[PATCH] cpukit/dev/can: Added CAN support
Prashanth S
fishesprashanth at gmail.com
Sun Jul 31 11:53:51 UTC 2022
---
cpukit/dev/can/can.c | 514 +++++++++++++++++++++++++++++
cpukit/include/dev/can/can-msg.h | 55 +++
cpukit/include/dev/can/can-queue.h | 127 +++++++
cpukit/include/dev/can/can.h | 102 ++++++
spec/build/cpukit/librtemscpu.yml | 6 +
5 files changed, 804 insertions(+)
create mode 100644 cpukit/dev/can/can.c
create mode 100644 cpukit/include/dev/can/can-msg.h
create mode 100644 cpukit/include/dev/can/can-queue.h
create mode 100644 cpukit/include/dev/can/can.h
diff --git a/cpukit/dev/can/can.c b/cpukit/dev/can/can.c
new file mode 100644
index 0000000000..8feec8800b
--- /dev/null
+++ b/cpukit/dev/can/can.c
@@ -0,0 +1,514 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup CANBus
+ *
+ * @brief Controller Area Network (CAN) Bus Implementation
+ *
+ */
+
+/*
+ * Copyright (C) 2022 Prashanth S (fishesprashanth at 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.
+ */
+
+#include <rtems/imfs.h>
+#include <rtems/thread.h>
+
+#include <dev/can/can-queue.h>
+#include <dev/can/can.h>
+
+#include <string.h>
+#include <stdlib.h>
+
+#include <fcntl.h>
+
+static ssize_t
+can_bus_open(rtems_libio_t *iop, const char *path, int oflag, mode_t mode);
+static ssize_t
+can_bus_read(rtems_libio_t *iop, void *buffer, size_t count);
+static ssize_t
+can_bus_write(rtems_libio_t *iop, const void *buffer, size_t count);
+static ssize_t
+can_bus_ioctl(rtems_libio_t *iop, ioctl_command_t request, void *buffer);
+
+static int can_xmit(struct can_bus *bus);
+
+static int can_create_sem(struct can_bus *);
+static int try_sem(struct can_bus *);
+static int take_sem(struct can_bus *);
+static int give_sem(struct can_bus *);
+
+/* sem_count this is for debug purpose, for debugging
+the take_sem and give_sem
+*/
+static int sem_count = 0;
+
+static void can_bus_obtain(can_bus *bus)
+{
+ rtems_recursive_mutex_lock(&bus->mutex);
+}
+
+static void can_bus_release(can_bus *bus)
+{
+ rtems_recursive_mutex_unlock(&bus->mutex);
+}
+
+int can_create_sem(struct can_bus *bus)
+{
+ int ret = 0;
+
+ ret = rtems_semaphore_create(rtems_build_name('c', 'a', 'n', bus->index),
+ CAN_TX_BUF_COUNT, RTEMS_FIFO | RTEMS_COUNTING_SEMAPHORE | RTEMS_LOCAL,
+ 0, &bus->tx_fifo_sem_id);
+
+ if (ret != 0) {
+ printf("can_create_sem: rtems_semaphore_create failed %d\n", ret);
+ }
+
+ return ret;
+}
+
+static void can_interrupt_lock_acquire(struct can_bus *bus)
+{
+ can_bus_obtain(bus);
+ bus->can_dev_ops->dev_int(bus->priv, false);
+}
+
+static void can_interrupt_lock_release(struct can_bus *bus)
+{
+ bus->can_dev_ops->dev_int(bus->priv, true);
+ can_bus_release(bus);
+}
+
+static int take_sem(struct can_bus *bus)
+{
+ int ret = rtems_semaphore_obtain(bus->tx_fifo_sem_id, RTEMS_WAIT,
