Port DIRECT_PINS from split_common/matrix.c to matrix.c (#5091)

* Port DIRECT_PINS from split_common/matrix.c to matrix.c

* Reorder matrix.c to remove foward declaration and match split_common/matrix.c

* Refactor nano to use DIRECT_PINS

* Reorder matrix.c to remove foward declaration and match split_common/matrix.c

* Add DIRECT_PINS documentation

* Reorder matrix.c to remove foward declaration and match split_common/matrix.c - fix logic from inherited from split_common

* Add DIRECT_PINS documentation - review comments

8 files changed, 146 insertions, 259 deletions

diff --git a/docs/config_options.md b/docs/config_options.md
index c5131a841..bc2a89058 100644
--- a/docs/config_options.md
+++ b/docs/config_options.md
@@ -59,6 +59,8 @@ This is a C header file that is one of the first things included, and will persi
   * define is matrix has ghost (unlikely)
 * `#define DIODE_DIRECTION COL2ROW`
   * COL2ROW or ROW2COL - how your matrix is configured. COL2ROW means the black mark on your diode is facing to the rows, and between the switch and the rows.
+* `#define DIRECT_PINS { { F1, F0, B0, C7 }, { F4, F5, F6, F7 } }`
+  * pins mapped to rows and columns, from left to right. Defines a matrix where each switch is connected to a separate pin and ground.
 * `#define AUDIO_VOICES`
   * turns on the alternate audio voices (to cycle through)
 * `#define C4_AUDIO`
diff --git a/docs/hardware_avr.md b/docs/hardware_avr.md
index 12a0059c3..acf7088a3 100644
--- a/docs/hardware_avr.md
+++ b/docs/hardware_avr.md
@@ -93,6 +93,24 @@ Finally, you can specify the direction your diodes point. This can be `COL2ROW`
 #define DIODE_DIRECTION COL2ROW
 ```
 
+#### Direct Pin Matrix
+To configure a keyboard where each switch is connected to a separate pin and ground instead of sharing row and column pins, use `DIRECT_PINS`. The mapping defines the pins of each switch in rows and columns, from left to right. Must conform to the sizes within `MATRIX_ROWS` and `MATRIX_COLS`, use `NO_PIN` to fill in blank spaces. Overrides the behaviour of `DIODE_DIRECTION`, `MATRIX_ROW_PINS` and `MATRIX_COL_PINS`.
+
+```c
+// #define MATRIX_ROW_PINS { D0, D5 }
+// #define MATRIX_COL_PINS { F1, F0, B0 }
+#define DIRECT_PINS { \
+    { F1, E6, B0, B2, B3 }, \
+    { F5, F0, B1, B7, D2 }, \
+    { F6, F7, C7, D5, D3 }, \
+    { B5, C6, B6, NO_PIN, NO_PIN } \
+}
+#define UNUSED_PINS
+
+/* COL2ROW, ROW2COL */
+//#define DIODE_DIRECTION
+```
+
 ### Backlight Configuration
 
 By default QMK supports backlighting on pins `B5`, `B6`, and `B7`. If you are using one of those you can simply enable it here. For more details see the [Backlight Documentation](feature_backlight.md).
diff --git a/docs/porting_your_keyboard_to_qmk_(arm_and_other_chibios_cpus).md b/docs/porting_your_keyboard_to_qmk_(arm_and_other_chibios_cpus).md
index c32c428cf..d8e084f46 100644
--- a/docs/porting_your_keyboard_to_qmk_(arm_and_other_chibios_cpus).md
+++ b/docs/porting_your_keyboard_to_qmk_(arm_and_other_chibios_cpus).md
@@ -22,6 +22,8 @@ The `MATRIX_ROW_PINS` and `MATRIX_COL_PINS` are the pins your MCU uses on each r
 
 For the `DIODE_DIRECTION`, most hand-wiring guides will instruct you to wire the diodes in the `COL2ROW` position, but it's possible that they are in the other - people coming from EasyAVR often use `ROW2COL`. Nothing will function if this is incorrect.
 
+To configure a keyboard where each switch is connected to a separate pin and ground instead of sharing row and column pins, use `DIRECT_PINS`. The mapping defines the pins of each switch in rows and columns, from left to right. Must conform to the sizes within `MATRIX_ROWS` and `MATRIX_COLS`, use `NO_PIN` to fill in blank spaces. Overrides the behaviour of `DIODE_DIRECTION`, `MATRIX_ROW_PINS` and `MATRIX_COL_PINS`.
