Add SN74x138 demultiplexer driver (#16217)

drivers/gpio/sn74x138.c

@@ -0,0 +1,65 @@
+/* Copyright 2022
+ *
+ * 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/>.
+ */
+
+#include "sn74x138.h"
+#include "gpio.h"
+
+#define ADDRESS_PIN_COUNT 3
+
+#ifndef SN74X138_ADDRESS_PINS
+#    error sn74x138: no address pins defined!
+#endif
+
+static const pin_t address_pins[ADDRESS_PIN_COUNT] = SN74X138_ADDRESS_PINS;
+
+void sn74x138_init(void) {
+    for (int i = 0; i < ADDRESS_PIN_COUNT; i++) {
+        setPinOutput(address_pins[i]);
+        writePinLow(address_pins[i]);
+    }
+
+#if defined(SN74X138_E1_PIN)
+    setPinOutput(SN74X138_E1_PIN);
+    writePinHigh(SN74X138_E1_PIN);
+#endif
+
+#if defined(SN74X138_E2_PIN)
+    setPinOutput(SN74X138_E2_PIN);
+    writePinHigh(SN74X138_E2_PIN);
+#endif
+#if defined(SN74X138_E3_PIN)
+    setPinOutput(SN74X138_E3_PIN);
+    writePinLow(SN74X138_E3_PIN);
+#endif
+}
+
+void sn74x138_set_enabled(bool enabled) {
+#if defined(SN74X138_E1_PIN)
+    writePin(SN74X138_E1_PIN, !enabled);
+#endif
+#if defined(SN74X138_E2_PIN)
+    writePin(SN74X138_E2_PIN, !enabled);
+#endif
+#if defined(SN74X138_E3_PIN)
+    writePin(SN74X138_E3_PIN, enabled);
+#endif
+}
+
+void sn74x138_set_addr(uint8_t address) {
+    for (int i = 0; i < ADDRESS_PIN_COUNT; i++) {
+        writePin(address_pins[i], address & (1 << i));
+    }
+}

drivers/gpio/sn74x138.h

@@ -0,0 +1,48 @@
+/* Copyright 2022
+ *
+ * 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/>.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/**
+ * Driver for 74x138 3-to-8 decoder/demultiplexer with inverting outputs
+ * https://assets.nexperia.com/documents/data-sheet/74HC_HCT138.pdf
+ */
+
+/**
+ * Initialize the address and output enable pins.
+ */
+void sn74x138_init(void);
+
+/**
+ * Set the enabled state.
+ *
+ * When enabled is true, pulls the E1 and E2 pins low, and the E3 pin high.
+ *
+ * \param enabled The enable state to set.
+ */
+void sn74x138_set_enabled(bool enabled);
+
+/**
+ * Set the output pin address.
+ * 
+ * The selected output pin will be pulled low, while the remaining output pins will be high.
+ *
+ * \param address The address to set, from 0 to 7.
+ */
+void sn74x138_set_addr(uint8_t address);

keyboards/evyd13/wasdat/config.h

@@ -41,22 +41,16 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
 */
 #define MATRIX_ROW_PINS { D6, D4, F6, F7, F4, F5, F0, F1 }
-#define MATRIX_COL_PINS { }
+#define MATRIX_COL_PINS { C7, B6, C6, B4, B5, D7, NO_PIN, NO_PIN, NO_PIN, NO_PIN, NO_PIN, NO_PIN, NO_PIN, D3, B7, B3 } // Columns 6-12 controlled by demux
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL*/
-#define DIODE_DIRECTION ROW2COL
+#define SN74X138_ADDRESS_PINS { D2, D1, D0 }
 
 // For QMK DFU
 #define QMK_ESC_OUTPUT D6
 #define QMK_ESC_INPUT D7
 #define QMK_LED B0
 
-/*
- * Split Keyboard specific options, make sure you have 'SPLIT_KEYBOARD = yes' in your rules.mk, and define SOFT_SERIAL_PIN.
- */
-//#define SOFT_SERIAL_PIN D0 // or D1, D2, D3, E6
-
 #define LED_NUM_LOCK_PIN B2
 #define LED_CAPS_LOCK_PIN B0
 #define LED_SCROLL_LOCK_PIN B1

keyboards/evyd13/wasdat/matrix.c

@@ -14,268 +14,66 @@ 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/>.
 */
+
 #include <stdint.h>
 #include <stdbool.h>
-#include "wait.h"
-#include "util.h"
 #include "matrix.h"
-#include "debounce.h"
 #include "quantum.h"
+#include "sn74x138.h"
 
