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.

1 files changed, 207 insertions, 432 deletions

diff --git a/quantum/split_common/matrix.c b/quantum/split_common/matrix.c
index 2c37053f8..c3d2857ed 100644
--- a/quantum/split_common/matrix.c
+++ b/quantum/split_common/matrix.c
@@ -25,529 +25,304 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "matrix.h"
 #include "split_util.h"
 #include "config.h"
-#include "timer.h"
 #include "split_flags.h"
 #include "quantum.h"
-
-#ifdef BACKLIGHT_ENABLE
-#   include "backlight.h"
-    extern backlight_config_t backlight_config;
-#endif
-
-#if defined(USE_I2C) || defined(EH)
-#  include "i2c.h"
-#else // USE_SERIAL
-#  include "serial.h"
-#endif
-
-#ifndef DEBOUNCING_DELAY
-#   define DEBOUNCING_DELAY 5
-#endif
-
-#if (DEBOUNCING_DELAY > 0)
-    static uint16_t debouncing_time;
-    static bool debouncing = false;
-#endif
-
-#if defined(USE_I2C) || defined(EH)
-
-#if (MATRIX_COLS <= 8)
-#    define print_matrix_header()  print("\nr/c 01234567\n")
-#    define print_matrix_row(row)  print_bin_reverse8(matrix_get_row(row))
-#    define matrix_bitpop(i)       bitpop(matrix[i])
-#    define ROW_SHIFTER ((uint8_t)1)
-#else
-#    error "Currently only supports 8 COLS"
-#endif
-
-#else // USE_SERIAL
+#include "debounce.h"
+#include "transport.h"
 
 #if (MATRIX_COLS <= 8)
-#    define print_matrix_header()  print("\nr/c 01234567\n")
-#    define print_matrix_row(row)  print_bin_reverse8(matrix_get_row(row))
-#    define matrix_bitpop(i)       bitpop(matrix[i])
-#    define ROW_SHIFTER ((uint8_t)1)
+#  define print_matrix_header() print("\nr/c 01234567\n")
+#  define print_matrix_row(row) print_bin_reverse8(matrix_get_row(row))
+#  define matrix_bitpop(i) bitpop(matrix[i])
+#  define ROW_SHIFTER ((uint8_t)1)
 #elif (MATRIX_COLS <= 16)
-#    define print_matrix_header()  print("\nr/c 0123456789ABCDEF\n")
-#    define print_matrix_row(row)  print_bin_reverse16(matrix_get_row(row))
-#    define matrix_bitpop(i)       bitpop16(matrix[i])
-#    define ROW_SHIFTER ((uint16_t)1)
+#  define print_matrix_header() print("\nr/c 0123456789ABCDEF\n")
+#  define print_matrix_row(row) print_bin_reverse16(matrix_get_row(row))
+#  define matrix_bitpop(i) bitpop16(matrix[i])
+#  define ROW_SHIFTER ((uint16_t)1)
 #elif (MATRIX_COLS <= 32)
-#    define print_matrix_header()  print("\nr/c 0123456789ABCDEF0123456789ABCDEF\n")
-#    define print_matrix_row(row)  print_bin_reverse32(matrix_get_row(row))
-#    define matrix_bitpop(i)       bitpop32(matrix[i])
-#    define ROW_SHIFTER  ((uint32_t)1)
-#endif
-
+#  define print_matrix_header() print("\nr/c 0123456789ABCDEF0123456789ABCDEF\n")
+#  define print_matrix_row(row) print_bin_reverse32(matrix_get_row(row))
+#  define matrix_bitpop(i) bitpop32(matrix[i])
+#  define ROW_SHIFTER ((uint32_t)1)
 #endif
-static matrix_row_t matrix_debouncing[MATRIX_ROWS];
 
 #define ERROR_DISCONNECT_COUNT 5
 
-#define ROWS_PER_HAND (MATRIX_ROWS/2)
-
-static uint8_t error_count = 0;
+#define ROWS_PER_HAND (MATRIX_ROWS / 2)
 
+#ifdef DIRECT_PINS
+static pin_t direct_pins[MATRIX_ROWS][MATRIX_COLS] = DIRECT_PINS;
+#else
 static pin_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS;
 static pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
+#endif
 
