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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- G N A T . S E R I A L _ C O M M U N I C A T I O N S --
-- --
-- B o d y --
-- --
-- Copyright (C) 2007-2023, AdaCore --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This is the GNU/Linux implementation of this package
--
-- Testing on GNU/Linux can be done with socat & stty tools.
--
-- First in a terminal create a virtual serial port:
--
-- * First solution, the terminal is one of the side of the channel
-- characters written with Write into the port will be displayed
-- there and characters typed into the terminal will be send to the
-- channel and will be received by a Read call.
--
-- $ socat PTY,link=/tmp/virtual-tty,raw,echo=1 -
--
-- * Second solution, the virtual channel contains two side and the
-- program can Read and Write date to it.
--
-- $ socat PTY,link=/tmp/virtual-tty,raw,echo=1 \
-- PTY,link=/tmp/virtual-tty,raw,echo=1
--
-- Connect to this virtual serial port with:
--
-- Open (Port => P, Name => "/tmp/virtual-tty");
--
-- Do any settings using the Set routine below, then you can check
-- the serial port configuration with:
--
-- $ stty --file /tmp/virtual-tty
--
with Ada.Streams; use Ada.Streams;
with System; use System;
with System.Communication; use System.Communication;
with System.CRTL; use System.CRTL;
with GNAT.OS_Lib; use GNAT.OS_Lib;
package body GNAT.Serial_Communications is
package OSC renames System.OS_Constants;
use type Interfaces.C.unsigned;
subtype unsigned is Interfaces.C.unsigned;
subtype char is Interfaces.C.char;
subtype unsigned_char is Interfaces.C.unsigned_char;
function fcntl (fd : int; cmd : int; value : int) return int;
pragma Import (C, fcntl, "fcntl");
C_Data_Rate : constant array (Data_Rate) of unsigned :=
[B75 => OSC.B75,
B110 => OSC.B110,
B150 => OSC.B150,
B300 => OSC.B300,
B600 => OSC.B600,
B1200 => OSC.B1200,
B2400 => OSC.B2400,
B4800 => OSC.B4800,
B9600 => OSC.B9600,
B19200 => OSC.B19200,
B38400 => OSC.B38400,
B57600 => OSC.B57600,
B115200 => OSC.B115200,
B230400 => OSC.B230400,
B460800 => OSC.B460800,
B500000 => OSC.B500000,
B576000 => OSC.B576000,
B921600 => OSC.B921600,
B1000000 => OSC.B1000000,
B1152000 => OSC.B1152000,
B1500000 => OSC.B1500000,
B2000000 => OSC.B2000000,
B2500000 => OSC.B2500000,
B3000000 => OSC.B3000000,
B3500000 => OSC.B3500000,
B4000000 => OSC.B4000000];
C_Bits : constant array (Data_Bits) of unsigned :=
[CS7 => OSC.CS7, CS8 => OSC.CS8];
C_Stop_Bits : constant array (Stop_Bits_Number) of unsigned :=
[One => 0, Two => OSC.CSTOPB];
C_Parity : constant array (Parity_Check) of unsigned :=
[None => 0,
Odd => OSC.PARENB or OSC.PARODD,
Even => OSC.PARENB];
procedure Raise_Error (Message : String; Error : Integer := Errno);
pragma No_Return (Raise_Error);
----------
-- Name --
----------
function Name (Number : Positive) return Port_Name is
N : constant Natural := Number - 1;
N_Img : constant String := Natural'Image (N);
begin
return Port_Name ("/dev/ttyS" & N_Img (N_Img'First + 1 .. N_Img'Last));
end Name;
----------
-- Open --
----------
procedure Open
(Port : out Serial_Port;
Name : Port_Name)
is
use OSC;
C_Name : constant String := String (Name) & ASCII.NUL;
Res : int;
begin
Port.H := Serial_Port_Descriptor (open
(C_Name (C_Name'First)'Address, int (O_RDWR + O_NOCTTY + O_NDELAY)));
if Port.H = -1 then
Raise_Error ("open: open failed");
end if;
-- By default we are in blocking mode
Res := fcntl (int (Port.H), F_SETFL, 0);
if Res = -1 then
Raise_Error ("open: fcntl failed");
end if;
end Open;
-----------------
-- Raise_Error --
-----------------
procedure Raise_Error (Message : String; Error : Integer := Errno) is
begin
raise Serial_Error with Message
& (if Error /= 0
then " (" & Errno_Message (Err => Error) & ')'
else "");
end Raise_Error;
----------
-- Read --
----------
overriding procedure Read
(Port : in out Serial_Port;
Buffer : out Stream_Element_Array;
Last : out Stream_Element_Offset)
is
Len : constant size_t := Buffer'Length;
Res : ssize_t;
begin
