[Keyboard] New Keyboard - Sugar Glider (#19933)

Co-authored-by: Drashna Jaelre <drashna@live.com>
Co-authored-by: Less/Rikki <86894501+lesshonor@users.noreply.github.com>
Co-authored-by: jack <0x6a73@protonmail.com>

keyboards/mechwild/sugarglider/matrix.c

@@ -0,0 +1,95 @@
+// Copyright 2023 Kyle McCreery
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "matrix.h"
+#include "mcp23018.h"
+#include "wait.h"
+#include "debug.h"
+#include "encoder.h"
+
+#define I2C_ADDR 0x20
+#define ROW_POS { 0b01000000, 0b10000000, 0b01000000, 0b10000000, 0b00000100, 0b00010000, 0b00100000, 0b00000010, 0b00001000 }
+
+static uint8_t mcp23018_errors = 0;
+
+static void mcp23018_init_cols(void) {
+    mcp23018_errors += !mcp23018_set_config(I2C_ADDR, mcp23018_PORTA, ALL_INPUT);
+    mcp23018_errors += !mcp23018_set_config(I2C_ADDR, mcp23018_PORTB, ALL_INPUT);
+}
+
+static void mcp23018_scan(void) {
+    if (!mcp23018_errors) {
+        return;
+    }
+
+    static uint16_t mcp23018_reset_loop = 0;
+    if (++mcp23018_reset_loop > 0x1FFF) {
+        // tuned to about 5s given the current scan rate
+        dprintf("trying to reset mcp23018\n");
+        mcp23018_reset_loop = 0;
+        mcp23018_errors     = 0;
+        mcp23018_init_cols();
+    }
+}
+
+static matrix_row_t read_cols(void) {
+    if (mcp23018_errors) {
+        return 0;
+    }
+
+    uint8_t ret = 0xFF;                                                         // sets all to 1
+    mcp23018_errors += !mcp23018_readPins(I2C_ADDR, mcp23018_PORTB, &ret);      // will update with values 0 = pulled down by connection, 1 = pulled up by pullup resistors
+
+    return (~ret) & 0b00111111; // Clears out the two row bits in the B buffer.
+}
+
+static void select_row(uint8_t row) {
+    uint8_t row_pos[MATRIX_ROWS] = ROW_POS;
+    if (mcp23018_errors) {
+        // wait to mimic i2c interactions
+        //wait_us(100);
+        return;
+    }
+    
+    if (row > 1) {
+        mcp23018_errors += !mcp23018_set_config(I2C_ADDR, mcp23018_PORTB, ALL_INPUT);
+        mcp23018_errors += !mcp23018_set_config(I2C_ADDR, mcp23018_PORTA, ~(row_pos[row]));
+    } else {
+        mcp23018_errors += !mcp23018_set_config(I2C_ADDR, mcp23018_PORTA, ALL_INPUT);
+        mcp23018_errors += !mcp23018_set_config(I2C_ADDR, mcp23018_PORTB, ~(row_pos[row]));
+    }
+}
+
+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 selection to stabilize
+    select_row(current_row);
+    // Skip the wait_us(30); as i2c is slow enough to debounce the io changes
+
+    current_matrix[current_row] = read_cols();
+
+    return (last_row_value != current_matrix[current_row]);
+}
+
+void matrix_init_custom(void) {
+    mcp23018_init(I2C_ADDR);
+    mcp23018_init_cols();
+}
+
+bool matrix_scan_custom(matrix_row_t current_matrix[]) {
+    mcp23018_scan();
+
+    bool changed = false;
+    for (uint8_t current_row = 0; current_row < MATRIX_ROWS; current_row++) {
+        changed |= read_cols_on_row(current_matrix, current_row);
+#ifdef ENCODER_ENABLE
+        encoder_read();
+#endif
+    }
+    return changed;
+}