qmk_firmware/keyboards/cipulot/common/ec_switch_matrix.c

319 lines
12 KiB
C

/* Copyright 2023 Cipulot
*
* 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 3 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 "ec_switch_matrix.h"
#include "analog.h"
#include "atomic_util.h"
#include "math.h"
#include "print.h"
#include "wait.h"
#if defined(__AVR__)
# error "AVR platforms not supported due to a variety of reasons. Among them there are limited memory, limited number of pins and ADC not being able to give satisfactory results."
#endif
#define OPEN_DRAIN_SUPPORT defined(PAL_MODE_OUTPUT_OPENDRAIN)
eeprom_ec_config_t eeprom_ec_config;
ec_config_t ec_config;
// Pin and port array
const pin_t row_pins[] = MATRIX_ROW_PINS;
const pin_t amux_sel_pins[] = AMUX_SEL_PINS;
const pin_t amux_en_pins[] = AMUX_EN_PINS;
const pin_t amux_n_col_sizes[] = AMUX_COL_CHANNELS_SIZES;
const pin_t amux_n_col_channels[][AMUX_MAX_COLS_COUNT] = {AMUX_COL_CHANNELS};
#define AMUX_SEL_PINS_COUNT ARRAY_SIZE(amux_sel_pins)
#define EXPECTED_AMUX_SEL_PINS_COUNT ceil(log2(AMUX_MAX_COLS_COUNT)
// Checks for the correctness of the configuration
_Static_assert(ARRAY_SIZE(amux_en_pins) == AMUX_COUNT, "AMUX_EN_PINS doesn't have the minimum number of bits required to enable all the multiplexers available");
// Check that number of select pins is enough to select all the channels
_Static_assert(AMUX_SEL_PINS_COUNT == EXPECTED_AMUX_SEL_PINS_COUNT), "AMUX_SEL_PINS doesn't have the minimum number of bits required address all the channels");
// Check that number of elements in AMUX_COL_CHANNELS_SIZES is enough to specify the number of channels for all the multiplexers available
_Static_assert(ARRAY_SIZE(amux_n_col_sizes) == AMUX_COUNT, "AMUX_COL_CHANNELS_SIZES doesn't have the minimum number of elements required to specify the number of channels for all the multiplexers available");
static uint16_t sw_value[MATRIX_ROWS][MATRIX_COLS];
static adc_mux adcMux;
// Initialize the row pins
void init_row(void) {
// Set all row pins as output and low
for (uint8_t idx = 0; idx < MATRIX_ROWS; idx++) {
gpio_set_pin_output(row_pins[idx]);
gpio_write_pin_low(row_pins[idx]);
}
}
// Initialize the multiplexers
void init_amux(void) {
for (uint8_t idx = 0; idx < AMUX_COUNT; idx++) {
gpio_set_pin_output(amux_en_pins[idx]);
gpio_write_pin_low(amux_en_pins[idx]);
}
for (uint8_t idx = 0; idx < AMUX_SEL_PINS_COUNT; idx++) {
gpio_set_pin_output(amux_sel_pins[idx]);
}
}
// Select the multiplexer channel of the specified multiplexer
void select_amux_channel(uint8_t channel, uint8_t col) {
// Get the channel for the specified multiplexer
uint8_t ch = amux_n_col_channels[channel][col];
// momentarily disable specified multiplexer
gpio_write_pin_high(amux_en_pins[channel]);
// Select the multiplexer channel
for (uint8_t i = 0; i < AMUX_SEL_PINS_COUNT; i++) {
gpio_write_pin(amux_sel_pins[i], ch & (1 << i));
}
// re enable specified multiplexer
gpio_write_pin_low(amux_en_pins[channel]);
}
// Disable all the unused multiplexers
void disable_unused_amux(uint8_t channel) {
// disable all the other multiplexers apart from the current selected one
for (uint8_t idx = 0; idx < AMUX_COUNT; idx++) {
if (idx != channel) {
gpio_write_pin_high(amux_en_pins[idx]);
}
}
}
// Discharge the peak hold capacitor
void discharge_capacitor(void) {
#ifdef OPEN_DRAIN_SUPPORT
gpio_write_pin_low(DISCHARGE_PIN);
#else