if Port.H = -1 then
Raise_Error ("read: port not opened", 0);
end if;
Res := read (Integer (Port.H), Buffer'Address, Len);
if Res = -1 then
Raise_Error ("read failed");
end if;
Last := Last_Index (Buffer'First, size_t (Res));
end Read;
---------
-- Set --
---------
procedure Set
(Port : Serial_Port;
Rate : Data_Rate := B9600;
Bits : Data_Bits := CS8;
Stop_Bits : Stop_Bits_Number := One;
Parity : Parity_Check := None;
Block : Boolean := True;
Local : Boolean := True;
Flow : Flow_Control := None;
Timeout : Duration := 10.0)
is
use OSC;
subtype speed_t is unsigned;
type termios is record
c_iflag : unsigned;
c_oflag : unsigned;
c_cflag : unsigned;
c_lflag : unsigned;
c_line : unsigned_char;
c_cc : Interfaces.C.char_array (0 .. 31);
c_ispeed : speed_t;
c_ospeed : speed_t;
end record;
pragma Convention (C, termios);
function tcgetattr (fd : int; termios_p : Address) return int;
pragma Import (C, tcgetattr, "tcgetattr");
function tcsetattr
(fd : int; action : int; termios_p : Address) return int;
pragma Import (C, tcsetattr, "tcsetattr");
function tcflush (fd : int; queue_selector : int) return int;
pragma Import (C, tcflush, "tcflush");
function cfsetospeed (termios_p : Address; speed : speed_t) return int;
pragma Import (C, cfsetospeed, "cfsetospeed");
function cfsetispeed (termios_p : Address; speed : speed_t) return int;
pragma Import (C, cfsetispeed, "cfsetispeed");
Current : termios;
Res : int := 0;
pragma Warnings (Off, Res);
-- Warnings off, since we don't always test the result
begin
if Port.H = -1 then
Raise_Error ("set: port not opened", 0);
end if;
-- Get current port settings
Res := tcgetattr (int (Port.H), Current'Address);
-- Change settings now
Current.c_cflag := C_Bits (Bits)
or C_Stop_Bits (Stop_Bits)
or C_Parity (Parity)
or CREAD;
Current.c_iflag := 0;
Current.c_lflag := 0;
Current.c_oflag := 0;
if Local then
Current.c_cflag := Current.c_cflag or CLOCAL;
end if;
case Flow is
when None =>
null;
when RTS_CTS =>
Current.c_cflag := Current.c_cflag or CRTSCTS;
when Xon_Xoff =>
Current.c_iflag := Current.c_iflag or IXON;
end case;
Current.c_ispeed := Data_Rate_Value (Rate);
Current.c_ospeed := Data_Rate_Value (Rate);
-- See man termios for descriptions about the different modes
if Block and then Timeout = 0.0 then
-- MIN > 0, TIME == 0 (blocking read)
Current.c_cc (VMIN) := char'Val (1);
Current.c_cc (VTIME) := char'Val (0);
else
-- MIN == 0, TIME > 0 (read with timeout)
-- MIN == 0, TIME == 0 (polling read)
Current.c_cc (VMIN) := char'Val (0);
Current.c_cc (VTIME) := char'Val (Natural (Timeout * 10));
Current.c_lflag := Current.c_lflag or not ICANON;
end if;
Res := cfsetispeed (Current'Address, C_Data_Rate (Rate));
if Res = -1 then
Raise_Error ("set: cfsetispeed failed");
end if;
Res := cfsetospeed (Current'Address, C_Data_Rate (Rate));
if Res = -1 then
Raise_Error ("set: cfsetospeed failed");
end if;
-- Set port settings
Res := tcflush (int (Port.H), TCIFLUSH);
Res := tcsetattr (int (Port.H), TCSANOW, Current'Address);
-- Block
if Block then
-- In blocking mode, remove the non-blocking flags set while
-- opening the serial port (see Open).
Res := fcntl (int (Port.H), F_SETFL, 0);
end if;
if Res = -1 then
Raise_Error ("set: fcntl failed");
end if;
end Set;
------------
-- To_Ada --
------------
procedure To_Ada (Port : out Serial_Port; Fd : Serial_Port_Descriptor) is
begin
Port.H := Fd;
end To_Ada;
-----------
-- Write --
-----------
overriding procedure Write
(Port : in out Serial_Port;
Buffer : Stream_Element_Array)
is
Len : constant size_t := Buffer'Length;
Res : ssize_t;
begin
if Port.H = -1 then
Raise_Error ("write: port not opened", 0);
end if;
Res := write (int (Port.H), Buffer'Address, Len);
if Res = -1 then
Raise_Error ("write failed");
end if;
pragma Assert (size_t (Res) = Len);
end Write;
-----------
-- Close --
-----------
procedure Close (Port : in out Serial_Port) is
Res : int;
pragma Unreferenced (Res);
begin
if Port.H /= -1 then
Res := close (int (Port.H));
Port.H := -1;
end if;
end Close;
end GNAT.Serial_Communications;