mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
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74 lines
2.6 KiB
C
74 lines
2.6 KiB
C
/*
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* FreeRTOS V202212.00
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* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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* https://www.FreeRTOS.org
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* https://www.github.com/FreeRTOS
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*
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*/
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#include <stdint.h>
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#include "ns16550.h"
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/* register definitions */
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#define REG_RBR 0x00 /* Receiver buffer reg. */
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#define REG_THR 0x00 /* Transmitter holding reg. */
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#define REG_IER 0x01 /* Interrupt enable reg. */
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#define REG_IIR 0x02 /* Interrupt ID reg. */
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#define REG_FCR 0x02 /* FIFO control reg. */
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#define REG_LCR 0x03 /* Line control reg. */
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#define REG_MCR 0x04 /* Modem control reg. */
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#define REG_LSR 0x05 /* Line status reg. */
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#define REG_MSR 0x06 /* Modem status reg. */
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#define REG_SCR 0x07 /* Scratch reg. */
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#define REG_BRDL 0x00 /* Divisor latch (LSB) */
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#define REG_BRDH 0x01 /* Divisor latch (MSB) */
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/* Line status */
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#define LSR_DR 0x01 /* Data ready */
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#define LSR_OE 0x02 /* Overrun error */
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#define LSR_PE 0x04 /* Parity error */
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#define LSR_FE 0x08 /* Framing error */
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#define LSR_BI 0x10 /* Break interrupt */
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#define LSR_THRE 0x20 /* Transmitter holding register empty */
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#define LSR_TEMT 0x40 /* Transmitter empty */
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#define LSR_EIRF 0x80 /* Error in RCVR FIFO */
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static uint8_t readb( uintptr_t addr )
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{
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return *( (uint8_t *) addr );
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}
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static void writeb( uint8_t b, uintptr_t addr )
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{
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*( (uint8_t *) addr ) = b;
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}
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void vOutNS16550( struct device *dev, unsigned char c )
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{
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uintptr_t addr = dev->addr;
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while ( (readb( addr + REG_LSR ) & LSR_THRE) == 0 ) {
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/* busy wait */
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}
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writeb( c, addr + REG_THR );
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}
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