altos: Add attiny architecture files

These are designed to work with the ATtiny85 processor, but can
presuambly be easily adapted to others in that series

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/src/attiny/ao_exti.c b/src/attiny/ao_exti.c
new file mode 100644
index 00000000..0ca10ca4
--- /dev/null
+++ b/src/attiny/ao_exti.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.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; version 2 of the License.
+ *
+ * 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.
+ */
+
+#include <ao.h>
+#include <ao_exti.h>
+
+static void 	(*pcint_callback)(void);
+static uint8_t	pcint_mask;
+
+ISR(PCINT0_vect)
+{
+	if (PINB & pcint_mask)
+		(*pcint_callback)();
+}
+
+void
+ao_exti_setup_port(uint8_t pin, uint8_t mode, void (*callback)(void))
+{
+	pcint_callback = callback;
+	pcint_mask = (1 << pin);
+	ao_exti_disable(PORTB, pin);
+	GIMSK |= (1 << PCIE);
+}