132 lines
2.7 KiB
C++
132 lines
2.7 KiB
C++
/*
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* Copyright (C) 2002-2004,2007-2011,2013,2014-2017,2020 by Jonathan Naylor G4KLX
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* Copyright (C) 1999-2001 by Thomas Sailor HB9JNX
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#if defined(__linux__)
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#include "I2CController.h"
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#include "Log.h"
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#include <cstring>
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#include <cassert>
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#include <sys/types.h>
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#include <sys/ioctl.h>
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#include <sys/stat.h>
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#include <cerrno>
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#include <fcntl.h>
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#include <unistd.h>
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#include <termios.h>
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#include <linux/i2c-dev.h>
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CI2CController::CI2CController(const std::string& device, unsigned int address) :
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m_device(device),
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m_address(address),
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m_fd(-1)
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{
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}
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CI2CController::~CI2CController()
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{
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}
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bool CI2CController::open()
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{
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assert(m_fd == -1);
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m_fd = ::open(m_device.c_str(), O_RDWR);
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if (m_fd < 0) {
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LogError("Cannot open device - %s", m_device.c_str());
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return false;
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}
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if (::ioctl(m_fd, I2C_TENBIT, 0) < 0) {
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LogError("I2C: failed to set 7bitaddress");
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::close(m_fd);
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return false;
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}
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if (::ioctl(m_fd, I2C_SLAVE, m_address) < 0) {
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LogError("I2C: Failed to acquire bus access/talk to slave 0x%02X", m_address);
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::close(m_fd);
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return false;
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}
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return true;
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}
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int CI2CController::read(unsigned char* buffer, unsigned int length)
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{
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assert(buffer != NULL);
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assert(m_fd != -1);
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if (length == 0U)
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return 0;
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unsigned int offset = 0U;
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while (offset < length) {
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ssize_t n = ::read(m_fd, buffer + offset, 1U);
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if (n < 0) {
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if (errno != EAGAIN) {
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LogError("Error returned from read(), errno=%d", errno);
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return -1;
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}
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}
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if (n > 0)
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offset += n;
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}
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return length;
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}
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int CI2CController::write(const unsigned char* buffer, unsigned int length)
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{
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assert(buffer != NULL);
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assert(m_fd != -1);
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if (length == 0U)
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return 0;
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unsigned int ptr = 0U;
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while (ptr < length) {
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ssize_t n = ::write(m_fd, buffer + ptr, 1U);
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if (n < 0) {
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if (errno != EAGAIN) {
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LogError("Error returned from write(), errno=%d", errno);
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return -1;
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}
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}
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if (n > 0)
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ptr += n;
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}
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return length;
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}
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void CI2CController::close()
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{
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assert(m_fd != -1);
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::close(m_fd);
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m_fd = -1;
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}
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#endif
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