xref: /netbsd-src/sys/dev/ic/z8530sc.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: z8530sc.c,v 1.22 2005/12/11 12:21:29 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This software was developed by the Computer Systems Engineering group
8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9  * contributed to Berkeley.
10  *
11  * All advertising materials mentioning features or use of this software
12  * must display the following acknowledgement:
13  *	This product includes software developed by the University of
14  *	California, Lawrence Berkeley Laboratory.
15  *
16  * Redistribution and use in source and binary forms, with or without
17  * modification, are permitted provided that the following conditions
18  * are met:
19  * 1. Redistributions of source code must retain the above copyright
20  *    notice, this list of conditions and the following disclaimer.
21  * 2. Redistributions in binary form must reproduce the above copyright
22  *    notice, this list of conditions and the following disclaimer in the
23  *    documentation and/or other materials provided with the distribution.
24  * 3. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  *
40  *	@(#)zs.c	8.1 (Berkeley) 7/19/93
41  */
42 
43 /*
44  * Copyright (c) 1994 Gordon W. Ross
45  *
46  * This software was developed by the Computer Systems Engineering group
47  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
48  * contributed to Berkeley.
49  *
50  * All advertising materials mentioning features or use of this software
51  * must display the following acknowledgement:
52  *	This product includes software developed by the University of
53  *	California, Lawrence Berkeley Laboratory.
54  *
55  * Redistribution and use in source and binary forms, with or without
56  * modification, are permitted provided that the following conditions
57  * are met:
58  * 1. Redistributions of source code must retain the above copyright
59  *    notice, this list of conditions and the following disclaimer.
60  * 2. Redistributions in binary form must reproduce the above copyright
61  *    notice, this list of conditions and the following disclaimer in the
62  *    documentation and/or other materials provided with the distribution.
63  * 3. All advertising materials mentioning features or use of this software
64  *    must display the following acknowledgement:
65  *	This product includes software developed by the University of
66  *	California, Berkeley and its contributors.
67  * 4. Neither the name of the University nor the names of its contributors
68  *    may be used to endorse or promote products derived from this software
69  *    without specific prior written permission.
70  *
71  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
72  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
73  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
74  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
75  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
76  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
77  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
78  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
79  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
80  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
81  * SUCH DAMAGE.
82  *
83  *	@(#)zs.c	8.1 (Berkeley) 7/19/93
84  */
85 
86 /*
87  * Zilog Z8530 Dual UART driver (common part)
88  *
89  * This file contains the machine-independent parts of the
90  * driver common to tty and keyboard/mouse sub-drivers.
91  */
92 
93 #include <sys/cdefs.h>
94 __KERNEL_RCSID(0, "$NetBSD: z8530sc.c,v 1.22 2005/12/11 12:21:29 christos Exp $");
95 
96 #include <sys/param.h>
97 #include <sys/systm.h>
98 #include <sys/proc.h>
99 #include <sys/device.h>
100 #include <sys/conf.h>
101 #include <sys/file.h>
102 #include <sys/ioctl.h>
103 #include <sys/tty.h>
104 #include <sys/time.h>
105 #include <sys/kernel.h>
106 #include <sys/syslog.h>
107 
108 #include <dev/ic/z8530reg.h>
109 #include <machine/z8530var.h>
110 
111 void
112 zs_break(cs, set)
113 	struct zs_chanstate *cs;
114 	int set;
115 {
116 
117 	if (set) {
118 		cs->cs_preg[5] |= ZSWR5_BREAK;
119 		cs->cs_creg[5] |= ZSWR5_BREAK;
120 	} else {
121 		cs->cs_preg[5] &= ~ZSWR5_BREAK;
122 		cs->cs_creg[5] &= ~ZSWR5_BREAK;
123 	}
124 	zs_write_reg(cs, 5, cs->cs_creg[5]);
125 }
126 
127 
128 /*
129  * drain on-chip fifo
130  */
131 void
132 zs_iflush(cs)
133 	struct zs_chanstate *cs;
134 {
135 	u_char c, rr0, rr1;
136 	int i;
137 
138 	/*
139 	 * Count how many times we loop. Some systems, such as some
140 	 * Apple PowerBooks, claim to have SCC's which they really don't.
141 	 */
142 	for (i = 0; i < 32; i++) {
143 		/* Is there input available? */
144 		rr0 = zs_read_csr(cs);
145 		if ((rr0 & ZSRR0_RX_READY) == 0)
146 			break;
147 
148 		/*
149 		 * First read the status, because reading the data
150 		 * destroys the status of this char.
151 		 */
152 		rr1 = zs_read_reg(cs, 1);
153 		c = zs_read_data(cs);
154 
155 		if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
156 			/* Clear the receive error. */
157 			zs_write_csr(cs, ZSWR0_RESET_ERRORS);
158 		}
159 	}
160 }
161 
162 
163 /*
164  * Write the given register set to the given zs channel in the proper order.