+ RTEMS_NO_TIMEOUT);
+ if (ret == RTEMS_SUCCESSFUL) {
+ CAN_DEBUG_LOCK("take_sem: Counting semaphore count = %d\n", ++sem_count);
+ if (sem_count > CAN_TX_BUF_COUNT) {
+ printf("take_sem error: sem_count is misleading\n");
+ while (1);
+ }
+ }
+
+ return ret;
+}
+
+static int give_sem(struct can_bus *bus)
+{
+ int ret = rtems_semaphore_release(bus->tx_fifo_sem_id);
+ if (ret == RTEMS_SUCCESSFUL) {
+ CAN_DEBUG_LOCK("give_sem: Counting semaphore count = %d\n", --sem_count);
+ if (sem_count < 0) {
+ printf("give_sem error: sem_count is misleading\n");
+ while (1);
+ }
+ }
+
+ return ret;
+}
+
+static int try_sem(struct can_bus *bus)
+{
+ int ret = rtems_semaphore_obtain(bus->tx_fifo_sem_id, RTEMS_NO_WAIT,
+ RTEMS_NO_TIMEOUT);
+ if (ret == RTEMS_SUCCESSFUL) {
+ CAN_DEBUG_LOCK("take_sem: Counting semaphore count = %d\n", ++sem_count);
+ if (sem_count > CAN_TX_BUF_COUNT) {
+ printf("take_sem error: sem_count is misleading\n");
+ while (1);
+ }
+ }
+
+ return ret;
+}
+
+static ssize_t
+can_bus_open(rtems_libio_t *iop, const char *path, int oflag, mode_t mode)
+{
+/*
+ can_bus *bus = IMFS_generic_get_context_by_iop(iop);
+
+ if (bus == NULL) {
+ return -RTEMS_NOT_DEFINED;
+ }
+*/
+ return 0;
+}
+
+int can_receive(struct can_bus *bus, struct can_msg *msg)
+{
+ int32_t ret = 0;
+
+ uint32_t count = 0;
+
+ ret = rtems_message_queue_broadcast(bus->rx_queue_id, msg, CAN_MSGLEN(msg),
+ &count);
+ if (ret != RTEMS_SUCCESSFUL) {
+ CAN_DEBUG_RX("rtems_message_queue_send failed\n");
+ }
+
+ CAN_DEBUG_RX("rtems_message_queue_broadcast = %u\n", count);
+
+ return ret;
+}
+
+/* count argument is not used here as struct can_msg has the dlc member */
+static ssize_t can_bus_read(rtems_libio_t *iop, void *buffer, size_t count)
+{
+ int32_t ret = 0;
+ uint32_t flags = 0;
+
+ can_bus *bus = IMFS_generic_get_context_by_iop(iop);
+
+ if (bus == NULL || bus->can_dev_ops->dev_rx == NULL) {
+ return -RTEMS_NOT_DEFINED;
+ }
+
+ struct can_msg *msg = (struct can_msg *)buffer;
+
+ if ((iop->flags & O_NONBLOCK) != 0) {
+ flags = RTEMS_NO_WAIT;
+ }
+
+ ret = rtems_message_queue_receive(bus->rx_queue_id, (void *)msg, &count,
+ flags, 0);
+ if (ret != RTEMS_SUCCESSFUL) {
+ return ret;
+ }
+
+ return count;
+}
+
+static int can_xmit(struct can_bus *bus)
+{
+ int ret = RTEMS_SUCCESSFUL;
+
+ struct can_msg *msg = NULL;
+
+ while (1) {
+ CAN_DEBUG_LOCK("can_xmit: acquiring lock\n");
+ can_interrupt_lock_acquire(bus);
+
+ ret = bus->can_dev_ops->dev_tx_ready(bus->priv);
+ if (ret != true) {
+ goto return_with_lock_release;
+ }
+
+ msg = can_tx_get_data_buf(bus);
+ if (msg == NULL) {
+ goto return_with_lock_release;
+ }
+
+ ret = bus->can_dev_ops->dev_tx(bus->priv, msg);
+ if (ret != RTEMS_SUCCESSFUL) {
+ printf("can_xmit: dev_send failed\n");
+ }
+
+ ret = give_sem(bus);
