Device.hpp

Go to the documentation of this file.

/****************************************************************************
 *
 *   Copyright (c) 2012-2017 PX4 Development Team. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name PX4 nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

#ifndef _DEVICE_DEVICE_HPP
#define _DEVICE_DEVICE_HPP

/*
 * Includes here should only cover the needs of the framework definitions.
 */
#include <px4_config.h>
#include <px4_posix.h>

#include <drivers/drv_device.h>

#define DEVICE_LOG(FMT, ...) PX4_LOG_NAMED(_name, FMT, ##__VA_ARGS__)
#define DEVICE_DEBUG(FMT, ...) PX4_LOG_NAMED_COND(_name, _debug_enabled, FMT, ##__VA_ARGS__)

namespace device
{

class __EXPORT Device
{
public:
    virtual ~Device() = default;

    /*
     * Direct access methods.
     */

    virtual int init() { return PX4_OK; }

    virtual int read(unsigned address, void *data, unsigned count) { return -ENODEV; }

    virtual int write(unsigned address, void *data, unsigned count) { return -ENODEV; }

    virtual int ioctl(unsigned operation, unsigned &arg)
    {
        switch (operation) {
        case DEVIOCGDEVICEID:
            return (int)_device_id.devid;
        }

        return -ENODEV;
    }

    enum DeviceBusType {
        DeviceBusType_UNKNOWN = 0,
        DeviceBusType_I2C     = 1,
        DeviceBusType_SPI     = 2,
        DeviceBusType_UAVCAN  = 3,
    };

    uint8_t get_device_bus() const { return _device_id.devid_s.bus; }

    uint32_t get_device_id() const { return _device_id.devid; }

    DeviceBusType get_device_bus_type() const { return _device_id.devid_s.bus_type; }

    static const char *get_device_bus_string(DeviceBusType bus)
    {
        switch (bus) {
        case DeviceBusType_I2C:
            return "I2C";

        case DeviceBusType_SPI:
            return "SPI";

        case DeviceBusType_UAVCAN:
            return "UAVCAN";

        case DeviceBusType_UNKNOWN:
        default:
            return "UNKNOWN";
        }
    }

    uint8_t get_device_address() const { return _device_id.devid_s.address; }

    void set_device_address(int address) { _device_id.devid_s.address = address; }

    void set_device_type(uint8_t devtype) { _device_id.devid_s.devtype = devtype; }

    virtual bool external() { return false; }

    /*
      broken out device elements. The bitfields are used to keep
      the overall value small enough to fit in a float accurately,
      which makes it possible to transport over the MAVLink
      parameter protocol without loss of information.
     */
    struct DeviceStructure {
        enum DeviceBusType bus_type : 3;
        uint8_t bus: 5;    // which instance of the bus type
        uint8_t address;   // address on the bus (eg. I2C address)
        uint8_t devtype;   // device class specific device type
    };

    union DeviceId {
        struct DeviceStructure devid_s;
        uint32_t devid;
    };

    static int device_id_print_buffer(char *buffer, int length, uint32_t id)
    {
        DeviceId dev_id;
        dev_id.devid = id;

        int num_written = snprintf(buffer, length, "Type: 0x%02X, %s:%d (0x%02X)", dev_id.devid_s.devtype,
                       get_device_bus_string(dev_id.devid_s.bus_type), dev_id.devid_s.bus, dev_id.devid_s.address);

        buffer[length - 1] = 0; // ensure 0-termination

        return num_written;
    }

protected:
    union DeviceId  _device_id;             
    const char  *_name;         
    bool        _debug_enabled{false};      
    Device(const char *name) : _name(name)
    {
        /* setup a default device ID. When bus_type is UNKNOWN the
           other fields are invalid */
        _device_id.devid = 0;
        _device_id.devid_s.bus_type = DeviceBusType_UNKNOWN;
        _device_id.devid_s.bus = 0;
        _device_id.devid_s.address = 0;
        _device_id.devid_s.devtype = 0;
    }

    Device(DeviceBusType bus_type, uint8_t bus, uint8_t address, uint8_t devtype = 0)
    {
        _device_id.devid = 0;
        _device_id.devid_s.bus_type = bus_type;
        _device_id.devid_s.bus = bus;
        _device_id.devid_s.address = address;
        _device_id.devid_s.devtype = devtype;
    }

    // no copy, assignment, move, move assignment
    Device(const Device &) = delete;
    Device &operator=(const Device &) = delete;
    Device(Device &&) = delete;
    Device &operator=(Device &&) = delete;

};

} // namespace device

#endif /* _DEVICE_DEVICE_HPP */