hci_mem_pool.h

00001 /*
00002  * Copyright (c) Nordic Semiconductor ASA
00003  * All rights reserved.
00004  *
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00006  * are permitted provided that the following conditions are met:
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00009  *   list of conditions and the following disclaimer.
00010  *
00011  *   2. Redistributions in binary form must reproduce the above copyright notice, this
00012  *   list of conditions and the following disclaimer in the documentation and/or
00013  *   other materials provided with the distribution.
00014  *
00015  *   3. Neither the name of Nordic Semiconductor ASA nor the names of other
00016  *   contributors to this software may be used to endorse or promote products
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00019  *
00020  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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00023  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
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00031  */
00032  
00033 /** @file
00034  *
00035  * @defgroup memory_pool Memory pool
00036  * @{
00037  * @ingroup app_common
00038  *
00039  * @brief Memory pool implementation
00040  *
00041  * Memory pool implementation, based on circular buffer data structure, which supports asynchronous 
00042  * processing of RX data. The current default implementation supports 1 TX buffer and 4 RX buffers.
00043  * The memory managed by the pool is allocated from static storage instead of heap. The internal 
00044  * design of the circular buffer implementing the RX memory layout is illustrated in the picture 
00045  * below. 
00046  *
00047  * @image html memory_pool.png "Circular buffer design"
00048  *
00049  * The expected call order for the RX APIs is as follows:
00050  * - hci_mem_pool_rx_produce
00051  * - hci_mem_pool_rx_data_size_set
00052  * - hci_mem_pool_rx_extract
00053  * - hci_mem_pool_rx_consume
00054  *
00055  * @warning If the above mentioned expected call order is violated the end result can be undefined.
00056  *
00057  * \par Component specific configuration options
00058  *
00059  * The following compile time configuration options are available to suit various implementations:
00060  * - TX_BUF_SIZE TX buffer size in bytes. 
00061  * - RX_BUF_SIZE RX buffer size in bytes. 
00062  * - RX_BUF_QUEUE_SIZE RX buffer element size.
00063  */
00064  
00065 #ifndef HCI_MEM_POOL_H__
00066 #define HCI_MEM_POOL_H__
00067 
00068 #include <stdint.h>
00069 #include "nrf_error.h"
00070 
00071 /**@brief Function for opening the module.
00072  *
00073  * @retval NRF_SUCCESS          Operation success. 
00074  */
00075 uint32_t hci_mem_pool_open(void);
00076 
00077 /**@brief Function for closing the module.
00078  *
00079  * @retval NRF_SUCCESS          Operation success. 
00080  */
00081 uint32_t hci_mem_pool_close(void);
00082 
00083 /**@brief Function for allocating requested amount of TX memory.
00084  *
00085  * @param[out] pp_buffer        Pointer to the allocated memory.
00086  *
00087  * @retval NRF_SUCCESS          Operation success. Memory was allocated.
00088  * @retval NRF_ERROR_NO_MEM     Operation failure. No memory available for allocation.
00089  * @retval NRF_ERROR_NULL       Operation failure. NULL pointer supplied.  
00090  */
00091 uint32_t hci_mem_pool_tx_alloc(void ** pp_buffer);
00092  
00093 /**@brief Function for freeing previously allocated TX memory.
00094  *
00095  * @note Memory management follows the FIFO principle meaning that free() order must match the 
00096  *       alloc(...) order, which is the reason for omitting exact memory block identifier as an 
00097  *       input parameter.
00098  *
00099  * @retval NRF_SUCCESS          Operation success. Memory was freed.
00100  */
00101 uint32_t hci_mem_pool_tx_free(void);
00102  
00103 /**@brief Function for producing a free RX memory block for usage.
00104  *
00105  * @note Upon produce request amount being 0, NRF_SUCCESS is returned.   
00106  *
00107  * @param[in]  length           Amount, in bytes, of free memory to be produced.
00108  * @param[out] pp_buffer        Pointer to the allocated memory.
00109  *
00110  * @retval NRF_SUCCESS          Operation success. Free RX memory block produced.
00111  * @retval NRF_ERROR_NO_MEM     Operation failure. No suitable memory available for allocation.
00112  * @retval NRF_ERROR_DATA_SIZE  Operation failure. Request size exceeds limit.  
00113  * @retval NRF_ERROR_NULL       Operation failure. NULL pointer supplied.   
00114  */
00115 uint32_t hci_mem_pool_rx_produce(uint32_t length, void ** pp_buffer);
00116 
00117 /**@brief Function for setting the length of the last produced RX memory block.
00118  *
00119  * @warning If call to this API is omitted the end result is that the following call to 
00120  *          mem_pool_rx_extract will return incorrect data in the p_length output parameter.
00121  *
00122  * @param[in]  length           Amount, in bytes, of actual memory used.
00123  *
00124  * @retval NRF_SUCCESS          Operation success. Length was set.
00125  */
00126 uint32_t hci_mem_pool_rx_data_size_set(uint32_t length);
00127  
00128 /**@brief Function for extracting a packet, which has been filled with read data, for further 
00129  * processing.
00130  *
00131  * @param[out] pp_buffer        Pointer to the packet data.
00132  * @param[out] p_length         Length of packet data in bytes.  
00133  *
00134  * @retval NRF_SUCCESS          Operation success. 
00135  * @retval NRF_ERROR_NO_MEM     Operation failure. No packet available to extract.
00136  * @retval NRF_ERROR_NULL       Operation failure. NULL pointer supplied.    
00137  */
00138 uint32_t hci_mem_pool_rx_extract(uint8_t ** pp_buffer, uint32_t * p_length);
00139  
00140 /**@brief Function for freeing previously extracted packet, which has been filled with read data.
00141  *
00142  * @param[in] p_buffer             Pointer to consumed buffer.
00143  *
00144  * @retval NRF_SUCCESS             Operation success. 
00145  * @retval NRF_ERROR_NO_MEM        Operation failure. No packet available to free. 
00146  * @retval NRF_ERROR_INVALID_ADDR  Operation failure. Not a valid pointer. 
00147  */
00148 uint32_t hci_mem_pool_rx_consume(uint8_t * p_buffer);
00149  
00150 #endif // HCI_MEM_POOL_H__
00151  
00152 /** @} */