gcc/ada/g-sercom-linux.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --           G N A T . S E R I A L _ C O M M U N I C A T I O N S            --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --                    Copyright (C) 2007-2009, AdaCore                      --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  This is the GNU/Linux implementation of this package
  35
  36 with Ada.Streams;                use Ada.Streams;
  37 with Ada;                        use Ada;
  38 with Ada.Unchecked_Deallocation;
  39
  40 with System;               use System;
  41 with System.Communication; use System.Communication;
  42 with System.CRTL;          use System.CRTL;
  43
  44 with GNAT.OS_Lib; use GNAT.OS_Lib;
  45
  46 package body GNAT.Serial_Communications is
  47
  48    use type Interfaces.C.unsigned;
  49
  50    type Port_Data is new int;
  51
  52    subtype unsigned is Interfaces.C.unsigned;
  53    subtype char is Interfaces.C.char;
  54    subtype unsigned_char is Interfaces.C.unsigned_char;
  55
  56    function fcntl (fd : int; cmd : int; value : int) return int;
  57    pragma Import (C, fcntl, "fcntl");
  58
  59    O_RDWR   : constant := 8#02#;
  60    O_NOCTTY : constant := 8#0400#;
  61    O_NDELAY : constant := 8#04000#;
  62    FNDELAY  : constant := O_NDELAY;
  63    F_SETFL  : constant := 4;
  64    TCSANOW  : constant := 0;
  65    TCIFLUSH : constant := 0;
  66    CLOCAL   : constant := 8#04000#;
  67    CREAD    : constant := 8#0200#;
  68    CSTOPB   : constant := 8#0100#;
  69    CRTSCTS  : constant := 8#020000000000#;
  70    PARENB   : constant := 8#00400#;
  71    PARODD   : constant := 8#01000#;
  72
  73    --  c_cc indexes
  74
  75    VTIME : constant := 5;
  76    VMIN  : constant := 6;
  77
  78    C_Data_Rate : constant array (Data_Rate) of unsigned :=
  79                    (B1200   => 8#000011#,
  80                     B2400   => 8#000013#,
  81                     B4800   => 8#000014#,
  82                     B9600   => 8#000015#,
  83                     B19200  => 8#000016#,
  84                     B38400  => 8#000017#,
  85                     B57600  => 8#010001#,
  86                     B115200 => 8#010002#);
  87
  88    C_Bits      : constant array (Data_Bits) of unsigned :=
  89                    (CS7 => 8#040#, CS8 => 8#060#);
  90
  91    C_Stop_Bits : constant array (Stop_Bits_Number) of unsigned :=
  92                    (One => 0, Two => CSTOPB);
  93
  94    C_Parity    : constant array (Parity_Check) of unsigned :=
  95                    (None => 0, Odd => PARENB or PARODD, Even => PARENB);
  96
  97    procedure Raise_Error (Message : String; Error : Integer := Errno);
  98    pragma No_Return (Raise_Error);
  99
 100    ----------
 101    -- Name --
 102    ----------
 103
 104    function Name (Number : Positive) return Port_Name is
 105       N     : constant Natural := Number - 1;
 106       N_Img : constant String  := Natural'Image (N);
 107    begin
 108       return Port_Name ("/dev/ttyS" & N_Img (N_Img'First + 1 .. N_Img'Last));
 109    end Name;
 110
 111    ----------
 112    -- Open --
 113    ----------
 114
 115    procedure Open
 116      (Port : out Serial_Port;
 117       Name : Port_Name)
 118    is
 119       C_Name : constant String := String (Name) & ASCII.NUL;
 120       Res    : int;
 121
 122    begin
 123       if Port.H = null then
 124          Port.H := new Port_Data;
 125       end if;
 126
 127       Port.H.all := Port_Data (open
 128          (C_Name (C_Name'First)'Address, int (O_RDWR + O_NOCTTY + O_NDELAY)));
 129
 130       if Port.H.all = -1 then
 131          Raise_Error ("open: open failed");
 132       end if;
 133
 134       --  By default we are in blocking mode
 135
 136       Res := fcntl (int (Port.H.all), F_SETFL, 0);
 137
 138       if Res = -1 then
 139          Raise_Error ("open: fcntl failed");
 140       end if;
 141    end Open;
 142
 143    -----------------
 144    -- Raise_Error --
 145    -----------------
 146
 147    procedure Raise_Error (Message : String; Error : Integer := Errno) is
 148    begin
 149       raise Serial_Error with Message & " (" & Integer'Image (Error) & ')';
 150    end Raise_Error;
 151
 152    ----------
 153    -- Read --
 154    ----------
 155
 156    overriding procedure Read
 157      (Port   : in out Serial_Port;
 158       Buffer : out Stream_Element_Array;
 159       Last   : out Stream_Element_Offset)