 /* matrix state(1:on, 0:off) */
 static matrix_row_t matrix[MATRIX_ROWS];
-static matrix_row_t matrix_debouncing[MATRIX_ROWS];
-
-#if (DIODE_DIRECTION == COL2ROW)
-    static void init_cols(void);
-    static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row);
-    static void unselect_rows(void);
-    static void select_row(uint8_t row);
-    static void unselect_row(uint8_t row);
-#elif (DIODE_DIRECTION == ROW2COL)
-    static void init_rows(void);
-    static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col);
-    static void unselect_cols(void);
-    static void unselect_col(uint8_t col);
-    static void select_col(uint8_t col);
-#endif
+static matrix_row_t raw_matrix[ROWS_PER_HAND];
 
-__attribute__ ((weak))
-void matrix_init_kb(void) {
-    matrix_init_user();
-}
+// row offsets for each hand
+uint8_t thisHand, thatHand;
 
-__attribute__ ((weak))
-void matrix_scan_kb(void) {
-    matrix_scan_user();
-}
+// user-defined overridable functions
 
-__attribute__ ((weak))
-void matrix_init_user(void) {
-}
+__attribute__((weak)) void matrix_init_kb(void) { matrix_init_user(); }
 
-__attribute__ ((weak))
-void matrix_scan_user(void) {
-}
+__attribute__((weak)) void matrix_scan_kb(void) { matrix_scan_user(); }
 
-__attribute__ ((weak))
-void matrix_slave_scan_user(void) {
-}
+__attribute__((weak)) void matrix_init_user(void) {}
 
-inline
-uint8_t matrix_rows(void)
-{
-    return MATRIX_ROWS;
-}
+__attribute__((weak)) void matrix_scan_user(void) {}
 
-inline
-uint8_t matrix_cols(void)
-{
-    return MATRIX_COLS;
-}
+__attribute__((weak)) void matrix_slave_scan_user(void) {}
 
-void matrix_init(void)
-{
-    debug_enable = true;
-    debug_matrix = true;
-    debug_mouse = true;
+// helper functions
 
-    // Set pinout for right half if pinout for that half is defined
-    if (!isLeftHand) {
-#ifdef MATRIX_ROW_PINS_RIGHT
-        const uint8_t row_pins_right[MATRIX_ROWS] = MATRIX_ROW_PINS_RIGHT;
-        for (uint8_t i = 0; i < MATRIX_ROWS; i++)
-            row_pins[i] = row_pins_right[i];
-#endif
-#ifdef MATRIX_COL_PINS_RIGHT
-        const uint8_t col_pins_right[MATRIX_COLS] = MATRIX_COL_PINS_RIGHT;
-        for (uint8_t i = 0; i < MATRIX_COLS; i++)
-            col_pins[i] = col_pins_right[i];
-#endif
-    }
+inline uint8_t matrix_rows(void) { return MATRIX_ROWS; }
 
-    // initialize row and col
-#if (DIODE_DIRECTION == COL2ROW)
-    unselect_rows();
-    init_cols();
-#elif (DIODE_DIRECTION == ROW2COL)
-    unselect_cols();
-    init_rows();
-#endif
+inline uint8_t matrix_cols(void) { return MATRIX_COLS; }
 
-    // initialize matrix state: all keys off
-    for (uint8_t i=0; i < MATRIX_ROWS; i++) {
-        matrix[i] = 0;
-        matrix_debouncing[i] = 0;
-    }
-    
-    matrix_init_quantum();
-    
+bool matrix_is_modified(void) {
+  if (debounce_active()) return false;
+  return true;
 }
 
-uint8_t _matrix_scan(void)
-{
-    int offset = isLeftHand ? 0 : (ROWS_PER_HAND);
-#if (DIODE_DIRECTION == COL2ROW)
-    // Set row, read cols
-    for (uint8_t current_row = 0; current_row < ROWS_PER_HAND; current_row++) {
-#       if (DEBOUNCING_DELAY > 0)
-            bool matrix_changed = read_cols_on_row(matrix_debouncing+offset, current_row);
-
-            if (matrix_changed) {
-                debouncing = true;
-                debouncing_time = timer_read();
-            }
-
-#       else
-            read_cols_on_row(matrix+offset, current_row);
-#       endif
-
-    }
+inline bool matrix_is_on(uint8_t row, uint8_t col) { return (matrix[row] & ((matrix_row_t)1 << col)); }
 
