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      1 /** @file
      2   NonCanonical Interactive Input Function.
      3 
      4   The functions assume that isatty() is TRUE at the time they are called.
      5   If _S_IWTTY is set, the device returns WIDE characters.
      6 
      7   Copyright (c) 2012 - 2014, Intel Corporation. All rights reserved.<BR>
      8   This program and the accompanying materials are licensed and made available
      9   under the terms and conditions of the BSD License which accompanies this
     10   distribution.  The full text of the license may be found at
     11   http://opensource.org/licenses/bsd-license.php.
     12 
     13   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
     14   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
     15 **/
     16 #include  <LibConfig.h>
     17 
     18 #include  <sys/syslimits.h>
     19 #include  <sys/termios.h>
     20 #include  <Containers/Fifo.h>
     21 #include  <Device/IIO.h>
     22 
     23 /** Perform a noncanonical read of input.
     24 
     25     @param[in]    filp        Pointer to a file descriptor structure.
     26     @param[in]    BufferSize  Maximum number of bytes to return.
     27 
     28     @retval    -1   An error has occurred.  Reason in errno.
     29     @retval    -1   No data returned.  None was ready.
     30     @retval    >0   The number of elements returned
     31 **/
     32 ssize_t
     33 IIO_NonCanonRead (
     34   struct __filedes *filp
     35   )
     36 {
     37   cIIO           *This;
     38   cFIFO          *InBuf;
     39   struct termios *Termio;
     40   ssize_t         NumRead;
     41   cc_t            tioMin;
     42   cc_t            tioTime;
     43   UINT32          InputType;
     44   wchar_t         InChar;     // Intermediate character buffer
     45 
     46   NumRead = -1;
     47   InChar  = 0;      // Initialize so compilers don't complain.
     48   This    = filp->devdata;
     49   Termio  = &This->Termio;
     50   InBuf   = This->InBuf;
     51   tioMin  = Termio->c_cc[VMIN];
     52   tioTime = Termio->c_cc[VTIME];
     53 
     54   if(tioMin >= MAX_INPUT) {
     55     tioMin = MAX_INPUT;
     56   }
     57   /*  There are four types of processing that may be done, based on
     58       the values of tioMin and tioTime.
     59           Min   Time    Type
     60           ---   ----    ----
     61            0      0       0   Return buffer contents or 1 new char
     62            0     >0       1   Return 0 or 1 character depending on timeout
     63           >0      0       2   Buffer Min chars. Return BufferSize chars.
     64           >0     >0       3   Return up to Min chars. Unless the inter-byte timer expires.
     65 
     66     Currently, only type 0 is implemented.
     67   */
     68   InputType = 0;
     69   if(tioMin   != 0)     InputType = 2;
     70   if(tioTime  != 0)   ++InputType;
     71   //switch(InputType) {
     72   //  case 0:
     73       if(InBuf->IsEmpty(InBuf)) {
     74         NumRead = filp->f_ops->fo_read(filp, &filp->f_offset, sizeof(wchar_t), &InChar);
     75         if(NumRead > 0) {
     76           (void) InBuf->Write(InBuf, &InChar, 1);  // Buffer the character
     77         }
     78       }
     79   //    break;
     80   //  case 1:
     81   //    break;
     82   //  case 2:
     83   //    break;
     84   //  case 3:
     85   //    break;
     86   //}
     87   return NumRead;
     88 }
     89