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/*
* @brief Common ring buffer support functions
*
* @note
* Copyright(C) NXP Semiconductors, 2012
* All rights reserved.
*
* @par
* Software that is described herein is for illustrative purposes only
* which provides customers with programming information regarding the
* LPC products. This software is supplied "AS IS" without any warranties of
* any kind, and NXP Semiconductors and its licensor disclaim any and
* all warranties, express or implied, including all implied warranties of
* merchantability, fitness for a particular purpose and non-infringement of
* intellectual property rights. NXP Semiconductors assumes no responsibility
* or liability for the use of the software, conveys no license or rights under any
* patent, copyright, mask work right, or any other intellectual property rights in
* or to any products. NXP Semiconductors reserves the right to make changes
* in the software without notification. NXP Semiconductors also makes no
* representation or warranty that such application will be suitable for the
* specified use without further testing or modification.
*
* @par
* Permission to use, copy, modify, and distribute this software and its
* documentation is hereby granted, under NXP Semiconductors' and its
* licensor's relevant copyrights in the software, without fee, provided that it
* is used in conjunction with NXP Semiconductors microcontrollers. This
* copyright, permission, and disclaimer notice must appear in all copies of
* this code.
*/
#ifndef __RING_BUFFER_H_
#define __RING_BUFFER_H_
#include "lpc_types.h"
/** @defgroup Ring_Buffer CHIP: Simple ring buffer implementation
* @ingroup CHIP_Common
* @{
*/
/**
* @brief Ring buffer structure
*/
typedef struct {
void *data;
int count;
int itemSz;
uint32_t head;
uint32_t tail;
} RINGBUFF_T;
/**
* @def RB_VHEAD(rb)
* volatile typecasted head index
*/
#define RB_VHEAD(rb) (*(volatile uint32_t *) &(rb)->head)
/**
* @def RB_VTAIL(rb)
* volatile typecasted tail index
*/
#define RB_VTAIL(rb) (*(volatile uint32_t *) &(rb)->tail)
/**
* @brief Initialize ring buffer
* @param RingBuff : Pointer to ring buffer to initialize
* @param buffer : Pointer to buffer to associate with RingBuff
* @param itemSize : Size of each buffer item size
* @param count : Size of ring buffer
* @note Memory pointed by @a buffer must have correct alignment of
* @a itemSize, and @a count must be a power of 2 and must at
* least be 2 or greater.
* @return Nothing
*/
int RingBuffer_Init(RINGBUFF_T *RingBuff, void *buffer, int itemSize, int count);
/**
* @brief Resets the ring buffer to empty
* @param RingBuff : Pointer to ring buffer
* @return Nothing
*/
STATIC INLINE void RingBuffer_Flush(RINGBUFF_T *RingBuff)
{
RingBuff->head = RingBuff->tail = 0;
}
/**
* @brief Return size the ring buffer
* @param RingBuff : Pointer to ring buffer
* @return Size of the ring buffer in bytes
*/
STATIC INLINE int RingBuffer_GetSize(RINGBUFF_T *RingBuff)
{
return RingBuff->count;
}
/**
* @brief Return number of items in the ring buffer
* @param RingBuff : Pointer to ring buffer
* @return Number of items in the ring buffer
*/
STATIC INLINE int RingBuffer_GetCount(RINGBUFF_T *RingBuff)
{
return RB_VHEAD(RingBuff) - RB_VTAIL(RingBuff);
}
/**
* @brief Return number of free items in the ring buffer
* @param RingBuff : Pointer to ring buffer
* @return Number of free items in the ring buffer
*/
STATIC INLINE int RingBuffer_GetFree(RINGBUFF_T *RingBuff)
{
return RingBuff->count - RingBuffer_GetCount(RingBuff);
}
/**
* @brief Return number of items in the ring buffer
* @param RingBuff : Pointer to ring buffer
* @return 1 if the ring buffer is full, otherwise 0
*/
STATIC INLINE int RingBuffer_IsFull(RINGBUFF_T *RingBuff)
{
return (RingBuffer_GetCount(RingBuff) >= RingBuff->count);
}
/**
* @brief Return empty status of ring buffer
* @param RingBuff : Pointer to ring buffer
* @return 1 if the ring buffer is empty, otherwise 0
*/
STATIC INLINE int RingBuffer_IsEmpty(RINGBUFF_T *RingBuff)
{
return RB_VHEAD(RingBuff) == RB_VTAIL(RingBuff);
}
/**
* @brief Insert a single item into ring buffer
* @param RingBuff : Pointer to ring buffer
* @param data : pointer to item
* @return 1 when successfully inserted,
* 0 on error (Buffer not initialized using
* RingBuffer_Init() or attempted to insert
* when buffer is full)
*/
int RingBuffer_Insert(RINGBUFF_T *RingBuff, const void *data);
/**
* @brief Insert an array of items into ring buffer
* @param RingBuff : Pointer to ring buffer
* @param data : Pointer to first element of the item array
* @param num : Number of items in the array
* @return number of items successfully inserted,
* 0 on error (Buffer not initialized using
* RingBuffer_Init() or attempted to insert
* when buffer is full)
*/
int RingBuffer_InsertMult(RINGBUFF_T *RingBuff, const void *data, int num);
/**
* @brief Pop an item from the ring buffer
* @param RingBuff : Pointer to ring buffer
* @param data : Pointer to memory where popped item be stored
* @return 1 when item popped successfuly onto @a data,
* 0 When error (Buffer not initialized using
* RingBuffer_Init() or attempted to pop item when
* the buffer is empty)
*/
int RingBuffer_Pop(RINGBUFF_T *RingBuff, void *data);
/**
* @brief Pop an array of items from the ring buffer
* @param RingBuff : Pointer to ring buffer
* @param data : Pointer to memory where popped items be stored
* @param num : Max number of items array @a data can hold
* @return Number of items popped onto @a data,
* 0 on error (Buffer not initialized using RingBuffer_Init()
* or attempted to pop when the buffer is empty)
*/
int RingBuffer_PopMult(RINGBUFF_T *RingBuff, void *data, int num);
/**
* @}
*/
#endif /* __RING_BUFFER_H_ */
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