-#elif (DIODE_DIRECTION == ROW2COL)
-    // Set col, read rows
-    for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++) {
-#       if (DEBOUNCING_DELAY > 0)
-            bool matrix_changed = read_rows_on_col(matrix_debouncing+offset, current_col);
-            if (matrix_changed) {
-                debouncing = true;
-                debouncing_time = timer_read();
-            }
-#       else
-             read_rows_on_col(matrix+offset, current_col);
-#       endif
+inline matrix_row_t matrix_get_row(uint8_t row) { return matrix[row]; }
 
-    }
-#endif
+void matrix_print(void) {
+  print_matrix_header();
 
-#   if (DEBOUNCING_DELAY > 0)
-        if (debouncing && (timer_elapsed(debouncing_time) > DEBOUNCING_DELAY)) {
-            for (uint8_t i = 0; i < ROWS_PER_HAND; i++) {
-                matrix[i+offset] = matrix_debouncing[i+offset];
-            }
-            debouncing = false;
-        }
-#   endif
+  for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
+    phex(row);
+    print(": ");
+    print_matrix_row(row);
+    print("\n");
+  }
+}
 
-    return 1;
+uint8_t matrix_key_count(void) {
+  uint8_t count = 0;
+  for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
+    count += matrix_bitpop(i);
+  }
+  return count;
 }
 
-#if defined(USE_I2C) || defined(EH)
-
-// Get rows from other half over i2c
-int i2c_transaction(void) {
-    int slaveOffset = (isLeftHand) ? (ROWS_PER_HAND) : 0;
-    int err = 0;
-    
-    // write backlight info
-    #ifdef BACKLIGHT_ENABLE
-        if (BACKLIT_DIRTY) {
-            err = i2c_master_start(SLAVE_I2C_ADDRESS + I2C_WRITE);
-            if (err) goto i2c_error;
-            
-            // Backlight location
-            err = i2c_master_write(I2C_BACKLIT_START);
-            if (err) goto i2c_error;
-            
-            // Write backlight 
-            i2c_master_write(get_backlight_level());
-            
-            BACKLIT_DIRTY = false;
-        }
-    #endif
+// matrix code
 
-    err = i2c_master_start(SLAVE_I2C_ADDRESS + I2C_WRITE);
-    if (err) goto i2c_error;
+#ifdef DIRECT_PINS
 
-    // start of matrix stored at I2C_KEYMAP_START
-    err = i2c_master_write(I2C_KEYMAP_START);
-    if (err) goto i2c_error;
+static void init_pins(void) {
+  for (int row = 0; row < MATRIX_ROWS; row++) {
+    for (int col = 0; col < MATRIX_COLS; col++) {
+      pin_t pin = direct_pins[row][col];
+      if (pin != NO_PIN) {
+        setPinInputHigh(pin);
+      }
+    }
+  }
+}
 
-    // Start read
-    err = i2c_master_start(SLAVE_I2C_ADDRESS + I2C_READ);
-    if (err) goto i2c_error;
+static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row) {
+  matrix_row_t last_row_value = current_matrix[current_row];
+  current_matrix[current_row] = 0;
 
-    if (!err) {
-        int i;
-        for (i = 0; i < ROWS_PER_HAND-1; ++i) {
-            matrix[slaveOffset+i] = i2c_master_read(I2C_ACK);
-        }
-        matrix[slaveOffset+i] = i2c_master_read(I2C_NACK);
-        i2c_master_stop();
-    } else {
-i2c_error: // the cable is disconnceted, or something else went wrong
-        i2c_reset_state();
-        return err;
+  for (uint8_t col_index = 0; col_index < MATRIX_COLS; col_index++) {
+    pin_t pin = direct_pins[current_row][col_index];
+    if (pin != NO_PIN) {
+      current_matrix[current_row] |= readPin(pin) ? 0 : (ROW_SHIFTER << col_index);
     }
-    
-    #ifdef RGBLIGHT_ENABLE
-        if (RGB_DIRTY) {
-            err = i2c_master_start(SLAVE_I2C_ADDRESS + I2C_WRITE);
-            if (err) goto i2c_error;
-            
-            // RGB Location
-            err = i2c_master_write(I2C_RGB_START);
-            if (err) goto i2c_error;
-            
-            uint32_t dword = eeconfig_read_rgblight();
-            
-            // Write RGB
-            err = i2c_master_write_data(&dword, 4);
-            if (err) goto i2c_error;
-            
-            RGB_DIRTY = false;
-            i2c_master_stop();
-        }
-    #endif
+  }
 
