kernel/gpio.c

   1 /*
   2  * mahatma - a simple kernel framework
   3  * Copyright (c) 2008, 2009 Daniel Mack <daniel@caiaq.de>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <stdio.h>
  20 #include <input.h>
  21 #include <regs.h>
  22 #include <msg.h>
  23 #include <wikireader.h>
  24 #include <wikilib.h>
  25
  26
  27 #if BOARD_SAMO_A1
  28 static const int keymap[] = {
  29         WL_INPUT_KEY_RANDOM,
  30         WL_INPUT_KEY_SEARCH,
  31         WL_INPUT_KEY_HISTORY,
  32 };
  33 #else
  34 static const int keymap[] = {
  35         WL_INPUT_KEY_SEARCH,
  36         WL_INPUT_KEY_HISTORY,
  37         WL_INPUT_KEY_RANDOM,
  38 };
  39 #endif
  40
  41 #define N_PINS 3
  42 STATIC_ASSERT(ARRAY_SIZE(keymap) == N_PINS, right_pins)
  43
  44 static unsigned char gpio_state;
  45 static unsigned char last_state;
  46
  47 void gpio_irq(void)
  48 {
  49         /* the current gpio state is our new comparison reference */
  50         gpio_state = get_key_state();
  51         REG_KINTCOMP_SCPK0 = gpio_state;
  52 }
  53
  54 int gpio_get_event(struct wl_input_event *ev)
  55 {
  56         unsigned int i, changed = gpio_state ^ last_state;
  57
  58         if (!changed)
  59                 return 0;
  60
  61         for (i = 0; i < N_PINS; i++) {
  62                 if (!(changed & (1 << i)))
  63                         continue;
  64
  65                 ev->type = WL_INPUT_EV_TYPE_KEYBOARD;
  66                 ev->key_event.keycode = keymap[i];
  67                 ev->key_event.value = !!(gpio_state & (1 << i));
  68                 last_state ^= (1 << i);
  69                 return 1;
  70         }
  71
  72         return 0;
  73 }
  74
  75 void gpio_init(void)
  76 {
  77         prepare_keys();
  78         gpio_state = 0;
  79         last_state = 0;
  80 }
  81