qmk-keychron-q3-colemak-dh/quantum/matrix.c
Michael Stapelberg 82aa9ad4a5
matrix: wait for row signal to go HIGH for every row (#12945)
I noticed this discrepancy (last row of the matrix treated differently than the
others) when optimizing the input latency of my keyboard controller, see also
https://michael.stapelberg.ch/posts/2021-05-08-keyboard-input-latency-qmk-kinesis/

Before this commit, when tuning the delays I noticed ghost key presses when
pressing the F2 key, which is on the last row of the keyboard matrix: the
dead_grave key, which is on the first row of the keyboard matrix, would be
incorrectly detected as pressed.

After this commit, all keyboard matrix rows are interpreted correctly.

I suspect that my setup is more susceptible to this nuance than others because I
use GPIO_INPUT_PIN_DELAY=0 and hence don’t have another delay that might mask
the problem.
2021-05-20 06:43:36 +10:00

226 lines
6.5 KiB
C

/*
Copyright 2012-2018 Jun Wako, Jack Humbert, Yiancar
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 <stdint.h>
#include <stdbool.h>
#include "util.h"
#include "matrix.h"
#include "debounce.h"
#include "quantum.h"
#ifdef DIRECT_PINS
static pin_t direct_pins[MATRIX_ROWS][MATRIX_COLS] = DIRECT_PINS;
#elif (DIODE_DIRECTION == ROW2COL) || (DIODE_DIRECTION == COL2ROW)
static const pin_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS;
static const pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
#endif
/* matrix state(1:on, 0:off) */
extern matrix_row_t raw_matrix[MATRIX_ROWS]; // raw values
extern matrix_row_t matrix[MATRIX_ROWS]; // debounced values
static inline void setPinOutput_writeLow(pin_t pin) {
ATOMIC_BLOCK_FORCEON {
setPinOutput(pin);
writePinLow(pin);
}
}
static inline void setPinInputHigh_atomic(pin_t pin) {
ATOMIC_BLOCK_FORCEON { setPinInputHigh(pin); }
}
// matrix code
#ifdef DIRECT_PINS
static void init_pins(void) {
for (int row = 0; row < MATRIX_ROWS; row++) {
for (int col = 0; col < MATRIX_COLS; col++) {
pin_t pin = direct_pins[row][col];
if (pin != NO_PIN) {
setPinInputHigh(pin);
}
}
}
}
static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row) {
// Start with a clear matrix row
matrix_row_t current_row_value = 0;
for (uint8_t col_index = 0; col_index < MATRIX_COLS; col_index++) {
pin_t pin = direct_pins[current_row][col_index];
if (pin != NO_PIN) {
current_row_value |= readPin(pin) ? 0 : (MATRIX_ROW_SHIFTER << col_index);
}
}
// If the row has changed, store the row and return the changed flag.
if (current_matrix[current_row] != current_row_value) {
current_matrix[current_row] = current_row_value;
return true;
}
return false;
}
#elif defined(DIODE_DIRECTION)
# if (DIODE_DIRECTION == COL2ROW)
static void select_row(uint8_t row) { setPinOutput_writeLow(row_pins[row]); }
static void unselect_row(uint8_t row) { setPinInputHigh_atomic(row_pins[row]); }
static void unselect_rows(void) {
for (uint8_t x = 0; x < MATRIX_ROWS; x++) {
setPinInputHigh_atomic(row_pins[x]);
}
}
static void init_pins(void) {
unselect_rows();
for (uint8_t x = 0; x < MATRIX_COLS; x++) {
setPinInputHigh_atomic(col_pins[x]);
}
}
static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row) {
// Start with a clear matrix row
matrix_row_t current_row_value = 0;
// Select row
select_row(current_row);
matrix_output_select_delay();
// For each col...
for (uint8_t col_index = 0; col_index < MATRIX_COLS; col_index++) {
// Select the col pin to read (active low)
uint8_t pin_state = readPin(col_pins[col_index]);
// Populate the matrix row with the state of the col pin
current_row_value |= pin_state ? 0 : (MATRIX_ROW_SHIFTER << col_index);
}
// Unselect row
unselect_row(current_row);
matrix_output_unselect_delay(); // wait for all Col signals to go HIGH
// If the row has changed, store the row and return the changed flag.
if (current_matrix[current_row] != current_row_value) {
current_matrix[current_row] = current_row_value;
return true;
}
return false;
}
# elif (DIODE_DIRECTION == ROW2COL)
static void select_col(uint8_t col) { setPinOutput_writeLow(col_pins[col]); }
static void unselect_col(uint8_t col) { setPinInputHigh_atomic(col_pins[col]); }
static void unselect_cols(void) {
for (uint8_t x = 0; x < MATRIX_COLS; x++) {
setPinInputHigh_atomic(col_pins[x]);
}
}
static void init_pins(void) {
unselect_cols();
for (uint8_t x = 0; x < MATRIX_ROWS; x++) {
setPinInputHigh_atomic(row_pins[x]);
}
}
static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col) {
bool matrix_changed = false;
// Select col
select_col(current_col);
matrix_output_select_delay();
// For each row...
for (uint8_t row_index = 0; row_index < MATRIX_ROWS; row_index++) {
// Store last value of row prior to reading
matrix_row_t last_row_value = current_matrix[row_index];
matrix_row_t current_row_value = last_row_value;
// Check row pin state
if (readPin(row_pins[row_index]) == 0) {
// Pin LO, set col bit
current_row_value |= (MATRIX_ROW_SHIFTER << current_col);
} else {
// Pin HI, clear col bit
current_row_value &= ~(MATRIX_ROW_SHIFTER << current_col);
}
// Determine if the matrix changed state
if ((last_row_value != current_row_value)) {
matrix_changed |= true;
current_matrix[row_index] = current_row_value;
}
}
// Unselect col
unselect_col(current_col);
matrix_output_unselect_delay(); // wait for all Row signals to go HIGH
return matrix_changed;
}
# else
# error DIODE_DIRECTION must be one of COL2ROW or ROW2COL!
# endif
#else
# error DIODE_DIRECTION is not defined!
#endif
void matrix_init(void) {
// initialize key pins
init_pins();
// initialize matrix state: all keys off
for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
raw_matrix[i] = 0;
matrix[i] = 0;
}
debounce_init(MATRIX_ROWS);
matrix_init_quantum();
}
uint8_t matrix_scan(void) {
bool changed = false;
#if defined(DIRECT_PINS) || (DIODE_DIRECTION == COL2ROW)
// Set row, read cols
for (uint8_t current_row = 0; current_row < MATRIX_ROWS; current_row++) {
changed |= read_cols_on_row(raw_matrix, current_row);
}
#elif (DIODE_DIRECTION == ROW2COL)
// Set col, read rows
for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++) {
changed |= read_rows_on_col(raw_matrix, current_col);
}
#endif
debounce(raw_matrix, matrix, MATRIX_ROWS, changed);
matrix_scan_quantum();
return (uint8_t)changed;
}