+ if (ret != RTEMS_SUCCESSFUL) {
+ printf("can_tx_done: rtems_semaphore_release failed = %d\n", ret);
+ }
+
+ CAN_DEBUG_LOCK("can_xmit: releasing lock\n");
+ can_interrupt_lock_release(bus);
+
+ //can_tx_done(bus);
+ }
+
+ return ret;
+
+return_with_lock_release:
+
+ CAN_DEBUG_LOCK("can_xmit: releasing lock\n");
+ can_interrupt_lock_release(bus);
+
+ return ret;
+}
+
+void can_print_msg(struct can_msg const *msg)
+{
+ printf("\n----------------------------------------------------------------\n");
+ printf("id = %d len = %d flags = 0x%08X\n", msg->id, msg->len, msg->flags);
+
+ for (int i = 0; i < msg->len; i++) {
+ printf("%02x ", msg->data[i]);
+ }
+
+ printf("\n-----------------------------------------------------------------\n");
+}
+
+/* can_tx_done should be called only with interrupts disabled */
+int can_tx_done(struct can_bus *bus)
+{
+ int ret = 0;
+
+ if (bus->can_dev_ops->dev_tx_ready(bus->priv) == true) {
+ can_xmit(bus);
+ }
+
+ return ret;
+}
+
+static ssize_t
+can_bus_write(rtems_libio_t *iop, const void *buffer, size_t count)
+{
+ can_bus *bus = IMFS_generic_get_context_by_iop(iop);
+
+ if (bus == NULL || bus->can_dev_ops->dev_tx == NULL) {
+ return -RTEMS_NOT_DEFINED;
+ }
+
+ int32_t ret = 0;
+
+ struct can_msg const *msg = buffer;
+ struct can_msg *fifo_buf = NULL;
+
+ CAN_DEBUG_LOCK("can_bus_write: acquiring lock tx_fifo.empty_count\n");
+ can_interrupt_lock_acquire(bus);
+ CAN_DEBUG_TX("can_bus_write: empty_count = %u\n", bus->tx_fifo.empty_count);
+ CAN_DEBUG_LOCK("can_bus_write: release lock tx_fifo.empty_count\n");
+ can_interrupt_lock_release(bus);
+
+ if ((iop->flags & O_NONBLOCK) != 0) {
+ ret = try_sem(bus);
+ if (ret != RTEMS_SUCCESSFUL) {
+ return -RTEMS_NO_MEMORY;
+ }
+ } else {
+ CAN_DEBUG_LOCK("can_bus_write: acquiring lock can_tx_buf_waiters++\n");
+ can_interrupt_lock_acquire(bus);
+ bus->can_tx_buf_waiters++;
+ CAN_DEBUG_LOCK("can_bus_write: release lock can_tx_buf_waiters++\n");
+ can_interrupt_lock_release(bus);
+
+ ret = take_sem(bus);
+
+ CAN_DEBUG_LOCK("can_bus_write: acquiring lock can_tx_buf_waiters--\n");
+ can_interrupt_lock_acquire(bus);
+ bus->can_tx_buf_waiters--;
+ CAN_DEBUG_LOCK("can_bus_write: release lock can_tx_buf_waiters--\n");
+ can_interrupt_lock_release(bus);
+
+ if (ret != RTEMS_SUCCESSFUL) {
+ printf("can_bus_write: cannot take semaphore\n");
+ ret = -RTEMS_INTERNAL_ERROR;
+ goto return_from_func;
+ }
+ }
+
+ /* sleep is for debug purpose to test concurrency issues */
+ printf("can_bus_write: calling sleep\n");
+ sleep(1);
+ printf("can_bus_write: coming out sleep\n");
+
+ CAN_DEBUG_LOCK("can_bus_write: acquiring lock can_tx_get_empty_buf\n");
+ can_interrupt_lock_acquire(bus);
+ fifo_buf = can_tx_get_empty_buf(bus);
+ CAN_DEBUG_LOCK("can_bus_write: releasing lock can_tx_get_empty_buf\n");
