Diff: noos_mbed/util/circular_buffer.c

Revision:

0:e8a1ba50c46b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/noos_mbed/util/circular_buffer.c	Thu Jan 14 19:12:57 2021 +0530
@@ -0,0 +1,412 @@
+/***************************************************************************//**
+ *   @file   circular_buffer.c
+ *   @brief  Circular buffer implementation
+ *   @author Mihail Chindris (mihail.chindris@analog.com)
+********************************************************************************
+ *   @copyright
+ * Copyright 2020(c) Analog Devices, Inc.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - 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.
+ *  - Neither the name of Analog Devices, Inc. nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *  - The use of this software may or may not infringe the patent rights
+ *    of one or more patent holders.  This license does not release you
+ *    from the requirement that you obtain separate licenses from these
+ *    patent holders to use this software.
+ *  - Use of the software either in source or binary form, must be run
+ *    on or directly connected to an Analog Devices Inc. component.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, 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 Files **********************************/
+/******************************************************************************/
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include "circular_buffer.h"
+#include "error.h"
+#include "util.h"
+
+/******************************************************************************/
+/*************************** Types Declarations *******************************/
+/******************************************************************************/
+
+/**
+ * @struct cb_ptr
+ * @brief Circular buffer pointer
+ */
+struct cb_ptr {
+	/** Index of data in the buffer */
+	uint32_t	idx;
+	/** Counts the number of times idx exceeds the liniar buffer */
+	uint32_t	spin_count;
+	/** Set if async transaction is active */
+	bool		async_started;
+	/** Number of bytes to update after an async transaction is finished */
+	uint32_t	async_size;
+};
+
+/**
+ * @struct circular_buffer
+ * @brief Circular buffer descriptor
+ */
+struct circular_buffer {
+	/** Size of the buffer in bytes */
+	uint32_t	size;
+	/** Address of the buffer */
+	int8_t		*buff;
+	/** Write pointer */
+	struct cb_ptr	write;
+	/** Read pointer */
+	struct cb_ptr	read;
+};
+
+/******************************************************************************/
+/************************ Functions Definitions *******************************/
+/******************************************************************************/
+
+/**
+ * @brief Create circular buffer structure
+ *
+ * @note Circular buffer implementation is thread safe for one write
+ * and one reader.
+ * If multiple writer or multiple readers access the circular buffer then
+ * function that updates the structure should be called inside a critical
+ * critical section.
+ *
+ * @param desc - Where to store the circular buffer reference
+ * @param buff_size - Buffer size
+ * @return
+ *  - \ref SUCCESS : On success
+ *  - \ref FAILURE : Otherwise
+ */
+int32_t cb_init(struct circular_buffer **desc, uint32_t buff_size)
+{
+	struct circular_buffer	*ldesc;
+
+	if (!desc || !buff_size)
+		return -EINVAL;
+
+	ldesc = (struct circular_buffer*)calloc(1, sizeof(*ldesc));
+	if (!ldesc)
+		return -ENOMEM;
+
+	*desc = ldesc;
+
+	ldesc->size = buff_size;
+	ldesc->buff = calloc(1, buff_size);
+	if (!ldesc->buff) {
+		free(ldesc);
+		return -ENOMEM;
+	}
+
+	return SUCCESS;
+}
+
+/**
+ * @brief Free the resources allocated for the circular buffer structure
+ * @param desc - Circular buffer reference
+ * @return
+ *  - \ref SUCCESS : On success
+ *  - \ref FAILURE : Otherwise
+ */
+int32_t cb_remove(struct circular_buffer *desc)
+{
+	if (!desc)
+		return FAILURE;
+
+	if (desc->buff)
+		free(desc->buff);
+	free(desc);
+
+	return SUCCESS;
+}
+
+/**
+ * @brief Get the number of elements in the buffer
