forked from Archive/PX4-Autopilot
156 lines
3.9 KiB
C++
156 lines
3.9 KiB
C++
/****************************************************************************
|
|
*
|
|
* Copyright (C) 2012 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.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/**
|
|
* @file Base class for devices connected via SPI.
|
|
*
|
|
* @todo Work out if caching the mode/frequency would save any time.
|
|
*
|
|
* @todo A separate bus/device abstraction would allow for mixed interrupt-mode
|
|
* and non-interrupt-mode clients to arbitrate for the bus. As things stand,
|
|
* a bus shared between clients of both kinds is vulnerable to races between
|
|
* the two, where an interrupt-mode client will ignore the lock held by the
|
|
* non-interrupt-mode client.
|
|
*/
|
|
|
|
#include <nuttx/arch.h>
|
|
|
|
#include "spi.h"
|
|
|
|
#ifndef CONFIG_SPI_EXCHANGE
|
|
# error This driver requires CONFIG_SPI_EXCHANGE
|
|
#endif
|
|
|
|
namespace device
|
|
{
|
|
|
|
SPI::SPI(const char *name,
|
|
const char *devname,
|
|
int bus,
|
|
enum spi_dev_e device,
|
|
enum spi_mode_e mode,
|
|
uint32_t frequency,
|
|
int irq) :
|
|
// base class
|
|
CDev(name, devname, irq),
|
|
// public
|
|
// protected
|
|
// private
|
|
_bus(bus),
|
|
_device(device),
|
|
_mode(mode),
|
|
_frequency(frequency),
|
|
_dev(nullptr)
|
|
{
|
|
}
|
|
|
|
SPI::~SPI()
|
|
{
|
|
// XXX no way to let go of the bus...
|
|
}
|
|
|
|
int
|
|
SPI::init()
|
|
{
|
|
int ret = OK;
|
|
|
|
// attach to the spi bus
|
|
if (_dev == nullptr)
|
|
_dev = up_spiinitialize(_bus);
|
|
|
|
if (_dev == nullptr) {
|
|
debug("failed to init SPI");
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
|
|
// call the probe function to check whether the device is present
|
|
ret = probe();
|
|
|
|
if (ret != OK) {
|
|
debug("probe failed");
|
|
goto out;
|
|
}
|
|
|
|
// do base class init, which will create the device node, etc.
|
|
ret = CDev::init();
|
|
|
|
if (ret != OK) {
|
|
debug("cdev init failed");
|
|
goto out;
|
|
}
|
|
|
|
// tell the workd where we are
|
|
log("on SPI bus %d at %d", _bus, _device);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
int
|
|
SPI::probe()
|
|
{
|
|
// assume the device is too stupid to be discoverable
|
|
return OK;
|
|
}
|
|
|
|
int
|
|
SPI::transfer(uint8_t *send, uint8_t *recv, unsigned len)
|
|
{
|
|
|
|
if ((send == nullptr) && (recv == nullptr))
|
|
return -EINVAL;
|
|
|
|
/* do common setup */
|
|
if (!up_interrupt_context())
|
|
SPI_LOCK(_dev, true);
|
|
|
|
SPI_SETFREQUENCY(_dev, _frequency);
|
|
SPI_SETMODE(_dev, _mode);
|
|
SPI_SETBITS(_dev, 8);
|
|
SPI_SELECT(_dev, _device, true);
|
|
|
|
/* do the transfer */
|
|
SPI_EXCHANGE(_dev, send, recv, len);
|
|
|
|
/* and clean up */
|
|
SPI_SELECT(_dev, _device, false);
|
|
|
|
if (!up_interrupt_context())
|
|
SPI_LOCK(_dev, false);
|
|
|
|
return OK;
|
|
}
|
|
|
|
} // namespace device
|