-    return 0;
+  return (last_row_value != current_matrix[current_row]);
 }
 
-#else // USE_SERIAL
-
+#elif (DIODE_DIRECTION == COL2ROW)
 
-typedef struct _Serial_s2m_buffer_t {
-    // TODO: if MATRIX_COLS > 8 change to uint8_t packed_matrix[] for pack/unpack
-    matrix_row_t smatrix[ROWS_PER_HAND];
-} Serial_s2m_buffer_t;
+static void select_row(uint8_t row) {
+  writePinLow(row_pins[row]);
+  setPinOutput(row_pins[row]);
+}
 
-volatile Serial_s2m_buffer_t serial_s2m_buffer = {};
-volatile Serial_m2s_buffer_t serial_m2s_buffer = {};
-uint8_t volatile status0 = 0;
+static void unselect_row(uint8_t row) { setPinInputHigh(row_pins[row]); }
 
-SSTD_t transactions[] = {
-    { (uint8_t *)&status0,
-      sizeof(serial_m2s_buffer), (uint8_t *)&serial_m2s_buffer,
-      sizeof(serial_s2m_buffer), (uint8_t *)&serial_s2m_buffer
+static void unselect_rows(void) {
+  for (uint8_t x = 0; x < ROWS_PER_HAND; x++) {
+    setPinInputHigh(row_pins[x]);
   }
-};
+}
 
-void serial_master_init(void)
-{ soft_serial_initiator_init(transactions, TID_LIMIT(transactions)); }
+static void init_pins(void) {
+  unselect_rows();
+  for (uint8_t x = 0; x < MATRIX_COLS; x++) {
+    setPinInputHigh(col_pins[x]);
+  }
+}
 
-void serial_slave_init(void)
-{ soft_serial_target_init(transactions, TID_LIMIT(transactions)); }
+static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row) {
+  // Store last value of row prior to reading
+  matrix_row_t last_row_value = current_matrix[current_row];
 
-int serial_transaction(void) {
-    int slaveOffset = (isLeftHand) ? (ROWS_PER_HAND) : 0;
+  // Clear data in matrix row
+  current_matrix[current_row] = 0;
 
-    if (soft_serial_transaction()) {
-        return 1;
-    }
+  // Select row and wait for row selecton to stabilize
+  select_row(current_row);
+  wait_us(30);
 
-    // TODO:  if MATRIX_COLS > 8 change to unpack()
-    for (int i = 0; i < ROWS_PER_HAND; ++i) {
-        matrix[slaveOffset+i] = serial_s2m_buffer.smatrix[i];
-    }
-    
-    #if defined(RGBLIGHT_ENABLE) && defined(RGBLIGHT_SPLIT)
-        // Code to send RGB over serial goes here (not implemented yet)
-    #endif
-    
-    #ifdef BACKLIGHT_ENABLE
-        // Write backlight level for slave to read
-        serial_m2s_buffer.backlight_level = backlight_config.enable ? backlight_config.level : 0;
-    #endif
-
-    return 0;
-}
-#endif
+  // For each col...
+  for (uint8_t col_index = 0; col_index < MATRIX_COLS; col_index++) {
+    // Populate the matrix row with the state of the col pin
+    current_matrix[current_row] |= readPin(col_pins[col_index]) ? 0 : (ROW_SHIFTER << col_index);
+  }
 
-uint8_t matrix_scan(void)
-{
-    uint8_t ret = _matrix_scan();
+  // Unselect row
+  unselect_row(current_row);
 
-#if defined(USE_I2C) || defined(EH)
-    if( i2c_transaction() ) {
-#else // USE_SERIAL
-    if( serial_transaction() ) {
-#endif
+  return (last_row_value != current_matrix[current_row]);
+}
 
-        error_count++;
+#elif (DIODE_DIRECTION == ROW2COL)
 
-        if (error_count > ERROR_DISCONNECT_COUNT) {
-            // reset other half if disconnected
-            int slaveOffset = (isLeftHand) ? (ROWS_PER_HAND) : 0;
-            for (int i = 0; i < ROWS_PER_HAND; ++i) {
-                matrix[slaveOffset+i] = 0;
-            }
-        }
-    } else {
-        error_count = 0;
-    }
-    matrix_scan_quantum();
-    return ret;
+static void select_col(uint8_t col) {
+  writePinLow(col_pins[col]);
+  setPinOutput(col_pins[col]);
 }
 
