xref: /openbsd-src/sys/dev/ic/z8530sc.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: z8530sc.c,v 1.7 2013/04/21 14:44:16 sebastia Exp $	*/
2 /*	$NetBSD: z8530sc.c,v 1.30 2009/05/22 03:51:30 mrg Exp $	*/
3 
4 /*
5  * Copyright (c) 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This software was developed by the Computer Systems Engineering group
9  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
10  * contributed to Berkeley.
11  *
12  * All advertising materials mentioning features or use of this software
13  * must display the following acknowledgement:
14  *	This product includes software developed by the University of
15  *	California, Lawrence Berkeley Laboratory.
16  *
17  * Redistribution and use in source and binary forms, with or without
18  * modification, are permitted provided that the following conditions
19  * are met:
20  * 1. Redistributions of source code must retain the above copyright
21  *    notice, this list of conditions and the following disclaimer.
22  * 2. Redistributions in binary form must reproduce the above copyright
23  *    notice, this list of conditions and the following disclaimer in the
24  *    documentation and/or other materials provided with the distribution.
25  * 3. Neither the name of the University nor the names of its contributors
26  *    may be used to endorse or promote products derived from this software
27  *    without specific prior written permission.
28  *
29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39  * SUCH DAMAGE.
40  *
41  *	@(#)zs.c	8.1 (Berkeley) 7/19/93
42  */
43 
44 /*
45  * Copyright (c) 1994 Gordon W. Ross
46  *
47  * This software was developed by the Computer Systems Engineering group
48  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
49  * contributed to Berkeley.
50  *
51  * All advertising materials mentioning features or use of this software
52  * must display the following acknowledgement:
53  *	This product includes software developed by the University of
54  *	California, Lawrence Berkeley Laboratory.
55  *
56  * Redistribution and use in source and binary forms, with or without
57  * modification, are permitted provided that the following conditions
58  * are met:
59  * 1. Redistributions of source code must retain the above copyright
60  *    notice, this list of conditions and the following disclaimer.
61  * 2. Redistributions in binary form must reproduce the above copyright
62  *    notice, this list of conditions and the following disclaimer in the
63  *    documentation and/or other materials provided with the distribution.
64  * 3. All advertising materials mentioning features or use of this software
65  *    must display the following acknowledgement:
66  *	This product includes software developed by the University of
67  *	California, Berkeley and its contributors.
68  * 4. Neither the name of the University nor the names of its contributors
69  *    may be used to endorse or promote products derived from this software
70  *    without specific prior written permission.
71  *
72  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
73  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
74  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
75  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
76  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
77  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
78  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
79  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
80  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
81  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
82  * SUCH DAMAGE.
83  *
84  *	@(#)zs.c	8.1 (Berkeley) 7/19/93
85  */
86 
87 /*
88  * Zilog Z8530 Dual UART driver (common part)
89  *
90  * This file contains the machine-independent parts of the
91  * driver common to tty and keyboard/mouse sub-drivers.
92  */
93 
94 #include <sys/param.h>
95 #include <sys/systm.h>
96 #include <sys/proc.h>
97 #include <sys/device.h>
98 #include <sys/conf.h>
99 #include <sys/file.h>
100 #include <sys/ioctl.h>
101 #include <sys/tty.h>
102 #include <sys/time.h>
103 #include <sys/kernel.h>
104 #include <sys/syslog.h>
105 
106 #include <dev/ic/z8530reg.h>
107 #include <machine/z8530var.h>
108 
109 void
110 zs_break(struct zs_chanstate *cs, int set)
111 {
112 
113 	if (set) {
114 		cs->cs_preg[5] |= ZSWR5_BREAK;
115 		cs->cs_creg[5] |= ZSWR5_BREAK;
116 	} else {
117 		cs->cs_preg[5] &= ~ZSWR5_BREAK;
118 		cs->cs_creg[5] &= ~ZSWR5_BREAK;
119 	}
120 	zs_write_reg(cs, 5, cs->cs_creg[5]);
121 }
122 
123 
124 /*
125  * drain on-chip fifo
126  */
127 void
128 zs_iflush(struct zs_chanstate *cs)
129 {
130 	uint8_t c, rr0, rr1;
131 	int i;
132 
133 	/*
134 	 * Count how many times we loop. Some systems, such as some
135 	 * Apple PowerBooks, claim to have SCC's which they really don't.
136 	 */
137 	for (i = 0; i < 32; i++) {
138 		/* Is there input available? */
139 		rr0 = zs_read_csr(cs);
140 		if ((rr0 & ZSRR0_RX_READY) == 0)
141 			break;
142 
143 		/*
144 		 * First read the status, because reading the data
145 		 * destroys the status of this char.
146 		 */
147 		rr1 = zs_read_reg(cs, 1);
148 		c = zs_read_data(cs);
149 
150 		if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
151 			/* Clear the receive error. */
152 			zs_write_csr(cs, ZSWR0_RESET_ERRORS);
153 		}
154 	}
155 }
156 
157 
158 /*
159  * Write the given register set to the given zs channel in the proper order.
