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) 2007-2008, 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.CRTL; use System, System.CRTL;
  41
  42 with GNAT.OS_Lib; use GNAT.OS_Lib;
  43
  44 package body GNAT.Serial_Communications is
  45
  46    use type Interfaces.C.unsigned;
  47
  48    type Port_Data is new int;
  49
  50    subtype unsigned is Interfaces.C.unsigned;
  51    subtype char is Interfaces.C.char;
  52    subtype unsigned_char is Interfaces.C.unsigned_char;
  53
  54    function fcntl (fd : int; cmd : int; value : int) return int;
  55    pragma Import (C, fcntl, "fcntl");
  56
  57    O_RDWR   : constant := 8#02#;
  58    O_NOCTTY : constant := 8#0400#;
  59    O_NDELAY : constant := 8#04000#;
  60    FNDELAY  : constant := O_NDELAY;
  61    F_SETFL  : constant := 4;
  62    TCSANOW  : constant := 0;
  63    TCIFLUSH : constant := 0;
  64    CLOCAL   : constant := 8#04000#;
  65    CREAD    : constant := 8#0200#;
  66    CSTOPB   : constant := 8#0100#;
  67    CRTSCTS  : constant := 8#020000000000#;
  68    PARENB   : constant := 8#00400#;
  69    PARODD   : constant := 8#01000#;
  70
  71    --  c_cc indexes
  72
  73    VTIME : constant := 5;
  74    VMIN  : constant := 6;
  75
  76    C_Data_Rate : constant array (Data_Rate) of unsigned :=
  77                    (B1200   => 8#000011#,
  78                     B2400   => 8#000013#,
  79                     B4800   => 8#000014#,
  80                     B9600   => 8#000015#,
  81                     B19200  => 8#000016#,
  82                     B38400  => 8#000017#,
  83                     B57600  => 8#010001#,
  84                     B115200 => 8#010002#);
  85
  86    C_Bits      : constant array (Data_Bits) of unsigned :=
  87                    (B7 => 8#040#, B8 => 8#060#);
  88
  89    C_Stop_Bits : constant array (Stop_Bits_Number) of unsigned :=
  90                    (One => 0, Two => CSTOPB);
  91
  92    C_Parity    : constant array (Parity_Check) of unsigned :=
  93                    (None => 0, Odd => PARENB or PARODD, Even => PARENB);
  94
  95    procedure Raise_Error (Message : String; Error : Integer := Errno);
  96    pragma No_Return (Raise_Error);
  97
  98    ----------
  99    -- Name --
 100    ----------
 101
 102    function Name (Number : Positive) return Port_Name is
 103       N     : constant Natural := Number - 1;
 104       N_Img : constant String  := Natural'Image (N);
 105    begin
 106       return Port_Name ("/dev/ttyS" & N_Img (N_Img'First + 1 .. N_Img'Last));
 107    end Name;
 108
 109    ----------
 110    -- Open --
 111    ----------
 112
 113    procedure Open
 114      (Port : out Serial_Port;
 115       Name : Port_Name)
 116    is
 117       C_Name : constant String := String (Name) & ASCII.NUL;
 118       Res    : int;
 119
 120    begin
 121       if Port.H = null then
 122          Port.H := new Port_Data;
 123       end if;
 124
 125       Port.H.all := Port_Data (open
 126          (C_Name (C_Name'First)'Address, int (O_RDWR + O_NOCTTY + O_NDELAY)));
 127
 128       if Port.H.all = -1 then
 129          Raise_Error ("open: open failed");
 130       end if;
 131
 132       --  By default we are in blocking mode
 133
 134       Res := fcntl (int (Port.H.all), F_SETFL, 0);
 135
 136       if Res = -1 then
 137          Raise_Error ("open: fcntl failed");
 138       end if;
 139    end Open;
 140
 141    -----------------
 142    -- Raise_Error --
 143    -----------------
 144
 145    procedure Raise_Error (Message : String; Error : Integer := Errno) is
 146    begin
