     plenty time between selecting a row and reading the columns, avoiding the
  37     need for explicit delays.
  38 */
  39
  40
  41 void button_init_device(void)
  42 {
  43     GPIOA_DIR &= ~((1<<7) | (1<<3));
  44     GPIOB_DIR &= ~((1<<2) | (1<<1) | (1<<0));
  45     GPIOC_PIN(4) = 0;
  46     GPIOC_PIN(5) = 0;
  47     GPIOC_PIN(6) = 0;
  48     GPIOC_DIR |= ((1<<6) | (1<<5) | (1<<4));
  49
  50     /* get initial readings */
  51     button_read_device();
  52     button_read_device();
  53     button_read_device();
  54 }
  55
  56 int button_read_device(void)
  57 {
  58     static int row = 0;
  59     static int buttons = 0;
  60     static unsigned power_counter = 0;
  61
  62     if(button_hold())
  63     {
  64         power_counter = HZ;
  65         return 0;
  66     }
  67
  68     /* direct GPIO connections */
  69     /* read power, but not if hold button was just released, since
  70      * you basically always hit power due to the slider mechanism after
  71      * releasing hold (wait 1 sec) */
  72     if (power_counter)
  73         power_counter--;
  74
  75     if (GPIOA_PIN(7) && !power_counter)
  76         buttons |= BUTTON_POWER;
  77     else
  78         buttons &= ~BUTTON_POWER;
  79
  80     /* This is a keypad using C4-C6 as columns and B0-B2 as rows */
  81     switch (row) {
  82
  83     case 0:
  84         buttons &= ~(BUTTON_VOL_UP | BUTTON_UP);
  85
  86         (void)GPIOB_PIN(0); /* C4B0 is unused */
  87
  88         if (GPIOB_PIN(1))
  89             buttons |= BUTTON_VOL_UP;
  90
  91         if (GPIOB_PIN(2))
  92             buttons |= BUTTON_UP;
  93
  94         GPIOC_PIN(4) = 0;
  95         GPIOC_PIN(5) = (1<<5);
  96         row++;
  97         break;
  98
  99     case 1:
 100         buttons &= ~(BUTTON_LEFT | BUTTON_SELECT | BUTTON_RIGHT);
 101
 102         if (GPIOB_PIN(0))
 103             buttons |= BUTTON_LEFT;
 104
 105         if (GPIOB_PIN(1))
 106             buttons |= BUTTON_SELECT;
 107
 108         if (GPIOB_PIN(2))
 109             buttons |= BUTTON_RIGHT;
 110
 111         GPIOC_PIN(5) = 0;
 112         GPIOC_PIN(6) = (1<<6);
 113         row++;
 114         break;
 115
 116     case 2:
 117         buttons &= ~(BUTTON_DOWN | BUTTON_VOL_DOWN | BUTTON_HOME);
 118
 119         if (GPIOB_PIN(0))
 120             buttons |= BUTTON_DOWN;
 121
 122         if (GPIOB_PIN(1))
 123             buttons |= BUTTON_VOL_DOWN;
 124
 125         if (GPIOB_PIN(2))
 126             buttons |= BUTTON_HOME;
 127
 128         GPIOC_PIN(6) = 0;
 129         GPIOC_PIN(4) = (1<<4);
 130
 131     default:
 132         row = 0;
 133         break;
 134     }
 135
 136     return buttons;
 137 }
 138
 139 bool button_hold(void)
 140 {
 141 #ifndef BOOTLOADER
 142     static bool hold_button_old = false;
 143 #endif
 144     bool hold_button = (GPIOA_PIN(3) != 0);
 145
 146 #ifndef BOOTLOADER
 147     /* light handling */
 148     if (hold_button != hold_button_old)
 149     {
 150         hold_button_old = hold_button;
 151         backlight_hold_changed(hold_button);
 152     }
 153 #endif /* BOOTLOADER */
 154
 155     return hold_button;
 156 }