portable/IAR/AVR32_UC3/write.c

/*This file is prepared for Doxygen automatic documentation generation.*/
/*! \file *********************************************************************
 *
 * \brief System-specific implementation of the \ref __write function used by
          the standard library.
 *
 * - Compiler:           IAR EWAVR32
 * - Supported devices:  All AVR32 devices with a USART module can be used.
 * - AppNote:
 *
 * \author               Atmel Corporation: http://www.atmel.com \n
 *                       Support and FAQ: http://support.atmel.no/
 *
 ******************************************************************************/

/* Copyright (c) 2007, Atmel Corporation All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. The name of ATMEL may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY ATMEL ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY AND
 * SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


#include <yfuns.h>
#include <avr32/io.h>
#include "usart.h"


_STD_BEGIN


#pragma module_name = "?__write"


//! Pointer to the base of the USART module instance to use for stdio.
__no_init volatile avr32_usart_t *volatile stdio_usart_base;


/*! \brief Writes a number of bytes, at most \a size, from the memory area
 *         pointed to by \a buffer.
 *
 * If \a buffer is zero then \ref __write performs flushing of internal buffers,
 * if any. In this case, \a handle can be \c -1 to indicate that all handles
 * should be flushed.
 *
 * \param handle File handle to write to.
 * \param buffer Pointer to buffer to read bytes to write from.
 * \param size Number of bytes to write.
 *
 * \return The number of bytes written, or \c _LLIO_ERROR on failure.
 */
size_t __write(int handle, const uint8_t *buffer, size_t size)
{
  size_t nChars = 0;

  if (buffer == 0)
  {
    // This means that we should flush internal buffers.
    return 0;
  }

  // This implementation only writes to stdout and stderr.
  // For all other file handles, it returns failure.
  if (handle != _LLIO_STDOUT && handle != _LLIO_STDERR)
  {
    return _LLIO_ERROR;
  }

  for (; size != 0; --size)
  {
    if (usart_putchar(stdio_usart_base, *buffer++) < 0)
    {
      return _LLIO_ERROR;
    }

    ++nChars;
  }

  return nChars;
}


_STD_END