+ can_interrupt_lock_release(bus);
+
+ if (fifo_buf == NULL) {
+ printf("can_bus_write: Buffer counts are not synchronized with semaphore count\n");
+ return -RTEMS_INTERNAL_ERROR;
+ }
+
+ /* sleep is for debug purpose to test concurrency issues */
+ printf("can_bus_write: calling sleep\n");
+ sleep(1);
+ printf("can_bus_write: coming out sleep\n");
+
+ uint32_t msg_size = (char *)&msg->data[msg->len] - (char *)msg;
+
+ CAN_DEBUG_TX("can_bus_write: can_msg_size = %u\n", msg_size);
+ if (msg_size > sizeof(struct can_msg)) {
+ printf("can_bus_write:"
+ "can message len error msg_size = %u struct can_msg = %u\n",
+ msg_size, sizeof(struct can_msg));
+ return -RTEMS_INVALID_SIZE;
+ }
+
+ CAN_DEBUG_TX("can_bus_write: copying msg from application to driver buffer\n");
+ memcpy(fifo_buf, msg, msg_size);
+ ret = msg_size;
+
+ /* sleep is for debug purpose to test concurrency issues */
+ printf("can_bus_write: calling sleep\n");
+ sleep(1);
+ printf("can_bus_write: coming out sleep\n");
+
+ if (bus->can_dev_ops->dev_tx_ready(bus->priv) == true) {
+ can_xmit(bus);
+ }
+
+return_from_func:
+ return ret;
+}
+
+static ssize_t
+can_bus_ioctl(rtems_libio_t *iop, ioctl_command_t request, void *buffer)
+{
+ can_bus *bus = IMFS_generic_get_context_by_iop(iop);
+
+ if (bus == NULL || bus->can_dev_ops->dev_ioctl == NULL) {
+ return -RTEMS_NOT_DEFINED;
+ }
+
+ can_bus_obtain(bus);
+
+ bus->can_dev_ops->dev_ioctl(bus->priv, NULL, 0);
+
+ can_bus_release(bus);
+
+ return RTEMS_SUCCESSFUL;
+}
+
+static const rtems_filesystem_file_handlers_r can_bus_handler = {
+ .open_h = can_bus_open,
+ .close_h = rtems_filesystem_default_close,
+ .read_h = can_bus_read,
+ .write_h = can_bus_write,
+ .ioctl_h = can_bus_ioctl,
+ .lseek_h = rtems_filesystem_default_lseek,
+ .fstat_h = IMFS_stat,
+ .ftruncate_h = rtems_filesystem_default_ftruncate,
+ .fsync_h = rtems_filesystem_default_fsync_or_fdatasync,
+ .fdatasync_h = rtems_filesystem_default_fsync_or_fdatasync,
+ .fcntl_h = rtems_filesystem_default_fcntl,
+ .kqfilter_h = rtems_filesystem_default_kqfilter,
+ .mmap_h = rtems_filesystem_default_mmap,
+ .poll_h = rtems_filesystem_default_poll,
+ .readv_h = rtems_filesystem_default_readv,
+ .writev_h = rtems_filesystem_default_writev
+};
+
+static void can_bus_node_destroy(IMFS_jnode_t *node)
+{
+ can_bus *bus;
+
+ bus = IMFS_generic_get_context_by_node(node);
+ (*bus->destroy)(bus);
+
+ IMFS_node_destroy_default(node);
+}
+
+static const
+IMFS_node_control can_bus_node_control = IMFS_GENERIC_INITIALIZER(&can_bus_handler,
+ IMFS_node_initialize_generic, can_bus_node_destroy);
+
+rtems_status_code can_bus_register(can_bus *bus, const char *bus_path)
+{
+ int ret = RTEMS_SUCCESSFUL;
+
+ static uint8_t index = 0;
+
+ if (index == 255) {
+ printf("can_bus_register: can bus registration limit reached\n");
