Debounce refactor / API

common_features.mk

@@ -263,11 +263,20 @@ ifneq ($(strip $(CUSTOM_MATRIX)), yes)
     endif
 endif
 
-# Include the standard debounce code if needed
-ifneq ($(strip $(CUSTOM_DEBOUNCE)), yes)
-    QUANTUM_SRC += $(QUANTUM_DIR)/debounce.c
+DEBOUNCE_DIR:= $(QUANTUM_DIR)/debounce
+# Debounce Modules. If implemented in matrix.c, don't use these.
+ifeq ($(strip $(DEBOUNCE_TYPE)), custom)
+    # Do nothing. do your debouncing in matrix.c
+else ifeq ($(strip $(DEBOUNCE_TYPE)), sym_g)
+    QUANTUM_SRC += $(DEBOUNCE_DIR)/debounce_sym_g.c
+else ifeq ($(strip $(DEBOUNCE_TYPE)), eager_pk)
+    QUANTUM_SRC += $(DEBOUNCE_DIR)/debounce_eager_pk.c
+else # default algorithm. Won't be used if we have a custom_matrix that doesn't utilize it
+    QUANTUM_SRC += $(DEBOUNCE_DIR)/debounce_sym_g.c
 endif
 
+
+
 ifeq ($(strip $(SPLIT_KEYBOARD)), yes)
     OPT_DEFS += -DSPLIT_KEYBOARD
 

docs/feature_debounce_algo.md

@@ -0,0 +1,44 @@
+# Debounce algorithm
+
+QMK supports multiple debounce algorithms through its debounce API.
+
+The underlying debounce algorithm is determined by which matrix.c file you are using.
+
+The logic for which debounce method called is below. It checks various defines that you have set in rules.mk
+
+```
+ifeq ($(strip $(DEBOUNCE_ALGO)), manual)
+    # Do nothing. do your debouncing in matrix.c
+else ifeq ($(strip $(DEBOUNCE_ALGO)), sym_g)
+    QUANTUM_SRC += $(DEBOUNCE)/debounce_sym_g.c
+else ifeq ($(strip $(DEBOUNCE_ALGO)), eager_pk)
+    QUANTUM_SRC += $(DEBOUNCE)/debounce_eager_pk.c
+else # default algorithm
+    QUANTUM_SRC += $(DEBOUNCE)/debounce_sym_g.c
+endif
+```
+
+# Debounce selection
+
+| DEBOUNCE_ALGO    | Description                                                 | What to do                    |
+| -------------    | ---------------------------------------------------         | ----------------------------- |
+| Not defined      | You are using the included matrix.c and debounce.c          | Nothing. Debounce_sym_g will be compiled, and used if necessary |
+| manual           | Use your own debounce.c                                     | ```SRC += debounce.c``` add your own debounce.c and implement necessary functions |
+| sym_g / eager_pk | You are using the included matrix.c and debounce.c          | Use an alternative debounce algorithm |
+
+**Regarding split keyboards**: 
+The debounce code is compatible with split keyboards.
+
+# Use your own debouncing code
+* Set ```DEBOUNCE_ALGO = manual```.
+* Add ```SRC += debounce.c```
+* Add your own ```debounce.c```. Look at included ```debounce_sym_g.c```s for sample implementations.
+* Debouncing occurs after every raw matrix scan.
+
+# Changing between included debouncing methods
+You can either use your own code, by including your own debounce.c, or switch to another included one.
+Included debounce methods are:
+* debounce_eager_pk - debouncing per key. On any state change, response is immediate, followed by ```DEBOUNCE_DELAY``` millseconds of no further input for that key
+* debounce_sym_g - debouncing per keyboard. On any state change, a global timer is set. When ```DEBOUNCE_DELAY``` milliseconds of no changes has occured, all input changes are pushed.
+
+

keyboards/handwired/xealous/rules.mk

@@ -68,7 +68,7 @@ SUBPROJECT_rev1 = yes
 SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
 
 CUSTOM_MATRIX = no
-CUSTOM_DEBOUNCE = yes
+DEBOUNCE_TYPE = custom
 
 LAYOUTS = split60
 

quantum/debounce.h

@@ -8,4 +8,4 @@ void debounce(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, bool
 
 bool debounce_active(void);
 
