ardupilot/libraries/AP_HAL_Linux/I2CDriver.cpp

288 lines
6.5 KiB
C++

#include <AP_HAL/AP_HAL.h>
#if CONFIG_HAL_BOARD == HAL_BOARD_LINUX
#include "I2CDriver.h"
#include "Util.h"
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#ifndef I2C_SMBUS_BLOCK_MAX
#include <linux/i2c.h>
#endif
extern const AP_HAL::HAL& hal;
using namespace Linux;
I2CDriver::I2CDriver(uint8_t bus)
: _fake_dev(I2CDeviceManager::from(hal.i2c_mgr)->get_device(bus, 0))
{
}
I2CDriver::I2CDriver(std::vector<const char *> devpaths)
: _fake_dev(I2CDeviceManager::from(hal.i2c_mgr)->get_device(devpaths, 0))
{
}
/*
tell the I2C library what device we want to talk to
*/
bool I2CDriver::set_address(uint8_t addr)
{
if (!_fake_dev) {
return false;
}
if (_addr == addr) {
/* nothing to do */
return true;
}
int fd = _fake_dev->get_fd();
if (ioctl(fd, I2C_SLAVE, addr) < 0) {
if (errno != EBUSY) {
return false;
}
/* Only print this message once per i2c bus */
if (_print_ioctl_error) {
hal.console->printf("couldn't set i2c slave address: %s\n",
strerror(errno));
hal.console->printf("trying I2C_SLAVE_FORCE\n");
_print_ioctl_error = false;
}
if (ioctl(fd, I2C_SLAVE_FORCE, addr) < 0) {
return false;
}
}
_addr = addr;
return true;
}
void I2CDriver::setTimeout(uint16_t ms)
{
// unimplemented
}
void I2CDriver::setHighSpeed(bool active)
{
// unimplemented
}
uint8_t I2CDriver::write(uint8_t addr, uint8_t len, uint8_t* data)
{
if (!set_address(addr)) {
return 1;
}
if (::write(_fake_dev->get_fd(), data, len) != len) {
return 1;
}
return 0; // success
}
uint8_t I2CDriver::writeRegisters(uint8_t addr, uint8_t reg,
uint8_t len, uint8_t* data)
{
uint8_t buf[len+1];
buf[0] = reg;
if (len != 0) {
memcpy(&buf[1], data, len);
}
return write(addr, len+1, buf);
}
/*
this is a copy of i2c_smbus_access() from i2c-dev.h. We need it for
platforms with older headers
*/
static inline __s32 _i2c_smbus_access(int file, char read_write, __u8 command,
int size, union i2c_smbus_data *data)
{
struct i2c_smbus_ioctl_data args;
args.read_write = read_write;
args.command = command;
args.size = size;
args.data = data;
return ioctl(file,I2C_SMBUS,&args);
}
uint8_t I2CDriver::writeRegister(uint8_t addr, uint8_t reg, uint8_t val)
{
if (!set_address(addr)) {
return 1;
}
union i2c_smbus_data data;
data.byte = val;
if (_i2c_smbus_access(_fake_dev->get_fd(),I2C_SMBUS_WRITE, reg,
I2C_SMBUS_BYTE_DATA, &data) == -1) {
return 1;
}
return 0;
}
uint8_t I2CDriver::read(uint8_t addr, uint8_t len, uint8_t* data)
{
if (!set_address(addr)) {
return 1;
}
if (::read(_fake_dev->get_fd(), data, len) != len) {
return 1;
}
return 0;
}
uint8_t I2CDriver::readRegisters(uint8_t addr, uint8_t reg,
uint8_t len, uint8_t* data)
{
if (!_fake_dev) {
return 1;
}
struct i2c_msg msgs[] = {
{
addr : addr,
flags : 0,
len : 1,
buf : (typeof(msgs->buf))&reg
},
{
addr : addr,
flags : I2C_M_RD,
len : len,
buf : (typeof(msgs->buf))data,
}
};
struct i2c_rdwr_ioctl_data i2c_data = {
msgs : msgs,
nmsgs : 2
};
// prevent valgrind error
memset(data, 0, len);
if (ioctl(_fake_dev->get_fd(), I2C_RDWR, &i2c_data) == -1) {
return 1;
}
return 0;
}
uint8_t I2CDriver::readRegistersMultiple(uint8_t addr, uint8_t reg,
uint8_t len,
uint8_t count, uint8_t* data)
{
#ifdef I2C_RDRW_IOCTL_MAX_MSGS
const uint8_t max_count = I2C_RDRW_IOCTL_MAX_MSGS / 2;
#else
const uint8_t max_count = 8;
#endif
if (!_fake_dev) {
return 1;
}
while (count > 0) {
uint8_t n = count > max_count ? max_count : count;
struct i2c_msg msgs[2*n];
struct i2c_rdwr_ioctl_data i2c_data = {
msgs : msgs,
nmsgs : (typeof(i2c_data.nmsgs))(2*n)
};
for (uint8_t i=0; i<n; i++) {
msgs[i*2].addr = addr;
msgs[i*2].flags = 0;
msgs[i*2].len = 1;
msgs[i*2].buf = (typeof(msgs->buf))&reg;
msgs[i*2+1].addr = addr;
msgs[i*2+1].flags = I2C_M_RD;
msgs[i*2+1].len = len;
msgs[i*2+1].buf = (typeof(msgs->buf))data;
data += len;
};
if (ioctl(_fake_dev->get_fd(), I2C_RDWR, &i2c_data) == -1) {
return 1;
}
count -= n;
}
return 0;
}
uint8_t I2CDriver::readRegister(uint8_t addr, uint8_t reg, uint8_t* data)
{
if (!set_address(addr)) {
return 1;
}
union i2c_smbus_data v;
memset(&v, 0, sizeof(v));
if (_i2c_smbus_access(_fake_dev->get_fd(),I2C_SMBUS_READ, reg,
I2C_SMBUS_BYTE_DATA, &v)) {
return 1;
}
*data = v.byte;
return 0;
}
/*
main transfer function
*/
bool I2CDriver::do_transfer(uint8_t addr, const uint8_t *send,
uint32_t send_len, uint8_t *recv,
uint32_t recv_len)
{
struct i2c_msg i2cmsg[2] = {
{
addr : addr,
flags : 0,
len : (typeof(i2cmsg->len))send_len,
buf : (typeof(i2cmsg->buf))send
},
{
addr : addr,
flags : I2C_M_RD,
len : (typeof(i2cmsg->len))recv_len,
buf : (typeof(i2cmsg->buf))recv,
}
};
struct i2c_rdwr_ioctl_data msg_rdwr;
if (send_len == 0 && recv_len) {
msg_rdwr.msgs = &i2cmsg[1];
msg_rdwr.nmsgs = 1;
}
else if (send_len && recv_len == 0) {
msg_rdwr.msgs = &i2cmsg[0];
msg_rdwr.nmsgs = 1;
}
else if (send_len && recv_len) {
msg_rdwr.msgs = &i2cmsg[0];
msg_rdwr.nmsgs = 2;
}
else {
return false;
}
return ioctl(_fake_dev->get_fd(), I2C_RDWR, &msg_rdwr) == (int)msg_rdwr.nmsgs;
}
uint8_t I2CDriver::lockup_count()
{
return 0;
}
AP_HAL::Semaphore *I2CDriver::get_semaphore()
{
return _fake_dev->get_semaphore();
}
#endif // CONFIG_HAL_BOARD