qmk-firmware/quantum/pincontrol.h

/* Copyright 2016 Wez Furlong
 *
 * 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/>.
 */
#pragma once
// Some helpers for controlling gpio pins
#include <avr/io.h>

enum {
    PinDirectionInput  = 0,
    PinDirectionOutput = 1,
    PinLevelHigh       = 1,
    PinLevelLow        = 0,
};

// ex: pinMode(B0, PinDirectionOutput);
static inline void pinMode(uint8_t pin, int mode) {
    uint8_t bv = _BV(pin & 0xf);
    if (mode == PinDirectionOutput) {
        _SFR_IO8((pin >> 4) + 1) |= bv;
    } else {
        _SFR_IO8((pin >> 4) + 1) &= ~bv;
        _SFR_IO8((pin >> 4) + 2) &= ~bv;
    }
}

// ex: digitalWrite(B0, PinLevelHigh);
static inline void digitalWrite(uint8_t pin, int mode) {
    uint8_t bv = _BV(pin & 0xf);
    if (mode == PinLevelHigh) {
        _SFR_IO8((pin >> 4) + 2) |= bv;
    } else {
        _SFR_IO8((pin >> 4) + 2) &= ~bv;
    }
}

// Return true if the pin is HIGH
// digitalRead(B0)
static inline bool digitalRead(uint8_t pin) { return _SFR_IO8(pin >> 4) & _BV(pin & 0xf); }