gpio_write_pin_low(DISCHARGE_PIN);
gpio_set_pin_output(DISCHARGE_PIN);
#endif
}
// Charge the peak hold capacitor
void charge_capacitor(uint8_t row) {
#ifdef OPEN_DRAIN_SUPPORT
gpio_write_pin_high(DISCHARGE_PIN);
#else
gpio_set_pin_input(DISCHARGE_PIN);
#endif
gpio_write_pin_high(row_pins[row]);
}
// Initialize the peripherals pins
int ec_init(void) {
// Initialize ADC
palSetLineMode(ANALOG_PORT, PAL_MODE_INPUT_ANALOG);
adcMux = pinToMux(ANALOG_PORT);
// Dummy call to make sure that adcStart() has been called in the appropriate state
adc_read(adcMux);
// Initialize discharge pin as discharge mode
gpio_write_pin_low(DISCHARGE_PIN);
#ifdef OPEN_DRAIN_SUPPORT
gpio_set_pin_output_open_drain(DISCHARGE_PIN);
#else
gpio_set_pin_output(DISCHARGE_PIN);
#endif
// Initialize drive lines
init_row();
// Initialize AMUXs
init_amux();
return 0;
}
// Get the noise floor
void ec_noise_floor(void) {
// Initialize the noise floor
for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
for (uint8_t col = 0; col < MATRIX_COLS; col++) {
ec_config.noise_floor[row][col] = 0;
}
}
// Sample the noise floor
for (uint8_t i = 0; i < DEFAULT_NOISE_FLOOR_SAMPLING_COUNT; i++) {
for (uint8_t amux = 0; amux < AMUX_COUNT; amux++) {
disable_unused_amux(amux);
for (uint8_t col = 0; col < amux_n_col_sizes[amux]; col++) {
uint8_t sum = 0;
for (uint8_t i = 0; i < (amux > 0 ? amux : 0); i++)
sum += amux_n_col_sizes[i];
uint8_t adjusted_col = col + sum;
for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
ec_config.noise_floor[row][adjusted_col] += ec_readkey_raw(amux, row, col);
}
}
}
wait_ms(5);
}
// Average the noise floor
for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
for (uint8_t col = 0; col < MATRIX_COLS; col++) {
ec_config.noise_floor[row][col] /= DEFAULT_NOISE_FLOOR_SAMPLING_COUNT;
}
}
}
// Scan key values and update matrix state
bool ec_matrix_scan(matrix_row_t current_matrix[]) {
bool updated = false;
for (uint8_t amux = 0; amux < AMUX_COUNT; amux++) {
disable_unused_amux(amux);
for (uint8_t col = 0; col < amux_n_col_sizes[amux]; col++) {
for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
uint8_t sum = 0;
for (uint8_t i = 0; i < (amux > 0 ? amux : 0); i++)
sum += amux_n_col_sizes[i];
uint8_t adjusted_col = col + sum;
sw_value[row][adjusted_col] = ec_readkey_raw(amux, row, col);
if (ec_config.bottoming_calibration) {
if (ec_config.bottoming_calibration_starter[row][adjusted_col]) {
ec_config.bottoming_reading[row][adjusted_col] = sw_value[row][adjusted_col];
ec_config.bottoming_calibration_starter[row][adjusted_col] = false;
} else if (sw_value[row][adjusted_col] > ec_config.bottoming_reading[row][adjusted_col]) {
ec_config.bottoming_reading[row][adjusted_col] = sw_value[row][adjusted_col];
}
} else {
updated |= ec_update_key(&current_matrix[row], row, adjusted_col, sw_value[row][adjusted_col]);
}
}
}
}
return ec_config.bottoming_calibration ? false : updated;
}
// Read the capacitive sensor value
uint16_t ec_readkey_raw(uint8_t channel, uint8_t row, uint8_t col) {
uint16_t sw_value = 0;
// Select the multiplexer
select_amux_channel(channel, col);
// Set the row pin to low state to avoid ghosting
gpio_write_pin_low(row_pins[row]);
ATOMIC_BLOCK_FORCEON {
// Set the row pin to high state and have capacitor charge
charge_capacitor(row);
// Read the ADC value
sw_value = adc_read(adcMux);
}
// Discharge peak hold capacitor
discharge_capacitor();