 147       raise Serial_Error with Message & " (" & Integer'Image (Error) & ')';
 148    end Raise_Error;
 149
 150    ----------
 151    -- Read --
 152    ----------
 153
 154    overriding procedure Read
 155      (Port   : in out Serial_Port;
 156       Buffer : out Stream_Element_Array;
 157       Last   : out Stream_Element_Offset)
 158    is
 159       Len : constant int := Buffer'Length;
 160       Res : int;
 161
 162    begin
 163       if Port.H = null then
 164          Raise_Error ("read: port not opened", 0);
 165       end if;
 166
 167       Res := read (Integer (Port.H.all), Buffer'Address, Len);
 168
 169       if Res = -1 then
 170          Last := 0;
 171          Raise_Error ("read failed");
 172       else
 173          Last := Buffer'First + Stream_Element_Offset (Res) - 1;
 174       end if;
 175    end Read;
 176
 177    ---------
 178    -- Set --
 179    ---------
 180
 181    procedure Set
 182      (Port      : Serial_Port;
 183       Rate      : Data_Rate        := B9600;
 184       Bits      : Data_Bits        := B8;
 185       Stop_Bits : Stop_Bits_Number := One;
 186       Parity    : Parity_Check     := None;
 187       Block     : Boolean          := True;
 188       Timeout   : Duration         := 10.0)
 189    is
 190       type termios is record
 191          c_iflag  : unsigned;
 192          c_oflag  : unsigned;
 193          c_cflag  : unsigned;
 194          c_lflag  : unsigned;
 195          c_line   : unsigned_char;
 196          c_cc     : Interfaces.C.char_array (0 .. 31);
 197          c_ispeed : unsigned;
 198          c_ospeed : unsigned;
 199       end record;
 200       pragma Convention (C, termios);
 201
 202       function tcgetattr (fd : int; termios_p : Address) return int;
 203       pragma Import (C, tcgetattr, "tcgetattr");
 204
 205       function tcsetattr
 206         (fd : int; action : int; termios_p : Address) return int;
 207       pragma Import (C, tcsetattr, "tcsetattr");
 208
 209       function tcflush (fd : int; queue_selector : int) return int;
 210       pragma Import (C, tcflush, "tcflush");
 211
 212       Current : termios;
 213       Res     : int;
 214
 215    begin
 216       if Port.H = null then
 217          Raise_Error ("set: port not opened", 0);
 218       end if;
 219
 220       --  Get current port settings
 221
 222       Res := tcgetattr (int (Port.H.all), Current'Address);
 223
 224       --  Change settings now
 225
 226       Current.c_cflag      := C_Data_Rate (Rate)
 227                                 or C_Bits (Bits)
 228                                 or C_Stop_Bits (Stop_Bits)
 229                                 or C_Parity (Parity)
 230                                 or CLOCAL
 231                                 or CREAD
 232                                 or CRTSCTS;
 233       Current.c_lflag      := 0;
 234       Current.c_iflag      := 0;
 235       Current.c_oflag      := 0;
 236       Current.c_ispeed     := Data_Rate_Value (Rate);
 237       Current.c_ospeed     := Data_Rate_Value (Rate);
 238       Current.c_cc (VMIN)  := char'Val (0);
 239       Current.c_cc (VTIME) := char'Val (Natural (Timeout * 10));
 240
 241       --  Set port settings
 242
 243       Res := tcflush (int (Port.H.all), TCIFLUSH);
 244       Res := tcsetattr (int (Port.H.all), TCSANOW, Current'Address);
 245
 246       --  Block
 247
 248       if Block then
 249          Res := fcntl (int (Port.H.all), F_SETFL, 0);
 250       else
 251          Res := fcntl (int (Port.H.all), F_SETFL, FNDELAY);
 252       end if;
 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;