/*This file is prepared for Doxygen automatic documentation generation.*/
/*! \file *********************************************************************
 *
 * \brief USART driver for AVR32 UC3.
 *
 * This file contains basic functions for the AVR32 USART, with support for all
 * modes, settings and clock speeds.
 *
 * - Compiler:           IAR EWAVR32 and GNU GCC for AVR32
 * - 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.
 */


#ifndef _USART_H_
#define _USART_H_

#include <avr32/io.h>
#include "compiler.h"


/*! \name Return Values
 */
//! @{
#define USART_SUCCESS           0 //!< Successful completion.
#define USART_FAILURE          -1 //!< Failure because of some unspecified reason.
#define USART_INVALID_INPUT     1 //!< Input value out of range.
#define USART_INVALID_ARGUMENT -1 //!< Argument value out of range.
#define USART_TX_BUSY           2 //!< Transmitter was busy.
#define USART_RX_EMPTY          3 //!< Nothing was received.
#define USART_RX_ERROR          4 //!< Transmission error occurred.
#define USART_MODE_FAULT        5 //!< USART not in the appropriate mode.
//! @}

//! Default time-out value (number of attempts).
#define USART_DEFAULT_TIMEOUT   10000

/*! \name Parity Settings
 */
//! @{
#define USART_EVEN_PARITY       AVR32_USART_MR_PAR_EVEN   //!< Use even parity on character transmission.
#define USART_ODD_PARITY        AVR32_USART_MR_PAR_ODD    //!< Use odd parity on character transmission.
#define USART_SPACE_PARITY      AVR32_USART_MR_PAR_SPACE  //!< Use a space as parity bit.
#define USART_MARK_PARITY       AVR32_USART_MR_PAR_MARK   //!< Use a mark as parity bit.
#define USART_NO_PARITY         AVR32_USART_MR_PAR_NONE   //!< Don't use a parity bit.
#define USART_MULTIDROP_PARITY  AVR32_USART_MR_PAR_MULTI  //!< Parity bit is used to flag address characters.
//! @}

/*! \name Operating Modes
 */
//! @{
#define USART_MODE_NORMAL       AVR32_USART_MR_MODE_NORMAL      //!< Normal RS232 mode.
#define USART_MODE_RS485        AVR32_USART_MR_MODE_RS485       //!< RS485 mode.
#define USART_MODE_HW_HSH       AVR32_USART_MR_MODE_HARDWARE    //!< RS232 mode with hardware handshaking.
#define USART_MODE_MODEM        AVR32_USART_MR_MODE_MODEM       //!< Modem mode.
#define USART_MODE_ISO7816_T0   AVR32_USART_MR_MODE_ISO7816_T0  //!< ISO7816, T = 0 mode.
#define USART_MODE_ISO7816_T1   AVR32_USART_MR_MODE_ISO7816_T1  //!< ISO7816, T = 1 mode.
#define USART_MODE_IRDA         AVR32_USART_MR_MODE_IRDA        //!< IrDA mode.
#define USART_MODE_SW_HSH       AVR32_USART_MR_MODE_SOFTWARE    //!< RS232 mode with software handshaking.
//! @}


/*! \name Channel Modes
 */
//! @{
#define USART_NORMAL_CHMODE     AVR32_USART_MR_CHMODE_NORMAL      //!< Normal communication.
#define USART_AUTO_ECHO         AVR32_USART_MR_CHMODE_ECHO        //!< Echo data.
#define USART_LOCAL_LOOPBACK    AVR32_USART_MR_CHMODE_LOCAL_LOOP  //!< Local loopback.
#define USART_REMOTE_LOOPBACK   AVR32_USART_MR_CHMODE_REMOTE_LOOP //!< Remote loopback.
//! @}

/*! \name Stop Bits Settings
 */
//! @{
#define USART_1_STOPBIT         AVR32_USART_MR_NBSTOP_1   //!< Use 1 stop bit.
#define USART_1_5_STOPBITS      AVR32_USART_MR_NBSTOP_1_5 //!< Use 1.5 stop bits.
#define USART_2_STOPBITS        AVR32_USART_MR_NBSTOP_2   //!< Use 2 stop bits (for more, just give the number of bits).
//! @}


