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
49void 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
74uint8 Uart16550GetPoll()
75{
76    while((UART16550_READ(OFS_LINE_STATUS) & 0x1) == 0);
77    return UART16550_READ(OFS_RCV_BUFFER);
78}
79
80
81void Uart16550Put(uint8 byte)
82{
83    while ((UART16550_READ(OFS_LINE_STATUS) &0x20) == 0);
84    UART16550_WRITE(OFS_SEND_BUFFER, byte);
85}
86
87