xref: /netbsd-src/sys/arch/evbppc/walnut/dev/ds1743.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /*	$NetBSD: ds1743.c,v 1.1 2002/12/09 12:16:23 scw Exp $	*/
2 
3 /*
4  * Copyright (c) 2001-2002 Wasabi Sysetms, Inc.
5  * Copyright (c) 1998 Mark Brinicombe.
6  * Copyright (c) 1998 Causality Limited.
7  * All rights reserved.
8  *
9  * Written by Mark Brinicombe, Causality Limited
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by Mark Brinicombe
22  *	for the NetBSD Project.
23  * 4. The name of the company nor the name of the author may be used to
24  *    endorse or promote products derived from this software without specific
25  *    prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY CAUASLITY LIMITED ``AS IS'' AND ANY EXPRESS
28  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
29  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
30  * DISCLAIMED. IN NO EVENT SHALL CAUSALITY LIMITED OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
33  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  */
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/device.h>
43 
44 #include <machine/rtc.h>
45 #include <machine/bus.h>
46 
47 #include <evbppc/walnut/dev/ds1743reg.h>
48 #include <evbppc/walnut/dev/todclockvar.h>
49 #include <evbppc/walnut/dev/pbusvar.h>
50 
51 struct dsrtc_softc {
52 	struct device	sc_dev;
53 	bus_space_tag_t	sc_iot;
54 	bus_space_handle_t sc_ioh;
55 };
56 
57 static void dsrtcattach(struct device *, struct device *, void *);
58 static int dsrtcmatch(struct device *, struct cfdata *, void *);
59 #if 0	/* Nothing uses these yet */
60 static int ds1743_ram_read(struct dsrtc_softc *, int);
61 static void ds1743_ram_write(struct dsrtc_softc *, int, int);
62 #endif
63 
64 static int dsrtc_read(void *, rtc_t *);
65 static int dsrtc_write(void *, rtc_t *);
66 static inline u_char ds1743_read(struct dsrtc_softc *, int);
67 static inline void ds1743_write(struct dsrtc_softc *, int, u_char);
68 static u_char ds1743_lock(struct dsrtc_softc *, u_char);
69 static void ds1743_unlock(struct dsrtc_softc *, u_char);
70 
71 /* device and attach structures */
72 CFATTACH_DECL(dsrtc, sizeof(struct dsrtc_softc),
73     dsrtcmatch, dsrtcattach, NULL, NULL);
74 
75 /*
76  * dsrtcmatch()
77  *
78  * Validate the IIC address to make sure its an RTC we understand
79  */
80 int ds1743found = 0;
81 
82 #define DS_SCRATCH_ADDR 0x1FF7
83 
84 static int
85 dsrtcmatch(struct device *parent, struct cfdata *cf, void *aux)
86 {
87 	struct pbus_attach_args *paa = aux;
88 	int retval = !ds1743found;
89 	bus_space_handle_t h;
90 	u_int8_t x;
91 
92 	/* match only RTC devices */
93 	if (strcmp(paa->pb_name, cf->cf_name) != 0)
94 		return 0;
95 
96 	if (bus_space_map(0, paa->pb_addr, DS_SIZE, 0, &h)) {
97 		printf("%s: can't map i/o space\n", paa->pb_name);
98 		return 0;
99 	}
100 
101 	/* Read one byte of what's supposed to be NVRAM */
102 	x = bus_space_read_1(0, h, DS_SCRATCH_ADDR);
103 	bus_space_write_1(0, h, DS_SCRATCH_ADDR, 0xAA);
104 	if (bus_space_read_1(0, h, DS_SCRATCH_ADDR) != 0xAA) {
105 		retval = 0;
106 		goto done;
107 	}
108 
109 	bus_space_write_1(0, h, DS_SCRATCH_ADDR, 0x55);
110 	if (bus_space_read_1(0, h, DS_SCRATCH_ADDR) != 0x55) {
111 		retval = 0;
112 		goto done;
113 	}
114 
115 	/* Restore scratch byte value */
116 	bus_space_write_1(0, h, DS_SCRATCH_ADDR, x);
117   done:
118 	bus_space_unmap(0, h, DS_SIZE);
119 
120 	return retval;
121 }
122 
123 /*
124  * dsrtcattach()
125  *