-void debounce_init(uint8_t num_rows);
+void debounce_init(uint8_t num_rows);

quantum/debounce/debounce_eager_pk.c

@@ -0,0 +1,121 @@
+/*
+Copyright 2017 Alex Ong<[email protected]>
+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 2 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 <http://www.gnu.org/licenses/>.
+*/
+
+/*
+Basic per-key algorithm. Uses an 8-bit counter per key.
+After pressing a key, it immediately changes state, and sets a counter.
+No further inputs are accepted until DEBOUNCE milliseconds have occurred.
+*/
+
+#include "matrix.h"
+#include "timer.h"
+#include "quantum.h"
+#include <stdlib.h>
+
+#ifndef DEBOUNCE
+  #define DEBOUNCE 5
+#endif
+
+
+#if (MATRIX_COLS <= 8)
+#    define ROW_SHIFTER ((uint8_t)1)
+#elif (MATRIX_COLS <= 16)
+#    define ROW_SHIFTER ((uint16_t)1)
+#elif (MATRIX_COLS <= 32)
+#    define ROW_SHIFTER  ((uint32_t)1)
+#endif
+
+
+
+#define debounce_counter_t uint8_t
+
+static debounce_counter_t *debounce_counters;
+
+#define DEBOUNCE_ELAPSED 251
+#define MAX_DEBOUNCE (DEBOUNCE_ELAPSED - 1)
+
+void update_debounce_counters(uint8_t num_rows, uint8_t current_time);
+void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time);
+
+//we use num_rows rather than MATRIX_ROWS to support split keyboards
+void debounce_init(uint8_t num_rows)
+{
+  debounce_counters = (debounce_counter_t*)malloc(num_rows*MATRIX_COLS * sizeof(debounce_counter_t));
+  int i = 0;
+  for (uint8_t r = 0; r < num_rows; r++)
+  {
+    for (uint8_t c = 0; c < MATRIX_COLS; c++)
+    {
+      debounce_counters[i++] = DEBOUNCE_ELAPSED;
+    }
+  }
+}
+
+void debounce(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, bool changed)
+{
+  uint8_t current_time = timer_read() % MAX_DEBOUNCE;
+  update_debounce_counters(num_rows, current_time);
+  transfer_matrix_values(raw, cooked, num_rows, current_time);
+}
+
+//If the current time is > debounce counter, set the counter to enable input.
+void update_debounce_counters(uint8_t num_rows, uint8_t current_time)
+{
+  debounce_counter_t *debounce_pointer = debounce_counters;
+  for (uint8_t row = 0; row < num_rows; row++)
+  {
+    for (uint8_t col = 0; col < MATRIX_COLS; col++)
+    {
+      if (*debounce_pointer != DEBOUNCE_ELAPSED)
+      {
+        if (TIMER_DIFF(current_time, *debounce_pointer, MAX_DEBOUNCE) >= DEBOUNCE) {
+          *debounce_pointer = DEBOUNCE_ELAPSED;
+        }
+      }
+      debounce_pointer++;
+    }
+  }
+}
+
+// upload from raw_matrix to final matrix;
+void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time)
+{
+  debounce_counter_t *debounce_pointer = debounce_counters;
+  for (uint8_t row = 0; row < num_rows; row++)
+  {
+    matrix_row_t existing_row = cooked[row]; 
+    matrix_row_t raw_row = raw[row];
+
+    for (uint8_t col = 0; col < MATRIX_COLS; col++)
+    {
+      matrix_row_t col_mask = (ROW_SHIFTER << col);
+      bool final_value = raw_row & col_mask;
+      bool existing_value = existing_row & col_mask;
+      if (*debounce_pointer == DEBOUNCE_ELAPSED &&
+          (existing_value != final_value))
+      {
+        *debounce_pointer = current_time;
+        existing_row ^= col_mask; //flip the bit.
+      }
+      debounce_pointer++;
+    }
+    cooked[row] = existing_row;
+  }  
+}
+
+bool debounce_active(void)
+{
+  return true;
+}
+