+ * @param desc - Circular buffer reference
+ * @param size - Where to store size of data available to read
+ * @return
+ *  - \ref SUCCESS   - No errors
+ *  - -EINVAL   - Wrong parameters used
+ *  - -EOVERRUN - A buffer overrun occurred
+ */
+int32_t cb_size(struct circular_buffer *desc, uint32_t *size)
+{
+	uint32_t nb_spins;
+
+	if (!desc || !size)
+		return -EINVAL;
+
+	if (desc->write.spin_count > desc->read.spin_count)
+		nb_spins = desc->write.spin_count - desc->read.spin_count;
+	else
+		/* Integer overflow on desc->write.spin_count */
+		nb_spins = UINT32_MAX - desc->read.spin_count +
+			   desc->write.spin_count + 1;
+
+	if (nb_spins > 0)
+		*size = desc->size + desc->write.idx - desc->read.idx;
+	else
+		*size = desc->write.idx - desc->read.idx;
+
+	if (*size > desc->size) {
+		*size = desc->size;
+		return -EOVERRUN;
+	}
+
+	return SUCCESS;
+}
+
+/*
+ * Functionality described at cb_prepare_async_write/read having the is_read
+ * parameter to specifiy if it is a read or write operation
+ */
+static int32_t cb_prepare_async_operation(struct circular_buffer *desc,
+		uint32_t requested_size,
+		void **buff,
+		uint32_t *raw_size_available,
+		bool is_read)
+{
+	struct cb_ptr	*ptr;
+	uint32_t	available_size;
+	uint32_t	ret;
+
+	if (!desc || !buff || !raw_size_available)
+		return -EINVAL;
+
+	ret = SUCCESS;
+	/* Select if read or write index will be updated */
+	ptr = is_read ? &desc->read : &desc->write;
+
+	/* Only one transaction type possible at a single time */
+	if (ptr->async_started)
+		return -EBUSY;
+
+	if (is_read) {
+		ret = cb_size(desc, &available_size);
+		if (ret == -EOVERRUN) {
+			/* Update read index */
+			desc->read.spin_count = desc->write.spin_count - 1;
+			desc->read.idx = desc->write.idx;
+		}
+
+		/* We can only read available data */
+		requested_size = min(requested_size, available_size);
+		if (!requested_size)
+			return -EAGAIN;
+	}
+
+	/* Size to end of buffer */
+	ptr->async_size = min(requested_size, desc->size - ptr->idx);
+
+	*raw_size_available = ptr->async_size;
+
+	/* Convert index to address in the buffer */
+	*buff = (void *)(desc->buff + ptr->idx);
+
+	ptr->async_started = true;
+
+	return ret;
+}
+
+/*
+ * Functionality described at cb_end_async_write/read having the is_read
+ * parameter to specifiy if it is a read or write operation
+ */
+static int32_t cb_end_async_operation(struct circular_buffer *desc,
+				      bool is_read)
+{
+	struct cb_ptr	*ptr;
+	uint32_t	new_val;
+
+
+	if (!desc)
+		return -EINVAL;
+
+	/* Select if read or write index will be updated */
+	ptr = is_read ? &desc->read : &desc->write;
+
+	/* Transaction not started */
+	if (!ptr->async_started)
+		return FAILURE;
+
+	/* Update pointer value */
+	new_val = ptr->idx + ptr->async_size;
+	if (new_val >= desc->size) {
+		ptr->spin_count++;
+		new_val %= desc->size;
+	}
+	ptr->idx = new_val;
+	ptr->async_size = 0;
+	ptr->async_started = false;
+
+	return SUCCESS;
+}
+
+/*
+ * Functionality described at cb_write/read having the is_read
+ * parameter to specifiy if it is a read or write operation
+ */
+static int32_t cb_operation(struct circular_buffer *desc,
+			    void *data, uint32_t size,
+			    bool is_read)
+{
+	uint8_t		*buff;
+	uint32_t	available_size;
+	int32_t		ret;
+	uint32_t	i;
+	bool		sticky_overrun;
+
+	if (!desc || !data || !size)
+		return -EINVAL;
+
+	sticky_overrun = 0;
+	i = 0;
+	while (i < size) {
+		do {
+			ret = cb_prepare_async_operation(desc, size - i,
+							 (void **)&buff,
+							 &available_size,
+							 is_read);
+		} while (ret == -EBUSY || ret == -EAGAIN);
+		if (ret == -EOVERRUN)
+			sticky_overrun = true;
+
+		if (is_read)
+			memcpy((uint8_t *)data + i, buff, available_size);
+		else
+			memcpy(buff, (uint8_t *)data + i, available_size);
+
+		cb_end_async_operation(desc, is_read);
+
+		i += available_size;
+	}
+
+	if (sticky_overrun)
+		return -EOVERRUN;
+
+	return SUCCESS;
+}
+
+/**
+ * @brief Prepare asynchronous write
+ *
+ * Get the inside raw buffer to be used in DMA transactions.