//! Input parameters when initializing RS232 and similar modes.
typedef struct
{
  //! Set baudrate of the USART.
  unsigned long baudrate;

  //! Number of bits to transmit as a character (5 to 9).
  unsigned char charlength;

  //! How to calculate the parity bit: \ref USART_EVEN_PARITY, \ref USART_ODD_PARITY,
  //! \ref USART_SPACE_PARITY, \ref USART_MARK_PARITY, \ref USART_NO_PARITY or
  //! \ref USART_MULTIDROP_PARITY.
  unsigned char paritytype;

  //! Number of stop bits between two characters: \ref USART_1_STOPBIT,
  //! \ref USART_1_5_STOPBITS, \ref USART_2_STOPBITS or any number from 3 to 257
  //! which will result in a time guard period of that length between characters.
  unsigned short stopbits;

  //! Run the channel in testmode: \ref USART_NORMAL_CHMODE, \ref USART_AUTO_ECHO,
  //! \ref USART_LOCAL_LOOPBACK or \ref USART_REMOTE_LOOPBACK.
  unsigned char channelmode;
} usart_options_t;

//! Input parameters when initializing ISO7816 modes.
typedef struct
{
  //! Set the frequency of the ISO7816 clock.
  unsigned long iso7816_hz;

  //! The number of ISO7816 clock ticks in every bit period (1 to 2047, 0 = disable clock).
  //! Bit rate = \ref iso7816_hz / \ref fidi_ratio.
  unsigned short fidi_ratio;

  //! Inhibit Non Acknowledge:\n
  //!   - 0: the NACK is generated;\n
  //!   - 1: the NACK is not generated.
  //!
  //! \note This bit will be used only in ISO7816 mode, protocol T = 0 receiver.
  int inhibit_nack;

  //! Disable successive NACKs.
  //! Successive parity errors are counted up to the value in the \ref max_iterations field.
  //! These parity errors generate a NACK on the ISO line. As soon as this value is reached,
  //! no addititional NACK is sent on the ISO line. The ITERATION flag is asserted.
  int dis_suc_nack;

  //! Max number of repetitions (0 to 7).
  unsigned char max_iterations;

  //! Bit order in transmitted characters:\n
  //!   - 0: LSB first;\n
  //!   - 1: MSB first.
  int bit_order;
} iso7816_options_t;

//! Input parameters when initializing ISO7816 modes.
typedef struct
{
  //! Set the frequency of the SPI clock.
  unsigned long baudrate;

  //! Number of bits to transmit as a character (5 to 9).
  unsigned char charlength;

  //! Run the channel in testmode: \ref USART_NORMAL_CHMODE, \ref USART_AUTO_ECHO,
  //! \ref USART_LOCAL_LOOPBACK or \ref USART_REMOTE_LOOPBACK.
  unsigned char channelmode;  
  
  //! Which SPI mode to use when transmitting.
  unsigned char spimode;
} usart_spi_options_t;
  
  



//------------------------------------------------------------------------------
/*! \name Initialization Functions
 */
//! @{

/*! \brief Resets the USART and disables TX and RX.
 *
 * \param usart Base address of the USART instance.
 */
extern void usart_reset(volatile avr32_usart_t *usart);

/*! \brief Sets up the USART to use the standard RS232 protocol.
 *
 * \param usart   Base address of the USART instance.
 * \param opt     Options needed to set up RS232 communication (see \ref usart_options_t).
 * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
 *
 * \retval USART_SUCCESS        Mode successfully initialized.
 * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
 */
extern int usart_init_rs232(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz);

/*! \brief Sets up the USART to use hardware handshaking.
 *
 * \param usart   Base address of the USART instance.
 * \param opt     Options needed to set up RS232 communication (see \ref usart_options_t).
 * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
 *
 * \retval USART_SUCCESS        Mode successfully initialized.
 * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
 *
 * \note \ref usart_init_rs232 does not need to be invoked before this function.
 */
extern int usart_init_hw_handshaking(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz);

