qmk_firmware/keyboards/frobiac/blackbowl/matrix.c

115 lines
3.9 KiB
C

// Copyright 2013 Oleg Kostyuk <cub.uanic@gmail.com>
// Copyright 2017 Erin Call <hello@erincall.com>
// Copyright 2023 @frobiac
// SPDX-License-Identifier: GPL-2.0-or-later
// This implements a matrix scan (lite) for the BlackBowl keyboard.
// Each side has a dedicated MCP23018 I2C expander.
#include <stdint.h>
#include <stdbool.h>
#include <avr/io.h>
#include "wait.h"
#include "action_layer.h"
#include "print.h"
#include "debug.h"
#include "util.h"
#include "matrix.h"
#include "blackbowl.h"
#include "i2c_master.h"
#include "timer.h"
#define MATRIX_ROWS_PER_SIDE (MATRIX_ROWS / 2)
#define ROW_SHIFTER ((matrix_row_t)1)
static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col);
static uint8_t expander_reset_loop;
uint8_t expander_status;
const uint8_t expander_input_mask = ((1 << MATRIX_ROWS_PER_SIDE) - 1); // No special mapping, 5 bits [0..4] per side
bool i2c_initialized = false;
static const uint8_t I2C_ADDR_RIGHT = 0x4E;
static const uint8_t I2C_ADDR_LEFT = 0x46;
static const uint8_t i2c_addr[] = {I2C_ADDR_RIGHT, I2C_ADDR_LEFT};
void matrix_init_custom(void) {
if (!i2c_initialized) {
i2c_init();
wait_ms(1000);
}
// Pin direction and pull-up depends on diode direction and column register:
// ROW2COL, GPIOA => input, output
uint8_t direction[2] = {0, expander_input_mask};
uint8_t pullup[2] = {0, expander_input_mask};
for (uint8_t i = 0; i < 2; ++i) {
expander_status = i2c_write_register(i2c_addr[i], IODIRA, direction, 2, I2C_TIMEOUT);
if (expander_status) return;
expander_status = i2c_write_register(i2c_addr[i], GPPUA, pullup, 2, I2C_TIMEOUT);
}
}
bool matrix_scan_custom(matrix_row_t current_matrix[]) {
bool matrix_has_changed = false;
if (expander_status) { // if there was an error
++expander_reset_loop;
if (++expander_reset_loop == 0) {
// since expander_reset_loop is 8 bit - we'll try to reset once in 255 matrix scans
// this will be approx bit more frequent than once per second
matrix_init_custom();
}
}
for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++) {
matrix_has_changed |= read_rows_on_col(current_matrix, current_col);
}
return matrix_has_changed;
}
static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col) {
bool matrix_changed = false;
uint8_t port = 0xFF & ~(1 << current_col);
uint8_t column_state[] = {0, 0};
// On both expanders: select col and read rows
for (size_t i = 0; i < 2; ++i) {
if (!expander_status) {
expander_status = i2c_write_register(i2c_addr[i], EXPANDER_COL_REGISTER, &port, 1, I2C_TIMEOUT);
}
wait_us(30);
if (expander_status) {
return false;
}
expander_status = i2c_read_register(i2c_addr[i], EXPANDER_ROW_REGISTER, &column_state[i], 1, I2C_TIMEOUT);
column_state[i] = (~column_state[i]) & ((1 << MATRIX_ROWS_PER_SIDE) - 1);
}
// now map rows 0..4 on each side to cumulative to 0..9
uint16_t col_state = column_state[0] | ((column_state[1] << MATRIX_ROWS_PER_SIDE) /*& 0x3e0*/);
for (uint8_t current_row = 0; current_row < MATRIX_ROWS; current_row++) {
// Store last value of row prior to reading
matrix_row_t last_row_value = current_matrix[current_row];
if (col_state & (1 << current_row)) {
// key closed; set state bit in matrix
current_matrix[current_row] |= (ROW_SHIFTER << current_col);
} else {
// key open; clear state bit in matrix
current_matrix[current_row] &= ~(ROW_SHIFTER << current_col);
}
// Determine whether the matrix changed state
if ((last_row_value != current_matrix[current_row]) && !(matrix_changed)) {
matrix_changed = true;
}
}
return matrix_changed;
}