mayhem-firmware/firmware/common/i2c_pp.hpp
2015-07-08 08:39:24 -07:00

97 lines
2.2 KiB
C++

/*
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
*
* This file is part of PortaPack.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef __I2C_PP_H__
#define __I2C_PP_H__
#include <cstdint>
#include "ch.h"
#include "hal.h"
struct I2CClockConfig {
float clock_source_f;
float bus_f;
float high_period_ns;
constexpr I2CClockConfig(
float clock_source_f,
float bus_f,
float high_period_ns
) : clock_source_f(clock_source_f),
bus_f(bus_f),
high_period_ns(high_period_ns)
{
}
static constexpr float period_ns(const float f) {
return 1e9 / f;
}
constexpr uint32_t i2c_period_count() {
return period_ns(bus_f) / period_ns(clock_source_f) + 0.5f;
}
constexpr uint32_t i2c_high_count() {
return high_period_ns / period_ns(clock_source_f) + 0.5f;
}
constexpr uint32_t i2c_low_count() {
return i2c_period_count() - i2c_high_count();
}
};
class I2C {
public:
using address_t = uint8_t;
constexpr I2C(I2CDriver* const driver) :
_driver(driver) {
}
void start(const I2CConfig& config);
void stop();
bool receive(
const address_t slave_address,
uint8_t* const data, const size_t count,
const systime_t timeout = TIME_INFINITE
);
bool transmit(
const address_t slave_address,
const uint8_t* const data, const size_t count,
const systime_t timeout = TIME_INFINITE
);
private:
I2CDriver* const _driver;
bool transfer(
const address_t slave_address,
const uint8_t* const data_tx, const size_t count_tx,
uint8_t* const data_rx, const size_t count_rx,
const systime_t timeout
);
};
#endif/*__I2C_PP_H__*/