ardupilot/libraries/AP_HAL_ChibiOS/GPIO.h

/*
 * This file 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 file 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/>.
 *
 * Code by Andrew Tridgell and Siddharth Bharat Purohit
 */
#pragma once

#include "AP_HAL_ChibiOS.h"

#ifndef HAL_GPIO_LED_ON
#define HAL_GPIO_LED_ON 0
#endif

#ifndef HAL_GPIO_LED_OFF
#define HAL_GPIO_LED_OFF 1
#endif

class ChibiOS::GPIO : public AP_HAL::GPIO {
public:
    GPIO();
    void    init() override;
    void    pinMode(uint8_t pin, uint8_t output) override;
    uint8_t read(uint8_t pin) override;
    void    write(uint8_t pin, uint8_t value) override;
    void    toggle(uint8_t pin) override;

    /* Alternative interface: */
    AP_HAL::DigitalSource* channel(uint16_t n) override;

    /* Interrupt interface - fast, for RCOutput and SPI radios */
    bool    attach_interrupt(uint8_t interrupt_num,
                             AP_HAL::Proc p,
                             INTERRUPT_TRIGGER_TYPE mode) override;

    /* Interrupt interface - for AP_HAL::GPIO */
    bool    attach_interrupt(uint8_t pin,
                             irq_handler_fn_t fn,
                             INTERRUPT_TRIGGER_TYPE mode) override;

    /* return true if USB cable is connected */
    bool    usb_connected(void) override;

    void set_usb_connected() { _usb_connected = true; }

    /* attach interrupt via ioline_t */
    bool _attach_interrupt(ioline_t line, AP_HAL::Proc p, uint8_t mode);

    /*
      block waiting for a pin to change. A timeout of 0 means wait
      forever. Return true on pin change, false on timeout
     */
    bool wait_pin(uint8_t pin, INTERRUPT_TRIGGER_TYPE mode, uint32_t timeout_us) override;
    
private:
    bool _usb_connected;
    bool _ext_started;

    bool _attach_interruptI(ioline_t line, palcallback_t cb, void *p, uint8_t mode);
    bool _attach_interrupt(ioline_t line, palcallback_t cb, void *p, uint8_t mode);
#ifdef HAL_PIN_ALT_CONFIG
    void setup_alt_config(void);
#endif
};

class ChibiOS::DigitalSource : public AP_HAL::DigitalSource {
public:
    DigitalSource(ioline_t line);
    void    mode(uint8_t output) override;
    uint8_t read() override;
    void    write(uint8_t value) override;
    void    toggle() override;
private:
    ioline_t line;
};