1/*	$NetBSD: zs_kgdb.c,v 1.9 2007/10/17 19:57:43 garbled Exp $	*/
2
3/*-
4 * Copyright (c) 1996 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Gordon W. Ross.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*
33 * Hooks for kgdb when attached via the z8530 driver
34 *
35 * To use this, build a kernel with: option KGDB, and
36 * boot that kernel with "-d".  (The kernel will call
37 * zs_kgdb_init, kgdb_connect.)  When the console prints
38 * "kgdb waiting..." you run "gdb -k kernel" and do:
39 *   (gdb) set remotebaud 19200
40 *   (gdb) target remote /dev/ttyb
41 */
42
43#include <sys/cdefs.h>
44__KERNEL_RCSID(0, "$NetBSD: zs_kgdb.c,v 1.9 2007/10/17 19:57:43 garbled Exp $");
45
46#include "opt_kgdb.h"
47
48#include <sys/param.h>
49#include <sys/systm.h>
50#include <sys/proc.h>
51#include <sys/device.h>
52#include <sys/conf.h>
53#include <sys/ioctl.h>
54#include <sys/kernel.h>
55#include <sys/syslog.h>
56#include <sys/kgdb.h>
57
58#include <dev/ic/z8530reg.h>
59#include <machine/z8530var.h>
60#include <machine/promlib.h>
61#include <sun2/dev/cons.h>
62
63static void zs_setparam(struct zs_chanstate *, int, int);
64struct zsops zsops_kgdb;
65
66extern int  zs_getc(void *arg);
67extern void zs_putc(void *arg, int c);
68
69static u_char zs_kgdb_regs[16] = {
70	0,	/* 0: CMD (reset, etc.) */
71	0,	/* 1: No interrupts yet. */
72#ifdef	ZS_INIT_IVECT
73	ZS_INIT_IVECT,	/* 2: IVECT */
74#else
75	0,	/* 2: IVECT */
76#endif
77	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
78	ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
79	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
80	0,	/* 6: TXSYNC/SYNCLO */
81	0,	/* 7: RXSYNC/SYNCHI */
82	0,	/* 8: alias for data port */
83#ifdef	ZS_INIT_IVECT
84	ZSWR9_MASTER_IE,
85#else
86	ZSWR9_MASTER_IE | ZSWR9_NO_VECTOR,
87#endif
88	0,	/*10: Misc. TX/RX control bits */
89	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
90	14,	/*12: BAUDLO (default=9600) */
91	0,	/*13: BAUDHI (default=9600) */
92	ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
93	ZSWR15_BREAK_IE,
94};
95
96/*
97 * This replaces "zs_reset()" in the sparc driver.
98 */
99static void
100zs_setparam(struct zs_chanstate *cs, int iena, int rate)
101{
102	int s, tconst;
103
104	memcpy(cs->cs_preg, zs_kgdb_regs, 16);
105
106	if (iena) {
107		cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE;
108	}
109
110	/* Initialize the speed, etc. */
111	tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate);
112	cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS;
113	cs->cs_preg[12] = tconst;
114	cs->cs_preg[13] = tconst >> 8;
115
116	s = splhigh();
117	zs_loadchannelregs(cs);
118	splx(s);
119}
120
121/*
122 * Set up for kgdb; called at boot time before configuration.
123 * KGDB interrupts will be enabled later when zs0 is configured.
124 * Called after cninit(), so printf() etc. works.