-void matrix_slave_scan(void) {
-    _matrix_scan();
-
-    int offset = (isLeftHand) ? 0 : ROWS_PER_HAND;
+static void unselect_col(uint8_t col) { setPinInputHigh(col_pins[col]); }
 
-#if defined(USE_I2C) || defined(EH)
-    for (int i = 0; i < ROWS_PER_HAND; ++i) {
-        i2c_slave_buffer[I2C_KEYMAP_START+i] = matrix[offset+i];
-    }   
-#else // USE_SERIAL
-    // TODO: if MATRIX_COLS > 8 change to pack()
-    for (int i = 0; i < ROWS_PER_HAND; ++i) {
-        serial_s2m_buffer.smatrix[i] = matrix[offset+i];
-    }
-#endif
-    matrix_slave_scan_user();
+static void unselect_cols(void) {
+  for (uint8_t x = 0; x < MATRIX_COLS; x++) {
+    setPinInputHigh(col_pins[x]);
+  }
 }
 
-bool matrix_is_modified(void)
-{
-    if (debouncing) return false;
-    return true;
+static void init_pins(void) {
+  unselect_cols();
+  for (uint8_t x = 0; x < ROWS_PER_HAND; x++) {
+    setPinInputHigh(row_pins[x]);
+  }
 }
 
-inline
-bool matrix_is_on(uint8_t row, uint8_t col)
-{
-    return (matrix[row] & ((matrix_row_t)1<<col));
-}
+static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col) {
+  bool matrix_changed = false;
 
-inline
-matrix_row_t matrix_get_row(uint8_t row)
-{
-    return matrix[row];
-}
+  // Select col and wait for col selecton to stabilize
+  select_col(current_col);
+  wait_us(30);
+
+  // For each row...
+  for (uint8_t row_index = 0; row_index < ROWS_PER_HAND; row_index++) {
+    // Store last value of row prior to reading
+    matrix_row_t last_row_value = current_matrix[row_index];
 
-void matrix_print(void)
-{
-    print("\nr/c 0123456789ABCDEF\n");
-    for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
-        phex(row); print(": ");
-        pbin_reverse16(matrix_get_row(row));
-        print("\n");
+    // Check row pin state
+    if (readPin(row_pins[row_index])) {
+      // Pin HI, clear col bit
+      current_matrix[row_index] &= ~(ROW_SHIFTER << current_col);
+    } else {
+      // Pin LO, set col bit
+      current_matrix[row_index] |= (ROW_SHIFTER << current_col);
     }
-}
 
-uint8_t matrix_key_count(void)
-{
-    uint8_t count = 0;
-    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
-        count += bitpop16(matrix[i]);
+    // Determine if the matrix changed state
+    if ((last_row_value != current_matrix[row_index]) && !(matrix_changed)) {
+      matrix_changed = true;
     }
-    return count;
-}
+  }
 
-#if (DIODE_DIRECTION == COL2ROW)
+  // Unselect col
+  unselect_col(current_col);
 
-static void init_cols(void)
-{
-    for(uint8_t x = 0; x < MATRIX_COLS; x++) {
-        setPinInputHigh(col_pins[x]);
-    }
+  return matrix_changed;
 }
 
-static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row)
-{
-    // Store last value of row prior to reading
-    matrix_row_t last_row_value = current_matrix[current_row];
-
-    // Clear data in matrix row
-    current_matrix[current_row] = 0;
+#endif
 
-    // Select row and wait for row selecton to stabilize
-    select_row(current_row);
-    wait_us(30);
+void matrix_init(void) {
+  debug_enable = true;
+  debug_matrix = true;
+  debug_mouse  = true;
 
-    // For each col...
-    for(uint8_t col_index = 0; col_index < MATRIX_COLS; col_index++) {
-        // Populate the matrix row with the state of the col pin
-        current_matrix[current_row] |=  readPin(col_pins[col_index]) ? 0 : (ROW_SHIFTER << col_index);
+  // Set pinout for right half if pinout for that half is defined
+  if (!isLeftHand) {
+#ifdef MATRIX_ROW_PINS_RIGHT
+    const uint8_t row_pins_right[MATRIX_ROWS] = MATRIX_ROW_PINS_RIGHT;
+    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
+      row_pins[i] = row_pins_right[i];
     }
+#endif
+#ifdef MATRIX_COL_PINS_RIGHT
+    const uint8_t col_pins_right[MATRIX_COLS] = MATRIX_COL_PINS_RIGHT;
+    for (uint8_t i = 0; i < MATRIX_COLS; i++) {
+      col_pins[i] = col_pins_right[i];
+    }
+#endif
+  }
 
