From cd91b37dce728b372f164355719a4e601e12e7b3 Mon Sep 17 00:00:00 2001 From: Prashanth S Date: Sun, 7 Aug 2022 19:23:13 +0530 Subject: cpukit/dev/can: Added CAN support --- cpukit/dev/can/can.c | 505 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 505 insertions(+) create mode 100644 cpukit/dev/can/can.c (limited to 'cpukit/dev') diff --git a/cpukit/dev/can/can.c b/cpukit/dev/can/can.c new file mode 100644 index 0000000000..2e6d5df65b --- /dev/null +++ b/cpukit/dev/can/can.c @@ -0,0 +1,505 @@ +/* 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. + */ + +#include +#include + +#include + +#include +#include + +#include +#include + +#define can_interrupt_lock_acquire(bus) \ + do { \ + CAN_DEBUG_LOCK("acquiring lock\n"); \ + real_can_interrupt_lock_acquire(bus); \ + } while (0); + +#define can_interrupt_lock_release(bus) \ + do { \ + CAN_DEBUG_LOCK("releasing lock\n"); \ + real_can_interrupt_lock_release(bus); \ + } while (0); + +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_bus_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 *); + + +static void can_bus_obtain(can_bus *bus) +{ + CAN_DEBUG("can_bus_obtain Entry\n"); + rtems_mutex_lock(&bus->mutex); + CAN_DEBUG("can_bus_obtain Exit\n"); +} + +static void can_bus_release(can_bus *bus) +{ + CAN_DEBUG("can_bus_release Entry\n"); + rtems_mutex_unlock(&bus->mutex); + CAN_DEBUG("can_bus_release Exit\n"); +} + +static void can_bus_destroy_mutex(struct can_bus *bus) +{ + rtems_mutex_destroy(&bus->mutex); +} + +static int can_bus_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) { + CAN_ERR("can_create_sem: rtems_semaphore_create failed %d\n", ret); + } + + return ret; +} + +static void can_bus_free_tx_semaphore(struct can_bus *bus) +{ + rtems_semaphore_delete(bus->tx_fifo_sem_id); +} + +static void real_can_interrupt_lock_acquire(struct can_bus *bus) +{ + bus->can_dev_ops->dev_int(bus->priv, false); + can_bus_obtain(bus); +} + +static void real_can_interrupt_lock_release(struct can_bus *bus) +{ + can_bus_release(bus); + bus->can_dev_ops->dev_int(bus->priv, true); +} + +static int take_sem(struct can_bus *bus) +{ + int ret = rtems_semaphore_obtain(bus->tx_fifo_sem_id, RTEMS_WAIT, + RTEMS_NO_TIMEOUT); +#ifdef CAN_DEBUG_LOCK + if (ret == RTEMS_SUCCESSFUL) { + bus->sem_count++; + CAN_DEBUG_LOCK("take_sem: Semaphore count = %d\n", bus->sem_count); + if (bus->sem_count > CAN_TX_BUF_COUNT) { + CAN_ERR("take_sem error: sem_count is misleading\n"); + return RTEMS_INTERNAL_ERROR; + } + } +#endif /* CAN_DEBUG_LOCK */ + + return ret; +} + +static int give_sem(struct can_bus *bus) +{ + int ret = rtems_semaphore_release(bus->tx_fifo_sem_id); + +#ifdef CAN_DEBUG_LOCK + if (ret == RTEMS_SUCCESSFUL) { + bus->sem_count--; + CAN_DEBUG_LOCK("give_sem: Semaphore count = %d\n", bus->sem_count); + if (bus->sem_count < 0) { + CAN_ERR("give_sem error: sem_count is misleading\n"); + return RTEMS_INTERNAL_ERROR; + } + } +#endif /* CAN_DEBUG_LOCK */ + + 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); +#ifdef CAN_DEBUG_LOCK + if (ret == RTEMS_SUCCESSFUL) { + bus->sem_count++; + CAN_DEBUG_LOCK("try_sem: Semaphore count = %d\n", bus->sem_count); + if (bus->sem_count > CAN_TX_BUF_COUNT) { + CAN_ERR("take_sem error: sem_count is misleading\n"); + return RTEMS_INTERNAL_ERROR; + } + } +#endif /* CAN_DEBUG_LOCK */ + + return ret; +} + +static ssize_t +can_bus_open(rtems_libio_t *iop, const char *path, int oflag, mode_t mode) +{ + CAN_DEBUG("can_bus_open\n"); + + return 0; +} + +/* Should be called only with CAN interrupts disabled */ +int can_receive(struct can_bus *bus, struct can_msg *msg) +{ + memcpy(&bus->can_rx_msg, msg, CAN_MSG_LEN(msg)); + + return CAN_MSG_LEN(msg); +} + +/* FIXME: Should be modified to read count number of bytes, Now sending one can_msg */ +static ssize_t can_bus_read(rtems_libio_t *iop, void *buffer, size_t count) +{ + int len; + + can_bus *bus = IMFS_generic_get_context_by_iop(iop); + if (bus == NULL) { + return -RTEMS_NOT_DEFINED; + } + + struct can_msg *msg = (struct can_msg *)buffer; + + len = CAN_MSG_LEN(&bus->can_rx_msg); + + if (count < len) { + CAN_DEBUG("can_bus_read: buffer size is small min sizeof(struct can_msg) = %u\n", + sizeof(struct can_msg)); + return -RTEMS_INVALID_SIZE; + } + + can_interrupt_lock_acquire(bus); + memcpy(msg, &bus->can_rx_msg, len); + can_interrupt_lock_release(bus); + + return len; +} + +/* This function is a critical section and should be called + * with CAN interrupts disabled and mutually exclusive + */ +static int can_xmit(struct can_bus *bus) +{ + int ret = RTEMS_SUCCESSFUL; + + struct can_msg *msg = NULL; + + CAN_DEBUG(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> can_xmit Entry\n"); + + while (1) { + CAN_DEBUG("can_dev_ops->dev_tx_ready\n"); + if (bus->can_dev_ops->dev_tx_ready(bus->priv) != true) { + break; + } + + CAN_DEBUG("can_tx_get_data_buf\n"); + msg = can_bus_tx_get_data_buf(bus); + if (msg == NULL) { + break; + } + + CAN_DEBUG("can_dev_ops->dev_tx\n"); + ret = bus->can_dev_ops->dev_tx(bus->priv, msg); + if (ret != RTEMS_SUCCESSFUL) { + CAN_ERR("can_xmit: dev_send failed\n"); + break; + } + + ret = give_sem(bus); + if (ret != RTEMS_SUCCESSFUL) { + CAN_ERR("can_xmit: rtems_semaphore_release failed = %d\n", ret); + break; + } + } + + CAN_DEBUG(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> can_xmit Exit\n"); + + return ret; +} + +void can_print_msg(struct can_msg const *msg) +{ +#ifdef CAN_DEBUG + CAN_DEBUG("\n----------------------------------------------------------------\n"); + CAN_DEBUG("id = %d len = %d flags = 0x%08X\n", msg->id, msg->len, msg->flags); + + CAN_DEBUG("msg->data[0] = 0x%08x\n", ((uint32_t *)msg->data)[0]); + CAN_DEBUG("msg->data[1] = 0x%08x\n", ((uint32_t *)msg->data)[1]); + + for (int i = 0; i < msg->len; i++) { + CAN_DEBUG("%02x\n", ((char *)msg->data)[i]); + } + + CAN_DEBUG("\n-----------------------------------------------------------------\n"); +#endif /* CAN_DEBUG */ +} + +/* can_tx_done should be called only with CAN interrupts disabled */ +int can_tx_done(struct can_bus *bus) +{ + CAN_DEBUG("------------ can_tx_done Entry\n"); + int ret = RTEMS_SUCCESSFUL; + + if (bus->can_dev_ops->dev_tx_ready(bus->priv) == true) { + ret = can_xmit(bus); + } + CAN_DEBUG("------------ can_tx_done Exit\n"); + + return ret; +} + +/* FIXME: Add support to send multiple CAN msgs for can_bus_write */ +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; + } + + int ret = RTEMS_SUCCESSFUL; + + struct can_msg const *msg = buffer; + struct can_msg *fifo_buf = NULL; + + uint32_t msg_size = CAN_MSG_LEN(msg); + + CAN_DEBUG_TX("can_bus_write: can_msg_size = %u\n", msg_size); + if (msg_size > sizeof(struct can_msg)) { + CAN_ERR("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; + } + + if ((iop->flags & O_NONBLOCK) != 0) { + ret = try_sem(bus); + if (ret != RTEMS_SUCCESSFUL) { + return -ret; + } + } else { + ret = take_sem(bus); + if (ret != RTEMS_SUCCESSFUL) { + CAN_ERR("can_bus_write: cannot take semaphore\n"); + return -ret; + } + } + + can_interrupt_lock_acquire(bus); + + fifo_buf = can_bus_tx_get_empty_buf(bus); + if (fifo_buf == NULL) { + /* This error will not happen until buffer counts are not synchronized */ + CAN_ERR("can_bus_write: Buffer counts are not synchronized with semaphore count\n"); + ret = -RTEMS_INTERNAL_ERROR; + goto release_lock_and_return; + } + + CAN_DEBUG_TX("can_bus_write: empty_count = %u\n", bus->tx_fifo.empty_count); + + CAN_DEBUG_TX("can_bus_write: copying msg from application to driver buffer\n"); + memcpy(fifo_buf, msg, msg_size); + + if (bus->can_dev_ops->dev_tx_ready(bus->priv) == true) { + ret = can_xmit(bus); + if (ret != RTEMS_SUCCESSFUL) { + ret = -ret; + goto release_lock_and_return; + } + } + + ret = msg_size; + +release_lock_and_return: + can_interrupt_lock_release(bus); + 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 == CAN_BUS_REG_MAX) { + CAN_ERR("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) { + CAN_ERR("can_bus_register: Creating node failed = %d\n", ret); + goto fail; + } + + if ((ret = can_bus_create_sem(bus)) != RTEMS_SUCCESSFUL) { + CAN_ERR("can_bus_register: can_create_sem failed = %d\n", ret); + goto fail; + } + + if ((ret = can_bus_create_tx_buffers(bus)) != RTEMS_SUCCESSFUL) { + CAN_ERR("can_bus_register: can_create_tx_buffers failed = %d\n", ret); + goto free_tx_semaphore; + } + + return ret; + +free_tx_semaphore: + rtems_semaphore_delete(bus->tx_fifo_sem_id); + +fail: + can_bus_destroy_mutex(bus); + return ret; + +} + +static void can_bus_destroy(can_bus *bus) +{ + can_bus_free_tx_buffers(bus); + can_bus_free_tx_semaphore(bus); + can_bus_destroy_mutex(bus); +} + +static int can_bus_do_init(can_bus *bus, void (*destroy)(can_bus *bus)) +{ + rtems_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) { + CAN_ERR("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) { + CAN_ERR("can_bus_alloc_and_init: can_bus_do_init failed\n"); + return NULL; + } + } + return bus; +} -- cgit v1.2.3