forked from Archive/PX4-Autopilot
149 lines
3.5 KiB
C++
149 lines
3.5 KiB
C++
/****************************************************************************
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*
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* Copyright (C) 2012 PX4 Development Team. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name PX4 nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/**
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* @file Base class for devices attached via the I2C bus.
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*
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* @todo Bus frequency changes; currently we do nothing with the value
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* that is supplied. Should we just depend on the bus knowing?
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*/
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#include "i2c.h"
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namespace device
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{
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I2C::I2C(const char *name,
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const char *devname,
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int bus,
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uint16_t address,
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uint32_t frequency,
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int irq) :
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// base class
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CDev(name, devname, irq),
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// public
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// protected
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// private
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_bus(bus),
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_address(address),
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_frequency(frequency),
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_dev(nullptr)
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{
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}
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I2C::~I2C()
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{
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if (_dev)
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up_i2cuninitialize(_dev);
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}
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int
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I2C::init()
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{
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int ret = OK;
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// attach to the i2c bus
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_dev = up_i2cinitialize(_bus);
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if (_dev == nullptr) {
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debug("failed to init I2C");
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ret = -ENOENT;
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goto out;
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}
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// call the probe function to check whether the device is present
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ret = probe();
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if (ret != OK) {
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debug("probe failed");
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goto out;
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}
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// do base class init, which will create device node, etc
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ret = CDev::init();
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if (ret != OK) {
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debug("cdev init failed");
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goto out;
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}
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// tell the world where we are
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log("on bus %d at 0x%02x", _bus, _address);
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out:
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return ret;
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}
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int
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I2C::probe()
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{
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// Assume the device is too stupid to be discoverable.
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return OK;
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}
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int
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I2C::transfer(uint8_t *send, unsigned send_len, uint8_t *recv, unsigned recv_len)
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{
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struct i2c_msg_s msgv[2];
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unsigned msgs;
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int ret;
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// debug("transfer out %p/%u in %p/%u", send, send_len, recv, recv_len);
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msgs = 0;
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if (send_len > 0) {
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msgv[msgs].addr = _address;
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msgv[msgs].flags = 0;
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msgv[msgs].buffer = send;
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msgv[msgs].length = send_len;
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msgs++;
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}
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if (recv_len > 0) {
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msgv[msgs].addr = _address;
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msgv[msgs].flags = I2C_M_READ;
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msgv[msgs].buffer = recv;
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msgv[msgs].length = recv_len;
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msgs++;
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}
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if (msgs == 0)
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return -EINVAL;
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ret = I2C_TRANSFER(_dev, &msgv[0], msgs);
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return ret;
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}
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} // namespace device
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