+ return RTEMS_TOO_MANY;
+ }
+
+ bus->index = index++;
+ CAN_DEBUG("Registering CAN bus index = %u\n", bus->index);
+
+ ret = IMFS_make_generic_node(bus_path, S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO,
+ &can_bus_node_control, bus);
+ if (ret != RTEMS_SUCCESSFUL) {
+ printf("can_bus_register: Creating node failed = %d\n", ret);
+ goto fail;
+ }
+
+ if ((ret = can_create_sem(bus)) != RTEMS_SUCCESSFUL) {
+ printf("can_bus_register: can_create_sem failed = %d\n", ret);
+ goto fail;
+ }
+
+ if ((ret = can_create_tx_buffers(bus)) != RTEMS_SUCCESSFUL) {
+ printf("can_bus_register: can_create_tx_buffers failed = %d\n", ret);
+ goto fail;
+ }
+
+ if ((ret = can_create_rx_buffers(bus)) != RTEMS_SUCCESSFUL) {
+ printf("can_bus_register: can_create_rx_buffers failed = %d\n", ret);
+ goto free_tx_buffers_return;
+ }
+
+ return ret;
+
+free_tx_buffers_return:
+ free(bus->tx_fifo.pbuf);
+
+fail:
+ (*bus->destroy)(bus);
+ return ret;
+
+}
+
+static void can_bus_destroy(can_bus *bus)
+{
+ rtems_recursive_mutex_destroy(&bus->mutex);
+}
+
+static int can_bus_do_init(can_bus *bus, void (*destroy)(can_bus *bus))
+{
+ rtems_recursive_mutex_init(&bus->mutex, "CAN Bus");
+ bus->destroy = can_bus_destroy;
+
+ return RTEMS_SUCCESSFUL;
+}
+
+static void can_bus_destroy_and_free(can_bus *bus)
+{
+ can_bus_destroy(bus);
+ free(bus);
+}
+
+int can_bus_init(can_bus *bus)
+{
+ memset(bus, 0, sizeof(*bus));
+
+ return can_bus_do_init(bus, can_bus_destroy);
+}
+
+can_bus *can_bus_alloc_and_init(size_t size)
+{
+ can_bus *bus = NULL;
+
+ if (size >= sizeof(*bus)) {
+ bus = calloc(1, size);
+ if (bus == NULL) {
+ printf("can_bus_alloc_and_init: calloc failed\b");
+ return NULL;
+ }
+
+ int rv = can_bus_do_init(bus, can_bus_destroy_and_free);
+ if (rv != 0) {
+ printf("can_bus_alloc_and_init: can_bus_do_init failed\n");
+ return NULL;
+ }
+ }
+ return bus;
+}
diff --git a/cpukit/include/dev/can/can-msg.h b/cpukit/include/dev/can/can-msg.h
new file mode 100644
index 0000000000..5c79b91600
--- /dev/null
+++ b/cpukit/include/dev/can/can-msg.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup CANBus
+ *
+ * @brief Controller Area Network (CAN) Bus Implementation
+ *
+ */
+
+/*
+ * Copyright (C) 2022 Prashanth S <fishesprashanth at 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_MSG_H
+#define _DEV_CAN_CAN_MSG_H
+
+#define CAN_MSG_MAX_SIZE (8u)
+
+#define CAN_TX_BUF_COUNT (2u)
+#define CAN_RX_BUF_COUNT (2u)
+
+#define CAN_MSGLEN(msg) (sizeof(struct can_msg) - (CAN_MSG_MAX_SIZE - msg->len))
+
+struct can_msg {
+ uint32_t id; // 32 bits to support extended id (29 bits).
+ uint32_t timestamp;
+ uint16_t flags; // RTR | BRS | EXT ...
+ uint16_t len;
+ uint8_t data[CAN_MSG_MAX_SIZE]; // For supporting data transfer up to 64 bytes.
