/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
                 2011,2012,2013 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    STM32/can_lld.h
 * @brief   STM32 CAN subsystem low level driver header.
 *
 * @addtogroup CAN
 * @{
 */

#ifndef _CAN_LLD_H_
#define _CAN_LLD_H_

#if HAL_USE_CAN || defined(__DOXYGEN__)

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

/*
 * The following macros from the ST header file are replaced with better
 * equivalents.
 */
#undef CAN_BTR_BRP
#undef CAN_BTR_TS1
#undef CAN_BTR_TS2
#undef CAN_BTR_SJW

/**
 * @brief   This switch defines whether the driver implementation supports
 *          a low power switch mode with automatic an wakeup feature.
 */
#define CAN_SUPPORTS_SLEEP          TRUE

/**
 * @brief   This implementation supports three transmit mailboxes.
 */
#define CAN_TX_MAILBOXES            3

/**
 * @brief   This implementation supports two receive mailboxes.
 */
#define CAN_RX_MAILBOXES            2

/**
 * @name    CAN registers helper macros
 * @{
 */
#define CAN_BTR_BRP(n)              (n)         /**< @brief BRP field macro.*/
#define CAN_BTR_TS1(n)              ((n) << 16) /**< @brief TS1 field macro.*/
#define CAN_BTR_TS2(n)              ((n) << 20) /**< @brief TS2 field macro.*/
#define CAN_BTR_SJW(n)              ((n) << 24) /**< @brief SJW field macro.*/

#define CAN_IDE_STD                 0           /**< @brief Standard id.    */
#define CAN_IDE_EXT                 1           /**< @brief Extended id.    */

#define CAN_RTR_DATA                0           /**< @brief Data frame.     */
#define CAN_RTR_REMOTE              1           /**< @brief Remote frame.   */
/** @} */

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

/**
 * @name    Configuration options
 * @{
 */
/**
 * @brief   CAN1 driver enable switch.
 * @details If set to @p TRUE the support for CAN1 is included.
 */
#if !defined(STM32_CAN_USE_CAN1) || defined(__DOXYGEN__)
#define STM32_CAN_USE_CAN1                  FALSE
#endif

/**
 * @brief   CAN2 driver enable switch.
 * @details If set to @p TRUE the support for CAN2 is included.
 */
#if !defined(STM32_CAN_USE_CAN2) || defined(__DOXYGEN__)
#define STM32_CAN_USE_CAN2                  FALSE
#endif

/**
 * @brief   CAN1 interrupt priority level setting.
 */
#if !defined(STM32_CAN_CAN1_IRQ_PRIORITY) || defined(__DOXYGEN__)
#define STM32_CAN_CAN1_IRQ_PRIORITY         11
#endif
/** @} */

/**
 * @brief   CAN2 interrupt priority level setting.
 */
#if !defined(STM32_CAN_CAN2_IRQ_PRIORITY) || defined(__DOXYGEN__)
#define STM32_CAN_CAN2_IRQ_PRIORITY         11
#endif
/** @} */

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

#if STM32_CAN_USE_CAN1 && !STM32_HAS_CAN1
#error "CAN1 not present in the selected device"
#endif

#if STM32_CAN_USE_CAN2 && !STM32_HAS_CAN2
#error "CAN2 not present in the selected device"
#endif

#if !STM32_CAN_USE_CAN1 && !STM32_CAN_USE_CAN2
#error "CAN driver activated but no CAN peripheral assigned"
#endif

#if CAN_USE_SLEEP_MODE && !CAN_SUPPORTS_SLEEP
#error "CAN sleep mode not supported in this architecture"
#endif

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

/**
 * @brief   Type of a transmission mailbox index.
 */
typedef uint32_t canmbx_t;

/**
 * @brief   CAN transmission frame.
 * @note    Accessing the frame data as word16 or word32 is not portable because
 *          machine data endianness, it can be still useful for a quick filling.
 */
typedef struct {
  struct {
    uint8_t                 DLC:4;          /**< @brief Data length.        */
    uint8_t                 RTR:1;          /**< @brief Frame type.         */
    uint8_t                 IDE:1;          /**< @brief Identifier type.    */
  };
  union {
    struct {
      uint32_t              SID:11;         /**< @brief Standard identifier.*/
    };
    struct {
      uint32_t              EID:29;         /**< @brief Extended identifier.*/
    };
  };
  union {
    uint8_t                 data8[8];       /**< @brief Frame data.         */
    uint16_t                data16[4];      /**< @brief Frame data.         */
    uint32_t                data32[2];      /**< @brief Frame data.         */
  };
} CANTxFrame;

/**
 * @brief   CAN received frame.
 * @note    Accessing the frame data as word16 or word32 is not portable because
 *          machine data endianness, it can be still useful for a quick filling.
 */
typedef struct {
  struct {
    uint8_t                 FMI;            /**< @brief Filter id.          */
    uint16_t                TIME;           /**< @brief Time stamp.         */
  };
  struct {
    uint8_t                 DLC:4;          /**< @brief Data length.        */
    uint8_t                 RTR:1;          /**< @brief Frame type.         */
    uint8_t                 IDE:1;          /**< @brief Identifier type.    */
  };
  union {
    struct {
      uint32_t              SID:11;         /**< @brief Standard identifier.*/
    };
    struct {
      uint32_t              EID:29;         /**< @brief Extended identifier.*/
    };
  };
  union {
    uint8_t                 data8[8];       /**< @brief Frame data.         */
    uint16_t                data16[4];      /**< @brief Frame data.         */
    uint32_t                data32[2];      /**< @brief Frame data.         */
  };
} CANRxFrame;

