ardupilot/libraries/AP_InertialSensor/AuxiliaryBus.h

134 lines
4.3 KiB
C++

/*
* Copyright (C) 2015 Intel Corporation. All rights reserved.
*
* 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/>.
*/
#pragma once
#include <inttypes.h>
#include <AP_HAL/Device.h>
class AuxiliaryBus;
class AP_InertialSensor_Backend;
namespace AP_HAL {
class Semaphore;
}
class AuxiliaryBusSlave
{
friend class AuxiliaryBus;
public:
virtual ~AuxiliaryBusSlave();
/*
* Read a block of registers from the slave. This is a one-time read. Must
* be implemented by the sensor exposing the AuxiliaryBus.
*
* This method cannot be called after the periodic read is configured
* since the registers for the periodic read may be shared with the
* passthrough reads.
*
* @reg: the first register of the block to use in this one time transfer
* @buf: buffer in which to write the values read
* @size: the buffer size
*
* Return the number of bytes read on success or < 0 on error
*/
virtual int passthrough_read(uint8_t reg, uint8_t *buf, uint8_t size) = 0;
/*
* Write a single value into a register of this slave. Must be implemented
* by the sensor exposing the AuxiliaryBus.
*
* This method cannot be called after the periodic read is configured
* since the registers for the periodic read may be shared with the
* passthrough writes.
*
* @reg: the register to use in this one time transfer
* @val: the value to write
*
* Return the number of bytes written on success or < 0 on error
*/
virtual int passthrough_write(uint8_t reg, uint8_t val) = 0;
/*
* Read the block of registers that were read from the slave on the last
* time a periodic read occurred.
*
* This method must be called after the periodic read is configured and
* the buffer must be large enough to accommodate the size configured.
*
* @buf: buffer in which to write the values read
*
* Return the number of bytes read on success or < 0 on error
*/
virtual int read(uint8_t *buf) = 0;
protected:
/* Only AuxiliaryBus is able to create a slave */
AuxiliaryBusSlave(AuxiliaryBus &bus, uint8_t addr, uint8_t instance);
AuxiliaryBus &_bus;
uint8_t _addr = 0;
uint8_t _instance = 0;
uint8_t _sample_reg_start = 0;
uint8_t _sample_size = 0;
bool _registered = false;
};
class AuxiliaryBus
{
friend class AP_InertialSensor_Backend;
public:
AP_InertialSensor_Backend &get_backend() { return _ins_backend; }
AuxiliaryBusSlave *request_next_slave(uint8_t addr);
int register_periodic_read(AuxiliaryBusSlave *slave, uint8_t reg, uint8_t size);
/* See AP_HAL::Device::register_periodic_callback() */
AP_HAL::Device::PeriodicHandle register_periodic_callback(uint32_t, AP_HAL::Device::PeriodicCb);
/*
* Get the semaphore needed to call methods on the bus this sensor is on.
* Internally no locks are taken and it's the caller's duty to lock and
* unlock the bus as needed.
*
* This method must be implemented by the sensor exposing the
* AuxiliaryBus.
*
* Return the semaphore used protect transfers on the bus
*/
virtual AP_HAL::Semaphore *get_semaphore() = 0;
protected:
/* Only AP_InertialSensor_Backend is able to create a bus */
AuxiliaryBus(AP_InertialSensor_Backend &backend, uint8_t max_slaves);
virtual ~AuxiliaryBus();
virtual AuxiliaryBusSlave *_instantiate_slave(uint8_t addr, uint8_t instance) = 0;
virtual int _configure_periodic_read(AuxiliaryBusSlave *slave, uint8_t reg,
uint8_t size) = 0;
uint8_t _n_slaves = 0;
const uint8_t _max_slaves;
AuxiliaryBusSlave **_slaves;
AP_InertialSensor_Backend &_ins_backend;
};