165  * The channel must not be transmitting at the time.  The receiver will
166  * be disabled for the time it takes to write all the registers.
167  * Call this with interrupts disabled.
168  */
169 void
170 zs_loadchannelregs(cs)
171 	struct zs_chanstate *cs;
172 {
173 	u_char *reg, v;
174 
175 	zs_write_csr(cs, ZSM_RESET_ERR); /* XXX: reset error condition */
176 
177 #if 1
178 	/*
179 	 * XXX: Is this really a good idea?
180 	 * XXX: Should go elsewhere! -gwr
181 	 */
182 	zs_iflush(cs);	/* XXX */
183 #endif
184 
185 	if (cs->cs_ctl_chan != NULL)
186 		v = ((cs->cs_ctl_chan->cs_creg[5] & (ZSWR5_RTS | ZSWR5_DTR)) !=
187 		    (cs->cs_ctl_chan->cs_preg[5] & (ZSWR5_RTS | ZSWR5_DTR)));
188 	else
189 		v = 0;
190 
191 	if (memcmp((caddr_t)cs->cs_preg, (caddr_t)cs->cs_creg, 16) == 0 && !v)
192 		return;	/* only change if values are different */
193 
194 	/* Copy "pending" regs to "current" */
195 	memcpy((caddr_t)cs->cs_creg, (caddr_t)cs->cs_preg, 16);
196 	reg = cs->cs_creg;	/* current regs */
197 
198 	/* disable interrupts */
199 	zs_write_reg(cs, 1, reg[1] & ~ZSWR1_IMASK);
200 
201 	/* baud clock divisor, stop bits, parity */
202 	zs_write_reg(cs, 4, reg[4]);
203 
204 	/* misc. TX/RX control bits */
205 	zs_write_reg(cs, 10, reg[10]);
206 
207 	/* char size, enable (RX/TX) */
208 	zs_write_reg(cs, 3, reg[3] & ~ZSWR3_RX_ENABLE);
209 	zs_write_reg(cs, 5, reg[5] & ~ZSWR5_TX_ENABLE);
210 
211 	/* synchronous mode stuff */
212 	zs_write_reg(cs, 6, reg[6]);
213 	zs_write_reg(cs, 7, reg[7]);
214 
215 #if 0
216 	/*
217 	 * Registers 2 and 9 are special because they are
218 	 * actually common to both channels, but must be
219 	 * programmed through channel A.  The "zsc" attach
220 	 * function takes care of setting these registers
221 	 * and they should not be touched thereafter.
222 	 */
223 	/* interrupt vector */
224 	zs_write_reg(cs, 2, reg[2]);
225 	/* master interrupt control */
226 	zs_write_reg(cs, 9, reg[9]);
227 #endif
228 
229 	/* Shut down the BRG */
230 	zs_write_reg(cs, 14, reg[14] & ~ZSWR14_BAUD_ENA);
231 
232 #ifdef	ZS_MD_SETCLK
233 	/* Let the MD code setup any external clock. */
234 	ZS_MD_SETCLK(cs);
235 #endif	/* ZS_MD_SETCLK */
236 
237 	/* clock mode control */
238 	zs_write_reg(cs, 11, reg[11]);
239 
240 	/* baud rate (lo/hi) */
241 	zs_write_reg(cs, 12, reg[12]);
242 	zs_write_reg(cs, 13, reg[13]);
243 
244 	/* Misc. control bits */
245 	zs_write_reg(cs, 14, reg[14]);
246 
247 	/* which lines cause status interrupts */
248 	zs_write_reg(cs, 15, reg[15]);
249 
250 	/*
251 	 * Zilog docs recommend resetting external status twice at this
252 	 * point. Mainly as the status bits are latched, and the first
253 	 * interrupt clear might unlatch them to new values, generating
254 	 * a second interrupt request.
255 	 */
256 	zs_write_csr(cs, ZSM_RESET_STINT);
257 	zs_write_csr(cs, ZSM_RESET_STINT);
258 
259 	/* char size, enable (RX/TX)*/
260 	zs_write_reg(cs, 3, reg[3]);
261 	zs_write_reg(cs, 5, reg[5]);
262 
263 	/* Write the status bits on the alternate channel also. */
264 	if (cs->cs_ctl_chan != NULL) {
265 		v = cs->cs_ctl_chan->cs_preg[5];
266 		cs->cs_ctl_chan->cs_creg[5] = v;
267 		zs_write_reg(cs->cs_ctl_chan, 5, v);
268 	}
269 
270 	/* interrupt enables: RX, TX, STATUS */
271 	zs_write_reg(cs, 1, reg[1]);
272 }
273 
274 
275 /*
276  * ZS hardware interrupt.  Scan all ZS channels.  NB: we know here that
277  * channels are kept in (A,B) pairs.
278  *
279  * Do just a little, then get out; set a software interrupt if more
280  * work is needed.
281  *
282  * We deliberately ignore the vectoring Zilog gives us, and match up
283  * only the number of `reset interrupt under service' operations, not
284  * the order.
