Simplify split_common Code significantly (#4772)

* Eliminate separate slave loop

Both master and slave run the standard keyboard_task main loop now.

* Refactor i2c/serial specific code

Simplify some of the preprocessor mess by using common function names.

* Fix missing #endif

* Move direct pin mapping support from miniaxe to split_common

For boards with more pins than sense--sorry, switches.

* Reordering and reformatting only

* Don't run matrix_scan_quantum on slave side

* Clean up the offset/slaveOffset calculations

* Cut undebounced matrix size in half

* Refactor debouncing

* Minor fixups

* Split split_common transport and debounce code into their own files

Can now be replaced with custom versions per keyboard using
CUSTOM_TRANSPORT = yes and CUSTOM_DEBOUNCE = yes

* Refactor debounce for non-split keyboards too

* Update handwired/xealous to build using new split_common

* Fix debounce breaking basic test

* Dodgy method to allow a split kb to only include one of i2c/serial

SPLIT_TRANSPORT = serial or SPLIT_TRANSPORT = i2c will include only
that driver code in the binary.

SPLIT_TRANSPORT = custom (or anything else) will include neither, the
keyboard must supply it's own code

if SPLIT_TRANSPORT is not defined then the original behaviour (include
both avr i2c and serial code) is maintained.

This could be better but it would require explicitly updating all the
existing split keyboards.

* Enable LTO to get lets_split/sockets under the line

* Add docs for SPLIT_TRANSPORT, CUSTOM_MATRIX, CUSTOM_DEBOUNCE

* Remove avr-specific sei() from split matrix_setup

Not needed now that slave doesn't have a separate main loop.
Both sides (on avr) call sei() in lufa's main() after exiting
keyboard_setup().

* Fix QUANTUM_LIB_SRC references and simplify SPLIT_TRANSPORT.

* Add comments and fix formatting.

2 files changed, 69 insertions, 4 deletions

diff --git a/keyboards/handwired/xealous/debounce.c b/keyboards/handwired/xealous/debounce.c
new file mode 100644
index 000000000..65a99f27f
--- /dev/null
+++ b/keyboards/handwired/xealous/debounce.c
@@ -0,0 +1,63 @@
+#include <string.h>
+#include "config.h"
+#include "matrix.h"
+#include "timer.h"
+#include "quantum.h"
+
+#ifndef DEBOUNCING_DELAY
+#   define DEBOUNCING_DELAY 5
+#endif
+
+//Debouncing counters
+typedef uint8_t debounce_counter_t;
+#define DEBOUNCE_COUNTER_MODULO 250
+#define DEBOUNCE_COUNTER_INACTIVE 251
+
+static debounce_counter_t *debounce_counters;
+
+void debounce_init(uint8_t num_rows)
+{
+  debounce_counters = malloc(num_rows*MATRIX_COLS);
+  memset(debounce_counters, DEBOUNCE_COUNTER_INACTIVE, num_rows*MATRIX_COLS);
+}
+
+void update_debounce_counters(uint8_t num_rows, uint8_t current_time)
+{
+  for (uint8_t row = 0; row < num_rows; row++)
+  {
+    for (uint8_t col = 0; col < MATRIX_COLS; col++)
+    {
+      if (debounce_counters[row*MATRIX_COLS + col] != DEBOUNCE_COUNTER_INACTIVE)
+      {
+        if (TIMER_DIFF(current_time, debounce_counters[row*MATRIX_COLS + col], DEBOUNCE_COUNTER_MODULO) >= DEBOUNCING_DELAY) {
+          debounce_counters[row*MATRIX_COLS + col] = DEBOUNCE_COUNTER_INACTIVE;
+        }
+      }
+    }
+  }
+}
+
+void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time)
+{
+    for (uint8_t row = 0; row < num_rows; row++)
+    {
+      matrix_row_t delta = raw[row] ^ cooked[row];
+
+      for (uint8_t col = 0; col < MATRIX_COLS; col++)
+      {
+          if (debounce_counters[row*MATRIX_COLS + col] == DEBOUNCE_COUNTER_INACTIVE && (delta & (1<<col)))
+          {
+              debounce_counters[row*MATRIX_COLS + col] = current_time;
+              cooked[row] ^= (1 << col);
+          }
+      }
+    }
+}
+
+void debounce(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, bool changed)
+{
+    uint8_t current_time = timer_read() % DEBOUNCE_COUNTER_MODULO;
+
+    update_debounce_counters(num_rows, current_time);
+    transfer_matrix_values(raw, cooked, num_rows, current_time);
+}
\ No newline at end of file
diff --git a/keyboards/handwired/xealous/rules.mk b/keyboards/handwired/xealous/rules.mk
index eebd11d86..07e1c875e 100644
--- a/keyboards/handwired/xealous/rules.mk
+++ b/keyboards/handwired/xealous/rules.mk
@@ -1,4 +1,5 @@
-SRC += matrix_scanrate.c matrix.c 
+#SRC += matrix_scanrate.c matrix.c
+SRC += debounce.c
 
 # MCU name
 MCU = atmega32u4
@@ -37,7 +38,7 @@ F_USB = $(F_CPU)
 
 # Bootloader
 #     This definition is optional, and if your keyboard supports multiple bootloaders of
-#     different sizes, comment this out, and the correct address will be loaded 
+#     different sizes, comment this out, and the correct address will be loaded
 #     automatically (+60). See bootloader.mk for all options.
 BOOTLOADER = caterina
 
@@ -59,14 +60,15 @@ MIDI_ENABLE = no            # MIDI controls
 AUDIO_ENABLE = yes          # Audio output on port C6
 UNICODE_ENABLE = no         # Unicode
 BLUETOOTH_ENABLE = no       # Enable Bluetooth with the Adafruit EZ-Key HID
-RGBLIGHT_ENABLE = no        # Enable WS2812 RGB underlight. 
+RGBLIGHT_ENABLE = no        # Enable WS2812 RGB underlight.
 SPLIT_KEYBOARD = yes        # Use shared split_common code
 SUBPROJECT_rev1 = yes
 
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
 
-CUSTOM_MATRIX = yes
+CUSTOM_MATRIX = no
+CUSTOM_DEBOUNCE = yes
 
 LAYOUTS = split60