160  * The channel must not be transmitting at the time.  The receiver will
161  * be disabled for the time it takes to write all the registers.
162  * Call this with interrupts disabled.
163  */
164 void
165 zs_loadchannelregs(struct zs_chanstate *cs)
166 {
167 	uint8_t *reg, v;
168 
169 	zs_write_csr(cs, ZSM_RESET_ERR); /* XXX: reset error condition */
170 
171 #if 1
172 	/*
173 	 * XXX: Is this really a good idea?
174 	 * XXX: Should go elsewhere! -gwr
175 	 */
176 	zs_iflush(cs);	/* XXX */
177 #endif
178 
179 	if (cs->cs_ctl_chan != NULL)
180 		v = ((cs->cs_ctl_chan->cs_creg[5] & (ZSWR5_RTS | ZSWR5_DTR)) !=
181 		    (cs->cs_ctl_chan->cs_preg[5] & (ZSWR5_RTS | ZSWR5_DTR)));
182 	else
183 		v = 0;
184 
185 	if (memcmp((void *)cs->cs_preg, (void *)cs->cs_creg, 16) == 0 && !v)
186 		return;	/* only change if values are different */
187 
188 	/* Copy "pending" regs to "current" */
189 	memcpy((void *)cs->cs_creg, (void *)cs->cs_preg, 16);
190 	reg = cs->cs_creg;	/* current regs */
191 
192 	/* disable interrupts */
193 	zs_write_reg(cs, 1, reg[1] & ~ZSWR1_IMASK);
194 
195 	/* baud clock divisor, stop bits, parity */
196 	zs_write_reg(cs, 4, reg[4]);
197 
198 	/* misc. TX/RX control bits */
199 	zs_write_reg(cs, 10, reg[10]);
200 
201 	/* char size, enable (RX/TX) */
202 	zs_write_reg(cs, 3, reg[3] & ~ZSWR3_RX_ENABLE);
203 	zs_write_reg(cs, 5, reg[5] & ~ZSWR5_TX_ENABLE);
204 
205 	/* synchronous mode stuff */
206 	zs_write_reg(cs, 6, reg[6]);
207 	if (reg[15] & ZSWR15_ENABLE_ENHANCED)
208 		zs_write_reg(cs, 15, 0);
209 	zs_write_reg(cs, 7, reg[7]);
210 
211 #if 0
212 	/*
213 	 * Registers 2 and 9 are special because they are
214 	 * actually common to both channels, but must be
215 	 * programmed through channel A.  The "zsc" attach
216 	 * function takes care of setting these registers
217 	 * and they should not be touched thereafter.
218 	 */
219 	/* interrupt vector */
220 	zs_write_reg(cs, 2, reg[2]);
221 	/* master interrupt control */
222 	zs_write_reg(cs, 9, reg[9]);
223 #endif
224 
225 	/* Shut down the BRG */
226 	zs_write_reg(cs, 14, reg[14] & ~ZSWR14_BAUD_ENA);
227 
228 #ifdef	ZS_MD_SETCLK
229 	/* Let the MD code setup any external clock. */
230 	ZS_MD_SETCLK(cs);
231 #endif	/* ZS_MD_SETCLK */
232 
233 	/* clock mode control */
234 	zs_write_reg(cs, 11, reg[11]);
235 
236 	/* baud rate (lo/hi) */
237 	zs_write_reg(cs, 12, reg[12]);
238 	zs_write_reg(cs, 13, reg[13]);
239 
240 	/* Misc. control bits */
241 	zs_write_reg(cs, 14, reg[14]);
242 
243 	/* which lines cause status interrupts */
244 	zs_write_reg(cs, 15, reg[15]);
245 
246 	/*
247 	 * Zilog docs recommend resetting external status twice at this
248 	 * point. Mainly as the status bits are latched, and the first
249 	 * interrupt clear might unlatch them to new values, generating
250 	 * a second interrupt request.
251 	 */
252 	zs_write_csr(cs, ZSM_RESET_STINT);
253 	zs_write_csr(cs, ZSM_RESET_STINT);
254 
255 	/* char size, enable (RX/TX)*/
256 	zs_write_reg(cs, 3, reg[3]);
257 	zs_write_reg(cs, 5, reg[5]);
258 
259 	/* Write the status bits on the alternate channel also. */
260 	if (cs->cs_ctl_chan != NULL) {
261 		v = cs->cs_ctl_chan->cs_preg[5];
262 		cs->cs_ctl_chan->cs_creg[5] = v;
263 		zs_write_reg(cs->cs_ctl_chan, 5, v);
264 	}
265 
266 	/* Register 7' if applicable */
267 	if (reg[15] & ZSWR15_ENABLE_ENHANCED)
268 		zs_write_reg(cs, 7, reg[16]);
269 
270 	/* interrupt enables: RX, TX, STATUS */
271 	zs_write_reg(cs, 1, reg[1]);
272 }
273 
274 /*
275  * ZS hardware interrupt.  Scan all ZS channels.  NB: we know here that
276  * channels are kept in (A,B) pairs.
