From ac570686b6bde1e5066ea68636ae780392739cb4 Mon Sep 17 00:00:00 2001
From: Kai Ryu <kai1103@gmail.com>
Date: Tue, 13 May 2014 14:57:13 +0900
Subject: [PATCH] New branch for 6KRO feature

---
 common.mk            |  4 ++
 common/action_util.c | 94 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 98 insertions(+)

diff --git a/common.mk b/common.mk
index 2ca06daae..62ac0ff78 100644
--- a/common.mk
+++ b/common.mk
@@ -48,6 +48,10 @@ ifdef NKRO_ENABLE
     OPT_DEFS += -DNKRO_ENABLE
 endif
 
+ifdef USB_6KRO_ENABLE
+    OPT_DEFS += -DUSB_6KRO_ENABLE
+endif
+
 ifdef SLEEP_LED_ENABLE
     SRC += $(COMMON_DIR)/sleep_led.c
     OPT_DEFS += -DSLEEP_LED_ENABLE
diff --git a/common/action_util.c b/common/action_util.c
index 99a3adaab..5f44b3812 100644
--- a/common/action_util.c
+++ b/common/action_util.c
@@ -30,6 +30,15 @@ static inline void del_key_bit(uint8_t code);
 static uint8_t real_mods = 0;
 static uint8_t weak_mods = 0;
 
+#ifdef USB_6KRO_ENABLE
+#define RO_ADD(a, b) ((a + b) % REPORT_KEYS)
+#define RO_SUB(a, b) ((a - b + REPORT_KEYS) % REPORT_KEYS)
+#define RO_INC(a) RO_ADD(a, 1)
+#define RO_DEC(a) RO_SUB(a, 1)
+static int8_t cb_head = 0;
+static int8_t cb_tail = 0;
+static int8_t cb_count = 0;
+#endif
 
 // TODO: pointer variable is not needed
 //report_keyboard_t keyboard_report = {};
@@ -158,7 +167,18 @@ uint8_t get_first_key(void)
         return i<<3 | biton(keyboard_report->nkro.bits[i]);
     }
 #endif
+#ifdef USB_6KRO_ENABLE
+    uint8_t i = cb_head;
+    do {
+        if (keyboard_report->keys[i] != 0) {
+            break;
+        }
+        i = RO_INC(i);
+    } while (i != cb_tail);
+    return keyboard_report->keys[i];
+#else
     return keyboard_report->keys[0];
+#endif
 }
 
 
@@ -166,6 +186,52 @@ uint8_t get_first_key(void)
 /* local functions */
 static inline void add_key_byte(uint8_t code)
 {
+#ifdef USB_6KRO_ENABLE
+    int8_t i = cb_head;
+    int8_t empty = -1;
+    if (cb_count) {
+        do {
+            if (keyboard_report->keys[i] == code) {
+                return;
+            }
+            if (empty == -1 && keyboard_report->keys[i] == 0) {
+                empty = i;
+            }
+            i = RO_INC(i);
+        } while (i != cb_tail);
+        if (i == cb_tail) {
+            if (cb_tail == cb_head) {
+                // buffer is full
+                if (empty == -1) {
+                    // pop head when has no empty space
+                    cb_head = RO_INC(cb_head);
+                    cb_count--;
+                }
+                else {
+                    // left shift when has empty space
+                    uint8_t offset = 1;
+                    i = RO_INC(empty);
+                    do {
+                        if (keyboard_report->keys[i] != 0) {
+                            keyboard_report->keys[empty] = keyboard_report->keys[i];
+                            keyboard_report->keys[i] = 0;
+                            empty = RO_INC(empty);
+                        }
+                        else {
+                            offset++;
+                        }
+                        i = RO_INC(i);
+                    } while (i != cb_tail);
+                    cb_tail = RO_SUB(cb_tail, offset);
+                }
+            }
+        }
+    }
+    // add to tail
+    keyboard_report->keys[cb_tail] = code;
+    cb_tail = RO_INC(cb_tail);
+    cb_count++;
+#else
     int8_t i = 0;
     int8_t empty = -1;
     for (; i < REPORT_KEYS; i++) {
@@ -181,15 +247,43 @@ static inline void add_key_byte(uint8_t code)
             keyboard_report->keys[empty] = code;
         }
     }
+#endif
 }
 
 static inline void del_key_byte(uint8_t code)
 {
+#ifdef USB_6KRO_ENABLE
+    uint8_t i = cb_head;
+    if (cb_count) {
+        do {
+            if (keyboard_report->keys[i] == code) {
+                keyboard_report->keys[i] = 0;
+                cb_count--;
+                if (cb_count == 0) {
+                    // reset head and tail
+                    cb_tail = cb_head = 0;
+                }
+                if (i == RO_DEC(cb_tail)) {
+                    // left shift when next to tail
+                    do {
+                        cb_tail = RO_DEC(cb_tail);
+                        if (keyboard_report->keys[RO_DEC(cb_tail)] != 0) {
+                            break;
+                        }
+                    } while (cb_tail != cb_head);
+                }
+                break;
+            }
+            i = RO_INC(i);
+        } while (i != cb_tail);
+    }
+#else
     for (uint8_t i = 0; i < REPORT_KEYS; i++) {
         if (keyboard_report->keys[i] == code) {
             keyboard_report->keys[i] = 0;
         }
     }
+#endif
 }
 
 #ifdef NKRO_ENABLE