fpc/rtl/unix/serial.pp
2014-02-23 18:32:09 +00:00

392 lines
11 KiB
ObjectPascal

{ Unit for handling the serial interfaces for Linux and similar Unices.
(c) 2000 Sebastian Guenther, sg@freepascal.org; modified MarkMLl 2012.
}
unit Serial;
{$MODE objfpc}
{$H+}
{$PACKRECORDS C}
interface
uses BaseUnix,termio,unix;
type
TSerialHandle = LongInt;
TParityType = (NoneParity, OddParity, EvenParity);
TSerialFlags = set of (RtsCtsFlowControl);
TSerialState = record
LineState: LongWord;
tios: termios;
end;
{ Open the serial device with the given device name, for example:
/dev/ttyS0, /dev/ttyS1... for normal serial ports
/dev/ttyI0, /dev/ttyI1... for ISDN emulated serial ports
other device names are possible; refer to your OS documentation.
Returns "0" if device could not be found }
function SerOpen(const DeviceName: String): TSerialHandle;
{ Closes a serial device previously opened with SerOpen. }
procedure SerClose(Handle: TSerialHandle);
{ Flushes the data queues of the given serial device. DO NOT USE THIS:
use either SerSync (non-blocking) or SerDrain (blocking). }
procedure SerFlush(Handle: TSerialHandle); deprecated;
{ Suggest to the kernel that buffered output data should be sent. This
is unlikely to have a useful effect except possibly in the case of
buggy ports that lose Tx interrupts, and is implemented as a preferred
alternative to the deprecated SerFlush procedure. }
procedure SerSync(Handle: TSerialHandle);
{ Wait until all buffered output has been transmitted. It is the caller's
responsibility to ensure that this won't block permanently due to an
inappropriate handshake state. }
procedure SerDrain(Handle: TSerialHandle);
{ Discard all pending input. }
procedure SerFlushInput(Handle: TSerialHandle);
{ Discard all unsent output. }
procedure SerFlushOutput(Handle: TSerialHandle);
{ Reads a maximum of "Count" bytes of data into the specified buffer.
Result: Number of bytes read. }
function SerRead(Handle: TSerialHandle; var Buffer; Count: LongInt): LongInt;
{ Tries to write "Count" bytes from "Buffer".
Result: Number of bytes written. }
function SerWrite(Handle: TSerialHandle; var Buffer; Count: LongInt): LongInt;
procedure SerSetParams(Handle: TSerialHandle; BitsPerSec: LongInt;
ByteSize: Integer; Parity: TParityType; StopBits: Integer;
Flags: TSerialFlags);
{ Saves and restores the state of the serial device. }
function SerSaveState(Handle: TSerialHandle): TSerialState;
procedure SerRestoreState(Handle: TSerialHandle; State: TSerialState);
{ Getting and setting the line states directly. }
procedure SerSetDTR(Handle: TSerialHandle; State: Boolean);
procedure SerSetRTS(Handle: TSerialHandle; State: Boolean);
function SerGetCTS(Handle: TSerialHandle): Boolean;
function SerGetDSR(Handle: TSerialHandle): Boolean;
function SerGetCD(Handle: TSerialHandle): Boolean;
function SerGetRI(Handle: TSerialHandle): Boolean;
{ Set a line break state. If the requested time is greater than zero this is in
mSec, in the case of unix this is likely to be rounded up to a few hundred
mSec and to increase by a comparable increment; on unix if the time is less
than or equal to zero its absolute value will be passed directly to the
operating system with implementation-specific effect. If the third parameter
is omitted or true there will be an implicit call of SerDrain() before and
after the break.
NOTE THAT on Linux, the only reliable mSec parameter is zero which results in
a break of around 250 mSec. Might be completely ineffective on Solaris.