 160    is
 161       Len : constant int := Buffer'Length;
 162       Res : int;
 163
 164    begin
 165       if Port.H = null then
 166          Raise_Error ("read: port not opened", 0);
 167       end if;
 168
 169       Res := read (Integer (Port.H.all), Buffer'Address, Len);
 170
 171       if Res = -1 then
 172          Raise_Error ("read failed");
 173       end if;
 174
 175       Last := Last_Index (Buffer'First, size_t (Res));
 176    end Read;
 177
 178    ---------
 179    -- Set --
 180    ---------
 181
 182    procedure Set
 183      (Port      : Serial_Port;
 184       Rate      : Data_Rate        := B9600;
 185       Bits      : Data_Bits        := CS8;
 186       Stop_Bits : Stop_Bits_Number := One;
 187       Parity    : Parity_Check     := None;
 188       Block     : Boolean          := True;
 189       Timeout   : Duration         := 10.0)
 190    is
 191       type termios is record
 192          c_iflag  : unsigned;
 193          c_oflag  : unsigned;
 194          c_cflag  : unsigned;
 195          c_lflag  : unsigned;
 196          c_line   : unsigned_char;
 197          c_cc     : Interfaces.C.char_array (0 .. 31);
 198          c_ispeed : unsigned;
 199          c_ospeed : unsigned;
 200       end record;
 201       pragma Convention (C, termios);
 202
 203       function tcgetattr (fd : int; termios_p : Address) return int;
 204       pragma Import (C, tcgetattr, "tcgetattr");
 205
 206       function tcsetattr
 207         (fd : int; action : int; termios_p : Address) return int;
 208       pragma Import (C, tcsetattr, "tcsetattr");
 209
 210       function tcflush (fd : int; queue_selector : int) return int;
 211       pragma Import (C, tcflush, "tcflush");
 212
 213       Current : termios;
 214
 215       Res : int;
 216       pragma Warnings (Off, Res);
 217       --  Warnings off, since we don't always test the result
 218
 219    begin
 220       if Port.H = null then
 221          Raise_Error ("set: port not opened", 0);
 222       end if;
 223
 224       --  Get current port settings
 225
 226       Res := tcgetattr (int (Port.H.all), Current'Address);
 227
 228       --  Change settings now
 229
 230       Current.c_cflag      := C_Data_Rate (Rate)
 231                                 or C_Bits (Bits)
 232                                 or C_Stop_Bits (Stop_Bits)
 233                                 or C_Parity (Parity)
 234                                 or CLOCAL
 235                                 or CREAD
 236                                 or CRTSCTS;
 237       Current.c_lflag      := 0;
 238       Current.c_iflag      := 0;
 239       Current.c_oflag      := 0;
 240       Current.c_ispeed     := Data_Rate_Value (Rate);
 241       Current.c_ospeed     := Data_Rate_Value (Rate);
 242       Current.c_cc (VMIN)  := char'Val (0);
 243       Current.c_cc (VTIME) := char'Val (Natural (Timeout * 10));
 244
 245       --  Set port settings
 246
 247       Res := tcflush (int (Port.H.all), TCIFLUSH);
 248       Res := tcsetattr (int (Port.H.all), TCSANOW, Current'Address);
 249
 250       --  Block
 251
 252       Res := fcntl (int (Port.H.all), F_SETFL, (if Block then 0 else FNDELAY));
 253
 254       if Res = -1 then
 255          Raise_Error ("set: fcntl failed");
 256       end if;
 257    end Set;
 258
 259    -----------
 260    -- Write --
 261    -----------
 262
 263    overriding procedure Write
 264      (Port   : in out Serial_Port;
 265       Buffer : Stream_Element_Array)
 266    is
 267       Len : constant int := Buffer'Length;
 268       Res : int;
 269
 270    begin
 271       if Port.H = null then
 272          Raise_Error ("write: port not opened", 0);
 273       end if;
 274
 275       Res := write (int (Port.H.all), Buffer'Address, Len);
 276       pragma Assert (Res = Len);
 277
 278       if Res = -1 then
 279          Raise_Error ("write failed");
 280       end if;
 281    end Write;
 282
 283    -----------
 284    -- Close --
 285    -----------
 286
 287    procedure Close (Port : in out Serial_Port) is
 288       procedure Unchecked_Free is
 289         new Unchecked_Deallocation (Port_Data, Port_Data_Access);
 290
 291       Res : int;
 292       pragma Unreferenced (Res);
 293
 294    begin
 295       if Port.H /= null then
 296          Res := close (int (Port.H.all));
 297          Unchecked_Free (Port.H);
 298       end if;
 299    end Close;
 300
 301 end GNAT.Serial_Communications;