285  */
286 int
287 zsc_intr_hard(arg)
288 	void *arg;
289 {
290 	struct zsc_softc *zsc = arg;
291 	struct zs_chanstate *cs;
292 	u_char rr3;
293 
294 	/* First look at channel A. */
295 	cs = zsc->zsc_cs[0];
296 
297 	/* Lock both channels */
298 	simple_lock(&cs->cs_lock);
299 	simple_lock(&zsc->zsc_cs[1]->cs_lock);
300 	/* Note: only channel A has an RR3 */
301 	rr3 = zs_read_reg(cs, 3);
302 
303 	/*
304 	 * Clear interrupt first to avoid a race condition.
305 	 * If a new interrupt condition happens while we are
306 	 * servicing this one, we will get another interrupt
307 	 * shortly.  We can NOT just sit here in a loop, or
308 	 * we will cause horrible latency for other devices
309 	 * on this interrupt level (i.e. sun3x floppy disk).
310 	 */
311 	if (rr3 & (ZSRR3_IP_A_RX | ZSRR3_IP_A_TX | ZSRR3_IP_A_STAT)) {
312 		zs_write_csr(cs, ZSWR0_CLR_INTR);
313 		if (rr3 & ZSRR3_IP_A_RX)
314 			(*cs->cs_ops->zsop_rxint)(cs);
315 		if (rr3 & ZSRR3_IP_A_STAT)
316 			(*cs->cs_ops->zsop_stint)(cs, 0);
317 		if (rr3 & ZSRR3_IP_A_TX)
318 			(*cs->cs_ops->zsop_txint)(cs);
319 	}
320 
321 	/* Done with channel A */
322 	simple_unlock(&cs->cs_lock);
323 
324 	/* Now look at channel B. */
325 	cs = zsc->zsc_cs[1];
326 	if (rr3 & (ZSRR3_IP_B_RX | ZSRR3_IP_B_TX | ZSRR3_IP_B_STAT)) {
327 		zs_write_csr(cs, ZSWR0_CLR_INTR);
328 		if (rr3 & ZSRR3_IP_B_RX)
329 			(*cs->cs_ops->zsop_rxint)(cs);
330 		if (rr3 & ZSRR3_IP_B_STAT)
331 			(*cs->cs_ops->zsop_stint)(cs, 0);
332 		if (rr3 & ZSRR3_IP_B_TX)
333 			(*cs->cs_ops->zsop_txint)(cs);
334 	}
335 
336 	simple_unlock(&cs->cs_lock);
337 
338 	/* Note: caller will check cs_x->cs_softreq and DTRT. */
339 	return (rr3);
340 }
341 
342 
343 /*
344  * ZS software interrupt.  Scan all channels for deferred interrupts.
345  */
346 int
347 zsc_intr_soft(arg)
348 	void *arg;
349 {
350 	struct zsc_softc *zsc = arg;
351 	struct zs_chanstate *cs;
352 	int rval, chan;
353 
354 	rval = 0;
355 	for (chan = 0; chan < 2; chan++) {
356 		cs = zsc->zsc_cs[chan];
357 
358 		/*
359 		 * The softint flag can be safely cleared once
360 		 * we have decided to call the softint routine.
361 		 * (No need to do splzs() first.)
362 		 */
363 		if (cs->cs_softreq) {
364 			cs->cs_softreq = 0;
365 			(*cs->cs_ops->zsop_softint)(cs);
366 			rval++;
367 		}
368 	}
369 	return (rval);
370 }
371 
372 /*
373  * Provide a null zs "ops" vector.
374  */
375 
376 static void zsnull_rxint  (struct zs_chanstate *);
377 static void zsnull_stint  (struct zs_chanstate *, int);
378 static void zsnull_txint  (struct zs_chanstate *);
379 static void zsnull_softint(struct zs_chanstate *);
380 
381 static void
382 zsnull_rxint(cs)
383 	struct zs_chanstate *cs;
384 {
385 	/* Ask for softint() call. */
386 	cs->cs_softreq = 1;
387 }
388 
389 static void
390 zsnull_stint(cs, force)
391 	struct zs_chanstate *cs;
392 	int force;
393 {
394 	/* Ask for softint() call. */
395 	cs->cs_softreq = 1;
396 }
397 
398 static void
399 zsnull_txint(cs)
400 	struct zs_chanstate *cs;
401 {
402 	/* Ask for softint() call. */
403 	cs->cs_softreq = 1;
404 }
405 
406 static void
407 zsnull_softint(cs)
408 	struct zs_chanstate *cs;
409 {
410 	zs_write_reg(cs,  1, 0);
411 	zs_write_reg(cs, 15, 0);
412 }
413 
414 struct zsops zsops_null = {
415 	zsnull_rxint,	/* receive char available */
416 	zsnull_stint,	/* external/status */
417 	zsnull_txint,	/* xmit buffer empty */
418 	zsnull_softint,	/* process software interrupt */
419 };
420