}
procedure SerBreak(Handle: TSerialHandle; mSec: LongInt=0; sync: boolean= true);
type TSerialIdle= procedure(h: TSerialHandle);
{ Set this to a shim around Application.ProcessMessages if calling SerReadTimeout(),
SerBreak() etc. from the main thread so that it doesn't lock up a Lazarus app. }
var SerialIdle: TSerialIdle= nil;
{ This is similar to SerRead() but adds a mSec timeout. Note that this variant
returns as soon as a single byte is available, or as dictated by the timeout. }
function SerReadTimeout(Handle: TSerialHandle; var Buffer; mSec: LongInt): LongInt;
{ This is similar to SerRead() but adds a mSec timeout. Note that this variant
attempts to accumulate as many bytes as are available, but does not exceed
the timeout. Set up a SerIdle callback if using this in a main thread in a
Lazarus app. }
function SerReadTimeout(Handle: TSerialHandle; var Buffer: array of byte; count, mSec: LongInt): LongInt;
{ ************************************************************************** }
implementation
function SerOpen(const DeviceName: String): TSerialHandle;
begin
Result := fpopen(DeviceName, O_RDWR or O_NOCTTY);
end;
procedure SerClose(Handle: TSerialHandle);
begin
fpClose(Handle);
end;
procedure SerFlush(Handle: TSerialHandle); deprecated;
begin
fpfsync(Handle);
end;
procedure SerSync(Handle: TSerialHandle);
begin
fpfsync(Handle)
end;
procedure SerDrain(Handle: TSerialHandle);
begin
tcdrain(Handle)
end;
procedure SerFlushInput(Handle: TSerialHandle);
begin
tcflush(Handle, TCIFLUSH)
end;
procedure SerFlushOutput(Handle: TSerialHandle);
begin
tcflush(Handle, TCOFLUSH)
end;
function SerRead(Handle: TSerialHandle; var Buffer; Count: LongInt): LongInt;
begin
Result := fpRead(Handle, Buffer, Count);
end;
function SerWrite(Handle: TSerialHandle; var Buffer; Count: LongInt): LongInt;
begin
Result := fpWrite(Handle, Buffer, Count);
end;
procedure SerSetParams(Handle: TSerialHandle; BitsPerSec: LongInt;
ByteSize: Integer; Parity: TParityType; StopBits: Integer;
Flags: TSerialFlags);
var
tios: termios;
begin
FillChar(tios, SizeOf(tios), #0);
case BitsPerSec of
50: tios.c_cflag := B50;
75: tios.c_cflag := B75;
110: tios.c_cflag := B110;
134: tios.c_cflag := B134;
150: tios.c_cflag := B150;
200: tios.c_cflag := B200;
300: tios.c_cflag := B300;
600: tios.c_cflag := B600;
1200: tios.c_cflag := B1200;
1800: tios.c_cflag := B1800;
2400: tios.c_cflag := B2400;
4800: tios.c_cflag := B4800;
19200: tios.c_cflag := B19200;
38400: tios.c_cflag := B38400;
57600: tios.c_cflag := B57600;
115200: tios.c_cflag := B115200;
230400: tios.c_cflag := B230400;
{$ifndef BSD}
460800: tios.c_cflag := B460800;
{$endif}
else tios.c_cflag := B9600;
end;
{$ifndef SOLARIS}
tios.c_ispeed := tios.c_cflag;
tios.c_ospeed := tios.c_ispeed;
{$endif}
tios.c_cflag := tios.c_cflag or CREAD or CLOCAL;
case ByteSize of
5: tios.c_cflag := tios.c_cflag or CS5;
6: tios.c_cflag := tios.c_cflag or CS6;
7: tios.c_cflag := tios.c_cflag or CS7;
else tios.c_cflag := tios.c_cflag or CS8;
end;
case Parity of
OddParity: tios.c_cflag := tios.c_cflag or PARENB or PARODD;
EvenParity: tios.c_cflag := tios.c_cflag or PARENB;
end;
if StopBits = 2 then
tios.c_cflag := tios.c_cflag or CSTOPB;
if RtsCtsFlowControl in Flags then
tios.c_cflag := tios.c_cflag or CRTSCTS;
tcflush(Handle, TCIOFLUSH);
tcsetattr(Handle, TCSANOW, tios)
end;
function SerSaveState(Handle: TSerialHandle): TSerialState;
begin
fpioctl(Handle, TIOCMGET, @Result.LineState);
// fpioctl(Handle, TCGETS, @Result.tios);
TcGetAttr(handle,result.tios);
end;
procedure SerRestoreState(Handle: TSerialHandle; State: TSerialState);
begin
// fpioctl(Handle, TCSETS, @State.tios);
TCSetAttr(handle,TCSANOW,State.tios);
