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Diffstat (limited to 'tinyusb/src/common/tusb_fifo.h')
| -rwxr-xr-x | tinyusb/src/common/tusb_fifo.h | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/tinyusb/src/common/tusb_fifo.h b/tinyusb/src/common/tusb_fifo.h new file mode 100755 index 00000000..18db289a --- /dev/null +++ b/tinyusb/src/common/tusb_fifo.h @@ -0,0 +1,151 @@ +/* + * 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_ */ |