/*! \brief Sets up the USART to use the IrDA protocol.
 *
 * \param usart       Base address of the USART instance.
 * \param opt         Options needed to set up RS232 communication (see \ref usart_options_t).
 * \param pba_hz      USART module input clock frequency (PBA clock, Hz).
 * \param irda_filter Counter used to distinguish received ones from zeros.
 *
 * \retval USART_SUCCESS        Mode successfully initialized.
 * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
 */
extern int usart_init_IrDA(volatile avr32_usart_t *usart, const usart_options_t *opt,
                           long pba_hz, unsigned char irda_filter);

/*! \brief Sets up the USART to use the modem protocol, activating dedicated inputs/outputs.
 *
 * \param usart   Base address of the USART instance.
 * \param opt     Options needed to set up RS232 communication (see \ref usart_options_t).
 * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
 *
 * \retval USART_SUCCESS        Mode successfully initialized.
 * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
 */
extern int usart_init_modem(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz);

/*! \brief Sets up the USART to use the RS485 protocol.
 *
 * \param usart       Base address of the USART instance.
 * \param opt         Options needed to set up RS232 communication (see \ref usart_options_t).
 * \param pba_hz      USART module input clock frequency (PBA clock, Hz).
 *
 * \retval USART_SUCCESS        Mode successfully initialized.
 * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
 */
extern int usart_init_rs485(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz);

/*! \brief Sets up the USART to use the ISO7816 T=0 or T=1 smartcard protocols.
 *
 * \param usart   Base address of the USART instance.
 * \param opt     Options needed to set up ISO7816 communication (see \ref iso7816_options_t).
 * \param t       ISO7816 mode to use (T=0 or T=1).
 * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
 *
 * \retval USART_SUCCESS        Mode successfully initialized.
 * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
 */
extern int usart_init_iso7816(volatile avr32_usart_t *usart, const iso7816_options_t *opt, int t, long pba_hz);

/*! \brief Sets up the USART to use the SPI mode as master.
 *
 * \param usart   Base address of the USART instance.
 * \param opt     Options needed to set up SPI mode (see \ref usart_spi_options_t).
 * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
 *
 * \retval USART_SUCCESS        Mode successfully initialized.
 * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
 */
extern int usart_init_spi_master(volatile avr32_usart_t *usart, const usart_spi_options_t *opt, long pba_hz);


/*! \brief Sets up the USART to use the SPI mode as slave.
 *
 * \param usart   Base address of the USART instance.
 * \param opt     Options needed to set up SPI mode (see \ref usart_spi_options_t).
 * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
 *
 * \retval USART_SUCCESS        Mode successfully initialized.
 * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
 */
extern int usart_init_spi_slave(volatile avr32_usart_t *usart, const usart_spi_options_t *opt, long pba_hz);

//! @}

//------------------------------------------------------------------------------
/*! \brief Selects slave chip.
 *
 * \param usart   Base address of the USART instance.
 *
 * \return Status.
 *   \retval USART_SUCCESS             Success.
 */
extern int usart_spi_selectChip(volatile avr32_usart_t *usart);

/*! \brief Unselects slave chip.
 *
 * \param usart   Base address of the USART instance.
 *
 * \return Status.
 *   \retval USART_SUCCESS             Success.
 *   \retval USART_FAILURE             Time out.
 */
extern int usart_spi_unselectChip(volatile avr32_usart_t *usart);

//------------------------------------------------------------------------------
/*! \name Read and Reset Error Status Bits
 */
//! @{

/*! \brief Resets the error status.
 *
 * This function resets the status bits indicating that a parity error,
 * framing error or overrun has occurred. The RXBRK bit, indicating
 * a start/end of break condition on the RX line, is also reset.
 *
 * \param usart Base address of the USART instance.
 */
#if __GNUC__
__attribute__((__always_inline__))
#endif
extern __inline__ void usart_reset_status(volatile avr32_usart_t *usart)
{
  usart->cr |= AVR32_USART_CR_RSTSTA_MASK;
}

/*! \brief Checks if a parity error has occurred since last status reset.
 *
 * \param usart Base address of the USART instance.
 *
 * \return \c 1 if a parity error has been detected, otherwise \c 0.
 */
#if __GNUC__
__attribute__((__always_inline__))
#endif
extern __inline__ int usart_parity_error(volatile avr32_usart_t *usart)
{
  return (usart->csr & AVR32_USART_CSR_PARE_MASK) != 0;
}

