93 lines
2.5 KiB
C
93 lines
2.5 KiB
C
/*
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LPCUSB, an USB device driver for LPC microcontrollers
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Copyright (C) 2006 Bertrik Sikken (bertrik@sikken.nl)
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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. The name of the author may not 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 AUTHOR ``AS IS'' AND ANY EXPRESS OR
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IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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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
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THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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// CodeRed - LPCUSB type.h renamed
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//#include "type.h"
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#include "lpcusb_type.h"
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#include "serial_fifo.h"
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void fifo_init(fifo_t *fifo, U8 *buf)
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{
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fifo->head = 0;
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fifo->tail = 0;
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fifo->buf = buf;
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}
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// TBF: only non-isr may call this
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BOOL fifo_put(fifo_t *fifo, U8 c)
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{
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int tail = fifo->tail;
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int head = fifo->head;
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// check if FIFO has room
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int next = (head + 1) % VCOM_FIFO_SIZE;
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if (next == tail) {
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// full
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return FALSE;
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}
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fifo->buf[head] = c;
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fifo->head = next;
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return TRUE;
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}
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// TBF: only USB isr may call this
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BOOL fifo_get(fifo_t *fifo, U8 *pc)
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{
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int next;
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// check if FIFO has data
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if (fifo->head == fifo->tail) {
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return FALSE;
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}
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next = (fifo->tail + 1) % VCOM_FIFO_SIZE;
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*pc = fifo->buf[fifo->tail];
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fifo->tail = next;
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return TRUE;
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}
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// TBF: only USB isr may call this
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int fifo_avail(fifo_t *fifo)
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{
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return (VCOM_FIFO_SIZE + fifo->head - fifo->tail) % VCOM_FIFO_SIZE;
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}
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// TBF: only USB isr may call this
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int fifo_free(fifo_t *fifo)
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{
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return (VCOM_FIFO_SIZE - 1 - fifo_avail(fifo));
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}
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