/****************************************************************************
*
* Copyright (c) 2013 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
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****************************************************************************/
/**
* @file ms5611_spi.cpp
*
* SPI interface for MS5611
*/
/* XXX trim includes */
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <assert.h>
#include <debug.h>
#include <errno.h>
#include <unistd.h>
#include <arch/board/board.h>
#include <drivers/device/spi.h>
#include "ms5611.h"
#include "board_config.h"
/* SPI protocol address bits */
#define DIR_READ (1<<7)
#define DIR_WRITE (0<<7)
#define ADDR_INCREMENT (1<<6)
#ifdef PX4_SPIDEV_BARO
device::Device *MS5611_spi_interface(ms5611::prom_u &prom_buf);
class MS5611_SPI : public device::SPI
{
public:
MS5611_SPI(int bus, spi_dev_e device, ms5611::prom_u &prom_buf);
virtual ~MS5611_SPI();
virtual int init();
virtual int read(unsigned offset, void *data, unsigned count);
virtual int ioctl(unsigned operation, unsigned &arg);
private:
ms5611::prom_u &_prom;
/**
* Send a reset command to the MS5611.
*
* This is required after any bus reset.
*/
int _reset();
/**
* Send a measure command to the MS5611.
*
* @param addr Which address to use for the measure operation.
*/
int _measure(unsigned addr);
/**
* Read the MS5611 PROM
*
* @return OK if the PROM reads successfully.
*/
int _read_prom();
/**
* Read a 16-bit register value.
*
* @param reg The register to read.
*/
uint16_t _reg16(unsigned reg);
/**
* Wrapper around transfer() that prevents interrupt-context transfers
* from pre-empting us. The sensor may (does) share a bus with sensors
* that are polled from interrupt context (or we may be pre-empted)
* so we need to guarantee that transfers complete without interruption.
*/
int _transfer(uint8_t *send, uint8_t *recv, unsigned len);
};
device::Device *
MS5611_spi_interface(ms5611::prom_u &prom_buf)
{
return new MS5611_SPI(1 /* XXX MAGIC NUMBER */, (spi_dev_e)PX4_SPIDEV_BARO, prom_buf);
}
MS5611_SPI::MS5611_SPI(int bus, spi_dev_e device, ms5611::prom_u &prom_buf) :
SPI("MS5611_SPI", nullptr, bus, device, SPIDEV_MODE3, 11*1000*1000 /* will be rounded to 10.4 MHz */),
_prom(prom_buf)
{
}
MS5611_SPI::~MS5611_SPI()
{
}
int
MS5611_SPI::init()
{
int ret;
ret = SPI::init();
if (ret != OK) {
debug("SPI init failed");
goto out;
}
/* send reset command */
ret = _reset();
if (ret != OK) {
debug("reset failed");
goto out;
}
/* read PROM */
ret = _read_prom();
if (ret != OK) {
debug("prom readout failed");
goto out;
}
out:
return ret;
}
int
MS5611_SPI::read(unsigned offset, void *data, unsigned count)
{
union _cvt {
uint8_t b[4];
uint32_t w;
} *cvt = (_cvt *)data;
uint8_t buf[4] = { 0 | DIR_WRITE, 0, 0, 0 };
/* read the most recent measurement */
int ret = _transfer(&buf[0], &buf[0], sizeof(buf));
if (ret == OK) {
/* fetch the raw value */
cvt->b[0] = buf[3];
cvt->b[1] = buf[2];
cvt->b[2] = buf[1];
cvt->b[3] = 0;
ret = count;
}
return ret;
}
int
MS5611_SPI::ioctl(unsigned operation, unsigned &arg)
{
int ret;
switch (operation) {
case IOCTL_RESET:
ret = _reset();
break;
case IOCTL_MEASURE:
ret = _measure(arg);
break;
default:
ret = EINVAL;
}
if (ret != OK) {
errno = ret;
return -1;
}
return 0;
}
int
MS5611_SPI::_reset()
{
uint8_t cmd = ADDR_RESET_CMD | DIR_WRITE;
return _transfer(&cmd, nullptr, 1);
}
int
MS5611_SPI::_measure(unsigned addr)
{
uint8_t cmd = addr | DIR_WRITE;
return _transfer(&cmd, nullptr, 1);
}
int
MS5611_SPI::_read_prom()
{
/*
* Wait for PROM contents to be in the device (2.8 ms) in the case we are
* called immediately after reset.
*/
usleep(3000);
/* read and convert PROM words */
bool all_zero = true;
for (int i = 0; i < 8; i++) {
uint8_t cmd = (ADDR_PROM_SETUP + (i * 2));
_prom.c[i] = _reg16(cmd);
if (_prom.c[i] != 0)
all_zero = false;
//debug("prom[%u]=0x%x", (unsigned)i, (unsigned)_prom.c[i]);
}
/* calculate CRC and return success/failure accordingly */
int ret = ms5611::crc4(&_prom.c[0]) ? OK : -EIO;
if (ret != OK) {
debug("crc failed");
}
if (all_zero) {
debug("prom all zero");
ret = -EIO;
}
return ret;
}
uint16_t
MS5611_SPI::_reg16(unsigned reg)
{
uint8_t cmd[3] = { (uint8_t)(reg | DIR_READ), 0, 0 };
_transfer(cmd, cmd, sizeof(cmd));
return (uint16_t)(cmd[1] << 8) | cmd[2];
}
int
MS5611_SPI::_transfer(uint8_t *send, uint8_t *recv, unsigned len)
{
return transfer(send, recv, len);
}
#endif /* PX4_SPIDEV_BARO */
