| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2001 MontaVista Software Inc. |
| 3 | * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License as published by the |
| 7 | * Free Software Foundation; either version 2 of the License, or (at your |
| 8 | * option) any later version. |
| 9 | * |
| 10 | */ |
| 11 | |
| 12 | |
| 13 | #include "uart16550.h" |
| 14 | |
| 15 | /* === CONFIG === */ |
| 16 | |
| 17 | #define BASE 0xb8058000 |
| 18 | #define MAX_BAUD 1152000 |
| 19 | #define REG_OFFSET 4 |
| 20 | |
| 21 | /* === END OF CONFIG === */ |
| 22 | |
| 23 | /* register offset */ |
| 24 | #define OFS_RCV_BUFFER (0*REG_OFFSET) |
| 25 | #define OFS_TRANS_HOLD (0*REG_OFFSET) |
| 26 | #define OFS_SEND_BUFFER (0*REG_OFFSET) |
| 27 | #define OFS_INTR_ENABLE (1*REG_OFFSET) |
| 28 | #define OFS_INTR_ID (2*REG_OFFSET) |
| 29 | #define OFS_DATA_FORMAT (3*REG_OFFSET) |
| 30 | #define OFS_LINE_CONTROL (3*REG_OFFSET) |
| 31 | #define OFS_MODEM_CONTROL (4*REG_OFFSET) |
| 32 | #define OFS_RS232_OUTPUT (4*REG_OFFSET) |
| 33 | #define OFS_LINE_STATUS (5*REG_OFFSET) |
| 34 | #define OFS_MODEM_STATUS (6*REG_OFFSET) |
| 35 | #define OFS_RS232_INPUT (6*REG_OFFSET) |
| 36 | #define OFS_SCRATCH_PAD (7*REG_OFFSET) |
| 37 | |
| 38 | #define OFS_DIVISOR_LSB (0*REG_OFFSET) |
| 39 | #define OFS_DIVISOR_MSB (1*REG_OFFSET) |
| 40 | |
| 41 | |
| 42 | /* memory-mapped read/write of the port */ |
| 43 | #define UART16550_READ(y) (*((volatile uint32*)(BASE + y))) |
| 44 | #define UART16550_WRITE(y, z) ((*((volatile uint32*)(BASE + y))) = z) |
| 45 | |
| 46 | #define DEBUG_LED (*(unsigned short*)0xb7ffffc0) |
| 47 | #define OutputLED(x) (DEBUG_LED = x) |
| 48 | |
| 49 | void Uart16550Init(uint32 baud, uint8 data, uint8 parity, uint8 stop) |
| 50 | { |
| 51 | /* disable interrupts */ |
| 52 | UART16550_WRITE(OFS_INTR_ENABLE, 0); |
| 53 | |
| 54 | /* set up buad rate */ |
| 55 | { |
| 56 | uint32 divisor; |
| 57 | |
| 58 | /* set DIAB bit */ |
| 59 | UART16550_WRITE(OFS_LINE_CONTROL, 0x80); |
| 60 | |
| 61 | /* set divisor */ |
| 62 | divisor = MAX_BAUD / baud; |
| 63 | UART16550_WRITE(OFS_DIVISOR_LSB, divisor & 0xff); |
| 64 | UART16550_WRITE(OFS_DIVISOR_MSB, (divisor & 0xff00)>>8); |
| 65 | |
| 66 | /* clear DIAB bit */ |
| 67 | UART16550_WRITE(OFS_LINE_CONTROL, 0x0); |
| 68 | } |
| 69 | |
| 70 | /* set data format */ |
| 71 | UART16550_WRITE(OFS_DATA_FORMAT, data | parity | stop); |
| 72 | } |
| 73 | |
| 74 | uint8 Uart16550GetPoll() |
| 75 | { |
| 76 | while((UART16550_READ(OFS_LINE_STATUS) & 0x1) == 0); |
| 77 | return UART16550_READ(OFS_RCV_BUFFER); |
| 78 | } |
| 79 | |
| 80 | |
| 81 | void Uart16550Put(uint8 byte) |
| 82 | { |
| 83 | while ((UART16550_READ(OFS_LINE_STATUS) &0x20) == 0); |
| 84 | UART16550_WRITE(OFS_SEND_BUFFER, byte); |
| 85 | } |
| 86 | |