quantum/debounce/debounce_sym_g.c

@@ -0,0 +1,57 @@
+/*
+Copyright 2017 Alex Ong<[email protected]>
+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 2 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 <http://www.gnu.org/licenses/>.
+*/
+
+/*
+Basic global debounce algorithm. Used in 99% of keyboards at time of implementation
+When no state changes have occured for DEBOUNCE milliseconds, we push the state.
+*/
+#include "matrix.h"
+#include "timer.h"
+#include "quantum.h"
+#ifndef DEBOUNCE
+  #define DEBOUNCE 5
+#endif
+
+void debounce_init(uint8_t num_rows) {}
+static bool debouncing = false;
+
+#if DEBOUNCE > 0
+static uint16_t debouncing_time;
+void debounce(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, bool changed)
+{
+  if (changed) {
+    debouncing = true;
+    debouncing_time = timer_read();
+  }
+
+  if (debouncing && timer_elapsed(debouncing_time) > DEBOUNCE) {
+    for (int i = 0; i < num_rows; i++) {
+      cooked[i] = raw[i];
+    }
+    debouncing = false;
+  }
+}
+#else //no debouncing.
+void debounce(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, bool changed)
+{
+  for (int i = 0; i < num_rows; i++) {
+    cooked[i] = raw[i];
+  }
+}
+#endif
+
+bool debounce_active(void) {
+  return debouncing;
+}
+

quantum/debounce/readme.md

@@ -0,0 +1,28 @@
+Debounce algorithms belong in this folder.
+Here are a few ideas
+
+1) Global vs Per-Key vs Per-Row
+ * Global - one timer for all keys. Any key change state affects global timer
+ * Per key - one timer per key
+ * Per row - one timer per row
+
+2) Eager vs symmetric vs assymetric
+ * Eager - any key change is reported immediately. All further inputs for DEBOUNCE ms are ignored.
+ * Symmetric - wait for no changes for DEBOUNCE ms before reporting change
+ * Assymetric - wait for different times depending on key-down/key-up. E.g. Eager key-down, DEBOUNCE ms key up.
+
+3) Timestamp vs cycles
+ * old old old code waits n cycles, decreasing count by one each matrix_scan
+ * newer code stores the millisecond the change occurred, and does subraction to figure out time elapsed.
+ * Timestamps are superior, i don't think cycles will ever be used again once upgraded.
+
+The default algorithm is symmetric and global.
+Here are a few that could be implemented:
+
+debounce_sym_g.c
+debounce_sym_pk.c 
+debounce_sym_pr.c 
+debounce_sym_pr_cycles.c //currently used in ergo-dox
+debounce_eager_g.c
+debounce_eager_pk.c
+debounce_eager_pr.c //could be used in ergo-dox!

quantum/matrix.c

@@ -51,10 +51,8 @@ static const pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
 #endif
 
 /* matrix state(1:on, 0:off) */
-static matrix_row_t raw_matrix[MATRIX_ROWS];
-
-static matrix_row_t matrix[MATRIX_ROWS];
-
+static matrix_row_t raw_matrix[MATRIX_ROWS]; //raw values
+static matrix_row_t matrix[MATRIX_ROWS]; //debounced values
 
 #if (DIODE_DIRECTION == COL2ROW)
     static void init_cols(void);
@@ -108,30 +106,6 @@ uint8_t matrix_cols(void) {
     return MATRIX_COLS;
 }
 
-// void matrix_power_up(void) {
-// #if (DIODE_DIRECTION == COL2ROW)
-//     for (int8_t r = MATRIX_ROWS - 1; r >= 0; --r) {
-//         /* DDRxn */
-//         _SFR_IO8((row_pins[r] >> 4) + 1) |= _BV(row_pins[r] & 0xF);
-//         toggle_row(r);
-//     }
-//     for (int8_t c = MATRIX_COLS - 1; c >= 0; --c) {
-//         /* PORTxn */
-//         _SFR_IO8((col_pins[c] >> 4) + 2) |= _BV(col_pins[c] & 0xF);
-//     }
-// #elif (DIODE_DIRECTION == ROW2COL)
-//     for (int8_t c = MATRIX_COLS - 1; c >= 0; --c) {
-//         /* DDRxn */
-//         _SFR_IO8((col_pins[c] >> 4) + 1) |= _BV(col_pins[c] & 0xF);
-//         toggle_col(c);
-//     }
-//     for (int8_t r = MATRIX_ROWS - 1; r >= 0; --r) {
-//         /* PORTxn */
-//         _SFR_IO8((row_pins[r] >> 4) + 2) |= _BV(row_pins[r] & 0xF);
-//     }
-// #endif
-// }
-
 void matrix_init(void) {
 
     // initialize row and col
@@ -175,6 +149,7 @@ uint8_t matrix_scan(void)
   return 1;
 }
 
+//Deprecated.
 bool matrix_is_modified(void)
 {
     if (debounce_active()) return false;