serial_lld.h

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/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
                 2011,2012 Giovanni Di Sirio.

    This file is part of ChibiOS/RT.

    ChibiOS/RT is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    ChibiOS/RT is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @file    AVR/serial_lld.h
 * @brief   AVR low level serial driver header.
 *
 * @addtogroup SERIAL
 * @{
 */

#ifndef _SERIAL_LLD_H_
#define _SERIAL_LLD_H_

#if HAL_USE_SERIAL || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver constants.                                                         */
/*===========================================================================*/

/*===========================================================================*/
/* Driver pre-compile time settings.                                         */
/*===========================================================================*/

/**
 * @brief   USART0 driver enable switch.
 * @details If set to @p TRUE the support for USART0 is included.
 * @note    The default is @p FALSE.
 */
#if !defined(USE_AVR_USART0) || defined(__DOXYGEN__)
#define USE_AVR_USART0              TRUE
#endif

/**
 * @brief   USART1 driver enable switch.
 * @details If set to @p TRUE the support for USART1 is included.
 * @note    The default is @p TRUE.
 */
#if !defined(USE_AVR_USART1) || defined(__DOXYGEN__)
#define USE_AVR_USART1              TRUE
#endif

/*===========================================================================*/
/* Derived constants and error checks.                                       */
/*===========================================================================*/

/*===========================================================================*/
/* Driver data structures and types.                                         */
/*===========================================================================*/

/**
 * @brief   AVR Serial Driver configuration structure.
 * @details An instance of this structure must be passed to @p sdStart()
 *          in order to configure and start a serial driver operations.
 */
typedef struct {
  /**
   * @brief Initialization value for the BRR register.
   */
  uint16_t                  sc_brr;
  /**
   * @brief Number of bits per character (USART_CHAR_SIZE_5 to USART_CHAR_SIZE_9).
   */
  uint8_t                   sc_bits_per_char;
} SerialConfig;

/**
 * @brief   @p SerialDriver specific data.
 */
#define _serial_driver_data                                                 \
  _base_asynchronous_channel_data                                           \
  /* Driver state.*/                                                        \
  sdstate_t                 state;                                          \
  /* Input queue.*/                                                         \
  InputQueue                iqueue;                                         \
  /* Output queue.*/                                                        \
  OutputQueue               oqueue;                                         \
  /* Input circular buffer.*/                                               \
  uint8_t                   ib[SERIAL_BUFFERS_SIZE];                        \
  /* Output circular buffer.*/                                              \
  uint8_t                   ob[SERIAL_BUFFERS_SIZE];                        \
  /* End of the mandatory fields.*/

/*===========================================================================*/
/* Driver macros.                                                            */
/*===========================================================================*/

/**
 * @brief   Macro for baud rate computation.
 * @note    Make sure the final baud rate is within tolerance.
 */
#define UBRR(b)     (((F_CPU / b) >> 4) - 1)

/**
 * @brief   Macro for baud rate computation when U2Xn == 1.
 * @note    Make sure the final baud rate is within tolerance.
 */
#define UBRR2x(b)    (((F_CPU / b) >> 3) - 1)

/**
* @brief   Macro for baud rate computation.
* @note    Make sure the final baud rate is within tolerance.
* @note    This version uses floating point math for greater accuracy.
*/
#define UBRR_F(b)   ((((double) F_CPU / (double) b) / 16.0) - 0.5)

/**
* @brief   Macro for baud rate computation when U2Xn == 1.
* @note    Make sure the final baud rate is within tolerance.
* @note    This version uses floating point math for greater accuracy.
*/
#define UBRR2x_F(b)  ((((double) F_CPU / (double) b) / 8.0) - 0.5)

#define USART_CHAR_SIZE_5      0
#define USART_CHAR_SIZE_6      1
#define USART_CHAR_SIZE_7      2
#define USART_CHAR_SIZE_8      3
#define USART_CHAR_SIZE_9      4

/*===========================================================================*/
/* External declarations.                                                    */
/*===========================================================================*/

#if USE_AVR_USART0 && !defined(__DOXYGEN__)
extern SerialDriver SD1;
#endif
#if USE_AVR_USART1 && !defined(__DOXYGEN__)
extern SerialDriver SD2;
#endif

#ifdef __cplusplus
extern "C" {
#endif
  void sd_lld_init(void);
  void sd_lld_start(SerialDriver *sdp, const SerialConfig *config);
  void sd_lld_stop(SerialDriver *sdp);
#ifdef __cplusplus
}
#endif

#endif /* HAL_USE_SERIAL */

#endif /* _SERIAL_LLD_H_ */

/** @} */