xref: /netbsd-src/sys/arch/newsmips/dev/zs.c (revision 207defd0369f03b80f291e7c291be1f3b7ab3397)
1 /*	$NetBSD: zs.c,v 1.28 2021/09/11 20:28:04 andvar 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  * Zilog Z8530 Dual UART driver (machine-dependent part)
34  *
35  * Runs two serial lines per chip using slave drivers.
36  * Plain tty/async lines use the zs_async slave.
37  * Sun keyboard/mouse uses the zs_kbd/zs_ms slaves.
38  */
39 
40 #include <sys/cdefs.h>
41 __KERNEL_RCSID(0, "$NetBSD: zs.c,v 1.28 2021/09/11 20:28:04 andvar Exp $");
42 
43 #include "opt_ddb.h"
44 
45 #include <sys/param.h>
46 #include <sys/device.h>
47 #include <sys/tty.h>
48 #include <sys/systm.h>
49 #include <sys/cpu.h>
50 #include <sys/intr.h>
51 
52 #include <machine/adrsmap.h>
53 #include <machine/z8530var.h>
54 
55 #include <dev/ic/z8530reg.h>
56 
57 #include "ioconf.h"
58 
59 void (*zs_delay)(void);
60 
61 #define ZS_DELAY() (*zs_delay)()
62 
63 /*
64  * Some warts needed by z8530tty.c -
65  * The default parity REALLY needs to be the same as the PROM uses,
66  * or you can not see messages done with printf during boot-up...
67  */
68 int zs_def_cflag = (CREAD | CS8 | HUPCL);
69 
70 int
zs_print(void * aux,const char * name)71 zs_print(void *aux, const char *name)
72 {
73 	struct zsc_attach_args *args = aux;
74 
75 	if (name != NULL)
76 		aprint_normal("%s: ", name);
77 
78 	if (args->channel != -1)
79 		aprint_normal(" channel %d", args->channel);
80 
81 	return UNCONF;
82 }
83 
84 /*
85  * Our ZS chips all share a common interrupt level,
86  * but we establish zshard handler per each ZS chips
87  * to avoid holding unnecessary locks in interrupt context.
88  */
89 int
zshard(void * arg)90 zshard(void *arg)
91 {
92 	struct zsc_softc *zsc = arg;
93 	int rval;
94 
95 	rval = zsc_intr_hard(zsc);
96 	if (zsc->zsc_cs[0]->cs_softreq || zsc->zsc_cs[1]->cs_softreq)
97 		softint_schedule(zsc->zsc_si);
98 
99 	return rval;
100 }
101 
102 /*
103  * Compute the current baud rate given a ZS channel.
104  */
105 int
zs_get_speed(struct zs_chanstate * cs)106 zs_get_speed(struct zs_chanstate *cs)
107 {
108 	int tconst;
109 
110 	tconst = zs_read_reg(cs, 12);
111 	tconst |= zs_read_reg(cs, 13) << 8;
112 	return TCONST_TO_BPS(cs->cs_brg_clk, tconst);
113 }
114 
115 /*
116  * MD functions for setting the baud rate and control modes.
117  */
118 int
zs_set_speed(struct zs_chanstate * cs,int bps)119 zs_set_speed(struct zs_chanstate *cs, int bps)
120 {
121 	int tconst, real_bps;
122 
123 	if (bps == 0)
124 		return 0;
125 
126 #ifdef	DIAGNOSTIC
127 	if (cs->cs_brg_clk == 0)
128 		panic("zs_set_speed");
129 #endif
130 
131 	tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
132 	if (tconst < 0)
133 		return EINVAL;
134 
135 	/* Convert back to make sure we can do it. */
136 	real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);
137 
138 	/* XXX - Allow some tolerance here? */
139 	if (real_bps != bps)
140 		return EINVAL;
141 
142 	cs->cs_preg[12] = tconst;
143 	cs->cs_preg[13] = tconst >> 8;
144 
145 	/* Caller will stuff the pending registers. */
146 	return 0;
147 }
148 
149 int
zs_set_modes(struct zs_chanstate * cs,int cflag)150 zs_set_modes(struct zs_chanstate *cs, int cflag)
151 {
152 	int s;
153 
154 	/*
155 	 * Output hardware flow control on the chip is horrendous:
156 	 * if carrier detect drops, the receiver is disabled, and if
157 	 * CTS drops, the transmitter is stopped IN MID CHARACTER!
