From ae6daa0e5c070b6c5fe2616ca009b48887ef0edb Mon Sep 17 00:00:00 2001
From: Jacob Alexander <haata@kiibohd.com>
Date: Fri, 6 Mar 2015 22:18:15 -0800
Subject: [PATCH] Adding DebounceThrottleDiv define to slow down the debounce
 rate.

By default:
DebounceThrottleDiv = 0;
This is the default infinity behaviour right now (may be changed in the future).

Increasing DebounceThrottleDiv will increase the scan rate divider.
DebounceThrottleDiv = 1; # Scans half as much
DebounceThrottleDiv = 2; # Scans a quarter as much
DebounceThrottleDiv = 3; # Scans an eigth as much
etc.

For ARM based uCs (like the Infinity) the maximum divider is 32.
---
 Scan/MatrixARM/capabilities.kll | 14 ++++++++++++++
 Scan/MatrixARM/matrix_scan.c    | 18 ++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/Scan/MatrixARM/capabilities.kll b/Scan/MatrixARM/capabilities.kll
index 319b81d..8221ec8 100644
--- a/Scan/MatrixARM/capabilities.kll
+++ b/Scan/MatrixARM/capabilities.kll
@@ -18,3 +18,17 @@ DebounceDivThreshold => DebounceDivThreshold_define;
 DebounceDivThreshold = 0xFFFF; # Default debounce
 #DebounceDivThreshold = 0xFFFFFFFF; # Max debounce
 
+# This defines how often the matrix is scanned
+# By, default the key matrix is scanned once per macro processing loop
+# For fast uCs and bouncy switches, this can be non-ideal
+# 0 - Bit-shift of 0
+# 1 - Bit-shift of 1 (i.e. divide by 2)
+# 2 - Bit-shift of 2 (i.e. divide by 4)
+# 3 - Bit-shift of 3 (i.e. divide by 8)
+# etc.
+# Depending on the architecture, this is either a maximum of 16 or 32
+# Increasing this value will increase switch latency
+DebounceThrottleDiv => DebounceThrottleDiv_define;
+DebounceThrottleDiv = 0; # Default
+#DebounceThrottleDiv = 2; # /4 divider
+
diff --git a/Scan/MatrixARM/matrix_scan.c b/Scan/MatrixARM/matrix_scan.c
index eaea368..85f8205 100644
--- a/Scan/MatrixARM/matrix_scan.c
+++ b/Scan/MatrixARM/matrix_scan.c
@@ -26,6 +26,7 @@
 
 // Project Includes
 #include <cli.h>
+#include <kll.h>
 #include <led.h>
 #include <print.h>
 #include <macro.h>
@@ -38,6 +39,14 @@
 
 
 
+// ----- Defines -----
+
+#if ( DebounceThrottleDiv_define > 0 )
+nat_ptr_t Matrix_divCounter = 0;
+#endif
+
+
+
 // ----- Function Declarations -----
 
 // CLI Functions
@@ -232,6 +241,15 @@ void Matrix_keyPositionDebug( KeyPosition pos )
 // NOTE: scanNum should be reset to 0 after a USB send (to reset all the counters)
 void Matrix_scan( uint16_t scanNum )
 {
+#if ( DebounceThrottleDiv_define > 0 )
+	// Scan-rate throttling
+	// By scanning using a divider, the scan rate slowed down
+	// DebounceThrottleDiv_define == 1 means -> /2 or half scan rate
+	// This helps with bouncy switches on fast uCs
+	if ( !( Matrix_divCounter++ & (1 << ( DebounceThrottleDiv_define - 1 )) ) )
+		return;
+#endif
+
 	// Increment stats counters
 	if ( scanNum > matrixMaxScans ) matrixMaxScans = scanNum;
 	if ( scanNum == 0 )