cpukit/dev/can: Added CAN support

1 files changed, 231 insertions, 0 deletions

diff --git a/cpukit/include/dev/can/canqueueimpl.h b/cpukit/include/dev/can/canqueueimpl.h
new file mode 100644
index 0000000000..ef0d56fe31
--- /dev/null
+++ b/cpukit/include/dev/can/canqueueimpl.h
@@ -0,0 +1,231 @@
+/* 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.
+ */
+
+#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>
+
+/**
+ * @defgroup Controller Area Network (CAN) Driver
+ *
+ * @ingroup RTEMSDeviceDrivers
+ *
+ * @brief Controller Area Network (CAN) bus and device driver support.
+ *
+ * @{
+ */
+
+/**
+ * @defgroup CANBus CAN Bus Driver
+ *
+ * @ingroup CAN
+ *
+ * @{
+ */
+
+/**
+ * @brief Create CAN tx buffers.
+ *
+ * @param[in] bus Bus control structure.
+ *
+ * @retval 0 Successful operation.
+ * @retval >0 error number in case of an error.
+ */
+static rtems_status_code can_bus_create_tx_buffers(struct can_bus *bus);
+
+/**
+ * @brief Free CAN tx buffers.
+ *
+ * @param[in] bus Bus control structure.
+ *
+ */
+static void can_bus_free_tx_buffers(struct can_bus *bus);
+
+/**
+ * @brief Check for atleast one empty CAN tx buffer.
+ *
+ * @param[in] bus Bus control structure.
+ *
+ * @retval true If atleast one CAN buffer is empty.
+ * @retval false If no CAN buffer is empty.
+ */
+static bool can_bus_tx_buf_is_empty(struct can_bus *bus);
+
+/**
+ * @brief Get a produced tx buffer to transmit from the tx fifo.
+ *
+ * @param[in] bus Bus control structure.
+ *
+ * @retval can_msg Pointer to can_msg structure buffer.
+ * @retval NULL If no can_msg buffer.
+ */
+static struct can_msg *can_bus_tx_get_data_buf(struct can_bus *bus);
+
+/**
+ * @brief Get a empty tx buffer.
+ *
+ * @param[in] bus Bus control structure.
+ *
+ * @retval can_msg Pointer to can_msg structure buffer.
+ * @retval NULL If no empty can_msg buffer.
+ */
+static struct can_msg *can_bus_tx_get_empty_buf(struct can_bus *bus);
+
+/**
+ * @brief Creates tx buffers for the CAN bus driver.
+ *
+ * @param[in] bus Bus control structure.
+ *
+ * @retval rtems_status_code
+ */
+static rtems_status_code can_bus_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) {
+    CAN_ERR("can_create_tx_buffers: malloc failed\n");
+    return RTEMS_NO_MEMORY;
+  }
+
+  bus->tx_fifo.empty_count = CAN_TX_BUF_COUNT;
+
+  return RTEMS_SUCCESSFUL;
+}
+
+/**
+ * @brief Free tx buffers for the CAN bus driver.
+ *
+ * @param[in] bus Bus control structure.
+ *
+ */
+static void can_bus_free_tx_buffers(struct can_bus *bus)
+{
+  free(bus->tx_fifo.pbuf);
+}
+
+/**
+ * @brief Check if there is atleast one tx buffer in the CAN
+ * bus driver.
+ *
+ * @param[in] bus Bus control structure.
+ *
+ * @retval true - If there is at least one free tx buffer.
+ *         false - If there is no free tx buffer.
+ */
+static bool can_bus_tx_buf_is_empty(struct can_bus *bus)
+{
+  if (bus->tx_fifo.empty_count == 0) {
+    return false;
+  }
+
+  return true;
+}
+
+/**
+ * @brief To get a can_msg tx buf which contains valid data to send in 
+ * in the CAN bus.
+ *
+ * Note: freeing the returned data buf is done in the same function,
+ * So the returned buffer should be sent before releasing the
+ * lock acquired while calling this function.
+ *
+ * @param[in] bus Bus control structure.
+ *
+ * @retval *can_msg - If there is atleast one tx buffer to send in the CAN bus.
+ *         NULL - If there is no valid tx buffer.
+ */
+static struct can_msg *can_bus_tx_get_data_buf(struct can_bus *bus)
+{
+  struct can_msg *msg = NULL;
+
+  if (bus->tx_fifo.empty_count == CAN_TX_BUF_COUNT || 
+                                    bus->tx_fifo.tail >= CAN_TX_BUF_COUNT) {
+    CAN_DEBUG_BUF("can_bus_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;
+}
+    
+/**
+ * @brief To get a can_msg tx buf which is empty (contains no valid data).
+ *
+ * Note: marking the returned buf valid is done in the same function
+ * So a valid CAN message should be copied to the returned buffer before
+ * releasing the lock acquired while calling this function.
+ *
+ * @param[in] bus Bus control structure.
+ *
+ * @retval *can_msg - If there is atleast one empty tx buffer.
+ *         NULL - If there is no empty tx buffer.
+ */
+static struct can_msg *can_bus_tx_get_empty_buf(struct can_bus *bus)
+{
+  struct can_msg *msg = NULL;
+
+  /* Check whether there is a empty CAN msg buffer */
+  if (can_bus_tx_buf_is_empty(bus) == false) {
+    CAN_DEBUG_BUF("can_bus_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;
+}
+
+/** @} */  /* end of CAN device driver */
+
+/** @} */
+
+#endif /*_DEV_CAN_CAN_QUEUE_H */