xref: /netbsd/sys/arch/sun3/dev/zs_kgdb.c (revision bf9ec67e)
1 /*	$NetBSD: zs_kgdb.c,v 1.15 2001/09/05 14:03:49 tsutsui 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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Hooks for kgdb when attached via the z8530 driver
41  *
42  * To use this, build a kernel with: option KGDB, and
43  * boot that kernel with "-d".  (The kernel will call
44  * zs_kgdb_init, kgdb_connect.)  When the console prints
45  * "kgdb waiting..." you run "gdb -k kernel" and do:
46  *   (gdb) set remotebaud 19200
47  *   (gdb) target remote /dev/ttyb
48  */
49 
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/proc.h>
53 #include <sys/device.h>
54 #include <sys/conf.h>
55 #include <sys/ioctl.h>
56 #include <sys/kernel.h>
57 #include <sys/syslog.h>
58 #include <sys/kgdb.h>
59 
60 #include <dev/ic/z8530reg.h>
61 #include <machine/z8530var.h>
62 #include <sun3/dev/zs_cons.h>
63 
64 /* The Sun3 provides a 4.9152 MHz clock to the ZS chips. */
65 #define PCLK	(9600 * 512)	/* PCLK pin input clock rate */
66 #define ZSHARD_PRI	6	/* Wired on the CPU board... */
67 
68 #define ZS_DELAY()			delay(2)
69 
70 /* The layout of this is hardware-dependent (padding, order). */
71 struct zschan {
72 	volatile u_char	zc_csr;		/* ctrl,status, and indirect access */
73 	u_char		zc_xxx0;
74 	volatile u_char	zc_data;	/* data */
75 	u_char		zc_xxx1;
76 };
77 
78 static void zs_setparam __P((struct zs_chanstate *, int, int));
79 static void zskgdb __P((struct zs_chanstate *));
80 
81 struct zsops zsops_kgdb;
82 
83 static u_char zs_kgdb_regs[16] = {
84 	0,	/* 0: CMD (reset, etc.) */
85 	0,	/* 1: ~(ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE) */
86 	0x18 + ZSHARD_PRI,	/* IVECT */
87 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
88 	ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
89 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
90 	0,	/* 6: TXSYNC/SYNCLO */
91 	0,	/* 7: RXSYNC/SYNCHI */
92 	0,	/* 8: alias for data port */
93 	ZSWR9_MASTER_IE,
94 	0,	/*10: Misc. TX/RX control bits */
95 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
96 	14,	/*12: BAUDLO (default=9600) */
97 	0,	/*13: BAUDHI (default=9600) */
98 	ZSWR14_BAUD_FROM_PCLK | ZSWR14_BAUD_ENA,
99 	ZSWR15_BREAK_IE,
100 };
101 
102 /*
103  * This replaces "zs_reset()" in the sparc driver.
104  */
105 static void
106 zs_setparam(cs, iena, rate)
107 	struct zs_chanstate *cs;
108 	int iena;
109 	int rate;
110 {
111 	int s, tconst;
112 
113 	memcpy(cs->cs_preg, zs_kgdb_regs, 16);
114 
115 	if (iena) {
116 		cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE;
117 	}
118 
119 	/* Initialize the speed, etc. */
120 	tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate);
121 	cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS;
122 	cs->cs_preg[12] = tconst;
123 	cs->cs_preg[13] = tconst >> 8;
124 
125 	s = splhigh();
126 	zs_loadchannelregs(cs);
127 	splx(s);
128 }
129 
130 /*
131  * Set up for kgdb; called at boot time before configuration.
132  * KGDB interrupts will be enabled later when zs0 is configured.
133  * Called after cninit(), so printf() etc. works.