+ *
+ * @param desc - Circular buffer reference
+ * @param size_to_write - Number of bytes needed to write to the buffer.
+ * @param write_buff - Address where to store the buffer where to write to.
+ * @param size_avilable - min(size_to_write, size until end of allocated buffer)
+ * @return
+ *  - \ref SUCCESS   - No errors
+ *  - -EINVAL   - Wrong parameters used
+ *  - -EBUSY    - Asynchronous transaction already started
+ */
+int32_t cb_prepare_async_write(struct circular_buffer *desc,
+			       uint32_t size_to_write,
+			       void **write_buff,
+			       uint32_t *size_avilable)
+{
+	return cb_prepare_async_operation(desc, size_to_write, write_buff,
+					  size_avilable, 0);
+}
+
+/**
+ * @brief Prepare asynchronous read
+ *
+ * Get the inside raw buffer to be used in DMA transactions.
+ *
+ * @param desc - Circular buffer reference
+ * @param size_to_read - Number of bytes needed to write to the buffer.
+ * @param read_buff - Address where to store the buffer where data will be read.
+ * @param size_avilable - min(size_to_read, size until end of allocated buffer)
+ * @return
+ *  - \ref SUCCESS   - No errors
+ *  - -EAGAIN   - No data available at this moment
+ *  - -EINVAL   - Wrong parameters used
+ *  - -EBUSY    - Asynchronous transaction already started
+ *  - -EOVERRUN - An overrun occurred and some data have been overwritten
+ */
+int32_t cb_prepare_async_read(struct circular_buffer *desc,
+			      uint32_t size_to_read,
+			      void **read_buff,
+			      uint32_t *size_avilable)
+{
+	return cb_prepare_async_operation(desc, size_to_read, read_buff,
+					  size_avilable, 1);
+}
+
+/**
+ * \defgroup end_async_group End Ashyncronous functions
+ * @brief End asynchronous transaction
+ *
+ * @param desc - Circular buffer reference
+ * @return
+ *  - \ref SUCCESS   - No errors
+ *  - \ref FAILURE   - Asynchronous transaction not started
+ *  - -EINVAL        - Wrong parameters used
+ * @{
+ */
+int32_t cb_end_async_write(struct circular_buffer *desc)
+{
+	return cb_end_async_operation(desc, 0);
+}
+
+int32_t cb_end_async_read(struct circular_buffer *desc)
+{
+
+	return cb_end_async_operation(desc, 1);
+}
+/** @} */
+
+/**
+ * @brief Write data to the buffer (Blocking)
+ * @param desc - Circular buffer reference
+ * @param data - Buffer from where data is copied to the circular buffer
+ * @param size - Size to write
+ * @return
+ *  - \ref SUCCESS - No errors
+ *  - -EINVAL      - Wrong parameters used
+ */
+int32_t cb_write(struct circular_buffer *desc, const void *data, uint32_t size)
+{
+	return cb_operation(desc, (void *)data, size, 0);
+}
+
+/**
+ * @brief Read data from the buffer (Blocking)
+ * @param desc - Circular buffer reference
+ * @param data - Buffer where to data is copied from the circular buffer
+ * @param size - Size to read
+ * @return
+ *  - \ref SUCCESS   - No errors
+ *  - -EINVAL   - Wrong parameters used
+ *  - -EOVERRUN - An overrun occurred and some data have been overwritten
+ */
+int32_t cb_read(struct circular_buffer *desc, void *data, uint32_t size)
+{
+	return cb_operation(desc, data, size, 1);
+}