Subversion Repositories sockit_owm

//---------------------------------------------------------------------------
// Copyright (C) 1999 Dallas Semiconductor Corporation, All Rights Reserved.
//
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// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY,  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
// IN NO EVENT SHALL DALLAS SEMICONDUCTOR BE LIABLE FOR ANY CLAIM, DAMAGES
// OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
//
// Except as contained in this notice, the name of Dallas Semiconductor
// shall not be used except as stated in the Dallas Semiconductor
// Branding Policy.
//---------------------------------------------------------------------------
//
//  todoses.C - Acquire and release a Session Todo for general 1-Wire Net
//              library
//
//  Version: 2.00
//           1.03 -> 2.00  Changed 'MLan' to 'ow'. Added support for
//                         multiple ports.
//
 
#include "ownet.h"
#include "sockit_owm.h"
 
extern sockit_owm_state sockit_owm;
 
// local function prototypes
SMALLINT owAcquire(int,char *);
void     owRelease(int);
 
//---------------------------------------------------------------------------
// Attempt to acquire a 1-Wire net
//
// 'portnum'    - number 0 to MAX_PORTNUM-1.  This number is provided to
//                indicate the symbolic port number.
// 'port_zstr'  - zero terminated port name.
//
// Returns: TRUE - success, port opened
//
// The current implementation does not wait for a port to be freed,
// it returns FALSE.
//
SMALLINT owAcquire(int portnum, char *port_zstr)
{
   // check if there are enough ports available
   if (sockit_owm.own <= portnum) {
      // TODO some error message might be added
      return FALSE;
   }
   // check if port is already in use
   if ((sockit_owm.use >> portnum) & 0x1) {
      return FALSE;
   }
   // if it is unused take it
   else {
      sockit_owm.use |= (0x1 << portnum);
      return TRUE;
   }
}
 
//---------------------------------------------------------------------------
// Release the previously acquired a 1-Wire net.
//
// 'portnum'    - number 0 to MAX_PORTNUM-1.  This number is provided to
//                indicate the symbolic port number.
//
void owRelease(int portnum)
{
   // check if port is already in use and release it
   if ((sockit_owm.use >> portnum) & 0x1) {
      sockit_owm.use &= ~(0x1 << portnum);
   }
   // releasing an unused port is not supported
   else {
      // TODO some error message might be added
   }
}