+
 `BACKLIGHT_PIN` is the pin that your PWM-controlled backlight (if one exists) is hooked-up to. Currently only B5, B6, and B7 are supported.
 
 `BACKLIGHT_BREATHING` is a fancier backlight feature that adds breathing/pulsing/fading effects to the backlight. It uses the same timer as the normal backlight. These breathing effects must be called by code in your keymap.
diff --git a/keyboards/40percentclub/nano/config.h b/keyboards/40percentclub/nano/config.h
index 36840d2f6..5eb65c74a 100644
--- a/keyboards/40percentclub/nano/config.h
+++ b/keyboards/40percentclub/nano/config.h
@@ -31,12 +31,29 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_ROWS 2
 #define MATRIX_COLS 4
 
+/*
+ * Keyboard Matrix Assignments
+ *
+ * Change this to how you wired your keyboard
+ * COLS: AVR pins used for columns, left to right
+ * ROWS: AVR pins used for rows, top to bottom
+ * DIODE_DIRECTION: COL2ROW = COL = Anode (+), ROW = Cathode (-, marked on diode)
+ *                  ROW2COL = ROW = Anode (+), COL = Cathode (-, marked on diode)
+ *                  NO_DIODE = switches are directly connected to AVR pins
+ *
+*/
+// #define MATRIX_ROW_PINS { D0, D5 }
+// #define MATRIX_COL_PINS { F1, F0, B0 }
+#define DIRECT_PINS {   \
+    { F4, F5, F6, F7 }, \
+    { D1, D0, D4, C6 }, \
+}
+#define UNUSED_PINS
+
+/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+//#define DIODE_DIRECTION CUSTOM_MATRIX
+
 /* ws2812 RGB LED */
 #define RGB_DI_PIN D3
 #define RGBLIGHT_ANIMATIONS
 #define RGBLED_NUM 6    // Number of LEDs
-
-/* COL2ROW or ROW2COL */
-#define DIODE_DIRECTION COL2ROW
-
-#define TAPPING_TERM 200
diff --git a/keyboards/40percentclub/nano/matrix.c b/keyboards/40percentclub/nano/matrix.c
deleted file mode 100644
index fa2461af5..000000000
--- a/keyboards/40percentclub/nano/matrix.c
+++ /dev/null
@@ -1,159 +0,0 @@
-/*
-
-Note for ErgoDox EZ customizers: Here be dragons!
-This is not a file you want to be messing with.
-All of the interesting stuff for you is under keymaps/ :)
-Love, Erez
-
-Copyright 2013 Oleg Kostyuk <cub.uanic@gmail.com>
-
-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/>.
-*/
-
-/*
- * scan matrix
- */
-#include <stdint.h>
-#include <stdbool.h>
-#include <avr/io.h>
-#include <util/delay.h>
-#include "action_layer.h"
-#include "print.h"
-#include "debug.h"
-#include "util.h"
-#include "matrix.h"
-#include "nano.h"
-#include <string.h>
-
-/* matrix state(1:on, 0:off) */
-static matrix_row_t matrix[MATRIX_ROWS];
-static matrix_row_t matrix_stage[MATRIX_ROWS];
-static matrix_row_t matrix_debouncing[MATRIX_ROWS];
-
-static uint16_t debouncing_time;
-static bool debouncing = false;
-
-__attribute__ ((weak))
-void matrix_init_kb(void) {
-    matrix_init_user();
-}
-
-__attribute__ ((weak))
-void matrix_scan_kb(void) {
-    matrix_scan_user();
-}
-
-__attribute__ ((weak))
-void matrix_init_user(void) {
-}
-
-__attribute__ ((weak))
-void matrix_scan_user(void) {
-}
-
-inline
-uint8_t matrix_rows(void)
-{
-    return MATRIX_ROWS;
-}
-
-inline
-uint8_t matrix_cols(void)
-{
-    return MATRIX_COLS;
-}
-
-void matrix_init(void)
-{
-
-    DDRF  &= ~(1<<4 | 1<<5 | 1<<6 | 1<<7);
-    PORTF |=  (1<<4 | 1<<5 | 1<<6 | 1<<7);
-    DDRC  &= ~(1<<6);
-    PORTC |=  (1<<6);
-    DDRD  &= ~(1<<0 | 1<<1 | 1<<4);
-    PORTD |=  (1<<0 | 1<<1 | 1<<4);
-
-    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
-        matrix[i] = 0;
-        matrix_debouncing[i] = 0;
-        matrix_stage[i] = 0;
-    }
-
-    matrix_init_quantum();
-
-}
-
