summaryrefslogtreecommitdiffstats
path: root/arch/mn10300/kernel/gdb-io-ttysm.c
blob: abdeea153c89643184df8f7b1c13805a504b0b7a (plain)
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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
/* MN10300 On-chip 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/tty.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/gdb-stub.h>
#include <asm/exceptions.h>
#include <unit/clock.h>
#include "mn10300-serial.h"

#if defined(CONFIG_GDBSTUB_ON_TTYSM0)
struct mn10300_serial_port *const gdbstub_port = &mn10300_serial_port_sif0;
#elif defined(CONFIG_GDBSTUB_ON_TTYSM1)
struct mn10300_serial_port *const gdbstub_port = &mn10300_serial_port_sif1;
#else
struct mn10300_serial_port *const gdbstub_port = &mn10300_serial_port_sif2;
#endif


/*
 * initialise the GDB stub I/O routines
 */
void __init gdbstub_io_init(void)
{
	uint16_t scxctr;
	int tmp;

	switch (gdbstub_port->clock_src) {
	case MNSCx_CLOCK_SRC_IOCLK:
		gdbstub_port->ioclk = MN10300_IOCLK;
		break;

#ifdef MN10300_IOBCLK
	case MNSCx_CLOCK_SRC_IOBCLK:
		gdbstub_port->ioclk = MN10300_IOBCLK;
		break;
#endif
	default:
		BUG();
	}

	/* set up the serial port */
	gdbstub_io_set_baud(115200);

	/* we want to get serial receive interrupts */
	set_intr_level(gdbstub_port->rx_irq,
		NUM2GxICR_LEVEL(CONFIG_GDBSTUB_IRQ_LEVEL));
	set_intr_level(gdbstub_port->tx_irq,
		NUM2GxICR_LEVEL(CONFIG_GDBSTUB_IRQ_LEVEL));
	set_intr_stub(NUM2EXCEP_IRQ_LEVEL(CONFIG_GDBSTUB_IRQ_LEVEL),
		gdbstub_io_rx_handler);

	*gdbstub_port->rx_icr |= GxICR_ENABLE;
	tmp = *gdbstub_port->rx_icr;

	/* enable the device */
	scxctr = SC01CTR_CLN_8BIT;	/* 1N8 */
	switch (gdbstub_port->div_timer) {
	case MNSCx_DIV_TIMER_16BIT:
		scxctr |= SC0CTR_CK_TM8UFLOW_8; /* == SC1CTR_CK_TM9UFLOW_8
						   == SC2CTR_CK_TM10UFLOW_8 */
		break;

	case MNSCx_DIV_TIMER_8BIT:
		scxctr |= SC0CTR_CK_TM2UFLOW_8;
		break;
	}

	scxctr |= SC01CTR_TXE | SC01CTR_RXE;

	*gdbstub_port->_control = scxctr;
	tmp = *gdbstub_port->_control;

	/* permit level 0 IRQs only */
	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)
{
	const unsigned bits = 10; /* 1 [start] + 8 [data] + 0 [parity] +
				   * 1 [stop] */
	unsigned long ioclk = gdbstub_port->ioclk;
	unsigned xdiv, tmp;
	uint16_t tmxbr;
	uint8_t tmxmd;

	if (!baud) {
		baud = 9600;
	} else if (baud == 134) {
		baud = 269;	/* 134 is really 134.5 */
		xdiv = 2;
	}

try_alternative:
	xdiv = 1;

	switch (gdbstub_port->div_timer) {
	case MNSCx_DIV_TIMER_16BIT:
		tmxmd = TM8MD_SRC_IOCLK;
		tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1;
		if (tmp > 0 && tmp <= 65535)
			goto timer_okay;

		tmxmd = TM8MD_SRC_IOCLK_8;
		tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1;
		if (tmp > 0 && tmp <= 65535)
			goto timer_okay;

		tmxmd = TM8MD_SRC_IOCLK_32;
		tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1;
		if (tmp > 0 && tmp <= 65535)
			goto timer_okay;

		break;

	case MNSCx_DIV_TIMER_8BIT:
		tmxmd = TM2MD_SRC_IOCLK;
		tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1;
		if (tmp > 0 && tmp <= 255)
			goto timer_okay;

		tmxmd = TM2MD_SRC_IOCLK_8;
		tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1;
		if (tmp > 0 && tmp <= 255)
			goto timer_okay;

		tmxmd = TM2MD_SRC_IOCLK_32;
		tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1;
		if (tmp > 0 && tmp <= 255)
			goto timer_okay;
		break;
	}

