/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @ingroup CANBus
*
* @brief Controller Area Network (CAN) Bus Implementation
*
*/
/*
* Copyright (C) 2022 Prashanth S (fishesprashanth@gmail.com)
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS 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 _DEV_CAN_CAN_H
#define _DEV_CAN_CAN_H
#include <rtems/imfs.h>
#include <rtems/thread.h>
#include <semaphore.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <dev/can/can-msg.h>
#define DEBUG(str, ...) \
do { \
printf("CAN: %s:%d ID: %08X ", __FILE__, __LINE__, rtems_task_self()); \
printf(str, ##__VA_ARGS__); \
} while (false);
#define CAN_DEBUG(str, ...) DEBUG(str, ##__VA_ARGS__)
#define CAN_DEBUG_BUF(str, ...) CAN_DEBUG(str, ##__VA_ARGS__)
#define CAN_DEBUG_ISR(str, ...) CAN_DEBUG(str, ##__VA_ARGS__)
#define CAN_DEBUG_LOCK(str, ...) CAN_DEBUG(str, ##__VA_ARGS__)
#define CAN_DEBUG_RX(str, ...) CAN_DEBUG(str, ##__VA_ARGS__)
#define CAN_DEBUG_TX(str, ...) CAN_DEBUG(str, ##__VA_ARGS__)
#define CAN_DEBUG_REG(str, ...) //CAN_DEBUG(str, ##__VA_ARGS__)
#define CAN_ERR(str, ...) DEBUG(str, ##__VA_ARGS__)
#define CAN_MSG_LEN(msg) ((char *)(&((struct can_msg *)msg)->data[(uint16_t)((struct can_msg *)msg)->len]) - (char *)(msg))
/* Maximum Bus Reg (255) */
#define CAN_BUS_REG_MAX (255)
/**
* @defgroup Controller Area Network (CAN) Driver
*
* @ingroup RTEMSDeviceDrivers
*
* @brief Controller Area Network (CAN) bus and device driver support.
*
* @{
*/
/**
* @defgroup CANBus CAN Bus Driver
*
* @ingroup CAN
*
* @{
*/
/**
* @brief CAN tx fifo data structure.
*/
struct ring_buf {
/**
* @brief Pointer to array of can_msg structure.
*/
struct can_msg *pbuf;
/**
* @brief Index of the next free buffer.
*/
uint32_t head;
/**
* @brief Index of the produced buffer.
*/
uint32_t tail;
/**
* @brief Number of empty buffers.
*/
uint32_t empty_count;
};
/**
* @brief CAN Controller device specific operations.
* These function pointers are initialized by the CAN device driver while
* registering (can_bus_register).
*/
typedef struct can_dev_ops {
/**
* @brief Transfers CAN messages to device fifo.
*
* @param[in] priv device control structure.
* @param[in] msg can_msg message structure.
*
* @retval 0 Successful operation.
* @retval >0 error number in case of an error.
*/
int32_t (*dev_tx)(void *priv, struct can_msg *msg);
/**
* @brief Check device is ready to transfer a CAN message
*
* @param[in] priv device control structure.
*
* @retval true device ready.
* @retval false device not ready.
*/
bool (*dev_tx_ready)(void *priv);
/**
* @brief Enable/Disable CAN interrupts.
*
* @param[in] priv device control structure.
* @param[in] flag true/false to Enable/Disable CAN interrupts.
*
*/
void (*dev_int)(void *priv, bool flag);
/**
* @brief CAN device specific I/O controls.
*
* @param[in] priv device control structure.
* @param[in] buffer This depends on the cmd.
* @param[in] cmd Device specific I/O commands.
*
* @retval 0 Depends on the cmd.
*/
int32_t (*dev_ioctl)(void *priv, void *buffer, size_t cmd);
} can_dev_ops;
/**
* @name CAN bus control
*
* @{
*/
/**
* @brief Obtains the bus.
*
* This command has no argument.
*/
typedef struct can_bus {
/**
* @brief Device specific control.
*/
void *priv;
/**
* @brief Device controller index.
*/
uint8_t index;
/**
* @brief Device specific operations.
*/
struct can_dev_ops *can_dev_ops;
/**
* @brief tx fifo.
*/
struct ring_buf tx_fifo;
/**
* @brief Counting semaphore id (for fifo sync).
*/
rtems_id tx_fifo_sem_id;
/* FIXME: Using only one CAN msg buffer, Should create a ring buffer */
/**
* @brief rx fifo.
*/
struct can_msg can_rx_msg;
/**
* @brief Mutex to handle bus concurrency.
*/
rtems_mutex mutex;
/**
* @brief Destroys the bus.
*
* @param[in] bus control structure.
*/
void (*destroy)(struct can_bus *bus);
#ifdef CAN_DEBUG_LOCK
/**
* @brief For debugging semaphore obtain/release.
*/
int sem_count;
#endif /* CAN_DEBUG_LOCK */
} can_bus;
/** @} */
/**
* @brief Register a CAN node with the CAN bus driver.
*
* @param[in] bus bus control structure.
* @param[in] bus_path path of device node.
*
* @retval >=0 rtems status.
*/
rtems_status_code can_bus_register(can_bus *bus, const char *bus_path);
/**
* @brief Allocate and initilaize bus control structure.
*
* @param[in] size Size of the bus control structure.
*
* @retval NULL No memory available.
* @retval Address Pointer to the allocated bus control structure.
*/
can_bus *can_bus_alloc_and_init(size_t size);
/**
* @brief initilaize bus control structure.
*
* @param[in] bus bus control structure.
*
* @retval 0 success.
* @retval >0 error number.
*/
int can_bus_init(can_bus *bus);
/**
* @brief Initiates CAN message transfer.
*
* Should be called with CAN interrupt disabled.
*
* @param[in] bus Bus control structure.
*
* @retval 0 success.
* @retval >0 error number.
*/
int can_tx_done(struct can_bus *bus);
/**
* @brief Sends the received CAN message to the application.
*
* Should be called by the device when CAN message should be sent to applicaiton.
* Should be called only with CAN interrupts disabled.
*
* @param[in] bus bus control structure.
* @param[in] msg can_msg structure.
*
* @retval 0 success.
* @retval >0 error number.
*/
int can_receive(struct can_bus *bus, struct can_msg *msg);
/**
* @brief Prints the can_msg values pointed by msg.
*
* @param[in] msg can_msg structure.
*
*/
void can_print_msg(struct can_msg const *msg);
/** @} */ /* end of CAN device driver */
/** @} */
#endif /* _DEV_CAN_CAN_H */
