ardupilot/libraries/AP_HAL_PX4/I2CDriver.cpp

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#include <AP_HAL/AP_HAL.h>
#if CONFIG_HAL_BOARD == HAL_BOARD_PX4
#include "I2CDriver.h"
#include <drivers/device/i2c.h>
#include <arch/board/board.h>
#include "board_config.h"
extern const AP_HAL::HAL& hal;
using namespace PX4;
/*
wrapper class for I2C to expose protected functions from PX4Firmware
*/
class PX4::PX4_I2C : public device::I2C {
public:
PX4_I2C(uint8_t bus);
bool do_transfer(uint8_t address, const uint8_t *send, uint32_t send_len, uint8_t *recv, uint32_t recv_len);
};
// constructor
PX4_I2C::PX4_I2C(uint8_t bus) :
I2C("AP_I2C", "/dev/api2c", bus, 0, 400000UL)
{
/*
attach to the bus. Return value can be ignored as we have no probe function
*/
init();
}
/*
main transfer function
*/
bool PX4_I2C::do_transfer(uint8_t address, const uint8_t *send, uint32_t send_len, uint8_t *recv, uint32_t recv_len)
{
set_address(address);
return transfer(send, send_len, recv, recv_len) == OK;
}
// constructor for main i2c class
PX4I2CDriver::PX4I2CDriver(void)
{
px4_i2c = new PX4_I2C(PX4_I2C_BUS_EXPANSION);
if (px4_i2c == nullptr) {
hal.scheduler->panic("Unable to allocate PX4 I2C driver");
}
}
/* write: for i2c devices which do not obey register conventions */
uint8_t PX4I2CDriver::write(uint8_t addr, uint8_t len, uint8_t* data)
{
return px4_i2c->do_transfer(addr, data, len, nullptr, 0) ? 0:1;
}
/* writeRegister: write a single 8-bit value to a register */
uint8_t PX4I2CDriver::writeRegister(uint8_t addr, uint8_t reg, uint8_t val)
{
uint8_t d[2] = { reg, val };
return px4_i2c->do_transfer(addr, d, sizeof(d), nullptr, 0) ? 0:1;
}
/* writeRegisters: write bytes to contigious registers */
uint8_t PX4I2CDriver::writeRegisters(uint8_t addr, uint8_t reg,
uint8_t len, uint8_t* data)
{
return write(addr, 1, &reg) == 0 && write(addr, len, data) == 0;
}
/* read: for i2c devices which do not obey register conventions */
uint8_t PX4I2CDriver::read(uint8_t addr, uint8_t len, uint8_t* data)
{
return px4_i2c->do_transfer(addr, nullptr, 0, data, len) ? 0:1;
}
/* readRegister: read from a device register - writes the register,
* then reads back an 8-bit value. */
uint8_t PX4I2CDriver::readRegister(uint8_t addr, uint8_t reg, uint8_t* data)
{
return px4_i2c->do_transfer(addr, &reg, 1, data, 1) ? 0:1;
}
/* readRegister: read contigious device registers - writes the first
* register, then reads back multiple bytes */
uint8_t PX4I2CDriver::readRegisters(uint8_t addr, uint8_t reg,
uint8_t len, uint8_t* data)
{
return px4_i2c->do_transfer(addr, &reg, 1, data, len) ? 0:1;
}
#endif // CONFIG_HAL_BOARD