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// Copyright 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "chrome/browser/extensions/api/serial/serial_connection.h"
#include <windows.h>
#include <string>
namespace extensions {
namespace {
int BitrateToSpeedConstant(int bitrate) {
#define BITRATE_TO_SPEED_CASE(x) case x: return CBR_ ## x;
switch (bitrate) {
BITRATE_TO_SPEED_CASE(110);
BITRATE_TO_SPEED_CASE(300);
BITRATE_TO_SPEED_CASE(600);
BITRATE_TO_SPEED_CASE(1200);
BITRATE_TO_SPEED_CASE(2400);
BITRATE_TO_SPEED_CASE(4800);
BITRATE_TO_SPEED_CASE(9600);
BITRATE_TO_SPEED_CASE(14400);
BITRATE_TO_SPEED_CASE(19200);
BITRATE_TO_SPEED_CASE(38400);
BITRATE_TO_SPEED_CASE(57600);
BITRATE_TO_SPEED_CASE(115200);
BITRATE_TO_SPEED_CASE(128000);
BITRATE_TO_SPEED_CASE(256000);
default:
// If the bitrate doesn't match that of one of the standard
// index constants, it may be provided as-is to the DCB
// structure, according to MSDN.
return bitrate;
}
#undef BITRATE_TO_SPEED_CASE
}
int DataBitsEnumToConstant(api::serial::DataBits data_bits) {
switch (data_bits) {
case api::serial::DATA_BITS_SEVEN:
return 7;
case api::serial::DATA_BITS_EIGHT:
default:
return 8;
}
}
int ParityBitEnumToConstant(api::serial::ParityBit parity_bit) {
switch (parity_bit) {
case api::serial::PARITY_BIT_EVEN:
return EVENPARITY;
case api::serial::PARITY_BIT_ODD:
return SPACEPARITY;
case api::serial::PARITY_BIT_NO:
default:
return NOPARITY;
}
}
int StopBitsEnumToConstant(api::serial::StopBits stop_bits) {
switch (stop_bits) {
case api::serial::STOP_BITS_TWO:
return TWOSTOPBITS;
case api::serial::STOP_BITS_ONE:
default:
return ONESTOPBIT;
}
}
int SpeedConstantToBitrate(int speed) {
#define SPEED_TO_BITRATE_CASE(x) case CBR_ ## x: return x;
switch (speed) {
SPEED_TO_BITRATE_CASE(110);
SPEED_TO_BITRATE_CASE(300);
SPEED_TO_BITRATE_CASE(600);
SPEED_TO_BITRATE_CASE(1200);
SPEED_TO_BITRATE_CASE(2400);
SPEED_TO_BITRATE_CASE(4800);
SPEED_TO_BITRATE_CASE(9600);
SPEED_TO_BITRATE_CASE(14400);
SPEED_TO_BITRATE_CASE(19200);
SPEED_TO_BITRATE_CASE(38400);
SPEED_TO_BITRATE_CASE(57600);
SPEED_TO_BITRATE_CASE(115200);
SPEED_TO_BITRATE_CASE(128000);
SPEED_TO_BITRATE_CASE(256000);
default:
// If it's not one of the standard index constants,
// it should be an integral baud rate, according to
// MSDN.
