archive MK1 AVR source

2010-09-06 23:51:48 +02:00
parent a6d66e7a8b
commit a9b84c3e0b
54 changed files with 1220 additions and 793 deletions
--- a/mk1-src/timer.c
+++ b/mk1-src/timer.c
@@ -0,0 +1,135 @@
+/* sd2snes - SD card based universal cartridge for the SNES
+   Copyright (C) 2009-2010 Maximilian Rehkopf <otakon@gmx.net>
+   This file was adapted from sd2iec, written by Ingo Korb.
+   Original copyright header follows:
+*/
+/* sd2iec - SD/MMC to Commodore serial bus interface/controller
+   Copyright (C) 2007-2009  Ingo Korb <ingo@akana.de>
+
+   Inspiration and low-level SD/MMC access based on code from MMC2IEC
+     by Lars Pontoppidan et al., see sdcard.c|h and config.h.
+
+   FAT filesystem access based on code from ChaN and Jim Brain, see ff.c|h.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License only.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+
+   timer.c: System timer (and button debouncer)
+
+*/
+
+#include "config.h"
+#include <avr/interrupt.h>
+#include <avr/io.h>
+#include "avrcompat.h"
+#include "led.h"
+#include "timer.h"
+
+volatile tick_t ticks;
+// Logical buttons
+volatile uint8_t active_keys;
+
+// Physical buttons
+uint8_t buttonstate;
+tick_t  lastbuttonchange;
+
+/* Called by the timer interrupt when the button state has changed */
+static void buttons_changed(void) {
+  /* Check if the previous state was stable for two ticks */
+  if (time_after(ticks, lastbuttonchange+2)) {
+    if (active_keys & IGNORE_KEYS) {
+      active_keys &= ~IGNORE_KEYS;
+    } else if (!(buttonstate & (BUTTON_PREV|BUTTON_NEXT))) {
+      /* Both buttons held down */
+        active_keys |= KEY_HOME;
+    } else if (!(buttonstate & BUTTON_NEXT) &&
+               (BUTTON_PIN & BUTTON_NEXT)) {
+      /* "Next" button released */
+      active_keys |= KEY_NEXT;
+    } else if (!(buttonstate & BUTTON_PREV) &&
+               (BUTTON_PIN & BUTTON_NEXT)) {
+      active_keys |= KEY_PREV;
+    }
+  }
+
+  lastbuttonchange = ticks;
+  buttonstate = BUTTON_PIN & BUTTON_MASK;
+}
+
+/* The main timer interrupt */
+ISR(TIMER1_COMPA_vect) {
+  uint8_t tmp = BUTTON_PIN & BUTTON_MASK;
+
+  if (tmp != buttonstate) {
+    buttons_changed();
+  }
+
+  ticks++;
+
+#ifdef SINGLE_LED
+  if (led_state & LED_ERROR) {
+    if ((ticks & 15) == 0)
+      DIRTY_LED_PORT ^= DIRTY_LED_BIT();
+  } else {
+    if ((led_state & LED_BUSY) || (led_state & LED_DIRTY)) {
+      DIRTY_LED_ON();
+    } else {
+      DIRTY_LED_OFF();
+    }
+  }
+#else
+  if (led_state & LED_ERROR)
+    if ((ticks & 15) == 0)
+      DIRTY_LED_PORT ^= DIRTY_LED_BIT();
+#endif
+
+  /* Sleep button triggers when held down for 2sec */
+  if (time_after(ticks, lastbuttonchange+2)) {
+    if (!(buttonstate & BUTTON_NEXT) &&
+        (buttonstate & BUTTON_PREV) &&
+        time_after(ticks, lastbuttonchange+2*HZ) &&
+        !key_pressed(KEY_SLEEP)) {
+      /* Set ignore flag so the release doesn't trigger KEY_NEXT */
+      active_keys |= KEY_SLEEP | IGNORE_KEYS;
+      /* Avoid triggering for the next two seconds */
+      lastbuttonchange = ticks;
+    }
+  }
+#if CONFIG_RTC_VARIANT == 1
+  increment_rtc();
+#endif
+
+#ifdef CONFIG_REMOTE_DISPLAY
+  /* Check if the display wants to be queried */
+  if (!(SOFTI2C_PIN & _BV(SOFTI2C_BIT_INTRQ))) {
+    active_keys |= KEY_DISPLAY;
+  }
+#endif
+}
+
+void timer_init(void) {
+  /* Count F_CPU/8 in timer 0 */
+  TCCR0B = _BV(CS01);
+
+  /* Set up a 100Hz interrupt using timer 1 */
+  OCR1A  = 1249;
+  TCNT1  = 0;
+  TCCR1A = 0;
+  TCCR1B = _BV(WGM12) | _BV(CS10) | _BV(CS11);
+  TIMSK1 |= _BV(OCIE1A);
+
+  /* Buttons */
+  BUTTON_DDR  &= (uint8_t)~BUTTON_MASK;
+  BUTTON_PORT |= BUTTON_MASK;
+}