PX4-Autopilot/src/drivers/mpu6000/mpu6000_spi.cpp

282 lines
6.4 KiB
C++

/****************************************************************************
*
* Copyright (c) 2012-2016 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
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* 2. Redistributions in binary form must reproduce the above copyright
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* 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 mpu6000_spi.cpp
*
* Driver for the Invensense MPU6000 connected via SPI.
*
* @author Andrew Tridgell
* @author Pat Hickey
* @author David sidrane
*/
#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_accel.h>
#include <drivers/drv_device.h>
#include "mpu6000.h"
#include <board_config.h>
#define DIR_READ 0x80
#define DIR_WRITE 0x00
#if PX4_SPIDEV_MPU
#ifdef PX4_SPI_BUS_EXT
#define EXTERNAL_BUS PX4_SPI_BUS_EXT
#else
#define EXTERNAL_BUS 0
#endif
/*
The MPU6000 can only handle high SPI bus speeds on the sensor and
interrupt status registers. All other registers have a maximum 1MHz
SPI speed
*/
#define MPU6000_LOW_SPI_BUS_SPEED 1000*1000
#define MPU6000_HIGH_SPI_BUS_SPEED 11*1000*1000 /* will be rounded to 10.4 MHz, within margins for MPU6K */
device::Device *MPU6000_SPI_interface(int bus, int device_type, bool external_bus);
class MPU6000_SPI : public device::SPI
{
public:
MPU6000_SPI(int bus, spi_dev_e device, int device_type);
virtual ~MPU6000_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);
protected:
virtual int probe();
private:
int _device_type;
/* Helper to set the desired speed and isolate the register on return */
void set_bus_frequency(unsigned &reg_speed_reg_out);
};
device::Device *
MPU6000_SPI_interface(int bus, int device_type, bool external_bus)
{
spi_dev_e cs = SPIDEV_NONE;
device::Device *interface = nullptr;
if (external_bus) {
#ifdef PX4_SPI_BUS_EXT
# if defined(PX4_SPIDEV_EXT_ICM)
cs = (spi_dev_e)(device_type == 6000 ? PX4_SPIDEV_EXT_MPU : PX4_SPIDEV_EXT_ICM);
# else
cs = (spi_dev_e) PX4_SPIDEV_EXT_MPU;
# endif
#endif
} else {
#if defined(PX4_SPIDEV_ICM)
cs = (spi_dev_e)(device_type == 6000 ? PX4_SPIDEV_MPU : PX4_SPIDEV_ICM);
#else
cs = (spi_dev_e) PX4_SPIDEV_MPU;
#endif
}
if (cs != SPIDEV_NONE) {
interface = new MPU6000_SPI(bus, cs, device_type);
}
return interface;
}
MPU6000_SPI::MPU6000_SPI(int bus, spi_dev_e device, int device_type) :
SPI("MPU6000", nullptr, bus, device, SPIDEV_MODE3, MPU6000_LOW_SPI_BUS_SPEED),
_device_type(device_type)
{
_device_id.devid_s.devtype = DRV_ACC_DEVTYPE_MPU6000;
}
MPU6000_SPI::~MPU6000_SPI()
{
}
int
MPU6000_SPI::init()
{
int ret;
ret = SPI::init();
if (ret != OK) {
DEVICE_DEBUG("SPI init failed");
return -EIO;
}
return OK;
}
int
MPU6000_SPI::ioctl(unsigned operation, unsigned &arg)
{
int ret;
switch (operation) {
case ACCELIOCGEXTERNAL:
#if defined(PX4_SPI_BUS_EXT)
return _bus == PX4_SPI_BUS_EXT ? 1 : 0;
#else
return 0;
#endif
case DEVIOCGDEVICEID:
return CDev::ioctl(nullptr, operation, arg);
case MPUIOCGIS_I2C:
return 0;
default: {
ret = -EINVAL;
}
}
return ret;
}
void
MPU6000_SPI::set_bus_frequency(unsigned &reg_speed)
{
/* Set the desired speed */
set_frequency(MPU6000_IS_HIGH_SPEED(reg_speed) ? MPU6000_HIGH_SPI_BUS_SPEED : MPU6000_LOW_SPI_BUS_SPEED);
/* Isoolate the register on return */
reg_speed = MPU6000_REG(reg_speed);
}
int
MPU6000_SPI::write(unsigned reg_speed, void *data, unsigned count)
{
uint8_t cmd[MPU_MAX_WRITE_BUFFER_SIZE];
if (sizeof(cmd) < (count + 1)) {
return -EIO;
}
/* Set the desired speed and isolate the register */
set_bus_frequency(reg_speed);
cmd[0] = reg_speed | DIR_WRITE;
cmd[1] = *(uint8_t *)data;
return transfer(&cmd[0], &cmd[0], count + 1);
}
int
MPU6000_SPI::read(unsigned reg_speed, void *data, unsigned count)
{
/* We want to avoid copying the data of MPUReport: So if the caller
* supplies a buffer not MPUReport in size, it is assume to be a reg or reg 16 read
* and we need to provied the buffer large enough for the callers data
* and our command.
*/
uint8_t cmd[3] = {0, 0, 0};
uint8_t *pbuff = count < sizeof(MPUReport) ? cmd : (uint8_t *) data ;
if (count < sizeof(MPUReport)) {
/* add command */
count++;
}
set_bus_frequency(reg_speed);
/* Set command */
pbuff[0] = reg_speed | DIR_READ ;
/* Transfer the command and get the data */
int ret = transfer(pbuff, pbuff, count);
if (ret == OK && pbuff == &cmd[0]) {
/* Adjust the count back */
count--;
/* Return the data */
memcpy(data, &cmd[1], count);
}
return ret == OK ? count : ret;
}
int
MPU6000_SPI::probe()
{
uint8_t whoami = 0;
uint8_t expected = _device_type == 6000 ? MPU_WHOAMI_6000 : ICM_WHOAMI_20608;
return (read(MPUREG_WHOAMI, &whoami, 1) > 0 && (whoami == expected)) ? 0 : -EIO;
}
#endif // PX4_SPIDEV_MPU