/**
 * @brief   CAN filter.
 * @note    Refer to the STM32 reference manual for info about filters.
 */
typedef struct {
  /**
   * @brief   Number of the filter to be programmed.
   */
  uint32_t                  filter;
  /**
   * @brief   Filter mode.
   * @note    This bit represent the CAN_FM1R register bit associated to this
   *          filter (0=mask mode, 1=list mode).
   */
  uint32_t                  mode:1;
  /**
   * @brief   Filter scale.
   * @note    This bit represent the CAN_FS1R register bit associated to this
   *          filter (0=16 bits mode, 1=32 bits mode).
   */
  uint32_t                  scale:1;
  /**
   * @brief   Filter mode.
   * @note    This bit represent the CAN_FFA1R register bit associated to this
   *          filter, must be set to zero in this version of the driver.
   */
  uint32_t                  assignment:1;
  /**
   * @brief   Filter register 1 (identifier).
   */
  uint32_t                  register1;
  /**
   * @brief   Filter register 2 (mask/identifier depending on mode=0/1).
   */
  uint32_t                  register2;
} CANFilter;

/**
 * @brief   Driver configuration structure.
 */
typedef struct {
  /**
   * @brief   CAN MCR register initialization data.
   * @note    Some bits in this register are enforced by the driver regardless
   *          their status in this field.
   */
  uint32_t                  mcr;
  /**
   * @brief   CAN BTR register initialization data.
   * @note    Some bits in this register are enforced by the driver regardless
   *          their status in this field.
   */
  uint32_t                  btr;
} CANConfig;

/**
 * @brief   Structure representing an CAN driver.
 */
typedef struct {
  /**
   * @brief   Driver state.
   */
  canstate_t                state;
  /**
   * @brief   Current configuration data.
   */
  const CANConfig           *config;
  /**
   * @brief   Transmission queue semaphore.
   */
  Semaphore                 txsem;
  /**
   * @brief   Receive queue semaphore.
   */
  Semaphore                 rxsem;
  /**
   * @brief   One or more frames become available.
   * @note    After broadcasting this event it will not be broadcasted again
   *          until the received frames queue has been completely emptied. It
   *          is <b>not</b> broadcasted for each received frame. It is
   *          responsibility of the application to empty the queue by
   *          repeatedly invoking @p chReceive() when listening to this event.
   *          This behavior minimizes the interrupt served by the system
   *          because CAN traffic.
   * @note    The flags associated to the listeners will indicate which
   *          receive mailboxes become non-empty.
   */
  EventSource               rxfull_event;
  /**
   * @brief   One or more transmission mailbox become available.
   * @note    The flags associated to the listeners will indicate which
   *          transmit mailboxes become empty.
   *
   */
  EventSource               txempty_event;
  /**
   * @brief   A CAN bus error happened.
   * @note    The flags associated to the listeners will indicate the
   *          error(s) that have occurred.
   */
  EventSource               error_event;
#if CAN_USE_SLEEP_MODE || defined (__DOXYGEN__)
  /**
   * @brief   Entering sleep state event.
   */
  EventSource               sleep_event;
  /**
   * @brief   Exiting sleep state event.
   */
  EventSource               wakeup_event;
#endif /* CAN_USE_SLEEP_MODE */
  /* End of the mandatory fields.*/
  /**
   * @brief   Pointer to the CAN registers.
   */
  CAN_TypeDef               *can;
} CANDriver;

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

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

#if STM32_CAN_USE_CAN1 && !defined(__DOXYGEN__)
extern CANDriver CAND1;
#endif

#if STM32_CAN_USE_CAN2 && !defined(__DOXYGEN__)
extern CANDriver CAND2;
#endif

#ifdef __cplusplus
extern "C" {
#endif
  void can_lld_init(void);
  void can_lld_start(CANDriver *canp);
  void can_lld_stop(CANDriver *canp);
  bool_t can_lld_is_tx_empty(CANDriver *canp,
                             canmbx_t mailbox);
  void can_lld_transmit(CANDriver *canp,
                        canmbx_t mailbox,
                        const CANTxFrame *crfp);
  bool_t can_lld_is_rx_nonempty(CANDriver *canp,
                                canmbx_t mailbox);
  void can_lld_receive(CANDriver *canp,
                       canmbx_t mailbox,
                       CANRxFrame *ctfp);
#if CAN_USE_SLEEP_MODE
  void can_lld_sleep(CANDriver *canp);
  void can_lld_wakeup(CANDriver *canp);
#endif /* CAN_USE_SLEEP_MODE */
#ifdef __cplusplus
}
#endif

#endif /* HAL_USE_CAN */

#endif /* _CAN_LLD_H_ */

/** @} */