diff options
Diffstat (limited to 'nuttx/drivers/can.c')
| -rw-r--r-- | nuttx/drivers/can.c | 845 |
1 files changed, 0 insertions, 845 deletions
diff --git a/nuttx/drivers/can.c b/nuttx/drivers/can.c deleted file mode 100644 index 2c1567781..000000000 --- a/nuttx/drivers/can.c +++ /dev/null @@ -1,845 +0,0 @@ -/**************************************************************************** - * drivers/can.c - * - * 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. - * - ****************************************************************************/ - -/**************************************************************************** - * Included Files - ****************************************************************************/ - -#include <nuttx/config.h> - -#include <sys/types.h> -#include <stdint.h> -#include <stdbool.h> -#include <unistd.h> -#include <string.h> -#include <semaphore.h> -#include <fcntl.h> -#include <assert.h> -#include <errno.h> -#include <debug.h> - -#include <nuttx/fs/fs.h> -#include <nuttx/arch.h> -#include <nuttx/can.h> - -#include <arch/irq.h> - -#ifdef CONFIG_CAN - -/**************************************************************************** - * Pre-processor Definitions - ****************************************************************************/ -/* Debug ********************************************************************/ -/* Non-standard debug that may be enabled just for testing CAN */ - -#ifdef CONFIG_DEBUG_CAN -# define candbg dbg -# define canvdbg vdbg -# define canlldbg lldbg -# define canllvdbg llvdbg -#else -# define candbg(x...) -# define canvdbg(x...) -# define canlldbg(x...) -# define canllvdbg(x...) -#endif - -/* Timing Definitions *******************************************************/ - -#define HALF_SECOND_MSEC 500 -#define HALF_SECOND_USEC 500000L - -/**************************************************************************** - * Private Type Definitions - ****************************************************************************/ - -/**************************************************************************** - * Private Function Prototypes - ****************************************************************************/ - -static int can_open(FAR struct file *filep); -static int can_close(FAR struct file *filep); -static ssize_t can_read(FAR struct file *filep, FAR char *buffer, size_t buflen); -static int can_xmit(FAR struct can_dev_s *dev); -static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); -static inline ssize_t can_rtrread(FAR struct can_dev_s *dev, FAR struct canioctl_rtr_s *rtr); -static int can_ioctl(FAR struct file *filep, int cmd, unsigned long arg); - -/**************************************************************************** - * Private Data - ****************************************************************************/ - -static const struct file_operations g_canops = -{ - can_open, /* open */ - can_close, /* close */ - can_read, /* read */ - can_write, /* write */ - 0, /* seek */ - can_ioctl /* ioctl */ -#ifndef CONFIG_DISABLE_POLL - , 0 /* poll */ -#endif -}; - -/**************************************************************************** - * Private Functions - ****************************************************************************/ - -/************************************************************************************ - * Name: can_open - * - * Description: - * This function is called whenever the CAN device is opened. - * - ************************************************************************************/ - -static int can_open(FAR struct file *filep) -{ - FAR struct inode *inode = filep->f_inode; - FAR struct can_dev_s *dev = inode->i_private; - uint8_t tmp; - int ret = OK; - - canvdbg("ocount: %d\n", dev->cd_ocount); - - /* If the port is the middle of closing, wait until the close is finished */ - - if (sem_wait(&dev->cd_closesem) != OK) - { - ret = -errno; - } - else - { - /* Increment the count of references to the device. If this the first - * time that the driver has been opened for this device, then initialize - * the device. - */ - - tmp = dev->cd_ocount + 1; - if (tmp == 0) - { - /* More than 255 opens; uint8_t overflows to zero */ - - ret = -EMFILE; - } - else - { - /* Check if this is the first time that the driver has been opened. */ - - if (tmp == 1) - { - /* Yes.. perform one time hardware initialization. */ - - irqstate_t flags = irqsave(); - ret = dev_setup(dev); - if (ret == OK) - { - /* Mark the FIFOs empty */ - - dev->cd_xmit.tx_head = 0; - dev->cd_xmit.tx_queue = 0; - dev->cd_xmit.tx_tail = 0; - dev->cd_recv.rx_head = 0; - dev->cd_recv.rx_tail = 0; - - /* Finally, Enable the CAN RX interrupt */ - - dev_rxint(dev, true); - - /* Save the new open count on success */ - - dev->cd_ocount = tmp; - } - irqrestore(flags); - } - } - sem_post(&dev->cd_closesem); - } - return ret; -} - -/************************************************************************************ - * Name: can_close - * - * Description: - * This routine is called when the CAN device is closed. - * It waits for the last remaining data to be sent. - * - ************************************************************************************/ - -static int can_close(FAR struct file *filep) -{ - FAR struct inode *inode = filep->f_inode; - FAR struct can_dev_s *dev = inode->i_private; - irqstate_t flags; - int ret = OK; - - canvdbg("ocount: %d\n", dev->cd_ocount); - - if (sem_wait(&dev->cd_closesem) != OK) - { - ret = -errno; - } - else - { - /* Decrement the references to the driver. If the reference count will - * decrement to 0, then uninitialize the driver. - */ - - if (dev->cd_ocount > 1) - { - dev->cd_ocount--; - sem_post(&dev->cd_closesem); - } - else - { - /* There are no more references to the port */ - - dev->cd_ocount = 0; - - /* Stop accepting input */ - - dev_rxint(dev, false); - - /* Now we wait for the transmit FIFO to clear */ - - while (dev->cd_xmit.tx_head != dev->cd_xmit.tx_tail) - { -#ifndef CONFIG_DISABLE_SIGNALS - usleep(HALF_SECOND_USEC); -#else - up_mdelay(HALF_SECOND_MSEC); -#endif - } - - /* And wait for the TX hardware FIFO to drain */ - - while (!dev_txempty(dev)) - { -#ifndef CONFIG_DISABLE_SIGNALS - usleep(HALF_SECOND_USEC); -#else - up_mdelay(HALF_SECOND_MSEC); -#endif - } - - /* Free the IRQ and disable the CAN device */ - - flags = irqsave(); /* Disable interrupts */ - dev_shutdown(dev); /* Disable the CAN */ - irqrestore(flags); - - sem_post(&dev->cd_closesem); - } - } - return ret; -} - -/************************************************************************************ - * Name: can_read - * - * Description: - * Read standard CAN messages - * - ************************************************************************************/ - -static ssize_t can_read(FAR struct file *filep, FAR char *buffer, size_t buflen) -{ - FAR struct inode *inode = filep->f_inode; - FAR struct can_dev_s *dev = inode->i_private; - size_t nread; - irqstate_t flags; - int ret = 0; - - canvdbg("buflen: %d\n", buflen); - - /* The caller must provide enough memory to catch the smallest possible message - * This is not a system error condition, but we won't permit it, Hence we return 0. - */ - - if (buflen >= CAN_MSGLEN(0)) - { - /* Interrupts must be disabled while accessing the cd_recv FIFO */ - - flags = irqsave(); - while (dev->cd_recv.rx_head == dev->cd_recv.rx_tail) - { - /* The receive FIFO is empty -- was non-blocking mode selected? */ - - if (filep->f_oflags & O_NONBLOCK) - { - ret = -EAGAIN; - goto return_with_irqdisabled; - } - - /* Wait for a message to be received */ - - ret = sem_wait(&dev->cd_recv.rx_sem); - if (ret < 0) - { - ret = -errno; - goto return_with_irqdisabled; - } - } - - /* The cd_recv FIFO is not empty. Copy all buffered data that will fit - * in the user buffer. - */ - - nread = 0; - do - { - /* Will the next message in the FIFO fit into the user buffer? */ - - FAR struct can_msg_s *msg = &dev->cd_recv.rx_buffer[dev->cd_recv.rx_head]; - int msglen = CAN_MSGLEN(msg->cm_hdr.ch_dlc); - - if (nread + msglen > buflen) - { - break; - } - - /* Copy the message to the user buffer */ - - memcpy(&buffer[nread], msg, msglen); - nread += msglen; - - /* Increment the head of the circular message buffer */ - - if (++dev->cd_recv.rx_head >= CONFIG_CAN_FIFOSIZE) - { - dev->cd_recv.rx_head = 0; - } - } - while (dev->cd_recv.rx_head != dev->cd_recv.rx_tail); - - /* All on the messages have bee transferred. Return the number of bytes - * that were read. - */ - - ret = nread; - -return_with_irqdisabled: - irqrestore(flags); - } - return ret; -} - -/************************************************************************************ - * Name: can_xmit - * - * Description: - * Send the message at the head of the cd_xmit FIFO - * - * Assumptions: - * Called with interrupts disabled - * - ************************************************************************************/ - -static int can_xmit(FAR struct can_dev_s *dev) -{ - int tmpndx; - int ret = -EBUSY; - - canllvdbg("xmit head: %d queue: %d tail: %d\n", - dev->cd_xmit.tx_head, dev->cd_xmit.tx_queue, dev->cd_xmit.tx_tail); - - /* If there is nothing to send, then just disable interrupts and return */ - - if (dev->cd_xmit.tx_head == dev->cd_xmit.tx_tail) - { - DEBUGASSERT(dev->cd_xmit.tx_queue == dev->cd_xmit.tx_head); - dev_txint(dev, false); - return -EIO; - } - - /* Check if we have already queued all of the data in the TX fifo. - * - * tx_tail: Incremented in can_write each time a message is queued in the FIFO - * tx_head: Incremented in can_txdone each time a message completes - * tx_queue: Incremented each time that a message is sent to the hardware. - * - * Logically (ignoring buffer wrap-around): tx_head <= tx_queue <= tx_tail - * tx_head == tx_queue == tx_tail means that the FIFO is empty - * tx_head < tx_queue == tx_tail means that all data has been queued, but - * we are still waiting for transmissions to complete. - */ - - while (dev->cd_xmit.tx_queue != dev->cd_xmit.tx_tail && dev_txready(dev)) - { - /* No.. The fifo should not be empty in this case */ - - DEBUGASSERT(dev->cd_xmit.tx_head != dev->cd_xmit.tx_tail); - - /* Increment the FIFO queue index before sending (because dev_send() - * might call can_txdone(). - */ - - tmpndx = dev->cd_xmit.tx_queue; - if (++dev->cd_xmit.tx_queue >= CONFIG_CAN_FIFOSIZE) - { - dev->cd_xmit.tx_queue = 0; - } - - /* Send the next message at the FIFO queue index */ - - ret = dev_send(dev, &dev->cd_xmit.tx_buffer[tmpndx]); - if (ret != OK) - { - candbg("dev_send failed: %d\n", ret); - break; - } - } - - /* Make sure that TX interrupts are enabled */ - - dev_txint(dev, true); - return ret; -} - -/************************************************************************************ - * Name: can_write - ************************************************************************************/ - -static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) -{ - FAR struct inode *inode = filep->f_inode; - FAR struct can_dev_s *dev = inode->i_private; - FAR struct can_txfifo_s *fifo = &dev->cd_xmit; - FAR struct can_msg_s *msg; - bool inactive; - ssize_t nsent = 0; - irqstate_t flags; - int nexttail; - int msglen; - int ret = 0; - - canvdbg("buflen: %d\n", buflen); - - /* Interrupts must disabled throughout the following */ - - flags = irqsave(); - - /* Check if the TX is inactive when we started. In certain race conditionas, there - * may be a pending interrupt to kick things back off, but we will here that there - * is not. That the hardware is IDLE and will need to be kick-started. - */ - - inactive = dev_txempty(dev); - - /* Add the messages to the FIFO. Ignore any trailing messages that are - * shorter than the minimum. - */ - - while ((buflen - nsent) >= CAN_MSGLEN(0)) - { - /* Check if adding this new message would over-run the drivers ability to enqueue - * xmit data. - */ - - nexttail = fifo->tx_tail + 1; - if (nexttail >= CONFIG_CAN_FIFOSIZE) - { - nexttail = 0; - } - - /* If the XMIT fifo becomes full, then wait for space to become available */ - - while (nexttail == fifo->tx_head) - { - /* The transmit FIFO is full -- was non-blocking mode selected? */ - - if (filep->f_oflags & O_NONBLOCK) - { - if (nsent == 0) - { - ret = -EAGAIN; - } - else - { - ret = nsent; - } - goto return_with_irqdisabled; - } - - /* If the TX hardware was inactive when we started, then we will have - * start the XMIT sequence generate