/************************************************************************************
* include/nuttx/can.h
*
* Copyright (C) 2008, 2009, 2011-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* 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 _INCLUDE_NUTTX_CAN_H
#define _INCLUDE_NUTTX_CAN_H
/************************************************************************************
* Included Files
************************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <semaphore.h>
#include <nuttx/fs/fs.h>
#ifdef CONFIG_CAN
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
/* Configuration ********************************************************************/
/* CONFIG_CAN - Enables CAN support (one or both of CONFIG_STM32_CAN1 or
* CONFIG_STM32_CAN2 must also be defined)
* CONFIG_CAN_EXTID - Enables support for the 29-bit extended ID. Default
* Standard 11-bit IDs.
* CONFIG_CAN_FIFOSIZE - The size of the circular buffer of CAN messages.
* Default: 8
* CONFIG_CAN_NPENDINGRTR - The size of the list of pending RTR requests.
* Default: 4
* CONFIG_CAN_LOOPBACK - A CAN driver may or may not support a loopback
* mode for testing. If the driver does support loopback mode, the setting
* will enable it. (If the driver does not, this setting will have no effect).
*/
/* Default configuration settings that may be overridden in the NuttX configuration
* file or in the board configuration file. The configured size is limited to 255
* to fit into a uint8_t.
*/
#if !defined(CONFIG_CAN_FIFOSIZE)
# define CONFIG_CAN_FIFOSIZE 8
#elif CONFIG_CAN_FIFOSIZE > 255
# undef CONFIG_CAN_FIFOSIZE
# define CONFIG_CAN_FIFOSIZE 255
#endif
#if !defined(CONFIG_CAN_NPENDINGRTR)
# define CONFIG_CAN_NPENDINGRTR 4
#elif CONFIG_CAN_NPENDINGRTR > 255
# undef CONFIG_CAN_NPENDINGRTR
# define CONFIG_CAN_NPENDINGRTR 255
#endif
/* Convenience macros */
#define dev_reset(dev) dev->cd_ops->co_reset(dev)
#define dev_setup(dev) dev->cd_ops->co_setup(dev)
#define dev_shutdown(dev) dev->cd_ops->co_shutdown(dev)
#define dev_txint(dev,enable) dev->cd_ops->co_txint(dev,enable)
#define dev_rxint(dev,enable) dev->cd_ops->co_rxint(dev,enable)
#define dev_ioctl(dev,cmd,arg) dev->cd_ops->co_ioctl(dev,cmd,arg)
#define dev_remoterequest(dev,id) dev->cd_ops->co_remoterequest(dev,id)
#define dev_send(dev,m) dev->cd_ops->co_send(dev,m)
#define dev_txready(dev) dev->cd_ops->co_txready(dev)
#define dev_txempty(dev) dev->cd_ops->co_txempty(dev)
/* CAN message support */
#define CAN_MAXDATALEN 8
#define CAN_MAX_MSGID 0x07ff
#define CAN_MAX_EXTMSGID 0x1fffffff
#define CAN_MSGLEN(nbytes) (sizeof(struct can_msg_s) - CAN_MAXDATALEN + (nbytes))
/* Built-in ioctl commands
*
* CANIOCTL_RTR: Send the remote transmission request and wait for the response.
*/
#define CANIOCTL_RTR 1 /* Argument is a reference to struct canioctl_rtr_s */
/* CANIOCTL_USER: Device specific ioctl calls can be supported with cmds greater
* than this value
*/
#define CANIOCTL_USER 2
/************************************************************************************
* Public Types
************************************************************************************/
/* CAN-message Format (without Extended ID suppport)
*
* One based CAN-message is represented with a maximum of 10 bytes. A message is
* composed of at least the first 2 bytes (when there are no data bytes present).
*
* Bytes 0-1: Hold a 16-bit value in host byte order
* Bits 0-3: Data Length Code (DLC)
* Bit 4: Remote Tranmission Request (RTR)
* Bits 5-15: The 11-bit CAN identifier
*
* Bytes 2-9: CAN data
*
* CAN-message Format (with Extended ID suppport)
*
* One CAN-message consists of a maximum of 13 bytes. A message is composed of at
* least the first 5 bytes (when there are no data bytes).
*
* Bytes 0-3: Hold 11- or 29-bit CAN ID in host byte order
* Byte 4: Bits 0-3: Data Length Code (DLC)
* Bit 4: Remote Tranmission Request (RTR)
* Bit 5: Extended ID indication
* Bits 6-7: Unused
* Bytes 5-12: CAN data
*
* The struct can_msg_s holds this information in a user-friendly, unpacked form.
* This is the form that is used at the read() and write() driver interfaces. The
* message structure is actually variable length -- the true length is given by
* the CAN_MSGLEN macro.
