Decouple hardware specific code from generic, agnostic code

2026-08-07 01:13:18 +00:00 · 2026-06-23 17:20:59 -07:00
parent fb130559e2
commit 0b0c9335f9
24 changed files with 768 additions and 910 deletions
@@ -0,0 +1,62 @@
+/*
+                        AVCLAN-Mockingboard
+    Copyright (C) 2015 Allen Hill <allenofthehills@gmail.com>
+
+    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, either version 3 of the License, or
+    (at your option) any later version.
+
+    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, see <https://www.gnu.org/licenses/>.
+*/
+
+// ATtiny3216 board bring-up: main-clock prescaler + GPIO config for pins not
+// owned by a peripheral's own init.
+
+#include <avr/interrupt.h>
+#include <avr/io.h>
+#include <avr/xmega.h> // _PROTECTED_WRITE
+
+#include "board.h"
+
+void board_init(void) {
+  // Main clock prescale (CLK_PRESCALE / CLK_PRESCALE_DIV come from the build).
+  _PROTECTED_WRITE(CLKCTRL.MCLKCTRLB, (CLK_PRESCALE | CLK_PRESCALE_DIV));
+
+  // Set pins PC2-3, PB0,3-5 as inputs
+  PORTC.DIRCLR = (PIN2_bm | // Unconnected
+                  PIN3_bm); // CTS
+  PORTB.DIRCLR = (PIN0_bm | // Unconnected
+                  PIN3_bm | // IGN_SENSE
+                  PIN4_bm | // Unused, but connected to WOC (PC0)
+                  PIN5_bm); // Unused, but connected to WOD (PC1)
+
+  // Enable pull-up resistor and disable input buffer (reduces any EM caused
+  // pin toggling and saves power) for unused and unconnected pins
+  PORTC.PIN2CTRL = PORT_PULLUPEN_bm | PORT_ISC_INPUT_DISABLE_gc;
+  PORTB.PIN0CTRL = PORT_PULLUPEN_bm | PORT_ISC_INPUT_DISABLE_gc;
+
+  // TODO: Remove once IGN_SENSE hardware is fixed
+  PORTB.DIRSET = PIN3_bm;
+  PORTB.OUTSET = PIN3_bm;
+
+  // Output only pins: PA3-5, PB1-2,4-5; PC0-1
+  // TODO: TxD (PA1), RTS (PA3) is output only, test if RxD needs the input
+  // buffer or if the UART peripheral bypasses it
+  PORTA.PIN3CTRL = PORT_ISC_INPUT_DISABLE_gc; // RTS
+  PORTA.PIN4CTRL = PORT_ISC_INPUT_DISABLE_gc; // WOA
+  PORTA.PIN5CTRL = PORT_ISC_INPUT_DISABLE_gc; // WOB
+  PORTB.PIN1CTRL = PORT_ISC_INPUT_DISABLE_gc; // MIC_CONTROL
+  PORTB.PIN4CTRL = PORT_ISC_INPUT_DISABLE_gc; // non-driving WOC
+  PORTB.PIN5CTRL = PORT_ISC_INPUT_DISABLE_gc; // non-driving WOD
+  PORTC.PIN0CTRL = PORT_ISC_INPUT_DISABLE_gc; // WOC
+  PORTC.PIN1CTRL = PORT_ISC_INPUT_DISABLE_gc; // WOD
+}
+
+void board_interruptsEnable(void) { sei(); }