PX4-Autopilot/src/drivers/lis3mdl/lis3mdl_spi.cpp

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/**
 * @file lis3mdl_spi.cpp
 *
 * SPI interface for LIS3MDL
 */

/* XXX trim includes */
#include <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 <arch/board/board.h>

#include <drivers/device/spi.h>
#include <drivers/drv_mag.h>
#include <drivers/drv_device.h>

#include "lis3mdl.h"
#include "board_config.h"

#ifdef PX4_SPIDEV_LIS

/* SPI protocol address bits */
#define DIR_READ			(1<<7)
#define DIR_WRITE			(0<<7)
#define ADDR_INCREMENT			(1<<6)

device::Device *LIS3MDL_SPI_interface(int bus);

class LIS3MDL_SPI : public device::SPI
{
public:
	LIS3MDL_SPI(int bus, spi_dev_e device);
	virtual ~LIS3MDL_SPI();

	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 *
LIS3MDL_SPI_interface(int bus)
{
	return new LIS3MDL_SPI(bus, (spi_dev_e)PX4_SPIDEV_LIS);
}

LIS3MDL_SPI::LIS3MDL_SPI(int bus, spi_dev_e device) :
	SPI("LIS3MDL_SPI", nullptr, bus, device, SPIDEV_MODE3, 11 * 1000 * 1000 /* will be rounded to 10.4 MHz */)
{
	_device_id.devid_s.devtype = DRV_MAG_DEVTYPE_LIS3MDL;
}

LIS3MDL_SPI::~LIS3MDL_SPI()
{
}

int
LIS3MDL_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 = 0;

	if (read(ADDR_WHO_AM_I, &data, 1)) {
		DEVICE_DEBUG("LIS3MDL read_reg fail");
	}

	if (data != ID_WHO_AM_I) {
		DEVICE_DEBUG("LIS3MDL bad ID: %02x", data);
		return -EIO;
	}

	return OK;
}

int
LIS3MDL_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
LIS3MDL_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
LIS3MDL_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_LIS */