libs/surfaces/tranzport/io_kernel.cc

   1 /*
   2  *   Copyright (C) 2006 Paul Davis
   3  *   Copyright (C) 2007 Michael Taht
   4  *
   5  *   This program is free software; you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation; either version 2 of the License, or
   8  *   (at your option) any later version.
   9  *
  10  *   This program is distributed in the hope that it will be useful,
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *   GNU General Public License for more details.
  14  *
  15  *   You should have received a copy of the GNU General Public License
  16  *   along with this program; if not, write to the Free Software
  17  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  *
  19  *   */
  20
  21 #if HAVE_TRANZPORT_KERNEL_DRIVER
  22 #include <fcntl.h>
  23 #include <errno.h>
  24 #include <poll.h>
  25 #include "tranzport_control_protocol.h"
  26
  27 // Something like open(/dev/surface/tranzport/event) for reading and raw for writing) would be better in the long run
  28 // Also support for multiple tranzports needs to be figured out
  29 // And bulk reads/writes in general
  30
  31 bool
  32 TranzportControlProtocol::probe ()
  33 {
  34         if((udev = ::open(TRANZPORT_DEVICE,O_RDWR))> 0) {
  35                 ::close(udev);
  36                 return true;
  37         }
  38         error << _("Tranzport: Can't open device for Read/Write: ") << endmsg;
  39         return false;
  40 }
  41
  42 int
  43 TranzportControlProtocol::open ()
  44 {
  45         if((udev=::open(TRANZPORT_DEVICE,O_RDWR))> 0) {
  46                 return(udev);
  47         }
  48         error << _("Tranzport: no device detected") << endmsg;
  49         return udev;
  50 }
  51
  52 int
  53 TranzportControlProtocol::close ()
  54 {
  55         int ret = 0;
  56
  57         if (udev < 1) {
  58                 return 0;
  59         }
  60
  61         if ((ret = ::close (udev)) != 0) {
  62                 error << _("Tranzport: cannot close device") << endmsg;
  63         }
  64
  65         return ret;
  66 }
  67
  68 // someday do buffered reads, presently this does blocking reads, which is bad...
  69
  70 int TranzportControlProtocol::read(uint8_t *buf, uint32_t timeout_override)
  71 {
  72         last_read_error = ::read (udev, (char *) buf, 8);
  73         switch(errno) {
  74         case -ENOENT:
  75         case -ENXIO:
  76         case -ECONNRESET:
  77         case -ESHUTDOWN:
  78         case -ENODEV:
  79                 cerr << "Tranzport disconnected, errno: " << last_read_error;
  80                 set_active(false);
  81                 break;
  82         case -ETIMEDOUT: // This is not normal, but lets see what happened
  83                 cerr << "Tranzport read timed out, errno: " << last_read_error;
  84                 break;
  85         default:
  86 #if DEBUG_TRANZPORT
  87                 cerr << "Got an unknown error on read:" << last_read_error "\n";
  88 #endif
  89                 break;
  90         }
  91
  92         return last_read_error;
  93 }
  94
  95
  96 int
  97 TranzportControlProtocol::write_noretry (uint8_t* cmd, uint32_t timeout_override)
  98 {
  99         // inflight is now taken care of by the driver, but...
 100         if(inflight > MAX_TRANZPORT_INFLIGHT) { return (-1); }
 101         int val = ::write (udev, (char*) cmd, 8);
 102
 103         if (val < 0 && val !=8) {
 104 #if DEBUG_TRANZPORT
 105                 printf("write failed: %d\n", val);
 106 #endif
 107                 last_write_error = errno;
 108                 switch(last_write_error) {
 109                 case -ENOENT:
 110                 case -ENXIO:
 111                 case -ECONNRESET:
 112                 case -ESHUTDOWN:
 113                 case -ENODEV:
 114                         cerr << "Tranzport disconnected, errno: " << last_write_error;
 115                         set_active(false);
 116                         break;
 117                 case -ETIMEDOUT: // This is not normal but
 118                         cerr << "Tranzport disconnected, errno: " << last_write_error;
 119                         break;
 120                 default:
 121 #if DEBUG_TRANZPORT
 122                         cerr << "Got an unknown error on read:" << last_write_error "\n";
 123 #endif
 124                         break;
 125                 }
 126                 return last_write_error;
 127         }
 128
 129         last_write_error = 0;
 130         ++inflight;
 131
 132         return 0;
 133
 134 }
 135
 136 int
 137 TranzportControlProtocol::write (uint8_t* cmd, uint32_t timeout_override)
 138 {
 139         return (write_noretry(cmd,timeout_override));
 140 }
 141
 142 // FIXME - install poll semantics
 143 #endif /* HAVE_TRANZPORT_KERNEL_DRIVER */
 144