text: /****************************************************************************
   *
   *   Copyright (c) 2013-2019 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
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   * 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 QMC5883_SPI.cpp
   *
   * SPI interface for HMC5983
   */
  
  /* XXX trim includes */
  #include <px4_platform_common/px4_config.h>
  
  #include <sys/types.h>
  #include <stdint.h>
  #include <stdbool.h>
  #include <string.h>
  #include <assert.h>
  #include <debug.h>
  #include <errno.h>
  #include <unistd.h>
  
  #include <drivers/device/spi.h>
  #include <drivers/drv_mag.h>
  #include <drivers/drv_device.h>
  
  #include "qmc5883.h"
  #include <board_config.h>
  
  #ifdef PX4_SPIDEV_HMC
  
  /* SPI protocol address bits */
  #define DIR_READ			(1<<7)
  #define DIR_WRITE			(0<<7)
  #define ADDR_INCREMENT			(1<<6)
  
  #define HMC_MAX_SEND_LEN		4
  #define HMC_MAX_RCV_LEN			8
  
  device::Device *QMC5883_SPI_interface(int bus);
  
  class QMC5883_SPI : public device::SPI
  {
  public:
  	QMC5883_SPI(int bus, uint32_t device);
  	virtual ~QMC5883_SPI() = default;
  
  	virtual int	init();
  	virtual int	read(unsigned address, void *data, unsigned count);
  	virtual int	write(unsigned address, void *data, unsigned count);
  
  	virtual int	ioctl(unsigned operation, unsigned &arg);
  
  };
  
  device::Device *
  QMC5883_SPI_interface(int bus)
  {
  	return new QMC5883_SPI(bus, PX4_SPIDEV_HMC);
  }
  
  QMC5883_SPI::QMC5883_SPI(int bus, uint32_t device) :
  	SPI("QMC5883_SPI", nullptr, bus, device, SPIDEV_MODE3, 11 * 1000 * 1000 /* will be rounded to 10.4 MHz */)
  {
  	_device_id.devid_s.devtype = DRV_MAG_DEVTYPE_QMC5883;
  }
  
  int
  QMC5883_SPI::init()
  {
  	int ret;
  
  	ret = SPI::init();
  
  	if (ret != OK) {
  		DEVICE_DEBUG("SPI init failed");
  		return -EIO;
  	}
  
  	// read WHO_AM_I value
  	uint8_t data[2] = {0, 0};
  
  	if (read(ADDR_ID_A, &data[0], 1) ||
  	    read(ADDR_ID_B, &data[1], 1)) {
  		DEVICE_DEBUG("read_reg fail");
  	}
  
  	if ((data[0] != ID_A_WHO_AM_I) ||
  	    (data[1] != ID_B_WHO_AM_I)) {
  		DEVICE_DEBUG("ID byte mismatch (%02x,%02x)", data[0], data[1]);
  		return -EIO;
  	}
  
  	return OK;
  }
  
  int
  QMC5883_SPI::ioctl(unsigned operation, unsigned &arg)
  {
  	int ret;
  
  	switch (operation) {
  
  	case MAGIOCGEXTERNAL:
  		/*
  		 * Even if this sensor is on the external SPI
  		 * bus it is still internal to the autopilot
  		 * assembly, so always return 0 for internal.
  		 */
  		return 0;
  
  	case DEVIOCGDEVICEID:
  		return CDev::ioctl(nullptr, operation, arg);
  
  	default: {
  			ret = -EINVAL;
  		}
  	}
  
  	return ret;
  }
  
  int
  QMC5883_SPI::write(unsigned address, void *data, unsigned count)
  {
  	uint8_t buf[32];
  
  	if (sizeof(buf) < (count + 1)) {
  		return -EIO;
  	}
  
  	buf[0] = address | DIR_WRITE;
  	memcpy(&buf[1], data, count);
  
  	return transfer(&buf[0], &buf[0], count + 1);
  }
  
  int
  QMC5883_SPI::read(unsigned address, void *data, unsigned count)
  {
  	uint8_t buf[32];
  
  	if (sizeof(buf) < (count + 1)) {
  		return -EIO;
  	}
  
  	buf[0] = address | DIR_READ | ADDR_INCREMENT;
  
  	int ret = transfer(&buf[0], &buf[0], count + 1);
  	memcpy(data, &buf[1], count);
  	return ret;
  }
  
  #endif /* PX4_SPIDEV_HMC */
  