218 lines
6.6 KiB
C
218 lines
6.6 KiB
C
/**************************************************************************/
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/*!
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@file fifo.c
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@author hathach (tinyusb.org)
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@section LICENSE
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Software License Agreement (BSD License)
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Copyright (c) 2013, hathach (tinyusb.org)
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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1. Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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3. Neither the name of the copyright holders nor the
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names of its contributors may be used to endorse or promote products
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derived from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
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EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
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DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND
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ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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This file is part of the tinyusb stack.
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*/
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/**************************************************************************/
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#include "fifo.h"
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/**************************************************************************/
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/*!
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@brief Disables the IRQ specified in the FIFO's 'irq' field
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to prevent reads/write issues with interrupts
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@param[in] f
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Pointer to the FIFO that should be protected
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*/
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/**************************************************************************/
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static inline void mutex_lock (fifo_t* f)
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{
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// if (f->irq > 0)
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// NVIC_DisableIRQ(f->irq);
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}
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/**************************************************************************/
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/*!
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@brief Re-enables the IRQ specified in the FIFO's 'irq' field
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@param[in] f
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Pointer to the FIFO that should be protected
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*/
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/**************************************************************************/
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static inline void mutex_unlock (fifo_t* f)
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{
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// if (f->irq > 0)
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// NVIC_EnableIRQ(f->irq);
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}
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/**************************************************************************/
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/*!
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@brief Initialises the FIFO buffer
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@param[in] f
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Pointer to the fifo_t object to intiialize
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@param[in] buffer
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Pointer to the buffer's location in memory
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@param[in] size
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The buffer size in bytes
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@param[in] overwritable
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Set to TRUE is the FIFO is overwritable when the FIFO
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is full (the first element will be overwritten)
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@param[in] irq
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The IRQ number to disable for MUTEX protection.
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Set the -1 if not required.
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*/
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/**************************************************************************/
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bool fifo_init(fifo_t* f, uint8_t* buffer, uint16_t size, bool overwritable) //, IRQn_Type irq)
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{
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ASSERT(size > 0, false);
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f->buf = buffer;
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f->size = size;
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f->rd_ptr = f->wr_ptr = f->len = 0;
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f->overwritable = overwritable;
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// f->irq = irq;
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return true;
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}
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/**************************************************************************/
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/*!
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@brief Read one byte out of the RX buffer.
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This function will return the byte located at the array index of the
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read pointer, and then increment the read pointer index. If the read
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pointer exceeds the maximum buffer size, it will roll over to zero.
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@param[in] f
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Pointer to the FIFO buffer to manipulate
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@param[in] data
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Pointer to the place holder for data read from the buffer
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@returns TRUE if the queue is not empty
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*/
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/**************************************************************************/
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bool fifo_read(fifo_t* f, uint8_t *data)
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{
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if (fifo_is_empty(f))
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return false;
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mutex_lock(f);
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*data = f->buf[f->rd_ptr];
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f->rd_ptr = (f->rd_ptr + 1) % f->size;
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f->len--;
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mutex_unlock(f);
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return true;
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}
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/**************************************************************************/
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/*!
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@brief Read a byte array from FIFO
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@param[in] f
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Pointer to the FIFO buffer to manipulate
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@param[in] rx
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Pointer to the place holder for data read from the buffer
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@param[in] maxlen
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The maximum number of bytes to read from the FIFO
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@returns The actual number of bytes read from the FIFO
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*/
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/**************************************************************************/
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uint16_t fifo_read_n(fifo_t* f, uint8_t* rx, uint16_t maxlen)
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{
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uint16_t len = 0;
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while ( len < maxlen && fifo_read(f, rx) )
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{
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len++;
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rx++;
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}
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return len;
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}
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/**************************************************************************/
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/*!
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@brief Write one byte into the RX buffer.
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This function will write one byte into the array index specified by
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the write pointer and increment the write index. If the write index
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exceeds the max buffer size, then it will roll over to zero.
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@param[in] f
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Pointer to the FIFO buffer to manipulate
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@param[in] data
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The byte to add to the FIFO
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@returns TRUE if the data was written to the FIFO (overwrittable
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FIFO will always return TRUE)
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*/
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/**************************************************************************/
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bool fifo_write(fifo_t* f, uint8_t data)
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{
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if ( fifo_is_full(f) && f->overwritable == false)
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return false;
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mutex_lock(f);
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f->buf[f->wr_ptr] = data;
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f->wr_ptr = (f->wr_ptr + 1) % f->size;
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if (fifo_is_full(f))
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{
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f->rd_ptr = f->wr_ptr; // keep the full state (rd == wr && len = size)
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}else
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{
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f->len++;
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}
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mutex_unlock(f);
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return true;
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}
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/**************************************************************************/
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/*!
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@brief Clear the fifo read and write pointers and set length to zero
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@param[in] f
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Pointer to the FIFO buffer to manipulate
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*/
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/**************************************************************************/
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void fifo_clear(fifo_t *f)
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{
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mutex_lock(f);
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f->rd_ptr = 0;
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f->wr_ptr = 0;
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f->len = 0;
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mutex_unlock(f);
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}
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