158 	 * Therefore, NEVER set the HFC bit, and instead use the
159 	 * status interrupt to detect CTS changes.
160 	 */
161 	s = splserial();
162 	cs->cs_rr0_pps = 0;
163 	if ((cflag & (CLOCAL | MDMBUF)) != 0) {
164 		cs->cs_rr0_dcd = 0;
165 		if ((cflag & MDMBUF) == 0)
166 			cs->cs_rr0_pps = ZSRR0_DCD;
167 	} else
168 		cs->cs_rr0_dcd = ZSRR0_DCD;
169 	if ((cflag & CRTSCTS) != 0) {
170 		cs->cs_wr5_dtr = ZSWR5_DTR;
171 		cs->cs_wr5_rts = ZSWR5_RTS;
172 		cs->cs_rr0_cts = ZSRR0_CTS;
173 	} else if ((cflag & MDMBUF) != 0) {
174 		cs->cs_wr5_dtr = 0;
175 		cs->cs_wr5_rts = ZSWR5_DTR;
176 		cs->cs_rr0_cts = ZSRR0_DCD;
177 	} else {
178 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
179 		cs->cs_wr5_rts = 0;
180 		cs->cs_rr0_cts = 0;
181 	}
182 	splx(s);
183 
184 	/* Caller will stuff the pending registers. */
185 	return 0;
186 }
187 
188 /*
189  * Read or write the chip with suitable delays.
190  */
191 
192 uint8_t
zs_read_reg(struct zs_chanstate * cs,uint8_t reg)193 zs_read_reg(struct zs_chanstate *cs, uint8_t reg)
194 {
195 	uint8_t val;
196 
197 	*cs->cs_reg_csr = reg;
198 	ZS_DELAY();
199 	val = *cs->cs_reg_csr;
200 	ZS_DELAY();
201 	return val;
202 }
203 
204 void
zs_write_reg(struct zs_chanstate * cs,uint8_t reg,uint8_t val)205 zs_write_reg(struct zs_chanstate *cs, uint8_t reg, uint8_t val)
206 {
207 
208 	*cs->cs_reg_csr = reg;
209 	ZS_DELAY();
210 	*cs->cs_reg_csr = val;
211 	ZS_DELAY();
212 }
213 
214 uint8_t
zs_read_csr(struct zs_chanstate * cs)215 zs_read_csr(struct zs_chanstate *cs)
216 {
217 	uint8_t val;
218 
219 	val = *cs->cs_reg_csr;
220 	ZS_DELAY();
221 	return val;
222 }
223 
224 void
zs_write_csr(struct zs_chanstate * cs,uint8_t val)225 zs_write_csr(struct zs_chanstate *cs, uint8_t val)
226 {
227 
228 	*cs->cs_reg_csr = val;
229 	ZS_DELAY();
230 }
231 
232 uint8_t
zs_read_data(struct zs_chanstate * cs)233  zs_read_data(struct zs_chanstate *cs)
234 {
235 	uint8_t val;
236 
237 	val = *cs->cs_reg_data;
238 	ZS_DELAY();
239 	return val;
240 }
241 
242 void
zs_write_data(struct zs_chanstate * cs,uint8_t val)243 zs_write_data(struct zs_chanstate *cs, uint8_t val)
244 {
245 
246 	*cs->cs_reg_data = val;
247 	ZS_DELAY();
248 }
249 
250 void
zs_abort(struct zs_chanstate * cs)251 zs_abort(struct zs_chanstate *cs)
252 {
253 
254 #ifdef DDB
255 	Debugger();
256 #endif
257 }
258