277  *
278  * Do just a little, then get out; set a software interrupt if more
279  * work is needed.
280  *
281  * We deliberately ignore the vectoring Zilog gives us, and match up
282  * only the number of `reset interrupt under service' operations, not
283  * the order.
284  */
285 int
286 zsc_intr_hard(void *arg)
287 {
288 	struct zsc_softc *zsc = arg;
289 	struct zs_chanstate *cs0, *cs1;
290 	int handled;
291 	uint8_t rr3;
292 
293 	handled = 0;
294 
295 	/* First look at channel A. */
296 	cs0 = zsc->zsc_cs[0];
297 	cs1 = zsc->zsc_cs[1];
298 
299 	/*
300 	 * We have to clear interrupt first to avoid a race condition,
301 	 * but it will be done in each MD handler.
302 	 */
303 	for (;;) {
304 		/* Note: only channel A has an RR3 */
305 		rr3 = zs_read_reg(cs0, 3);
306 
307 		if ((rr3 & (ZSRR3_IP_A_RX | ZSRR3_IP_A_TX | ZSRR3_IP_A_STAT |
308 		    ZSRR3_IP_B_RX | ZSRR3_IP_B_TX | ZSRR3_IP_B_STAT)) == 0) {
309 			break;
310 		}
311 		handled = 1;
312 
313 		/* First look at channel A. */
314 		if (rr3 & (ZSRR3_IP_A_RX | ZSRR3_IP_A_TX | ZSRR3_IP_A_STAT))
315 			zs_write_csr(cs0, ZSWR0_CLR_INTR);
316 
317 		if (rr3 & ZSRR3_IP_A_RX)
318 			(*cs0->cs_ops->zsop_rxint)(cs0);
319 		if (rr3 & ZSRR3_IP_A_STAT)
320 			(*cs0->cs_ops->zsop_stint)(cs0, 0);
321 		if (rr3 & ZSRR3_IP_A_TX)
322 			(*cs0->cs_ops->zsop_txint)(cs0);
323 
324 		/* Now look at channel B. */
325 		if (rr3 & (ZSRR3_IP_B_RX | ZSRR3_IP_B_TX | ZSRR3_IP_B_STAT))
326 			zs_write_csr(cs1, ZSWR0_CLR_INTR);
327 
328 		if (rr3 & ZSRR3_IP_B_RX)
329 			(*cs1->cs_ops->zsop_rxint)(cs1);
330 		if (rr3 & ZSRR3_IP_B_STAT)
331 			(*cs1->cs_ops->zsop_stint)(cs1, 0);
332 		if (rr3 & ZSRR3_IP_B_TX)
333 			(*cs1->cs_ops->zsop_txint)(cs1);
334 	}
335 
336 	/* Note: caller will check cs_x->cs_softreq and DTRT. */
337 	return handled;
338 }
339 
340 
341 /*
342  * ZS software interrupt.  Scan all channels for deferred interrupts.
343  */
344 int
345 zsc_intr_soft(void *arg)
346 {
347 	struct zsc_softc *zsc = arg;
348 	struct zs_chanstate *cs;
349 	int rval, chan;
350 
351 	rval = 0;
352 	for (chan = 0; chan < 2; chan++) {
353 		cs = zsc->zsc_cs[chan];
354 
355 		/*
356 		 * The softint flag can be safely cleared once
357 		 * we have decided to call the softint routine.
358 		 * (No need to do splzs() first.)
359 		 */
360 		if (cs->cs_softreq) {
361 			cs->cs_softreq = 0;
362 			(*cs->cs_ops->zsop_softint)(cs);
363 			rval++;
364 		}
365 	}
366 	return (rval);
367 }
368 
369 /*
370  * Provide a null zs "ops" vector.
371  */
372 
373 static void zsnull_rxint  (struct zs_chanstate *);
374 static void zsnull_stint  (struct zs_chanstate *, int);
375 static void zsnull_txint  (struct zs_chanstate *);
376 static void zsnull_softint(struct zs_chanstate *);
377 
378 static void
379 zsnull_rxint(struct zs_chanstate *cs)
380 {
381 
382 	/* Ask for softint() call. */
383 	cs->cs_softreq = 1;
384 }
385 
386 static void
387 zsnull_stint(struct zs_chanstate *cs, int force)
388 {
389 
390 	/* Ask for softint() call. */
391 	cs->cs_softreq = 1;
392 }
393 
394 static void
395 zsnull_txint(struct zs_chanstate *cs)
396 {
397 
398 	/* Ask for softint() call. */
399 	cs->cs_softreq = 1;
400 }
401 
402 static void
403 zsnull_softint(struct zs_chanstate *cs)
404 {
405 
406 	zs_write_reg(cs,  1, 0);
407 	zs_write_reg(cs, 15, 0);
408 }
409 
410 struct zsops zsops_null = {
411 	zsnull_rxint,	/* receive char available */
412 	zsnull_stint,	/* external/status */
413 	zsnull_txint,	/* xmit buffer empty */
414 	zsnull_softint,	/* process software interrupt */
415 };
416