/************************************************************************************ * include/nuttx/can.h * * Copyright (C) 2008, 2009 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 __NUTTX_CAN_H #define __NUTTX_CAN_H /************************************************************************************ * Included Files ************************************************************************************/ #include #include #include #include #include #include /************************************************************************************ * Pre-processor Definitions ************************************************************************************/ /* Default configuration settings that may be overridden 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_txempty(dev) dev->cd_ops->co_txempty(dev) /* CAN message support */ #define CAN_MAXDATALEN 8 #define CAN_ID(hdr) ((uint16_t)(hdr) >> 5) #define CAN_RTR(hdr) (((hdr) & 0x0010) != 0) #define CAN_DLC(hdr) ((hdr) & 0x0f) #define CAN_MSGLEN(hdr) (sizeof(struct can_msg_s) - (CAN_MAXDATALEN - CAN_DLC(hdr))) /* 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 * * One CAN-message consists of a maximum of 10 bytes. A message is composed of at * least the first 2 bytes (when there are no data bytes). * * Byte 0: Bits 0-7: Bits 3-10 of the 11-bit CAN identifier * Byte 1: Bits 5-7: Bits 0-2 of the 11-bit CAN identifier * Bit 4: Remote Tranmission Request (RTR) * Bits 0-3: Data Length Code (DLC) * Bytes 2-10: 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. */ struct can_msg_s { uint16_t cm_hdr; /* The 16-bit CAN header */ uint8_t cm_data[CAN_MAXDATALEN]; /* CAN message data (0-8 byte) */ }; /* This structure defines a CAN message FIFO. */ struct can_fifo_s { sem_t cf_sem; /* Counting semaphore */ uint8_t cf_head; /* Index to the head [IN] index in the circular buffer */ uint8_t cf_tail; /* Index to the tail [OUT] index in the circular buffer */ /* Circular buffer of CAN messages */ struct can_msg_s cf_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. Interrupts * are all 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 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 */ 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_fifo_s cd_xmit; /* Describes transmit FIFO */ struct can_fifo_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 specifi 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, uint16_t 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 specifi 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_txdone(FAR struct can_dev_s *dev); #undef EXTERN #if defined(__cplusplus) } #endif #endif /* __NUTTX_CAN_H */