From 6fafb86d46f4ba75fcba159882f87e21bb43508e Mon Sep 17 00:00:00 2001
From: Raphael Assenat <raph@raphnet.net>
Date: Sat, 17 Oct 2015 18:34:11 -0400
Subject: [PATCH] Use a timer for controller polling interval

---
 Makefile.inc    |  2 +-
 intervaltimer.c | 39 +++++++++++++++++++++++++++++++++++++++
 intervaltimer.h |  9 +++++++++
 main.c          |  8 ++++++--
 4 files changed, 55 insertions(+), 3 deletions(-)
 create mode 100644 intervaltimer.c
 create mode 100644 intervaltimer.h

diff --git a/Makefile.inc b/Makefile.inc
index 92abf2a..9e96f35 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -1 +1 @@
-OBJS=main.o usb.o usbpad.o mappings.o gcn64_protocol.o n64.o gamecube.o usart1.o bootloader.o eeprom.o config.o hiddata.o usbstrings.o
+OBJS=main.o usb.o usbpad.o mappings.o gcn64_protocol.o n64.o gamecube.o usart1.o bootloader.o eeprom.o config.o hiddata.o usbstrings.o intervaltimer.o
diff --git a/intervaltimer.c b/intervaltimer.c
new file mode 100644
index 0000000..d47efad
--- /dev/null
+++ b/intervaltimer.c
@@ -0,0 +1,39 @@
+#include <avr/io.h>
+#include "intervaltimer.h"
+
+
+void intervaltimer_init(void)
+{
+	TCCR1A = 0;
+	TCCR1B = (1<<WGM12) | (1<<CS12) | (1<<CS00); // CTC, /1024 prescaler
+}
+
+void intervaltimer_set(int interval_ms)
+{
+	static int cur_interval = 0;
+
+	// We are setting TCNT back to zero, and updating
+	// the compare match register.
+	//
+	// To allows for simple repeated calling of this
+	// function from the main loop, only touch
+	// the counter when the interval changes.
+	if (cur_interval != interval_ms) {
+		cur_interval = interval_ms;
+
+		TCNT1 = 0;
+		OCR1A = interval_ms * (F_CPU/1024) / 1000;
+	}
+}
+
+char intervaltimer_get(void)
+{
+	char a;
+
+	if (TIFR1 & (1<<OCF1A)) {
+		TIFR1 = 1<<OCF1A;
+		return 1;
+	}
+
+	return 0;
+}
diff --git a/intervaltimer.h b/intervaltimer.h
new file mode 100644
index 0000000..f881597
--- /dev/null
+++ b/intervaltimer.h
@@ -0,0 +1,9 @@
+#ifndef _interval_timer_h__
+#define _interval_timer_h__
+
+void intervaltimer_init(void);
+void intervaltimer_set(int interval_ms);
+char intervaltimer_get(void);
+
+#endif // _interval_timer_h__
+
diff --git a/main.c b/main.c
index 515fb20..77c6b36 100644
--- a/main.c
+++ b/main.c
@@ -18,6 +18,7 @@
 #include "eeprom.h"
 #include "hiddata.h"
 #include "usbstrings.h"
+#include "intervaltimer.h"
 
 /* Those .c files are included rather than linked for we
  * want the sizeof() operator to work on the arrays */
@@ -269,6 +270,7 @@ int main(void)
 	hwinit();
 	usart1_init();
 	eeprom_init();
+	intervaltimer_init();
 
 	/* Init the buffer with idle data */
 	usbpad_update(NULL);
@@ -287,8 +289,10 @@ int main(void)
 		{
 			case STATE_WAIT_POLLTIME:
 				if (!g_polling_suspended) {
-					pollDelay();
-					state = STATE_POLL_PAD;
+					intervaltimer_set(g_eeprom_data.cfg.poll_interval[0]);
+					if (intervaltimer_get()) {
+						state = STATE_POLL_PAD;
+					}
 				}
 				break;