/*! \brief Checks if a framing error has occurred since last status reset.
 *
 * \param usart Base address of the USART instance.
 *
 * \return \c 1 if a framing error has been detected, otherwise \c 0.
 */
#if __GNUC__
__attribute__((__always_inline__))
#endif
extern __inline__ int usart_framing_error(volatile avr32_usart_t *usart)
{
  return (usart->csr & AVR32_USART_CSR_FRAME_MASK) != 0;
}

/*! \brief Checks if an overrun error has occurred since last status reset.
 *
 * \param usart Base address of the USART instance.
 *
 * \return \c 1 if a overrun error has been detected, otherwise \c 0.
 */
#if __GNUC__
__attribute__((__always_inline__))
#endif
extern __inline__ int usart_overrun_error(volatile avr32_usart_t *usart)
{
  return (usart->csr & AVR32_USART_CSR_OVRE_MASK) != 0;
}

//! @}


//------------------------------------------------------------------------------
/*! \name Transmit/Receive Functions
 */
//! @{

/*! \brief Addresses a receiver.
 *
 * While in RS485 mode, receivers only accept data addressed to them.
 * A packet/char with the address tag set has to precede any data.
 * This function is used to address a receiver. This receiver should read
 * all the following data, until an address packet addresses another receiver.
 *
 * \param usart   Base address of the USART instance.
 * \param address Address of the target device.
 *
 * \retval USART_SUCCESS    Address successfully sent (if current mode is RS485).
 * \retval USART_MODE_FAULT Wrong operating mode.
 */
extern int usart_send_address(volatile avr32_usart_t *usart, int address);

/*! \brief Writes the given character to the TX buffer if the transmitter is ready.
 *
 * \param usart Base address of the USART instance.
 * \param c     The character (up to 9 bits) to transmit.
 *
 * \retval USART_SUCCESS  The transmitter was ready.
 * \retval USART_TX_BUSY  The transmitter was busy.
 */
extern int usart_write_char(volatile avr32_usart_t *usart, int c);

/*! \brief An active wait writing a character to the USART.
 *
 * \param usart Base address of the USART instance.
 * \param c     The character (up to 9 bits) to transmit.
 */
#if __GNUC__
__attribute__((__always_inline__))
#endif
extern __inline__ void usart_bw_write_char(volatile avr32_usart_t *usart, int c)
{
  while (usart_write_char(usart, c) != USART_SUCCESS);
}

/*! \brief Sends a character with the USART.
 *
 * \param usart Base address of the USART instance.
 * \param c     Character to write.
 *
 * \retval USART_SUCCESS  The character was written.
 * \retval USART_FAILURE  The function timed out before the USART transmitter became ready to send.
 */
extern int usart_putchar(volatile avr32_usart_t *usart, int c);

/*! \brief Checks the RX buffer for a received character, and stores it at the
 *         given memory location.
 *
 * \param usart Base address of the USART instance.
 * \param c     Pointer to the where the read character should be stored
 *              (must be at least short in order to accept 9-bit characters).
 *
 * \retval USART_SUCCESS  The character was read successfully.
 * \retval USART_RX_EMPTY The RX buffer was empty.
 * \retval USART_RX_ERROR An error was deteceted.
 */
extern int usart_read_char(volatile avr32_usart_t *usart, int *c);

/*! \brief Waits until a character is received, and returns it.
 *
 * \param usart Base address of the USART instance.
 *
 * \return The received character, or \ref USART_FAILURE upon error.
 */
extern int usart_getchar(volatile avr32_usart_t *usart);

/*! \brief Writes one character string to the USART.
 *
 * \param usart   Base address of the USART instance.
 * \param string  String to be written.
 */
extern void usart_write_line(volatile avr32_usart_t *usart, const char *string);

/*! \brief Gets and echoes characters until end of line.
 *
 * \param usart Base address of the USART instance.
 *
 * \retval USART_SUCCESS  Success.
 * \retval USART_FAILURE  ETX character received.
 */
extern int usart_get_echo_line(volatile avr32_usart_t *usart);

//! @}


#endif  // _USART_H_