-#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
-
-// matrix code
-
-#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);
-            }
-        }
-    }
-}
-
-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;
-
-    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 : (MATRIX_ROW_SHIFTER << col_index);
-        }
-    }
-
-    return (last_row_value != current_matrix[current_row]);
-}
-
-#elif (DIODE_DIRECTION == COL2ROW)
-
-static void select_row(uint8_t row) {
-    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++) {
-        setPinInputHigh(row_pins[x]);
-    }
-}
+static const pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
 
-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
-    matrix_row_t last_row_value = current_matrix[current_row];
-
-    // Clear data in matrix row
-    current_matrix[current_row] = 0;
-
-    // Select row and wait for row selecton to stabilize
-    select_row(current_row);
-    wait_us(30);
-
-    // For each col...
-    for (uint8_t col_index = 0; col_index < MATRIX_COLS; col_index++) {
-
-        // Select the col pin to read (active low)
-        uint8_t pin_state = readPin(col_pins[col_index]);
-
-        // Populate the matrix row with the state of the col pin
-        current_matrix[current_row] |= pin_state ? 0 : (MATRIX_ROW_SHIFTER << col_index);
-    }
-
-    // Unselect row
-    unselect_row(current_row);
-
-    return (last_row_value != current_matrix[current_row]);
-}
-
-#elif (DIODE_DIRECTION == ROW2COL)
-
-/* Cols 0 - 15
- * col 0: C7
- * col 1:  B6
+/* col 0: C7
+ * col 1: B6
  * col 2: C6
- * col 3:  B4
- * col 4:  B5
- * col 5:   D7
- * These columns use a 74HC237D 3 to 8 bit demultiplexer.
- *                A0   A1   A2
- * col / pin:    PD2  PD1  PD0
- * 6:             1    1    1
- * 7:             0    1    1
- * 8:             1    0    1
- * 9:             0    0    1
- * 10:            1    1    0
- * 11:            0    1    0
- * 12:            1    0    0
- * col 13:  D3
- * col 14:  B7
- * col 15:  B3
+ * col 3: B4
+ * col 4: B5
+ * col 5: D7
+ *
+ * These columns use a 74HC138 3 to 8 bit demultiplexer.
+ *                A2   A1   A0
+ * col / pin:    PD0  PD1  PD2
+ * 6:              1    1    1
+ * 7:              1    1    0
+ * 8:              1    0    1
+ * 9:              1    0    0
+ * 10:             0    1    1
+ * 11:             0    1    0
+ * 12:             0    0    1
+ *
+ * col 13: D3
+ * col 14: B7
+ * col 15: B3
  */
 static void select_col(uint8_t col) {
-    switch (col) {
-        case 0:
-            writePinLow(C7);
-            break;
-        case 1:
-            writePinLow(B6);
-            break;
-        case 2:
-            writePinLow(C6);
-            break;
-        case 3:
-            writePinLow(B4);
-            break;
-        case 4:
-            writePinLow(B5);
-            break;
-        case 5:
-            writePinLow(D7);
-            break;
-        case 6:
-            writePinHigh(D0);
-            writePinHigh(D1);
-            writePinHigh(D2);
-            break;
-        case 7:
-            writePinHigh(D0);
-            writePinHigh(D1);
-            break;
-        case 8:
-            writePinHigh(D0);
-            writePinHigh(D2);
-            break;
-        case 9:
-            writePinHigh(D0);
-            break;
-        case 10:
-            writePinHigh(D1);
-            writePinHigh(D2);
-            break;
-        case 11:
-            writePinHigh(D1);
-            break;
-        case 12:
-            writePinHigh(D2);
-            break;
-        case 13:
-            writePinLow(D3);
-            break;
-        case 14:
-            writePinLow(B7);
-            break;
-        case 15:
-            writePinLow(B3);
-            break;
+    if (col_pins[col] != NO_PIN) {
+        writePinLow(col_pins[col]);
+    } else {
+        sn74x138_set_addr(13 - col);
     }
 }
 