134  */
135 void
136 zs_kgdb_init()
137 {
138 	struct zs_chanstate cs;
139 	volatile struct zschan *zc;
140 	int channel, zsc_unit;
141 
142 	/* printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); */
143 	if (major(kgdb_dev) != zs_major)
144 		return;
145 
146 	/* Note: (ttya,ttyb) on zsc1, and (ttyc,ttyd) on zsc0 */
147 	zsc_unit = (kgdb_dev & 2) ? 0 : 1;
148 	channel  =  kgdb_dev & 1;
149 	printf("zs_kgdb_init: attaching tty%c at %d baud\n",
150 		   'a' + (kgdb_dev & 3), kgdb_rate);
151 
152 	/* Setup temporary chanstate. */
153 	memset((caddr_t)&cs, 0, sizeof(cs));
154 	zc = zs_get_chan_addr(zsc_unit, channel);
155 	if (zc == NULL) {
156 		printf("zs_kgdb_init: zs not mapped.\n");
157 		kgdb_dev = -1;
158 		return;
159 	}
160 
161 	cs.cs_channel = channel;
162 	cs.cs_brg_clk = PCLK / 16;
163 	cs.cs_reg_csr  = &zc->zc_csr;
164 	cs.cs_reg_data = &zc->zc_data;
165 
166 	/* Now set parameters. (interrupts disabled) */
167 	zs_setparam(&cs, 0, kgdb_rate);
168 
169 	/* Store the getc/putc functions and arg. */
170 	kgdb_attach(zs_getc, zs_putc, (void *)zc);
171 }
172 
173 /*
174  * This is a "hook" called by zstty_attach to allow the tty
175  * to be "taken over" for exclusive use by kgdb.
176  * Return non-zero if this is the kgdb port.
177  *
178  * Set the speed to kgdb_rate, CS8, etc.
179  */
180 int
181 zs_check_kgdb(cs, dev)
182 	struct zs_chanstate *cs;
183 	int dev;
184 {
185 
186 	if (dev != kgdb_dev)
187 		return (0);
188 
189 	/*
190 	 * Yes, this is port in use by kgdb.
191 	 */
192 	cs->cs_private = NULL;
193 	cs->cs_ops = &zsops_kgdb;
194 
195 	/* Now set parameters. (interrupts enabled) */
196 	zs_setparam(cs, 1, kgdb_rate);
197 
198 	return (1);
199 }
200 
201 /*
202  * KGDB framing character received: enter kernel debugger.  This probably
203  * should time out after a few seconds to avoid hanging on spurious input.
204  */
205 static void
206 zskgdb(cs)
207 	struct zs_chanstate *cs;
208 {
209 	int unit = minor(kgdb_dev);
210 
211 	printf("zstty%d: kgdb interrupt\n", unit);
212 	/* This will trap into the debugger. */
213 	kgdb_connect(1);
214 }
215 
216 
217 /****************************************************************
218  * Interface to the lower layer (zscc)
219  ****************************************************************/
220 
221 static void zs_kgdb_rxint __P((struct zs_chanstate *));
222 static void zs_kgdb_stint __P((struct zs_chanstate *, int));
223 static void zs_kgdb_txint __P((struct zs_chanstate *));
224 static void zs_kgdb_softint __P((struct zs_chanstate *));
225 
226 int kgdb_input_lost;
227 
228 static void
229 zs_kgdb_rxint(cs)
230 	struct zs_chanstate *cs;
231 {
232 	u_char c, rr1;
233 
234 	/*
235 	 * First read the status, because reading the received char
236 	 * destroys the status of this char.
237 	 */
238 	rr1 = zs_read_reg(cs, 1);
239 	c = zs_read_data(cs);
240 
241 	if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
242 		/* Clear the receive error. */
243 		zs_write_csr(cs, ZSWR0_RESET_ERRORS);
244 	}
245 
246 	if (c == KGDB_START) {
247 		zskgdb(cs);
248 	} else {
249 		kgdb_input_lost++;
250 	}
251 }
252 
253 static void
254 zs_kgdb_txint(cs)
255 	struct zs_chanstate *cs;
256 {
257 	int rr0;
258 
259 	rr0 = zs_read_csr(cs);
260 	zs_write_csr(cs, ZSWR0_RESET_TXINT);
261 }
262 
263 static void
264 zs_kgdb_stint(cs, force)
265 	struct zs_chanstate *cs;
266 	int force;
267 {
268 	int rr0;
269 
270 	rr0 = zs_read_csr(cs);
271 	zs_write_csr(cs, ZSWR0_RESET_STATUS);
272 
273 	/*
274 	 * Check here for console break, so that we can abort
275 	 * even when interrupts are locking up the machine.
276 	 */
277 	if (rr0 & ZSRR0_BREAK) {
278 		zskgdb(cs);
279 	}
280 }
281 
282 static void
283 zs_kgdb_softint(cs)
284 	struct zs_chanstate *cs;
285 {
286 	printf("zs_kgdb_softint?\n");
287 }
288 
289 struct zsops zsops_kgdb = {
290 	zs_kgdb_rxint,	/* receive char available */
291 	zs_kgdb_stint,	/* external/status */
292 	zs_kgdb_txint,	/* xmit buffer empty */
293 	zs_kgdb_softint,	/* process software interrupt */
294 };
295