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- // 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
- // Need to frequently read the encoder pins while scanning because the I/O expander takes a long time in comparison.
- encoder_driver_task();
- #endif
- }
- return changed;
- }
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