LPS22HB_SPI.cpp 3.48 KB
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/**
 * @file LPS22HB_SPI.cpp
 *
 * SPI interface for LPS22HB
 */

#include "LPS22HB.hpp"

#include <drivers/device/spi.h>

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

device::Device *LPS22HB_SPI_interface(int bus, uint32_t devid, int bus_frequency, spi_mode_e spi_mode);

class LPS22HB_SPI : public device::SPI
{
public:
	LPS22HB_SPI(int bus, uint32_t device, int bus_frequency, spi_mode_e spi_mode);
	~LPS22HB_SPI() override = default;

	int	read(unsigned address, void *data, unsigned count) override;
	int	write(unsigned address, void *data, unsigned count) override;

protected:
	int	probe() override;
};

device::Device *
LPS22HB_SPI_interface(int bus, uint32_t devid, int bus_frequency, spi_mode_e spi_mode)
{
	return new LPS22HB_SPI(bus, devid, bus_frequency, spi_mode);
}

LPS22HB_SPI::LPS22HB_SPI(int bus, uint32_t device, int bus_frequency, spi_mode_e spi_mode) :
	SPI(DRV_BARO_DEVTYPE_LPS22HB, MODULE_NAME, bus, device, spi_mode, bus_frequency)
{
}

int LPS22HB_SPI::probe()
{
	// read WHO_AM_I value
	uint8_t id = 0;

	if (read(WHO_AM_I, &id, 1)) {
		DEVICE_DEBUG("read_reg fail");
		return -EIO;
	}

	if (id != LPS22HB_ID_WHO_AM_I) {
		DEVICE_DEBUG("ID byte mismatch (%02x != %02x)", LPS22HB_ID_WHO_AM_I, id);
		return -EIO;
	}

	return PX4_OK;
}

int LPS22HB_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 LPS22HB_SPI::read(unsigned address, void *data, unsigned count)
{
	uint8_t buf[32];

	if (sizeof(buf) < (count + 1)) {
		return -EIO;
	}

	buf[0] = address | DIR_READ;

	int ret = transfer(&buf[0], &buf[0], count + 1);
	memcpy(data, &buf[1], count);
	return ret;
}