48 lines
1.6 KiB
C
48 lines
1.6 KiB
C
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/*
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* Software timer based UART driver.
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*
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* Copyright (C) 2018 to 2019 OurAirQuality.org
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*
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* Licensed under the Apache License, Version 2.0, January 2004 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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* http://www.apache.org/licenses/
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE CONTRIBUTORS OR COPYRIGHT
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* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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* DEALINGS WITH THE SOFTWARE.
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*
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*/
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#ifndef _TSOFTUART_H
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#define _TSOFTUART_H
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#include "mactimer/mactimer.h"
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typedef struct tsoftuart {
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uint32_t tx_pin;
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/* Bit time period in usec * 256 */
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uint32_t td;
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mactimer_t output_mactimer;
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uint32_t output_queue[16];
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volatile uint64_t output_start_time;
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volatile size_t output_queue_head;
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volatile size_t output_queue_tail;
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size_t output_queue_state;
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uint64_t output_expected_time;
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int32_t output_queue_error_high;
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int32_t output_queue_error_low;
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uint32_t output_done;
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} tsoftuart_t;
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void tsoftuart_putc(tsoftuart_t *uart, uint8_t ch);
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ssize_t tsoftuart_write(tsoftuart_t *uart, const void *ptr, size_t len);
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tsoftuart_t *tsoftuart_init(uint8_t tx_pin, uint32_t baud_rate);
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#endif /* _TSOFTUART_H */
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