+};
+
+#endif /* _DEV_CAN_CAN_MSG_H */
diff --git a/cpukit/include/dev/can/can-queue.h b/cpukit/include/dev/can/can-queue.h
new file mode 100644
index 0000000000..c018441320
--- /dev/null
+++ b/cpukit/include/dev/can/can-queue.h
@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup CANBus
+ *
+ * @brief Controller Area Network (CAN) Bus Implementation
+ *
+ */
+
+/*
+ * Copyright (C) 2022 Prashanth S <fishesprashanth at 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_QUEUE_H
+#define _DEV_CAN_CAN_QUEUE_H
+
+#include <rtems/imfs.h>
+#include <rtems/thread.h>
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <dev/can/can-msg.h>
+#include <dev/can/can.h>
+
+static rtems_status_code can_create_tx_buffers(struct can_bus *bus);
+static rtems_status_code can_create_rx_buffers(struct can_bus *bus);
+static bool can_tx_buf_isempty(struct can_bus *bus);
+static struct can_msg *can_tx_get_data_buf(struct can_bus *bus);
+static struct can_msg *can_tx_get_empty_buf(struct can_bus *bus);
+
+static rtems_status_code can_create_rx_buffers(struct can_bus *bus)
+{
+ return rtems_message_queue_create(rtems_build_name('c', 'a', 'n', bus->index),
+ CAN_RX_BUF_COUNT, sizeof(struct can_msg),
+ RTEMS_FIFO | RTEMS_LOCAL, &bus->rx_queue_id);
+}
+
+static rtems_status_code can_create_tx_buffers(struct can_bus *bus)
+{
+ bus->tx_fifo.pbuf = (struct can_msg *)malloc(CAN_TX_BUF_COUNT *
+ sizeof(struct can_msg));
+ if (bus->tx_fifo.pbuf == NULL) {
+ printf("can_create_tx_buffers: malloc failed\n");
+ return RTEMS_NO_MEMORY;
+ }
+
+ bus->tx_fifo.empty_count = CAN_TX_BUF_COUNT;
+
+ return RTEMS_SUCCESSFUL;
+}
+
+static bool can_tx_buf_isempty(struct can_bus *bus)
+{
+ if (bus->tx_fifo.empty_count == 0) {
+ return false;
+ }
+
+ return true;
+}
+
+// TODO: free the given data buf is done in the same function
+// SO the returned buffer should be consumed before releasing the
+// lock acquired while calling this function.
+static struct can_msg *can_tx_get_data_buf(struct can_bus *bus)
+{
+ struct can_msg *msg = NULL;
+
+ if (bus->tx_fifo.empty_count == CAN_TX_BUF_COUNT) {
+ CAN_DEBUG_BUF("can_tx_get_data_buf: All buffers are empty\n");
+ return NULL;
+ }
+
+ msg = &bus->tx_fifo.pbuf[bus->tx_fifo.tail];
+ bus->tx_fifo.empty_count++;
+ bus->tx_fifo.tail = (bus->tx_fifo.tail + 1) % CAN_TX_BUF_COUNT;
+
+ return msg;
+}
+
+// TODO: marking the given buf as produced is done in the same function
+// So the returned buffer should be produced before releasing the
+// lock acquired while calling this function.