-uint8_t matrix_scan(void)
-{
-    matrix_stage[0] =
-        (PINF&(1<<4) ? 0 : (1<<0)) |
-        (PINF&(1<<5) ? 0 : (1<<1)) |
-        (PINF&(1<<6) ? 0 : (1<<2)) |
-        (PINF&(1<<7) ? 0 : (1<<3));
-    matrix_stage[1] =
-        (PIND&(1<<1) ? 0 : (1<<0)) |
-        (PIND&(1<<0) ? 0 : (1<<1)) |
-        (PIND&(1<<4) ? 0 : (1<<2)) |
-        (PINC&(1<<6) ? 0 : (1<<3));
-
-    if (memcmp(matrix_debouncing, matrix_stage, sizeof(matrix)) != 0) {
-        debouncing = true;
-        debouncing_time = timer_read();
-    }
-
-    matrix_debouncing[0] = matrix_stage[0];
-    matrix_debouncing[1] = matrix_stage[1];
-
-    if (debouncing && (timer_elapsed(debouncing_time) > 20)) {
-        for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
-            matrix[i] = matrix_debouncing[i];
-        }
-        debouncing = false;
-    }
-
-    matrix_scan_quantum();
-
-    return 1;
-}
-
-bool matrix_is_modified(void)
-{
-    return true;
-}
-
-inline
-bool matrix_is_on(uint8_t row, uint8_t col)
-{
-    return (matrix[row] & ((matrix_row_t)1<<col));
-}
-
-inline
-matrix_row_t matrix_get_row(uint8_t row)
-{
-    return matrix[row];
-}
-
-void matrix_print(void)
-{
-}
-
-uint8_t matrix_key_count(void)
-{
-    uint8_t count = 0;
-    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
-        count += bitpop16(matrix[i]);
-    }
-    return count;
-}
-
diff --git a/keyboards/40percentclub/nano/nano.h b/keyboards/40percentclub/nano/nano.h
index ae297ac12..881309738 100644
--- a/keyboards/40percentclub/nano/nano.h
+++ b/keyboards/40percentclub/nano/nano.h
@@ -2,10 +2,12 @@
 
 #include "quantum.h"
 
-#define LAYOUT( \
+#define LAYOUT_ortho_2x4( \
     k01, k02, k03, k04, \
     k05, k06, k07, k08  \
   ) { \
     { k01, k02, k03, k04 }, \
     { k05, k06, k07, k08 } \
 }
+
+#define LAYOUT LAYOUT_ortho_2x4 
diff --git a/keyboards/40percentclub/nano/rules.mk b/keyboards/40percentclub/nano/rules.mk
index 66ad3ffc6..e3c97e0d4 100644
--- a/keyboards/40percentclub/nano/rules.mk
+++ b/keyboards/40percentclub/nano/rules.mk
@@ -76,7 +76,3 @@ RGBLIGHT_ENABLE = yes       # Enable WS2812 RGB underlight.
 
 # 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 setup
-SRC = matrix.c
-CUSTOM_MATRIX = yes
diff --git a/quantum/matrix.c b/quantum/matrix.c
index f7cad1a0f..ca63f50f2 100644
--- a/quantum/matrix.c
+++ b/quantum/matrix.c
@@ -45,7 +45,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
     extern const matrix_row_t matrix_mask[];
 #endif
 
-#if (DIODE_DIRECTION == ROW2COL) || (DIODE_DIRECTION == COL2ROW)
+#ifdef DIRECT_PINS
+static pin_t direct_pins[MATRIX_ROWS][MATRIX_COLS] = DIRECT_PINS;
+#elif (DIODE_DIRECTION == ROW2COL) || (DIODE_DIRECTION == COL2ROW)
 static const pin_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS;
 static const pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
 #endif
@@ -54,20 +56,6 @@ static const pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
 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);
-    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
-
 __attribute__ ((weak))
 void matrix_init_quantum(void) {
     matrix_init_kb();
@@ -106,49 +94,6 @@ uint8_t matrix_cols(void) {
     return MATRIX_COLS;
 }
 
-void matrix_init(void) {
-
-    // initialize row and col
-#if (DIODE_DIRECTION == COL2ROW)
-    unselect_rows();
-    init_cols();
-#elif (DIODE_DIRECTION == ROW2COL)
-    unselect_cols();
-    init_rows();
-#endif
-
-    // initialize matrix state: all keys off
-    for (uint8_t i=0; i < MATRIX_ROWS; i++) {
-        raw_matrix[i] = 0;
-        matrix[i] = 0;
-    }
-    debounce_init(MATRIX_ROWS);
-
-    matrix_init_quantum();
-}
-