// Waiting for the ghost capacitor to discharge fully
wait_us(DISCHARGE_TIME);
return sw_value;
}
// Update press/release state of key
bool ec_update_key(matrix_row_t* current_row, uint8_t row, uint8_t col, uint16_t sw_value) {
bool current_state = (*current_row >> col) & 1;
// Real Time Noise Floor Calibration
if (sw_value < (ec_config.noise_floor[row][col] - NOISE_FLOOR_THRESHOLD)) {
uprintf("Noise Floor Change: %d, %d, %d\n", row, col, sw_value);
ec_config.noise_floor[row][col] = sw_value;
ec_config.rescaled_mode_0_actuation_threshold[row][col] = rescale(ec_config.mode_0_actuation_threshold, 0, 1023, ec_config.noise_floor[row][col], eeprom_ec_config.bottoming_reading[row][col]);
ec_config.rescaled_mode_0_release_threshold[row][col] = rescale(ec_config.mode_0_release_threshold, 0, 1023, ec_config.noise_floor[row][col], eeprom_ec_config.bottoming_reading[row][col]);
ec_config.rescaled_mode_1_initial_deadzone_offset[row][col] = rescale(ec_config.mode_1_initial_deadzone_offset, 0, 1023, ec_config.noise_floor[row][col], eeprom_ec_config.bottoming_reading[row][col]);
}
// Normal board-wide APC
if (ec_config.actuation_mode == 0) {
if (current_state && sw_value < ec_config.rescaled_mode_0_release_threshold[row][col]) {
*current_row &= ~(1 << col);
uprintf("Key released: %d, %d, %d\n", row, col, sw_value);
return true;
}
if ((!current_state) && sw_value > ec_config.rescaled_mode_0_actuation_threshold[row][col]) {
*current_row |= (1 << col);
uprintf("Key pressed: %d, %d, %d\n", row, col, sw_value);
return true;
}
}
// Rapid Trigger
else if (ec_config.actuation_mode == 1) {
// Is key in active zone?
if (sw_value > ec_config.rescaled_mode_1_initial_deadzone_offset[row][col]) {
// Is key pressed while in active zone?
if (current_state) {
// Is the key still moving down?
if (sw_value > ec_config.extremum[row][col]) {
ec_config.extremum[row][col] = sw_value;
uprintf("Key pressed: %d, %d, %d\n", row, col, sw_value);
}
// Has key moved up enough to be released?
else if (sw_value < ec_config.extremum[row][col] - ec_config.mode_1_release_offset) {
ec_config.extremum[row][col] = sw_value;
*current_row &= ~(1 << col);
uprintf("Key released: %d, %d, %d\n", row, col, sw_value);
return true;
}
}
// Key is not pressed while in active zone
else {
// Is the key still moving up?
if (sw_value < ec_config.extremum[row][col]) {
ec_config.extremum[row][col] = sw_value;
}
// Has key moved down enough to be pressed?
else if (sw_value > ec_config.extremum[row][col] + ec_config.mode_1_actuation_offset) {
ec_config.extremum[row][col] = sw_value;
*current_row |= (1 << col);
uprintf("Key pressed: %d, %d, %d\n", row, col, sw_value);
return true;
}
}
}
// Key is not in active zone
else {
// Check to avoid key being stuck in pressed state near the active zone threshold
if (sw_value < ec_config.extremum[row][col]) {
ec_config.extremum[row][col] = sw_value;
*current_row &= ~(1 << col);
return true;
}
}
}
return false;
}
// Print the matrix values
void ec_print_matrix(void) {
for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
for (uint8_t col = 0; col < MATRIX_COLS - 1; col++) {
uprintf("%4d,", sw_value[row][col]);
}
uprintf("%4d\n", sw_value[row][MATRIX_COLS - 1]);
}
print("\n");
}
// Rescale the value to a different range
uint16_t rescale(uint16_t x, uint16_t in_min, uint16_t in_max, uint16_t out_min, uint16_t out_max) {
return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}