the TX done interrrupts needed - * to clear the FIFO. - */ - - if (inactive) - { - can_xmit(dev); - } - - /* Wait for a message to be sent */ - - do - { - DEBUGASSERT(dev->cd_ntxwaiters < 255); - dev->cd_ntxwaiters++; - ret = sem_wait(&fifo->tx_sem); - dev->cd_ntxwaiters--; - - if (ret < 0 && errno != EINTR) - { - ret = -errno; - goto return_with_irqdisabled; - } - } - while (ret < 0); - - /* Re-check the FIFO state */ - - inactive = dev_txempty(dev); - } - - /* We get here if there is space at the end of the FIFO. Add the new - * CAN message at the tail of the FIFO. - */ - - msg = (FAR struct can_msg_s *)&buffer[nsent]; - msglen = CAN_MSGLEN(msg->cm_hdr.ch_dlc); - memcpy(&fifo->tx_buffer[fifo->tx_tail], msg, msglen); - - /* Increment the tail of the circular buffer */ - - fifo->tx_tail = nexttail; - - /* Increment the number of bytes that were sent */ - - nsent += msglen; - } - - /* We get here after all messages have been added to the FIFO. Check if - * we need to kick of the XMIT sequence. - */ - - if (inactive) - { - can_xmit(dev); - } - - /* Return the number of bytes that were sent */ - - ret = nsent; - -return_with_irqdisabled: - irqrestore(flags); - return ret; -} - -/************************************************************************************ - * Name: can_rtrread - * - * Description: - * Read RTR messages. The RTR message is a special message -- it is an outgoing - * message that says "Please re-transmit the message with the same identifier as - * this message. So the RTR read is really a send-wait-receive operation. - * - ************************************************************************************/ - -static inline ssize_t can_rtrread(FAR struct can_dev_s *dev, FAR struct canioctl_rtr_s *rtr) -{ - FAR struct can_rtrwait_s *wait = NULL; - irqstate_t flags; - int i; - int ret = -ENOMEM; - - /* Disable interrupts through this operation */ - - flags = irqsave(); - - /* Find an avaiable slot in the pending RTR list */ - - for (i = 0; i < CONFIG_CAN_NPENDINGRTR; i++) - { - FAR struct can_rtrwait_s *tmp = &dev->cd_rtr[i]; - if (!rtr->ci_msg) - { - tmp->cr_id = rtr->ci_id; - tmp->cr_msg = rtr->ci_msg; - dev->cd_npendrtr++; - wait = tmp; - break; - } - } - - if (wait) - { - /* Send the remote transmission request */ - - ret = dev_remoterequest(dev, wait->cr_id); - if (ret == OK) - { - /* Then wait for the response */ - - ret = sem_wait(&wait->cr_sem); - } - } - irqrestore(flags); - return ret; -} - -/************************************************************************************ - * Name: can_ioctl - ************************************************************************************/ - -static int can_ioctl(FAR struct file *filep, int cmd, unsigned long arg) -{ - FAR struct inode *inode = filep->f_inode; - FAR struct can_dev_s *dev = inode->i_private; - int ret = OK; - - canvdbg("cmd: %d arg: %ld\n", cmd, arg); - - /* Handle built-in ioctl commands */ - - switch (cmd) - { - /* CANIOCTL_RTR: Send the remote transmission request and wait for the response. - * Argument is a reference to struct canioctl_rtr_s (casting to uintptr_t first - * eliminates complaints on some architectures where the sizeof long is different - * from the size of a pointer). - */ - - case CANIOCTL_RTR: - ret = can_rtrread(dev, (struct canioctl_rtr_s*)((uintptr_t)arg)); - break; - - /* Not a "built-in" ioctl command.. perhaps it is unique to this device driver */ - - default: - ret = dev_ioctl(dev, cmd, arg); - break; - } - return ret; -} - -/**************************************************************************** - * Public Functions - ****************************************************************************/ - -/************************************************************************************ - * Name: can_register - * - * Description: - * Register serial console and serial ports. - * - ************************************************************************************/ - -int can_register(FAR const char *path, FAR struct can_dev_s *dev) -{ - int i; - - /* Initialize the CAN device structure */ - - dev->cd_ocount = 0; - - sem_init(&dev->cd_xmit.tx_sem, 0, 