aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mn10300/kernel/gdb-io-serial.c
blob: df51242744cc4617eeca151f72a8f93601367cd9 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/* 16550 serial driver for gdbstub I/O
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/console.h>
#include <linux/init.h>
#include <linux/nmi.h>

#include <asm/pgtable.h>
#include <asm/gdb-stub.h>
#include <asm/exceptions.h>
#include <asm/serial-regs.h>
#include <unit/serial.h>
#include <asm/smp.h>

/*
 * initialise the GDB stub
 */
void gdbstub_io_init(void)
{
	u16 tmp;

	/* set up the serial port */
	GDBPORT_SERIAL_LCR = UART_LCR_WLEN8; /* 1N8 */
	GDBPORT_SERIAL_FCR = (UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
			      UART_FCR_CLEAR_XMIT);

	FLOWCTL_CLEAR(DTR);
	FLOWCTL_SET(RTS);

	gdbstub_io_set_baud(115200);

	/* we want to get serial receive interrupts */
	XIRQxICR(GDBPORT_SERIAL_IRQ) = 0;
	tmp = XIRQxICR(GDBPORT_SERIAL_IRQ);

#if   CONFIG_GDBSTUB_IRQ_LEVEL == 0
	IVAR0 = EXCEP_IRQ_LEVEL0;
#elif CONFIG_GDBSTUB_IRQ_LEVEL == 1
	IVAR1 = EXCEP_IRQ_LEVEL1;
#elif CONFIG_GDBSTUB_IRQ_LEVEL == 2
	IVAR2 = EXCEP_IRQ_LEVEL2;
#elif CONFIG_GDBSTUB_IRQ_LEVEL == 3
	IVAR3 = EXCEP_IRQ_LEVEL3;
#elif CONFIG_GDBSTUB_IRQ_LEVEL == 4
	IVAR4 = EXCEP_IRQ_LEVEL4;
#elif CONFIG_GDBSTUB_IRQ_LEVEL == 5
	IVAR5 = EXCEP_IRQ_LEVEL5;
#else
#error "Unknown irq level for gdbstub."
#endif

	set_intr_stub(NUM2EXCEP_IRQ_LEVEL(CONFIG_GDBSTUB_IRQ_LEVEL),
		gdbstub_io_rx_handler);

	XIRQxICR(GDBPORT_SERIAL_IRQ) &= ~GxICR_REQUEST;
	XIRQxICR(GDBPORT_SERIAL_IRQ) =
		GxICR_ENABLE | NUM2GxICR_LEVEL(CONFIG_GDBSTUB_IRQ_LEVEL);
	tmp = XIRQxICR(GDBPORT_SERIAL_IRQ);

	GDBPORT_SERIAL_IER = UART_IER_RDI | UART_IER_RLSI;

	/* permit level 0 IRQs to take place */
	arch_local_change_intr_mask_level(
		NUM2EPSW_IM(CONFIG_GDBSTUB_IRQ_LEVEL + 1));
}

/*
 * set up the GDB stub serial port baud rate timers
 */
void gdbstub_io_set_baud(unsigned baud)
{
	unsigned value;
	u8 lcr;

	value = 18432000 / 16 / baud;

	lcr = GDBPORT_SERIAL_LCR;
	GDBPORT_SERIAL_LCR |= UART_LCR_DLAB;
	GDBPORT_SERIAL_DLL = value & 0xff;
	GDBPORT_SERIAL_DLM = (value >> 8) & 0xff;
	GDBPORT_SERIAL_LCR = lcr;
}

/*
 * wait for a character to come from the debugger
 */
int gdbstub_io_rx_char(unsigned char *_ch, int nonblock)
{
	unsigned ix;
	u8 ch, st;
#if defined(CONFIG_MN10300_WD_TIMER)
	int cpu;
#endif

	*_ch = 0xff;

	if (gdbstub_rx_unget) {
		*_ch = gdbstub_rx_unget;
		gdbstub_rx_unget = 0;
		return 0;
	}

 try_again:
	/* pull chars out of the buffer */
	ix = gdbstub_rx_outp;
	barrier();
	if (ix == gdbstub_rx_inp) {
		if (nonblock)
			return -EAGAIN;
#ifdef CONFIG_MN10300_WD_TIMER
	for (cpu = 0; cpu < NR_CPUS; cpu++)
		watchdog_alert_counter[cpu] = 0;
#endif
		goto try_again;
	}

	ch = gdbstub_rx_buffer[ix++];
	st = gdbstub_rx_buffer[ix++];
	barrier();
	gdbstub_rx_outp = ix & 0x00000fff;

	if (st & UART_LSR_BI) {
		gdbstub_proto("### GDB Rx Break Detected ###\n");
		return -EINTR;
	} else if (st & (UART_LSR_FE | UART_LSR_OE | UART_LSR_PE)) {
		gdbstub_proto("### GDB Rx Error (st=%02x) ###\n", st);
		return -EIO;
	} else {
		gdbstub_proto("### GDB Rx %02x (st=%02x) ###\n", ch, st);
		*_ch = ch & 0x7f;
		return 0;
	}
}

/*
 * send a character to the debugger
 */
void gdbstub_io_tx_char(unsigned char ch)
{
	FLOWCTL_SET(DTR);
	LSR_WAIT_FOR(THRE);
	/* FLOWCTL_WAIT_FOR(CTS); */

	if (ch == 0x0a) {
		GDBPORT_SERIAL_TX = 0x0d;
		LSR_WAIT_FOR(THRE);
		/* FLOWCTL_WAIT_FOR(CTS); */
	}
	GDBPORT_SERIAL_TX = ch;

	FLOWCTL_CLEAR(DTR);
}

/*
 * send a character to the debugger
 */
void gdbstub_io_tx_flush(void)
{
	LSR_WAIT_FOR(TEMT);
	LSR_WAIT_FOR(THRE);
	FLOWCTL_CLEAR(DTR);
}