125 */
126void
127zs_kgdb_init(void)
128{
129	struct zs_chanstate cs;
130	struct zsdevice *zsd;
131	volatile struct zschan *zc;
132	int channel, promzs_unit;
133	extern const struct cdevsw zstty_cdevsw;
134
135	/* printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); */
136	if (cdevsw_lookup(kgdb_dev) != &zstty_cdevsw)
137		return;
138
139	/* Note: (ttya,ttyb) on zs0, and (ttyc,ttyd) on zs2 */
140	promzs_unit = (kgdb_dev & 2) ? 2 : 0;
141	channel  =  kgdb_dev & 1;
142	printf("zs_kgdb_init: attaching tty%c at %d baud\n",
143		   'a' + (kgdb_dev & 3), kgdb_rate);
144
145	/* Setup temporary chanstate. */
146	memset((void *)&cs, 0, sizeof(cs));
147	zsd = zs_find_prom(promzs_unit);
148	if (zsd == NULL) {
149		printf("zs_kgdb_init: zs not mapped.\n");
150		return;
151	}
152	zc = (channel == 0) ? &zsd->zs_chan_a : &zsd->zs_chan_b;
153
154	cs.cs_channel = channel;
155	cs.cs_brg_clk = PCLK / 16;
156	cs.cs_reg_csr  = &zc->zc_csr;
157	cs.cs_reg_data = &zc->zc_data;
158
159	/* Now set parameters. (interrupts disabled) */
160	zs_setparam(&cs, 0, kgdb_rate);
161
162	/* Store the getc/putc functions and arg. */
163	kgdb_attach(zs_getc, zs_putc, __UNVOLATILE(zc));
164}
165
166/*
167 * This is a "hook" called by zstty_attach to allow the tty
168 * to be "taken over" for exclusive use by kgdb.
169 * Return non-zero if this is the kgdb port.
170 *
171 * Set the speed to kgdb_rate, CS8, etc.
172 */
173int
174zs_check_kgdb(struct zs_chanstate *cs, int dev)
175{
176
177	if (dev != kgdb_dev)
178		return (0);
179
180	/*
181	 * Yes, this is port in use by kgdb.
182	 */
183	cs->cs_private = NULL;
184	cs->cs_ops = &zsops_kgdb;
185
186	/* Now set parameters. (interrupts enabled) */
187	zs_setparam(cs, 1, kgdb_rate);
188
189	return (1);
190}
191
192/*
193 * KGDB framing character received: enter kernel debugger.  This probably
194 * should time out after a few seconds to avoid hanging on spurious input.
195 */
196void
197zskgdb(struct zs_chanstate *cs)
198{
199	int unit = minor(kgdb_dev);
200
201	printf("zstty%d: kgdb interrupt\n", unit);
202	/* This will trap into the debugger. */
203	kgdb_connect(1);
204}
205
206
207/****************************************************************
208 * Interface to the lower layer (zscc)
209 ****************************************************************/
210
211static void zs_kgdb_rxint(struct zs_chanstate *);
212static void zs_kgdb_stint(struct zs_chanstate *, int);
213static void zs_kgdb_txint(struct zs_chanstate *);
214static void zs_kgdb_softint(struct zs_chanstate *);
215
216int kgdb_input_lost;
217
218static void
219zs_kgdb_rxint(struct zs_chanstate *cs)
220{
221	u_char c, rr1;
222
223	/*
224	 * First read the status, because reading the received char
225	 * destroys the status of this char.
226	 */
227	rr1 = zs_read_reg(cs, 1);
228	c = zs_read_data(cs);
229
230	if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
231		/* Clear the receive error. */
232		zs_write_csr(cs, ZSWR0_RESET_ERRORS);
233	}
234
235	if (c == KGDB_START) {
236		zskgdb(cs);
237	} else {
238		kgdb_input_lost++;
239	}
240}
241
242static void
243zs_kgdb_txint(struct zs_chanstate *cs)
244{
245	int rr0;
246
247	rr0 = zs_read_csr(cs);
248	zs_write_csr(cs, ZSWR0_RESET_TXINT);
249}
250
251static void
252zs_kgdb_stint(struct zs_chanstate *cs, int force)
253{
254	int rr0;
255
256	rr0 = zs_read_csr(cs);
257	zs_write_csr(cs, ZSWR0_RESET_STATUS);
258
259	/*
260	 * Check here for console break, so that we can abort
261	 * even when interrupts are locking up the machine.
262	 */
263	if (rr0 & ZSRR0_BREAK) {
264		zskgdb(cs);
265	}
266}
267
268static void
269zs_kgdb_softint(struct zs_chanstate *cs)
270{
271	printf("zs_kgdb_softint?\n");
272}
273
274struct zsops zsops_kgdb = {
275	zs_kgdb_rxint,	/* receive char available */
276	zs_kgdb_stint,	/* external/status */
277	zs_kgdb_txint,	/* xmit buffer empty */
278	zs_kgdb_softint,	/* process software interrupt */
279};
280