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/*
* Author: Brendan Le Foll <brendan.le.foll@intel.com>
* Copyright (c) 2014 Intel Corporation.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#pragma once
#include "i2c.h"
#include "types.hpp"
#include <stdexcept>
namespace mraa
{
/**
* @brief API to Inter-Integrated Circuit
*
* An I2c object represents an i2c master and can talk multiple i2c slaves by
* selecting the correct address
* @htmlinclude i2c.txt
*
* @snippet I2c-compass.cpp Interesting
*/
class I2c
{
public:
/**
* Instantiates an i2c bus. Multiple instances of the same bus can
* exist and the bus is not guarranteed to be on the correct address
* before read/write.
*
* @param bus The i2c bus to use
* @param raw Whether to disable pinmapper for your board
*/
I2c(int bus, bool raw = false)
{
if (raw) {
m_i2c = mraa_i2c_init_raw(bus);
} else {
m_i2c = mraa_i2c_init(bus);
}
if (m_i2c == NULL) {
throw std::invalid_argument("Invalid i2c bus");
}
}
/**
* I2C constructor, takes a pointer to a I2C context and initialises the I2C class
*
* @param void * to an I2C context
*/
I2c(void* i2c_context)
{
m_i2c = (mraa_i2c_context) i2c_context;
if (m_i2c == NULL) {
throw std::invalid_argument("Invalid I2C context");
}
}
/**
* Closes the I2c Bus used. This does not guarrantee the bus will not
* be usable by anyone else or communicates this disconnect to any
* slaves.
*/
~I2c()
{
mraa_i2c_stop(m_i2c);
}
/**
* Sets the i2c Frequency for communication. Your board may not support
* the set frequency. Anyone can change this at any time and this will
* affect every slave on the bus
*
* @param mode Frequency to set the bus to
* @return Result of operation
*/
Result
frequency(I2cMode mode)
{
return (Result) mraa_i2c_frequency(m_i2c, (mraa_i2c_mode_t) mode);
}
/**
* Set the slave to talk to, typically called before every read/write
* operation
*
* @param address Communicate to the i2c slave on this address
* @return Result of operation
*/
Result
address(uint8_t address)
{
return (Result) mraa_i2c_address(m_i2c, address);
}
/**
* Read exactly one byte from the bus
*
* @throws std::invalid_argument in case of error
* @return char read from the bus
*/
uint8_t
readByte()
{
int x = mraa_i2c_read_byte(m_i2c);
if (x == -1) {
throw std::invalid_argument("Unknown error in I2c::readByte()");
}
return (uint8_t) x;
}
/**
* Read length bytes from the bus into *data pointer
*
* @param data Data to read into
* @param length Size of read in bytes to make
* @return length of read, should match length
*/
int
read(uint8_t* data, int length)
{
return mraa_i2c_read(m_i2c, data, length);
}
/**
* Read byte from an i2c register
*
* @param reg Register to read from
*
* @throws std::invalid_argument in case of error
* @return char read from register
*/
uint8_t
readReg(uint8_t reg)
{
int x = mraa_i2c_read_byte_data(m_i2c, reg);
if (x == -1) {
throw std::invalid_argument("Unknown error in I2c::readReg()");
}
return (uint8_t) x;
}
/**
* Read word from an i2c register
*
* @param reg Register to read from
*
* @throws std::invalid_argument in case of error
* @return char read from register
*/
uint16_t
readWordReg(uint8_t reg)
{
int x = mraa_i2c_read_word_data(m_i2c, reg);
if (x == -1) {
throw std::invalid_argument("Unknown error in I2c::readReg()");
}
return (uint16_t) x;
}
/**
* Read length bytes from the bus into *data pointer starting from
* an i2c register
*
* @param reg Register to read from
* @param data pointer to the byte array to read data in to
* @param length max number of bytes to read
* @return length passed to the function or -1
*/
int
readBytesReg(uint8_t reg, uint8_t* data, int length)
{
return mraa_i2c_read_bytes_data(m_i2c, reg, data, length);
}
/**
* Write a byte on the bus
*
* @param data The byte to send on the bus
* @return Result of operation
*/
Result
writeByte(uint8_t data)
{
return (Result) mraa_i2c_write_byte(m_i2c, data);
}
/**
* Write length bytes to the bus, the first byte in the array is the
* command/register to write
*
* @param data Buffer to send on the bus, first byte is i2c command
* @param length Size of buffer to send
* @return Result of operation
*/
Result
write(const uint8_t* data, int length)
{
return (Result) mraa_i2c_write(m_i2c, data, length);
}
/**
* Write a byte to an i2c register
*
* @param reg Register to write to
* @param data Value to write to register
* @return Result of operation
*/
Result
writeReg(uint8_t reg, uint8_t data)
{
return (Result) mraa_i2c_write_byte_data(m_i2c, data, reg);
}
/**
* Write a word to an i2c register
*
* @param reg Register to write to
* @param data Value to write to register
* @return Result of operation
*/
Result
writeWordReg(uint8_t reg, uint16_t data)
{
return (Result) mraa_i2c_write_word_data(m_i2c, data, reg);
}
private:
mraa_i2c_context m_i2c;
};
}
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