fpioctl(Handle, TIOCMSET, @State.LineState);
end;
procedure SerSetDTR(Handle: TSerialHandle; State: Boolean);
const
DTR: Cardinal = TIOCM_DTR;
begin
if State then
fpioctl(Handle, TIOCMBIS, @DTR)
else
fpioctl(Handle, TIOCMBIC, @DTR);
end;
procedure SerSetRTS(Handle: TSerialHandle; State: Boolean);
const
RTS: Cardinal = TIOCM_RTS;
begin
if State then
fpioctl(Handle, TIOCMBIS, @RTS)
else
fpioctl(Handle, TIOCMBIC, @RTS);
end;
function SerGetCTS(Handle: TSerialHandle): Boolean;
var
Flags: Cardinal;
begin
fpioctl(Handle, TIOCMGET, @Flags);
Result := (Flags and TIOCM_CTS) <> 0;
end;
function SerGetDSR(Handle: TSerialHandle): Boolean;
var
Flags: Cardinal;
begin
fpioctl(Handle, TIOCMGET, @Flags);
Result := (Flags and TIOCM_DSR) <> 0;
end;
function SerGetCD(Handle: TSerialHandle): Boolean;
var
Flags: Cardinal;
begin
fpioctl(Handle, TIOCMGET, @Flags);
Result := (Flags and TIOCM_CD) <> 0
end;
function SerGetRI(Handle: TSerialHandle): Boolean;
var
Flags: Cardinal;
begin
fpioctl(Handle, TIOCMGET, @Flags);
Result := (Flags and TIOCM_RI) <> 0;
end;
procedure SerBreak(Handle: TSerialHandle; mSec: LongInt= 0; sync: boolean= true);
begin
if sync then
tcdrain(Handle);
if mSec <= 0 then
tcsendbreak(Handle, Abs(mSec))
else
tcsendbreak(Handle, Trunc(mSec / 250));
if sync then
tcdrain(Handle)
end;
function SerReadTimeout(Handle: TSerialHandle; var Buffer; mSec: LongInt): LongInt;
VAR readSet: TFDSet;
selectTimeout: TTimeVal;
begin
fpFD_ZERO(readSet);
fpFD_SET(Handle, readSet);
selectTimeout.tv_sec := mSec div 1000;
selectTimeout.tv_usec := (mSec mod 1000) * 1000;
result := 0;
if fpSelect(Handle + 1, @readSet, nil, nil, @selectTimeout) > 0 then
result := fpRead(Handle, Buffer, 1)
end { SerReadTimeout } ;
{$ifdef LINUX}
{$define SELECT_UPDATES_TIMEOUT}
{$endif}
{$ifdef SELECT_UPDATES_TIMEOUT}
function SerReadTimeout(Handle: TSerialHandle; var Buffer: array of byte; count, mSec: LongInt): LongInt;
VAR readSet: TFDSet;
selectTimeout: TTimeVal;
begin
fpFD_ZERO(readSet);
fpFD_SET(Handle, readSet);
selectTimeout.tv_sec := mSec div 1000;
selectTimeout.tv_usec := (mSec mod 1000) * 1000;
result := 0;
// Note: this variant of fpSelect() is a thin wrapper around the kernel's syscall.
// In the case of Linux the syscall DOES update the timeout parameter.
while fpSelect(Handle + 1, @readSet, nil, nil, @selectTimeout) > 0 do begin
Inc(result,fpRead(Handle, Buffer[result], count - result));
if result >= count then
break;
if Assigned(SerialIdle) then
SerialIdle(Handle)
end
end { SerReadTimeout } ;
{$else}
function SerReadTimeout(Handle: TSerialHandle; var Buffer: array of byte; count, mSec: LongInt): LongInt;
VAR readSet: TFDSet;
selectTimeout: TTimeVal;
uSecOnEntry, uSecElapsed: QWord;
function now64uSec: QWord;
var tv: timeval;
begin
fpgettimeofday(@tv, nil);
result := tv.tv_sec * 1000000 + tv.tv_usec
end { now64uSec } ;
begin
fpFD_ZERO(readSet);
fpFD_SET(Handle, readSet);
selectTimeout.tv_sec := mSec div 1000;
selectTimeout.tv_usec := (mSec mod 1000) * 1000;
result := 0;
uSecOnEntry := now64uSec;
// Note: this variant of fpSelect() is a thin wrapper around the kernel's syscall.
// In the case of Solaris the syscall DOES NOT update the timeout parameter.
while fpSelect(Handle + 1, @readSet, nil, nil, @selectTimeout) > 0 do begin
Inc(result,fpRead(Handle, Buffer[result], count - result));
uSecElapsed := now64uSec - uSecOnEntry;
if (result >= count) or (uSecElapsed >= mSec * 1000) then
break;
selectTimeout.tv_sec := (mSec * 1000 - uSecElapsed) div 1000000;
selectTimeout.tv_usec := (mSec * 1000 - uSecElapsed) mod 1000000;
if Assigned(SerialIdle) then
SerialIdle(Handle)
end
end { SerReadTimeout } ;
{$endif}
end.