+static struct can_msg *can_tx_get_empty_buf(struct can_bus *bus)
+{
+ struct can_msg *msg = NULL;
+
+ /* Check whether there is a empty CAN msg buffer */
+ if (can_tx_buf_isempty(bus) == false) {
+ CAN_DEBUG_BUF("can_tx_get_empty_buf: No empty buffer\n");
+ return NULL;
+ }
+
+ bus->tx_fifo.empty_count--;
+
+ /* tx_fifo.head always points to a empty buffer if there is atleast one */
+ msg = &bus->tx_fifo.pbuf[bus->tx_fifo.head];
+ bus->tx_fifo.head = (bus->tx_fifo.head + 1) % CAN_TX_BUF_COUNT;
+
+ return msg;
+}
+
+#endif /*_DEV_CAN_CAN_QUEUE_H */
diff --git a/cpukit/include/dev/can/can.h b/cpukit/include/dev/can/can.h
new file mode 100644
index 0000000000..eeb2eb2c0b
--- /dev/null
+++ b/cpukit/include/dev/can/can.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup CANBus
+ *
+ * @brief Controller Area Network (CAN) Bus Implementation
+ *
+ */
+
+/*
+ * Copyright (C) 2022 Prashanth S (fishesprashanth at 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 CAN_DEBUG(str, ...) printf(str, ##__VA_ARGS__)
+#define CAN_DEBUG_BUF(str, ...) printf(str, ##__VA_ARGS__)
+#define CAN_DEBUG_ISR(str, ...) printf(str, ##__VA_ARGS__)
+#define CAN_DEBUG_LOCK(str, ...) printf(str, ##__VA_ARGS__)
+#define CAN_DEBUG_RX(str, ...) printf(str, ##__VA_ARGS__)
+#define CAN_DEBUG_TX(str, ...) printf(str, ##__VA_ARGS__)
+
+struct ring_buf {
+ struct can_msg *pbuf;
+ uint32_t head;
+ uint32_t tail;
+ uint32_t empty_count;
+};
+
+typedef struct can_dev_ops {
+ int32_t (*dev_rx)(void *priv, void *buffer);
+ int32_t (*dev_tx)(void *priv, void *buffer);
+ bool (*dev_tx_ready)(void *priv);
+ void (*dev_int)(void *priv, bool);
+ int32_t (*dev_ioctl)(void *priv, void *buffer, size_t cmd);
+} can_dev_ops;
+
+typedef struct can_bus {
+ void *priv; // CAN controller specific struct.
+ uint8_t index;
+ struct can_dev_ops *can_dev_ops; // CAN controller operations.
+
+ struct ring_buf tx_fifo; // TX fifo
+ rtems_id tx_fifo_sem_id; // TX fifo counting semaphore id
+ uint32_t can_tx_buf_waiters;
+
+ rtems_id rx_queue_id;
+ uint32_t rx_queue_name;
+
+ rtems_recursive_mutex mutex; // For handling driver concurrency.
+ RTEMS_INTERRUPT_LOCK_MEMBER(can_bus_lock);
+
+ void (*destroy)(struct can_bus *bus); // Clean the CAN controller specific resources.
+} can_bus;
+
+extern rtems_status_code can_bus_register(can_bus *bus, const char *bus_path);
+
+extern can_bus *can_bus_alloc_and_init(size_t size);
+extern int can_bus_init(can_bus *bus);
+extern int can_tx_done(struct can_bus *);
+extern int can_receive(struct can_bus *, struct can_msg *);
+
+extern uint16_t can_len_to_dlc(uint16_t len);
+extern uint16_t can_dlc_to_len(uint16_t dlc);
+
+extern void can_print_msg(struct can_msg const *);
+
+#endif /* _DEV_CAN_CAN_H */
diff --git a/spec/build/cpukit/librtemscpu.yml b/spec/build/cpukit/librtemscpu.yml
index 31a68cf85a..b7f6c0457c 100644
--- a/spec/build/cpukit/librtemscpu.yml
+++ b/spec/build/cpukit/librtemscpu.yml
@@ -50,6 +50,11 @@ install:
- destination: ${BSP_INCLUDEDIR}/dev/spi
source:
- cpukit/include/dev/spi/spi.h
+- destination: ${BSP_INCLUDEDIR}/dev/can
+ source:
+ - cpukit/include/dev/can/can.h
+ - cpukit/include/dev/can/can-msg.h
+ - cpukit/include/dev/can/can-queue.h
- destination: ${BSP_INCLUDEDIR}/linux
source:
- cpukit/include/linux/i2c-dev.h
@@ -530,6 +535,7 @@ source:
- cpukit/dev/serial/sc16is752-spi.c
- cpukit/dev/serial/sc16is752.c
- cpukit/dev/spi/spi-bus.c
+- cpukit/dev/can/can.c
- cpukit/dtc/libfdt/fdt.c
- cpukit/dtc/libfdt/fdt_addresses.c
- cpukit/dtc/libfdt/fdt_empty_tree.c
--
2.25.1
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