qmk_firmware/keyboards/massdrop/alt/matrix.c

/*
Copyright 2018 Massdrop Inc.

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 "alt.h"
#include "d51_util.h"

const uint8_t row_ports[] = {MATRIX_ROW_PORTS};
const uint8_t row_pins[]  = {MATRIX_ROW_PINS};
const uint8_t col_ports[] = {MATRIX_COL_PORTS};
const uint8_t col_pins[]  = {MATRIX_COL_PINS};
uint32_t      row_masks[2];  // NOTE: If more than PA PB used in the future, adjust code to accommodate

void matrix_init_custom(void) {
    row_masks[PA] = 0;
    row_masks[PB] = 0;

    for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
        PORT->Group[row_ports[row]].DIRCLR.reg                       = 1 << row_pins[row];  // Input
        PORT->Group[row_ports[row]].OUTCLR.reg                       = 1 << row_pins[row];  // Low
        PORT->Group[row_ports[row]].PINCFG[row_pins[row]].bit.INEN   = 1;                   // Input Enable,
        PORT->Group[row_ports[row]].PINCFG[row_pins[row]].bit.PULLEN = 1;                   // Pull Enable
        row_masks[row_ports[row]] |= 1 << row_pins[row];                                    // Add pin to proper row mask
    }

    for (uint8_t col = 0; col < MATRIX_COLS; col++) {
        PORT->Group[col_ports[col]].DIRSET.reg = 1 << col_pins[col];  // Output
        PORT->Group[col_ports[col]].OUTCLR.reg = 1 << col_pins[col];  // Low
    }
}

bool matrix_scan_custom(matrix_row_t current_matrix[]) {
    matrix_row_t raw[MATRIX_ROWS] = {0};
    uint32_t     scans[2];  // PA PB

    for (uint8_t col = 0; col < MATRIX_COLS; col++) {
        PORT->Group[col_ports[col]].OUTSET.reg = 1 << col_pins[col];  // Set col output

        matrix_io_delay();  // Delay for output

        scans[PA] = PORT->Group[PA].IN.reg & row_masks[PA];  // Read PA row pins data
        scans[PB] = PORT->Group[PB].IN.reg & row_masks[PB];  // Read PB row pins data

        PORT->Group[col_ports[col]].OUTCLR.reg = 1 << col_pins[col];  // Clear col output

        for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
            // Move scan bits from scans array into proper row bit locations
            if (scans[row_ports[row]] & (1 << row_pins[row])) {
                raw[row] |= 1 << col;
            }
        }
    }

    bool changed = false;
    for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
        if (current_matrix[row] != raw[row]) {
            current_matrix[row] = raw[row];
            changed             = true;
        }
    }

    return changed;
}