 static void unselect_col(uint8_t col) {
-    switch (col) {
-        case 0:
-            writePinHigh(C7);
-            break;
-        case 1:
-            writePinHigh(B6);
-            break;
-        case 2:
-            writePinHigh(C6);
-            break;
-        case 3:
-            writePinHigh(B4);
-            break;
-        case 4:
-            writePinHigh(B5);
-            break;
-        case 5:
-            writePinHigh(D7);
-            break;
-        case 6:
-            writePinLow(D0);
-            writePinLow(D1);
-            writePinLow(D2);
-            break;
-        case 7:
-            writePinLow(D0);
-            writePinLow(D1);
-            break;
-        case 8:
-            writePinLow(D0);
-            writePinLow(D2);
-            break;
-        case 9:
-            writePinLow(D0);
-            break;
-        case 10:
-            writePinLow(D1);
-            writePinLow(D2);
-            break;
-        case 11:
-            writePinLow(D1);
-            break;
-        case 12:
-            writePinLow(D2);
-            break;
-        case 13:
-            writePinHigh(D3);
-            break;
-        case 14:
-            writePinHigh(B7);
-            break;
-        case 15:
-            writePinHigh(B3);
-            break;
+    if (col_pins[col] != NO_PIN) {
+        setPinOutput(col_pins[col]);
+        writePinHigh(col_pins[col]);
+    } else {
+        sn74x138_set_addr(0);
     }
 }
 
 static void unselect_cols(void) {
-    //Native
-    setPinOutput(D3);
-    setPinOutput(D7);
-    writePinHigh(D3);
-    writePinHigh(D7);
-
-    setPinOutput(C6);
-    setPinOutput(C7);
-    writePinHigh(C6);
-    writePinHigh(C7);
-
-    setPinOutput(B3);
-    setPinOutput(B4);
-    setPinOutput(B5);
-    setPinOutput(B6);
-    setPinOutput(B7);
-    writePinHigh(B3);
-    writePinHigh(B4);
-    writePinHigh(B5);
-    writePinHigh(B6);
-    writePinHigh(B7);
+    // Native
+    for (uint8_t x = 0; x < MATRIX_COLS; x++) {
+        if (col_pins[x] != NO_PIN) {
+            setPinOutput(col_pins[x]);
+            writePinHigh(col_pins[x]);
+        }
+    }
 
-    //Demultiplexer
-    setPinOutput(D0);
-    setPinOutput(D1);
-    setPinOutput(D2);
-    writePinLow(D0);
-    writePinLow(D1);
-    writePinLow(D2);
+    // Demultiplexer
+    sn74x138_set_addr(0);
 }
 
 static void init_pins(void) {
@@ -288,9 +86,9 @@ static void init_pins(void) {
 static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col) {
     bool matrix_changed = false;
 
-    // Select col and wait for col selecton to stabilize
+    // Select col and wait for col selection to stabilize
     select_col(current_col);
-    wait_us(30);
+    matrix_io_delay();
 
     // For each row...
     for (uint8_t row_index = 0; row_index < MATRIX_ROWS; row_index++) {
@@ -318,27 +116,20 @@ static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col)
     return matrix_changed;
 }
 
-#endif
-
 void matrix_init_custom(void) {
     // initialize key pins
     init_pins();
+    // initialize demultiplexer
+    sn74x138_init();
 }
 
 bool matrix_scan_custom(matrix_row_t current_matrix[]) {
     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(current_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(current_matrix, current_col);
     }
-#endif
 
     return changed;
 }

keyboards/evyd13/wasdat/rules.mk

@@ -18,6 +18,7 @@ RGBLIGHT_ENABLE = no        # Enable keyboard RGB underglow
 AUDIO_ENABLE = no           # Audio output
 
 CUSTOM_MATRIX = lite
-SRC += matrix.c
+VPATH += drivers/gpio
+SRC += matrix.c sn74x138.c
 
 LAYOUTS = fullsize_ansi fullsize_iso tkl_ansi tkl_iso