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/*
* The MIT License (MIT)
*
* Copyright (c) 2019 Ha Thach (tinyusb.org)
* Copyright (c) 2020 Reinhard Panhuber - rework to unmasked pointers
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* This file is part of the TinyUSB stack.
*/
#ifndef _TUSB_FIFO_H_
#define _TUSB_FIFO_H_
#ifdef __cplusplus
extern "C" {
#endif
// Due to the use of unmasked pointers, this FIFO does not suffer from loosing
// one item slice. Furthermore, write and read operations are completely
// decoupled as write and read functions do not modify a common state. Henceforth,
// writing or reading from the FIFO within an ISR is safe as long as no other
// process (thread or ISR) interferes.
// Also, this FIFO is ready to be used in combination with a DMA as the write and
// read pointers can be updated from within a DMA ISR. Overflows are detectable
// within a certain number (see tu_fifo_overflow()).
#include "common/tusb_common.h"
// mutex is only needed for RTOS
// for OS None, we don't get preempted
#define CFG_FIFO_MUTEX (CFG_TUSB_OS != OPT_OS_NONE)
#if CFG_FIFO_MUTEX
#include "osal/osal.h"
#define tu_fifo_mutex_t osal_mutex_t
#endif
typedef struct
{
uint8_t* buffer ; ///< buffer pointer
uint16_t depth ; ///< max items
uint16_t item_size ; ///< size of each item
bool overwritable ;
uint16_t non_used_index_space ; ///< required for non-power-of-two buffer length
uint16_t max_pointer_idx ; ///< maximum absolute pointer index
volatile uint16_t wr_idx ; ///< write pointer
volatile uint16_t rd_idx ; ///< read pointer
#if CFG_FIFO_MUTEX
tu_fifo_mutex_t mutex_wr;
tu_fifo_mutex_t mutex_rd;
#endif
} tu_fifo_t;
typedef struct
{
uint16_t len_lin ; ///< linear length in item size
uint16_t len_wrap ; ///< wrapped length in item size
void * ptr_lin ; ///< linear part start pointer
void * ptr_wrap ; ///< wrapped part start pointer
} tu_fifo_buffer_info_t;
#define TU_FIFO_INIT(_buffer, _depth, _type, _overwritable) \
{ \
.buffer = _buffer, \
.depth = _depth, \
.item_size = sizeof(_type), \
.overwritable = _overwritable, \
.non_used_index_space = UINT16_MAX - (2*(_depth)-1), \
.max_pointer_idx = 2*(_depth)-1, \
}
#define TU_FIFO_DEF(_name, _depth, _type, _overwritable) \
uint8_t _name##_buf[_depth*sizeof(_type)]; \
tu_fifo_t _name = TU_FIFO_INIT(_name##_buf, _depth, _type, _overwritable)
bool tu_fifo_set_overwritable(tu_fifo_t *f, bool overwritable);
bool tu_fifo_clear(tu_fifo_t *f);
bool tu_fifo_config(tu_fifo_t *f, void* buffer, uint16_t depth, uint16_t item_size, bool overwritable);
#if CFG_FIFO_MUTEX
TU_ATTR_ALWAYS_INLINE static inline
void tu_fifo_config_mutex(tu_fifo_t *f, tu_fifo_mutex_t write_mutex_hdl, tu_fifo_mutex_t read_mutex_hdl)
{
f->mutex_wr = write_mutex_hdl;
f->mutex_rd = read_mutex_hdl;
}
#endif
bool tu_fifo_write (tu_fifo_t* f, void const * p_data);
uint16_t tu_fifo_write_n (tu_fifo_t* f, void const * p_data, uint16_t n);
uint16_t tu_fifo_write_n_const_addr_full_words (tu_fifo_t* f, const void * data, uint16_t n);
bool tu_fifo_read (tu_fifo_t* f, void * p_buffer);
uint16_t tu_fifo_read_n (tu_fifo_t* f, void * p_buffer, uint16_t n);
uint16_t tu_fifo_read_n_const_addr_full_words (tu_fifo_t* f, void * buffer, uint16_t n);
bool tu_fifo_peek (tu_fifo_t* f, void * p_buffer);
uint16_t tu_fifo_peek_n (tu_fifo_t* f, void * p_buffer, uint16_t n);
uint16_t tu_fifo_count (tu_fifo_t* f);
uint16_t tu_fifo_remaining (tu_fifo_t* f);
bool tu_fifo_empty (tu_fifo_t* f);
bool tu_fifo_full (tu_fifo_t* f);
bool tu_fifo_overflowed (tu_fifo_t* f);
void tu_fifo_correct_read_pointer (tu_fifo_t* f);
TU_ATTR_ALWAYS_INLINE static inline
uint16_t tu_fifo_depth(tu_fifo_t* f)
{
return f->depth;
}
// Pointer modifications intended to be used in combinations with DMAs.
// USE WITH CARE - NO SAFTY CHECKS CONDUCTED HERE! NOT MUTEX PROTECTED!
void tu_fifo_advance_write_pointer(tu_fifo_t *f, uint16_t n);
void tu_fifo_advance_read_pointer (tu_fifo_t *f, uint16_t n);
// If you want to read/write from/to the FIFO by use of a DMA, you may need to conduct two copies
// to handle a possible wrapping part. These functions deliver a pointer to start
// reading/writing from/to and a valid linear length along which no wrap occurs.
void tu_fifo_get_read_info (tu_fifo_t *f, tu_fifo_buffer_info_t *info);
void tu_fifo_get_write_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info);
#ifdef __cplusplus
}
#endif
#endif /* _TUSB_FIFO_H_ */
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