forked from forks/qmk_firmware
147 lines
4 KiB
C
147 lines
4 KiB
C
// Copyright 2023 John Barbero Unenge (@jbarberu)
|
|
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
|
|
#include "matrix.h"
|
|
#include "gpio.h"
|
|
#include "wait.h"
|
|
#include "string.h"
|
|
|
|
#define SNES_CLOCK GP0
|
|
#define SNES_LATCH GP1
|
|
#define SNES_D0 GP2
|
|
#define SNES_D1 GP3
|
|
#define SNES_IO GP4
|
|
|
|
#define KBD_ROW0 GP24
|
|
#define KBD_ROW1 GP23
|
|
#define KBD_ROW2 GP22
|
|
#define KBD_NUM_ROWS 3
|
|
|
|
#define KBD_COL0 GP18
|
|
#define KBD_COL1 GP19
|
|
#define KBD_COL2 GP20
|
|
#define KBD_COL3 GP21
|
|
#define KBD_ROW_SETUP_DELAY_US 5
|
|
|
|
// The real snes will clock 16 bits out of the controller, but only really has 12 bits of data
|
|
#define SNES_DATA_BITS 16
|
|
#define SNES_DATA_SETUP_DELAY_US 10
|
|
#define SNES_CLOCK_PULSE_DURATION 10
|
|
|
|
static const int kbd_pin_map[] = {
|
|
KBD_ROW0,
|
|
KBD_ROW1,
|
|
KBD_ROW2
|
|
};
|
|
|
|
void matrix_init_custom(void) {
|
|
// init snes controller
|
|
gpio_set_pin_input_high(SNES_D0);
|
|
// todo: look into protocol for other strange snes controllers that use D1 and IO
|
|
// gpio_set_pin_input_high(SNES_D1);
|
|
// gpio_set_pin_input_high(SNES_IO);
|
|
gpio_set_pin_output(SNES_CLOCK);
|
|
gpio_set_pin_output(SNES_LATCH);
|
|
gpio_write_pin_low(SNES_CLOCK);
|
|
gpio_write_pin_low(SNES_LATCH);
|
|
|
|
// init rows
|
|
gpio_set_pin_output(KBD_ROW0);
|
|
gpio_set_pin_output(KBD_ROW1);
|
|
gpio_set_pin_output(KBD_ROW2);
|
|
gpio_write_pin_high(KBD_ROW0);
|
|
gpio_write_pin_high(KBD_ROW1);
|
|
gpio_write_pin_high(KBD_ROW2);
|
|
|
|
// init columns
|
|
gpio_set_pin_input_high(KBD_COL0);
|
|
gpio_set_pin_input_high(KBD_COL1);
|
|
gpio_set_pin_input_high(KBD_COL2);
|
|
gpio_set_pin_input_high(KBD_COL3);
|
|
}
|
|
|
|
static matrix_row_t readRow(size_t row, int setupDelay) {
|
|
const int pin = kbd_pin_map[row];
|
|
|
|
// select the row
|
|
gpio_set_pin_output(pin);
|
|
gpio_write_pin_low(pin);
|
|
wait_us(setupDelay);
|
|
|
|
// read the column data
|
|
const matrix_row_t ret =
|
|
(gpio_read_pin(KBD_COL0) ? 0 : 1 << 0)
|
|
| (gpio_read_pin(KBD_COL1) ? 0 : 1 << 1)
|
|
| (gpio_read_pin(KBD_COL2) ? 0 : 1 << 2)
|
|
| (gpio_read_pin(KBD_COL3) ? 0 : 1 << 3);
|
|
|
|
// deselect the row
|
|
gpio_set_pin_output(pin);
|
|
gpio_write_pin_high(pin);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void readKeyboard(matrix_row_t current_matrix[]) {
|
|
for (size_t row = 0; row < KBD_NUM_ROWS; ++row) {
|
|
current_matrix[row] = readRow(row, KBD_ROW_SETUP_DELAY_US);
|
|
}
|
|
}
|
|
|
|
static matrix_row_t getBits(uint16_t value, size_t bit0, size_t bit1, size_t bit2, size_t bit3) {
|
|
matrix_row_t ret = 0;
|
|
ret |= (value >> bit3) & 1;
|
|
ret <<= 1;
|
|
ret |= (value >> bit2) & 1;
|
|
ret <<= 1;
|
|
ret |= (value >> bit1) & 1;
|
|
ret <<= 1;
|
|
ret |= (value >> bit0) & 1;
|
|
return ret;
|
|
}
|
|
|
|
static void readSnesController(matrix_row_t current_matrix[]) {
|
|
uint16_t controller = 0;
|
|
|
|
gpio_write_pin_high(SNES_LATCH);
|
|
|
|
for (size_t bit = 0; bit < SNES_DATA_BITS; ++bit) {
|
|
// Wait for shift register to setup the data line
|
|
wait_us(SNES_DATA_SETUP_DELAY_US);
|
|
|
|
// Shift accumulated data and read data pin
|
|
controller <<= 1;
|
|
controller |= gpio_read_pin(SNES_D0) ? 0 : 1;
|
|
// todo: maybe read D1 and IO here too
|
|
|
|
// Shift next bit in
|
|
gpio_write_pin_high(SNES_CLOCK);
|
|
wait_us(SNES_CLOCK_PULSE_DURATION);
|
|
gpio_write_pin_low(SNES_CLOCK);
|
|
}
|
|
|
|
gpio_write_pin_low(SNES_LATCH);
|
|
|
|
controller >>= 4;
|
|
|
|
// SNES button order is pretty random, and we'd like them to be a bit tidier
|
|
current_matrix[3] = getBits(controller, 1, 0, 8, 9);
|
|
current_matrix[4] = getBits(controller, 7, 6, 5, 4);
|
|
current_matrix[5] = getBits(controller, 3, 11, 2, 10);
|
|
}
|
|
|
|
bool matrix_scan_custom(matrix_row_t current_matrix[]) {
|
|
const size_t MATRIX_ARRAY_SIZE = MATRIX_ROWS * sizeof(matrix_row_t);
|
|
|
|
// create a copy of the current_matrix, before we read hardware state
|
|
matrix_row_t last_value[MATRIX_ROWS];
|
|
memcpy(last_value, current_matrix, MATRIX_ARRAY_SIZE);
|
|
|
|
// read hardware state into current_matrix
|
|
readKeyboard(current_matrix);
|
|
readSnesController(current_matrix);
|
|
|
|
// check if anything changed
|
|
return memcmp(last_value, current_matrix, MATRIX_ARRAY_SIZE) != 0;
|
|
}
|