	/* as a last resort, if the quotient is zero, default to 9600 bps */
	baud = 9600;
	goto try_alternative;

timer_okay:
	gdbstub_port->uart.timeout = (2 * bits * HZ) / baud;
	gdbstub_port->uart.timeout += HZ / 50;

	/* set the timer to produce the required baud rate */
	switch (gdbstub_port->div_timer) {
	case MNSCx_DIV_TIMER_16BIT:
		*gdbstub_port->_tmxmd = 0;
		*gdbstub_port->_tmxbr = tmxbr;
		*gdbstub_port->_tmxmd = TM8MD_INIT_COUNTER;
		*gdbstub_port->_tmxmd = tmxmd | TM8MD_COUNT_ENABLE;
		break;

	case MNSCx_DIV_TIMER_8BIT:
		*gdbstub_port->_tmxmd = 0;
		*(volatile u8 *) gdbstub_port->_tmxbr = (u8)tmxbr;
		*gdbstub_port->_tmxmd = TM2MD_INIT_COUNTER;
		*gdbstub_port->_tmxmd = tmxmd | TM2MD_COUNT_ENABLE;
		break;
	}
}

/*
 * 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 & (PAGE_SIZE - 1);

	st &= SC01STR_RXF | SC01STR_RBF | SC01STR_FEF | SC01STR_PEF |
		SC01STR_OEF;

	/* deal with what we've got
	 * - note that the UART doesn't do BREAK-detection for us
	 */
	if (st & SC01STR_FEF && ch == 0) {
		switch (gdbstub_port->rx_brk) {
		case 0:	gdbstub_port->rx_brk = 1;	goto try_again;
		case 1:	gdbstub_port->rx_brk = 2;	goto try_again;
		case 2:
			gdbstub_port->rx_brk = 3;
			gdbstub_proto("### GDB MNSERIAL Rx Break Detected"
				      " ###\n");
			return -EINTR;
		default:
			goto try_again;
		}
	} else if (st & SC01STR_FEF) {
		if (gdbstub_port->rx_brk)
			goto try_again;

		gdbstub_proto("### GDB MNSERIAL Framing Error ###\n");
		return -EIO;
	} else if (st & SC01STR_OEF) {
		if (gdbstub_port->rx_brk)
			goto try_again;

		gdbstub_proto("### GDB MNSERIAL Overrun Error ###\n");
		return -EIO;
	} else if (st & SC01STR_PEF) {
		if (gdbstub_port->rx_brk)
			goto try_again;

		gdbstub_proto("### GDB MNSERIAL Parity Error ###\n");
		return -EIO;
	} else {
		/* look for the tail-end char on a break run */
		if (gdbstub_port->rx_brk == 3) {
			switch (ch) {
			case 0xFF:
			case 0xFE:
			case 0xFC:
			case 0xF8:
			case 0xF0:
			case 0xE0:
			case 0xC0:
			case 0x80:
			case 0x00:
				gdbstub_port->rx_brk = 0;
				goto try_again;
			default:
				break;
			}
		}

		gdbstub_port->rx_brk = 0;
		gdbstub_io("### 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)
{
	while (*gdbstub_port->_status & SC01STR_TBF)
		continue;

	if (ch == 0x0a) {
		*(u8 *) gdbstub_port->_txb = 0x0d;
		while (*gdbstub_port->_status & SC01STR_TBF)
			continue;
	}

	*(u8 *) gdbstub_port->_txb = ch;
}

/*
 * flush the transmission buffers
 */
void gdbstub_io_tx_flush(void)
{
	while (*gdbstub_port->_status & (SC01STR_TBF | SC01STR_TXF))
		continue;
}