qmk_firmware/keyboards/keychron/v3/matrix.c
2022-12-19 20:39:36 +11:00

222 lines
5.9 KiB
C

/* Copyright 2021 @ Keychron (https://www.keychron.com)
*
* 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 "matrix.h"
#include "quantum.h"
// Pin connected to DS of 74HC595
#define DATA_PIN A7
// Pin connected to SH_CP of 74HC595
#define CLOCK_PIN B1
// Pin connected to ST_CP of 74HC595
#define LATCH_PIN B0
#ifdef MATRIX_ROW_PINS
static pin_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS;
#endif // MATRIX_ROW_PINS
#ifdef MATRIX_COL_PINS
static pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
#endif // MATRIX_COL_PINS
#define ROWS_PER_HAND (MATRIX_ROWS)
static inline void setPinOutput_writeLow(pin_t pin) {
ATOMIC_BLOCK_FORCEON {
setPinOutput(pin);
writePinLow(pin);
}
}
static inline void setPinOutput_writeHigh(pin_t pin) {
ATOMIC_BLOCK_FORCEON {
setPinOutput(pin);
writePinHigh(pin);
}
}
static inline void setPinInputHigh_atomic(pin_t pin) {
ATOMIC_BLOCK_FORCEON {
setPinInputHigh(pin);
}
}
static inline uint8_t readMatrixPin(pin_t pin) {
if (pin != NO_PIN) {
return readPin(pin);
} else {
return 1;
}
}
// At 3.6V input, three nops (37.5ns) should be enough for all signals
#define small_delay() __asm__ __volatile__("nop;nop;nop;\n\t" ::: "memory")
#define compiler_barrier() __asm__ __volatile__("" ::: "memory")
static void shiftOut(uint8_t dataOut) {
ATOMIC_BLOCK_FORCEON {
for (uint8_t i = 0; i < 8; i++) {
compiler_barrier();
if (dataOut & 0x1) {
writePinHigh(DATA_PIN);
} else {
writePinLow(DATA_PIN);
}
dataOut = dataOut >> 1;
compiler_barrier();
writePinHigh(CLOCK_PIN);
small_delay();
writePinLow(CLOCK_PIN);
}
compiler_barrier();
writePinHigh(LATCH_PIN);
small_delay();
writePinLow(LATCH_PIN);
compiler_barrier();
}
}
static void shiftOut_single(uint8_t data) {
ATOMIC_BLOCK_FORCEON {
compiler_barrier();
if (data & 0x1) {
writePinHigh(DATA_PIN);
} else {
writePinLow(DATA_PIN);
}
compiler_barrier();
writePinHigh(CLOCK_PIN);
small_delay();
writePinLow(CLOCK_PIN);
compiler_barrier();
writePinHigh(LATCH_PIN);
small_delay();
writePinLow(LATCH_PIN);
compiler_barrier();
}
}
static bool select_col(uint8_t col) {
pin_t pin = col_pins[col];
if (pin != NO_PIN) {
setPinOutput_writeLow(pin);
return true;
} else {
if (col == 8) {
shiftOut_single(0x00);
}
return true;
}
return false;
}
static void unselect_col(uint8_t col) {
pin_t pin = col_pins[col];
if (pin != NO_PIN) {
#ifdef MATRIX_UNSELECT_DRIVE_HIGH
setPinOutput_writeHigh(pin);
#else
setPinInputHigh_atomic(pin);
#endif
} else {
shiftOut_single(0x01);
}
}
static void unselect_cols(void) {
for (uint8_t x = 0; x < MATRIX_COLS; x++) {
pin_t pin = col_pins[x];
if (pin != NO_PIN) {
#ifdef MATRIX_UNSELECT_DRIVE_HIGH
setPinOutput_writeHigh(pin);
#else
setPinInputHigh_atomic(pin);
#endif
} else {
if (x == 8)
// unselect shift Register
shiftOut(0xFF);
}
}
}
static void matrix_init_pins(void) {
setPinOutput(DATA_PIN);
setPinOutput(CLOCK_PIN);
setPinOutput(LATCH_PIN);
#ifdef MATRIX_UNSELECT_DRIVE_HIGH
for (uint8_t x = 0; x < MATRIX_COLS; x++) {
if (col_pins[x] != NO_PIN) {
setPinOutput(col_pins[x]);
}
}
#endif
unselect_cols();
for (uint8_t x = 0; x < MATRIX_ROWS; x++) {
if (row_pins[x] != NO_PIN) {
setPinInputHigh_atomic(row_pins[x]);
}
}
}
static void matrix_read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col, matrix_row_t row_shifter) {
bool key_pressed = false;
// Select col
if (!select_col(current_col)) { // select col
return; // skip NO_PIN col
}
matrix_output_select_delay();
// For each row...
for (uint8_t row_index = 0; row_index < ROWS_PER_HAND; row_index++) {
// Check row pin state
if (readMatrixPin(row_pins[row_index]) == 0) {
// Pin LO, set col bit
current_matrix[row_index] |= row_shifter;
key_pressed = true;
} else {
// Pin HI, clear col bit
current_matrix[row_index] &= ~row_shifter;
}
}
// Unselect col
unselect_col(current_col);
matrix_output_unselect_delay(current_col, key_pressed); // wait for all Row signals to go HIGH
}
void matrix_init_custom(void) {
// initialize key pins
matrix_init_pins();
}
bool matrix_scan_custom(matrix_row_t current_matrix[]) {
matrix_row_t curr_matrix[MATRIX_ROWS] = {0};
// Set col, read rows
matrix_row_t row_shifter = MATRIX_ROW_SHIFTER;
for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++, row_shifter <<= 1) {
matrix_read_rows_on_col(curr_matrix, current_col, row_shifter);
}
bool changed = memcmp(current_matrix, curr_matrix, sizeof(curr_matrix)) != 0;
if (changed) memcpy(current_matrix, curr_matrix, sizeof(curr_matrix));
return changed;
}