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/*
* FreeRTOS V202104.00
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* 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.
*
* https://www.FreeRTOS.org
* https://www.github.com/FreeRTOS
*
* 1 tab == 4 spaces!
*/
#include <stdint.h>
#include "ns16550.h"
/* register definitions */
#define REG_RBR 0x00 /* Receiver buffer reg. */
#define REG_THR 0x00 /* Transmitter holding reg. */
#define REG_IER 0x01 /* Interrupt enable reg. */
#define REG_IIR 0x02 /* Interrupt ID reg. */
#define REG_FCR 0x02 /* FIFO control reg. */
#define REG_LCR 0x03 /* Line control reg. */
#define REG_MCR 0x04 /* Modem control reg. */
#define REG_LSR 0x05 /* Line status reg. */
#define REG_MSR 0x06 /* Modem status reg. */
#define REG_SCR 0x07 /* Scratch reg. */
#define REG_BRDL 0x00 /* Divisor latch (LSB) */
#define REG_BRDH 0x01 /* Divisor latch (MSB) */
/* Line status */
#define LSR_DR 0x01 /* Data ready */
#define LSR_OE 0x02 /* Overrun error */
#define LSR_PE 0x04 /* Parity error */
#define LSR_FE 0x08 /* Framing error */
#define LSR_BI 0x10 /* Break interrupt */
#define LSR_THRE 0x20 /* Transmitter holding register empty */
#define LSR_TEMT 0x40 /* Transmitter empty */
#define LSR_EIRF 0x80 /* Error in RCVR FIFO */
static uint8_t readb( uintptr_t addr )
{
return *( (uint8_t *) addr );
}
static void writeb( uint8_t b, uintptr_t addr )
{
*( (uint8_t *) addr ) = b;
}
void vOutNS16550( struct device *dev, unsigned char c )
{
uintptr_t addr = dev->addr;
while ( (readb( addr + REG_LSR ) & LSR_THRE) == 0 ) {
/* busy wait */
}
writeb( c, addr + REG_THR );
}
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