*/
#ifdef CONFIG_CAN_EXTID
struct can_hdr_s
{
uint32_t ch_id; /* 11- or 29-bit ID (3-bits unsed) */
uint8_t ch_dlc : 4; /* 4-bit DLC */
uint8_t ch_rtr : 1; /* RTR indication */
uint8_t ch_extid : 1; /* Extended ID indication */
uint8_t ch_unused : 2; /* Unused */
} packed_struct;
#else
struct can_hdr_s
{
uint16_t ch_dlc : 4; /* 4-bit DLC */
uint16_t ch_rtr : 1; /* RTR indication */
uint16_t ch_id : 11; /* 11-bit standard ID */
} packed_struct;
#endif
struct can_msg_s
{
struct can_hdr_s cm_hdr; /* The CAN header */
uint8_t cm_data[CAN_MAXDATALEN]; /* CAN message data (0-8 byte) */
} packed_struct;
/* This structure defines a CAN message FIFO. */
struct can_rxfifo_s
{
sem_t rx_sem; /* Counting semaphore */
uint8_t rx_head; /* Index to the head [IN] in the circular buffer */
uint8_t rx_tail; /* Index to the tail [OUT] in the circular buffer */
/* Circular buffer of CAN messages */
struct can_msg_s rx_buffer[CONFIG_CAN_FIFOSIZE];
};
struct can_txfifo_s
{
sem_t tx_sem; /* Counting semaphore */
uint8_t tx_head; /* Index to the head [IN] in the circular buffer */
uint8_t tx_queue; /* Index to next message to send */
uint8_t tx_tail; /* Index to the tail [OUT] in the circular buffer */
/* Circular buffer of CAN messages */
struct can_msg_s tx_buffer[CONFIG_CAN_FIFOSIZE];
};
/* The following structure define the logic to handle one RTR message transaction */
struct can_rtrwait_s
{
sem_t cr_sem; /* Wait for RTR response */
uint16_t cr_id; /* The ID that is waited for */
FAR struct can_msg_s *cr_msg; /* This is where the RTR reponse goes */
};
/* This structure defines all of the operations providd by the architecture specific
* logic. All fields must be provided with non-NULL function pointers by the
* caller of can_register().
*/
struct can_dev_s;
struct can_ops_s
{
/* Reset the CAN device. Called early to initialize the hardware. This
* is called, before co_setup() and on error conditions.
*/
CODE void (*co_reset)(FAR struct can_dev_s *dev);
/* Configure the CAN. This method is called the first time that the CAN
* device is opened. This will occur when the port is first opened.
* This setup includes configuring and attaching CAN interrupts. All CAN
* interrupts are disabled upon return.
*/
CODE int (*co_setup)(FAR struct can_dev_s *dev);
/* Disable the CAN. This method is called when the CAN device is closed.
* This method reverses the operation the setup method.
*/
CODE void (*co_shutdown)(FAR struct can_dev_s *dev);
/* Call to enable or disable RX interrupts */
CODE void (*co_rxint)(FAR struct can_dev_s *dev, bool enable);
/* Call to enable or disable TX interrupts */
CODE void (*co_txint)(FAR struct can_dev_s *dev, bool enable);
/* All ioctl calls will be routed through this method */
CODE int (*co_ioctl)(FAR struct can_dev_s *dev, int cmd, unsigned long arg);
/* Send a remote request */
CODE int (*co_remoterequest)(FAR struct can_dev_s *dev, uint16_t id);
/* This method will send one message on the CAN */
CODE int (*co_send)(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg);
/* Return true if the CAN hardware can accept another TX message. */
CODE bool (*co_txready)(FAR struct can_dev_s *dev);
/* Return true if all message have been sent. If for example, the CAN
* hardware implements FIFOs, then this would mean the transmit FIFO is
* empty. This method is called when the driver needs to make sure that
* all characters are "drained" from the TX hardware before calling co_shutdown().
*/
CODE bool (*co_txempty)(FAR struct can_dev_s *dev);
};
/* This is the device structure used by the driver. The caller of
* can_register() must allocate and initialize this structure. The
* calling logic need only set all fields to zero except:
*
* The elements of 'cd_ops', and 'cd_priv'
*
* The common logic will initialize all semaphores.
*/
struct can_dev_s
{
uint8_t cd_ocount; /* The number of times the device has been opened */
uint8_t cd_npendrtr; /* Number of pending RTR messages */
uint8_t cd_ntxwaiters; /* Number of threads waiting to enqueue a message */
sem_t cd_closesem; /* Locks out new opens while close is in progress */
sem_t cd_recvsem; /* Used to wakeup user waiting for space in cd_recv.buffer */
struct can_txfifo_s cd_xmit; /* Describes transmit FIFO */
struct can_rxfifo_s cd_recv; /* Describes receive FIFO */
/* List of pending RTR requests */
struct can_rtrwait_s cd_rtr[CONFIG_CAN_NPENDINGRTR];
FAR const struct can_ops_s *cd_ops; /* Arch-specific operations */
FAR void *cd_priv; /* Used by the arch-specific logic */
};
/* Structures used with ioctl calls */
struct canioctl_rtr_s
{
uint16_t ci_id; /* The 11-bit ID to use in the RTR message */
FAR struct can_msg_s *ci_msg; /* The location to return the RTR response */
};
/************************************************************************************
* Public Data
************************************************************************************/
/************************************************************************************
* Public Functions
************************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif
/************************************************************************************
* Name: can_register
*
* Description:
* Register a CAN driver.
*
************************************************************************************/
EXTERN int can_register(FAR const char *path, FAR struct can_dev_s *dev);
/************************************************************************************
* Name: can_receive
*
* Description:
* Called from the CAN interrupt handler when new read data is available
*
* Parameters:
* dev - The specific CAN device
* hdr - The 16-bit CAN header
* data - An array contain the CAN data.
*
* Return:
* OK on success; a negated errno on failure.
*
************************************************************************************/
EXTERN int can_receive(FAR struct can_dev_s *dev, FAR struct can_hdr_s *hdr,
FAR uint8_t *data);
/************************************************************************************
* Name: can_txdone
*
* Description:
* Called from the CAN interrupt handler at the completion of a send operation.
*
* Parameters:
* dev - The specific CAN device
*
* Return:
* OK on success; a negated errno on failure.
*
************************************************************************************/
EXTERN int can_txdone(FAR struct can_dev_s *dev);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* CONFIG_CAN */
#endif /* _INCLUDE_NUTTX_CAN_H */