-    // Unselect row
-    unselect_row(current_row);
+  thisHand = isLeftHand ? 0 : (ROWS_PER_HAND);
+  thatHand = ROWS_PER_HAND - thisHand;
 
-    return (last_row_value != current_matrix[current_row]);
-}
+  // initialize key pins
+  init_pins();
 
-static void select_row(uint8_t row)
-{
-    writePinLow(row_pins[row]);
-    setPinOutput(row_pins[row]);
-}
+  // initialize matrix state: all keys off
+  for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
+    matrix[i] = 0;
+  }
 
-static void unselect_row(uint8_t row)
-{
-    setPinInputHigh(row_pins[row]);
-}
+  debounce_init(ROWS_PER_HAND);
 
-static void unselect_rows(void)
-{
-    for(uint8_t x = 0; x < ROWS_PER_HAND; x++) {
-        setPinInputHigh(row_pins[x]);
-    }
+  matrix_init_quantum();
 }
 
+uint8_t _matrix_scan(void) {
+  bool changed = false;
+
+#if defined(DIRECT_PINS) || (DIODE_DIRECTION == COL2ROW)
+  // Set row, read cols
+  for (uint8_t current_row = 0; current_row < ROWS_PER_HAND; current_row++) {
+    changed |= read_cols_on_row(raw_matrix, current_row);
+  }
 #elif (DIODE_DIRECTION == ROW2COL)
+  // Set col, read rows
+  for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++) {
+    changed |= read_rows_on_col(raw_matrix, current_col);
+  }
+#endif
 
-static void init_rows(void)
-{
-    for(uint8_t x = 0; x < ROWS_PER_HAND; x++) {
-        setPinInputHigh(row_pins[x]);
-    }
-}
+  debounce(raw_matrix, matrix + thisHand, ROWS_PER_HAND, changed);
 
-static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col)
-{
-    bool matrix_changed = false;
+  return 1;
+}
 
-    // Select col and wait for col selecton to stabilize
-    select_col(current_col);
-    wait_us(30);
+uint8_t matrix_scan(void) {
+  uint8_t ret = _matrix_scan();
 
-    // For each row...
-    for(uint8_t row_index = 0; row_index < ROWS_PER_HAND; row_index++)
-    {
+  if (is_keyboard_master()) {
+    static uint8_t error_count;
 
-        // Store last value of row prior to reading
-        matrix_row_t last_row_value = current_matrix[row_index];
+    if (!transport_master(matrix + thatHand)) {
+      error_count++;
 
-        // Check row pin state
-        if (readPin(row_pins[row_index]))
-        {
-            // Pin HI, clear col bit
-            current_matrix[row_index] &= ~(ROW_SHIFTER << current_col);
-        }
-        else
-        {
-            // Pin LO, set col bit
-            current_matrix[row_index] |= (ROW_SHIFTER << current_col);
-        }
-
-        // Determine if the matrix changed state
-        if ((last_row_value != current_matrix[row_index]) && !(matrix_changed))
-        {
-            matrix_changed = true;
+      if (error_count > ERROR_DISCONNECT_COUNT) {
+        // reset other half if disconnected
+        for (int i = 0; i < ROWS_PER_HAND; ++i) {
+          matrix[thatHand + i] = 0;
         }
+      }
+    } else {
+      error_count = 0;
     }
 
-    // Unselect col
-    unselect_col(current_col);
-
-    return matrix_changed;
-}
-
-static void select_col(uint8_t col)
-{
-    writePinLow(col_pins[col]);
-    setPinOutput(col_pins[col]);
-}
-
-static void unselect_col(uint8_t col)
-{
-    setPinInputHigh(col_pins[col]);
-}
+    matrix_scan_quantum();
+  } else {
+    transport_slave(matrix + thisHand);
+    matrix_slave_scan_user();
+  }
 
-static void unselect_cols(void)
-{
-    for(uint8_t x = 0; x < MATRIX_COLS; x++) {
-        setPinInputHigh(col_pins[x]);
-    }
+  return ret;
 }
-
-#endif