return speed;
}
#undef SPEED_TO_BITRATE_CASE
}
api::serial::DataBits DataBitsConstantToEnum(int data_bits) {
switch (data_bits) {
case 7:
return api::serial::DATA_BITS_SEVEN;
case 8:
default:
return api::serial::DATA_BITS_EIGHT;
}
}
api::serial::ParityBit ParityBitConstantToEnum(int parity_bit) {
switch (parity_bit) {
case EVENPARITY:
return api::serial::PARITY_BIT_EVEN;
case ODDPARITY:
return api::serial::PARITY_BIT_ODD;
case NOPARITY:
default:
return api::serial::PARITY_BIT_NO;
}
}
api::serial::StopBits StopBitsConstantToEnum(int stop_bits) {
switch (stop_bits) {
case TWOSTOPBITS:
return api::serial::STOP_BITS_TWO;
case ONESTOPBIT:
default:
return api::serial::STOP_BITS_ONE;
}
}
} // namespace
bool SerialConnection::ConfigurePort(
const api::serial::ConnectionOptions& options) {
DCB config = { 0 };
config.DCBlength = sizeof(config);
if (!GetCommState(file_.GetPlatformFile(), &config)) {
return false;
}
if (options.bitrate.get())
config.BaudRate = BitrateToSpeedConstant(*options.bitrate);
if (options.data_bits != api::serial::DATA_BITS_NONE)
config.ByteSize = DataBitsEnumToConstant(options.data_bits);
if (options.parity_bit != api::serial::PARITY_BIT_NONE)
config.Parity = ParityBitEnumToConstant(options.parity_bit);
if (options.stop_bits != api::serial::STOP_BITS_NONE)
config.StopBits = StopBitsEnumToConstant(options.stop_bits);
if (options.cts_flow_control.get()) {
if (*options.cts_flow_control) {
config.fOutxCtsFlow = TRUE;
config.fRtsControl = RTS_CONTROL_HANDSHAKE;
} else {
config.fOutxCtsFlow = FALSE;
config.fRtsControl = RTS_CONTROL_ENABLE;
}
}
return SetCommState(file_.GetPlatformFile(), &config) != 0;
}
bool SerialConnection::PostOpen() {
// A ReadIntervalTimeout of MAXDWORD will cause async reads to complete
// immediately with any data that's available, even if there is none.
// This is OK because we never issue a read request until WaitCommEvent
// signals that data is available.
COMMTIMEOUTS timeouts = { 0 };
timeouts.ReadIntervalTimeout = MAXDWORD;
if (!::SetCommTimeouts(file_.GetPlatformFile(), &timeouts)) {
return false;
}
DCB config = { 0 };
config.DCBlength = sizeof(config);
if (!GetCommState(file_.GetPlatformFile(), &config)) {
return false;
}
// Setup some sane default state.
config.fBinary = TRUE;
config.fParity = FALSE;
config.fAbortOnError = TRUE;
config.fOutxCtsFlow = FALSE;
config.fOutxDsrFlow = FALSE;
config.fRtsControl = RTS_CONTROL_ENABLE;
config.fDtrControl = DTR_CONTROL_ENABLE;
config.fDsrSensitivity = FALSE;
config.fOutX = FALSE;
config.fInX = FALSE;
return SetCommState(file_.GetPlatformFile(), &config) != 0;
}
bool SerialConnection::Flush() const {
return PurgeComm(file_.GetPlatformFile(), PURGE_RXCLEAR | PURGE_TXCLEAR) != 0;
}
bool SerialConnection::GetControlSignals(
api::serial::DeviceControlSignals* signals) const {
DWORD status;
if (!GetCommModemStatus(file_.GetPlatformFile(), &status)) {
return false;
}
signals->dcd = (status & MS_RLSD_ON) != 0;
signals->cts = (status & MS_CTS_ON) != 0;
signals->dsr = (status & MS_DSR_ON) != 0;
signals->ri = (status & MS_RING_ON) != 0;
return true;
}
bool SerialConnection::SetControlSignals(
const api::serial::HostControlSignals& signals) {
if (signals.dtr.get()) {
if (!EscapeCommFunction(file_.GetPlatformFile(),
*signals.dtr ? SETDTR : CLRDTR)) {
return false;
}
}
if (signals.rts.get()) {
if (!EscapeCommFunction(file_.GetPlatformFile(),
*signals.rts ? SETRTS : CLRRTS)) {
return false;
}
}
return true;
}
bool SerialConnection::GetPortInfo(api::serial::ConnectionInfo* info) const {
DCB config = { 0 };
config.DCBlength = sizeof(config);
if (!GetCommState(file_.GetPlatformFile(), &config)) {
return false;
}
info->bitrate.reset(new int(SpeedConstantToBitrate(config.BaudRate)));
info->data_bits = DataBitsConstantToEnum(config.ByteSize);
info->parity_bit = ParityBitConstantToEnum(config.Parity);
info->stop_bits = StopBitsConstantToEnum(config.StopBits);
info->cts_flow_control.reset(new bool(config.fOutxCtsFlow != 0));
return true;
}
std::string SerialConnection::MaybeFixUpPortName(
const std::string &port_name) {
// For COM numbers less than 9, CreateFile is called with a string such as
// "COM1". For numbers greater than 9, a prefix of "\\\\.\\" must be added.
if (port_name.length() > std::string("COM9").length())
return std::string("\\\\.\\").append(port_name);
return port_name;
}
} // namespace extensions
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