1/*
2 * kgdb debug routines for SiByte boards.
3 *
4 * Copyright (C) 2001 MontaVista Software Inc.
5 * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
6 *
7 * This program is free software; you can redistribute  it and/or modify it
8 * under  the terms of  the GNU General  Public License as published by the
9 * Free Software Foundation;  either version 2 of the  License, or (at your
10 * option) any later version.
11 *
12 */
13
14/* -------------------- BEGINNING OF CONFIG --------------------- */
15
16#include <linux/delay.h>
17#include <asm/io.h>
18#include <asm/sibyte/sb1250.h>
19#include <asm/sibyte/sb1250_regs.h>
20#include <asm/sibyte/sb1250_uart.h>
21#include <asm/sibyte/sb1250_int.h>
22#include <asm/addrspace.h>
23
24/*
25 * We use the second serial port for kgdb traffic.
26 * 	115200, 8, N, 1.
27 */
28
29#define	BAUD_RATE		115200
30#define	CLK_DIVISOR		V_DUART_BAUD_RATE(BAUD_RATE)
31#define	DATA_BITS		V_DUART_BITS_PER_CHAR_8		/* or 7    */
32#define	PARITY			V_DUART_PARITY_MODE_NONE	/* or even */
33#define	STOP_BITS		M_DUART_STOP_BIT_LEN_1		/* or 2    */
34
35static int duart_initialized = 0;	/* 0: need to be init'ed by kgdb */
36
37/* -------------------- END OF CONFIG --------------------- */
38extern int kgdb_port;
39
40#define	duart_out(reg, val)	csr_out32(val, IOADDR(A_DUART_CHANREG(kgdb_port,reg)))
41#define duart_in(reg)		csr_in32(IOADDR(A_DUART_CHANREG(kgdb_port,reg)))
42
43void putDebugChar(unsigned char c);
44unsigned char getDebugChar(void);
45static void
46duart_init(int clk_divisor, int data, int parity, int stop)
47{
48	duart_out(R_DUART_MODE_REG_1, data | parity);
49	duart_out(R_DUART_MODE_REG_2, stop);
50	duart_out(R_DUART_CLK_SEL, clk_divisor);
51
52	duart_out(R_DUART_CMD, M_DUART_RX_EN | M_DUART_TX_EN);	/* enable rx and tx */
53}
54
55void
56putDebugChar(unsigned char c)
57{
58	if (!duart_initialized) {
59		duart_initialized = 1;
60		duart_init(CLK_DIVISOR, DATA_BITS, PARITY, STOP_BITS);
61	}
62	while ((duart_in(R_DUART_STATUS) & M_DUART_TX_RDY) == 0);
63	duart_out(R_DUART_TX_HOLD, c);
64}
65
66unsigned char
67getDebugChar(void)
68{
69	if (!duart_initialized) {
70		duart_initialized = 1;
71		duart_init(CLK_DIVISOR, DATA_BITS, PARITY, STOP_BITS);
72	}
73	while ((duart_in(R_DUART_STATUS) & M_DUART_RX_RDY) == 0) ;
74	return duart_in(R_DUART_RX_HOLD);
75}
76