0); - sem_init(&dev->cd_recv.rx_sem, 0, 0); - sem_init(&dev->cd_closesem, 0, 1); - - for (i = 0; i < CONFIG_CAN_NPENDINGRTR; i++) - { - sem_init(&dev->cd_rtr[i].cr_sem, 0, 0); - dev->cd_rtr[i].cr_msg = NULL; - dev->cd_npendrtr--; - } - - /* Initialize/reset the CAN hardware */ - - dev_reset(dev); - - /* Register the CAN device */ - - canvdbg("Registering %s\n", path); - return register_driver(path, &g_canops, 0666, dev); -} - -/************************************************************************************ - * Name: can_receive - * - * Description: - * Called from the CAN interrupt handler when new read data is available - * - * Parameters: - * dev - CAN driver state structure - * hdr - CAN message header - * data - CAN message data (if DLC > 0) - * - * Assumptions: - * CAN interrupts are disabled. - * - ************************************************************************************/ - -int can_receive(FAR struct can_dev_s *dev, FAR struct can_hdr_s *hdr, FAR uint8_t *data) -{ - FAR struct can_rxfifo_s *fifo = &dev->cd_recv; - FAR uint8_t *dest; - int nexttail; - int err = -ENOMEM; - int i; - - canllvdbg("ID: %d DLC: %d\n", hdr->ch_id, hdr->ch_dlc); - - /* Check if adding this new message would over-run the drivers ability to enqueue - * read data. - */ - - nexttail = fifo->rx_tail + 1; - if (nexttail >= CONFIG_CAN_FIFOSIZE) - { - nexttail = 0; - } - - /* First, check if this response matches any RTR response that we may be waiting for */ - - if (dev->cd_npendrtr > 0) - { - /* There are pending RTR requests -- search the lists of requests - * and see any any matches this new message. - */ - - for (i = 0; i < CONFIG_CAN_NPENDINGRTR; i++) - { - FAR struct can_rtrwait_s *rtr = &dev->cd_rtr[i]; - FAR struct can_msg_s *msg = rtr->cr_msg; - - /* Check if the entry is valid and if the ID matches. A valid entry has - * a non-NULL receiving address - */ - - if (msg && hdr->ch_id == rtr->cr_id) - { - /* We have the response... copy the data to the user's buffer */ - - memcpy(&msg->cm_hdr, hdr, sizeof(struct can_hdr_s)); - for (i = 0, dest = msg->cm_data; i < hdr->ch_dlc; i++) - { - *dest++ = *data++; - } - - /* Mark the entry unused */ - - rtr->cr_msg = NULL; - - /* And restart the waiting thread */ - - sem_post(&rtr->cr_sem); - } - } - } - - /* Refuse the new data if the FIFO is full */ - - if (nexttail != fifo->rx_head) - { - /* Add the new, decoded CAN message at the tail of the FIFO */ - - memcpy(&fifo->rx_buffer[fifo->rx_tail].cm_hdr, hdr, sizeof(struct can_hdr_s)); - for (i = 0, dest = fifo->rx_buffer[fifo->rx_tail].cm_data; i < hdr->ch_dlc; i++) - { - *dest++ = *data++; - } - - /* Increment the tail of the circular buffer */ - - fifo->rx_tail = nexttail; - - /* The increment the counting semaphore. The maximum value should be - * CONFIG_CAN_FIFOSIZE -- one possible count for each allocated message buffer. - */ - - sem_post(&fifo->rx_sem); - err = OK; - } - return err; -} - -/************************************************************************************ - * Name: can_txdone - * - * Description: - * Called from the CAN interrupt handler at the completion of a send operation. - * - * 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. - * - ************************************************************************************/ - -int can_txdone(FAR struct can_dev_s *dev) -{ - int ret = -ENOENT; - - canllvdbg("xmit head: %d queue: %d tail: %d\n", - dev->cd_xmit.tx_head, dev->cd_xmit.tx_queue, dev->cd_xmit.tx_tail); - - /* Verify that the xmit FIFO is not empty */ - - if (dev->cd_xmit.tx_head != dev->cd_xmit.tx_tail) - { - DEBUGASSERT(dev->cd_xmit.tx_head != dev->cd_xmit.tx_queue); - - /* Remove the message at the head of the xmit FIFO */ - - if (++dev->cd_xmit.tx_head >= CONFIG_CAN_FIFOSIZE) - { - dev->cd_xmit.tx_head = 0; - } - - /* Send the next message in the FIFO */ - - ret = can_xmit(dev); - - /* Are there any threads waiting for space in the TX FIFO? */ - - if (ret == OK && dev->cd_ntxwaiters > 0) - { - /* Yes.. Inform them that new xmit space is available */ - - ret = sem_post(&dev->cd_xmit.tx_sem); - } - } - return ret; -} - -#endif /* CONFIG_CAN */ |