?? uart16550.c
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/* * Copyright (C) 2001 MontaVista Software Inc. * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. * */#include "uart16550.h"/* === CONFIG === */#define BASE 0xb0000080#define MAX_BAUD 1152000#define REG_OFFSET 4/* === END OF CONFIG === *//* register offset */#define OFS_RCV_BUFFER (0*REG_OFFSET)#define OFS_TRANS_HOLD (0*REG_OFFSET)#define OFS_SEND_BUFFER (0*REG_OFFSET)#define OFS_INTR_ENABLE (1*REG_OFFSET)#define OFS_INTR_ID (2*REG_OFFSET)#define OFS_DATA_FORMAT (3*REG_OFFSET)#define OFS_LINE_CONTROL (3*REG_OFFSET)#define OFS_MODEM_CONTROL (4*REG_OFFSET)#define OFS_RS232_OUTPUT (4*REG_OFFSET)#define OFS_LINE_STATUS (5*REG_OFFSET)#define OFS_MODEM_STATUS (6*REG_OFFSET)#define OFS_RS232_INPUT (6*REG_OFFSET)#define OFS_SCRATCH_PAD (7*REG_OFFSET)#define OFS_DIVISOR_LSB (0*REG_OFFSET)#define OFS_DIVISOR_MSB (1*REG_OFFSET)/* memory-mapped read/write of the port */#define UART16550_READ(y) (*((volatile uint8*)(BASE + y)))#define UART16550_WRITE(y, z) ((*((volatile uint8*)(BASE + y))) = z)#define DEBUG_LED (*(unsigned short*)0xb7ffffc0)#define OutputLED(x) (DEBUG_LED = x)void Uart16550Init(uint32 baud, uint8 data, uint8 parity, uint8 stop){ /* disable interrupts */ UART16550_WRITE(OFS_INTR_ENABLE, 0); /* set up buad rate */ { uint32 divisor; /* set DIAB bit */ UART16550_WRITE(OFS_LINE_CONTROL, 0x80); /* set divisor */ divisor = MAX_BAUD / baud; UART16550_WRITE(OFS_DIVISOR_LSB, divisor & 0xff); UART16550_WRITE(OFS_DIVISOR_MSB, (divisor & 0xff00)>>8); /* clear DIAB bit */ UART16550_WRITE(OFS_LINE_CONTROL, 0x0); } /* set data format */ UART16550_WRITE(OFS_DATA_FORMAT, data | parity | stop);}uint8 Uart16550GetPoll(){ while((UART16550_READ(OFS_LINE_STATUS) & 0x1) == 0); return UART16550_READ(OFS_RCV_BUFFER);}void Uart16550Put(uint8 byte){ while ((UART16550_READ(OFS_LINE_STATUS) &0x20) == 0); UART16550_WRITE(OFS_SEND_BUFFER, byte);}
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