-uint8_t matrix_scan(void)
-{
-  bool changed = false;
-
-#if (DIODE_DIRECTION == COL2ROW)
-  // Set row, read cols
-  for (uint8_t current_row = 0; current_row < MATRIX_ROWS; 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
-
-  debounce(raw_matrix, matrix, MATRIX_ROWS, changed);
-
-  matrix_scan_quantum();
-  return 1;
-}
-
 //Deprecated.
 bool matrix_is_modified(void)
 {
@@ -195,16 +140,60 @@ uint8_t matrix_key_count(void)
 }
 
 
+#ifdef DIRECT_PINS
+
+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);
+      }
+    }
+  }
+}
 
-#if (DIODE_DIRECTION == COL2ROW)
+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;
 
-static void init_cols(void)
+  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);
+    }
+  }
+
+  return (last_row_value != current_matrix[current_row]);
+}
+
+#elif (DIODE_DIRECTION == COL2ROW)
+
+static void select_row(uint8_t row)
 {
-    for(uint8_t x = 0; x < MATRIX_COLS; x++) {
-        setPinInputHigh(col_pins[x]);
+    setPinOutput(row_pins[row]);
+    writePinLow(row_pins[row]);
+}
+
+static void unselect_row(uint8_t row)
+{
+    setPinInputHigh(row_pins[row]);
+}
+
+static void unselect_rows(void)
+{
+    for(uint8_t x = 0; x < MATRIX_ROWS; x++) {
+        setPinInput(row_pins[x]);
     }
 }
 
+static void init_pins(void) {
+  unselect_rows();
+  for (uint8_t x = 0; x < MATRIX_COLS; x++) {
+    setPinInputHigh(col_pins[x]);
+  }
+}
+
 static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row)
 {
     // Store last value of row prior to reading
@@ -233,31 +222,31 @@ static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row)
     return (last_row_value != current_matrix[current_row]);
 }
 
-static void select_row(uint8_t row)
+#elif (DIODE_DIRECTION == ROW2COL)
+
+static void select_col(uint8_t col)
 {
-    setPinOutput(row_pins[row]);
-    writePinLow(row_pins[row]);
+    setPinOutput(col_pins[col]);
+    writePinLow(col_pins[col]);
 }
 
-static void unselect_row(uint8_t row)
+static void unselect_col(uint8_t col)
 {
-    setPinInputHigh(row_pins[row]);
+    setPinInputHigh(col_pins[col]);
 }
 
-static void unselect_rows(void)
+static void unselect_cols(void)
 {
-    for(uint8_t x = 0; x < MATRIX_ROWS; x++) {
-        setPinInput(row_pins[x]);
+    for(uint8_t x = 0; x < MATRIX_COLS; x++) {
+        setPinInputHigh(col_pins[x]);
     }
 }
 
-#elif (DIODE_DIRECTION == ROW2COL)
-
-static void init_rows(void)
-{
-    for(uint8_t x = 0; x < MATRIX_ROWS; x++) {
-        setPinInputHigh(row_pins[x]);
-    }
+static void init_pins(void) {
+  unselect_cols();
+  for (uint8_t x = 0; x < MATRIX_ROWS; x++) {
+    setPinInputHigh(row_pins[x]);
+  }
 }
 
 static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col)
@@ -300,22 +289,42 @@ static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col)
     return matrix_changed;
 }
 
-static void select_col(uint8_t col)
-{
-    setPinOutput(col_pins[col]);
-    writePinLow(col_pins[col]);
-}
+#endif
 
-static void unselect_col(uint8_t col)
-{
-    setPinInputHigh(col_pins[col]);
-}
+void matrix_init(void) {
 
-static void unselect_cols(void)
-{
-    for(uint8_t x = 0; x < MATRIX_COLS; x++) {
-        setPinInputHigh(col_pins[x]);
+    // initialize key pins
+    init_pins();
+
+    // initialize matrix state: all keys off
+    for (uint8_t i=0; i < MATRIX_ROWS; i++) {
+        raw_matrix[i] = 0;
+        matrix[i] = 0;
     }
+
+    debounce_init(MATRIX_ROWS);
+
+    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 < MATRIX_ROWS; 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
+
+  debounce(raw_matrix, matrix, MATRIX_ROWS, changed);
+
+  matrix_scan_quantum();
+  return 1;
+}