126  * Attach the rtc device
127  */
128 
129 static void
130 dsrtcattach(struct device *parent, struct device *self, void *aux)
131 {
132 	struct dsrtc_softc *sc = (struct dsrtc_softc *)self;
133 	struct pbus_attach_args *paa = aux;
134 	struct todclock_attach_args ta;
135 
136 	ds1743found = 1;
137 
138 	sc->sc_iot = 0;
139 	sc->sc_ioh = paa->pb_addr;
140 	if (bus_space_map(sc->sc_iot, paa->pb_addr, DS_SIZE, 0, &sc->sc_ioh)) {
141 		printf(": can't map i/o space\n");
142 		return;
143 	}
144 
145 	ds1743_unlock(sc,0);	/* Make sure the clock is running */
146 	if ((ds1743_read(sc, DS_DAY) & DS_CTL_BF) == 0)
147 		printf(": lithium cell is dead, RTC unreliable");
148 	printf("\n");
149 
150 #ifdef DEBUG
151 	{
152 		rtc_t rtc;
153 		dsrtc_read(sc,&rtc);
154 		printf("RTC: %d/%d/%02d%02d %d:%02d:%02d\n",
155 			rtc.rtc_mon, rtc.rtc_day, rtc.rtc_cen, rtc.rtc_year,
156 			rtc.rtc_hour, rtc.rtc_min, rtc.rtc_sec);
157 	}
158 #endif
159 
160 
161 	ta.ta_name = "todclock";
162 	ta.ta_rtc_arg = sc;
163 	ta.ta_rtc_write = dsrtc_write;
164 	ta.ta_rtc_read = dsrtc_read;
165 	ta.ta_flags = 0;
166 	config_found(self, &ta, NULL);
167 }
168 
169 static inline u_char
170 ds1743_read(struct dsrtc_softc *sc, int addr)
171 {
172 
173 	return(bus_space_read_1(sc->sc_iot, sc->sc_ioh, addr));
174 }
175 
176 static inline void
177 ds1743_write(struct dsrtc_softc *sc, int addr, u_char data)
178 {
179 
180 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, addr, data);
181 }
182 
183 
184 #if 0	/* Nothing uses these yet */
185 static u_char
186 ds1743_ram_read(struct dsrtc_softc *sc, int addr)
187 {
188 
189 	if (addr >= DS_RAM_SIZE)
190 		return(-1);
191 	return(ds1743_read(sc, addr));
192 }
193 
194 static void
195 ds1743_ram_write(struct dsrtc_softc *sc, int addr, u_char val)
196 {
197 
198 	if (addr >= DS_RAM_SIZE)
199 		return (-1);
200 	ds1743_write(sc,addr,val);
201 }
202 #endif
203 
204 #define BCD(x)	((((x)/10)<<4)|(x%10))
205 #define unBCD(v,x)	v=x; v = ((v>>4) & 0xf)*10+(v & 0xf)
206 
207 static u_char
208 ds1743_lock(struct dsrtc_softc *sc, u_char mode)
209 {
210 	u_char octl,ctl;
211 
212 	octl = ds1743_read(sc,DS_CENTURY);
213 	ctl = octl | (mode & DS_CTL_RW);
214 	ds1743_write(sc,DS_CENTURY, ctl);	/* Lock RTC for both reading and writing */
215 	return octl;
216 }
217 
218 static void
219 ds1743_unlock(struct dsrtc_softc *sc, u_char key)
220 {
221 	int ctl;
222 
223 	ctl = ds1743_read(sc,DS_CENTURY);
224 	ctl = (ctl & 0x3f) | (key & DS_CTL_RW);
225 	ds1743_write(sc,DS_CENTURY, ctl);	/* Enable updates */
226 }
227 
228 static int
229 dsrtc_write(void * arg, rtc_t * rtc)
230 {
231 	struct dsrtc_softc *sc = arg;
232 	u_char key;
233 
234 	key = ds1743_lock(sc,DS_CTL_W);
235 
236 	ds1743_write(sc, DS_SECONDS, BCD(rtc->rtc_sec) & 0x7f);
237 	ds1743_write(sc, DS_MINUTES, BCD(rtc->rtc_min) & 0x7f);
238 	ds1743_write(sc, DS_HOURS, BCD(rtc->rtc_hour)  & 0x3f);
239 	ds1743_write(sc, DS_DATE, BCD(rtc->rtc_day)    & 0x3f);
240 	ds1743_write(sc, DS_MONTH, BCD(rtc->rtc_mon)   & 0x1f);
241 	ds1743_write(sc, DS_YEAR, BCD(rtc->rtc_year));
242 	ds1743_write(sc, DS_CENTURY, ((ds1743_read(sc,DS_CENTURY) & DS_CTL_RW)
243 				      | BCD(rtc->rtc_cen)));
244 
245 	ds1743_unlock(sc,key);
246 	dsrtc_read(arg,rtc);
247 	return(1);
248 }
249 
250 static int
251 dsrtc_read(void *arg, rtc_t *rtc)
252 {
253 	struct dsrtc_softc *sc = arg;
254 	u_char key;
255 
256 	key = ds1743_lock(sc,DS_CTL_R);
257 	rtc->rtc_micro = 0;
258 	rtc->rtc_centi = 0;
259 	unBCD(rtc->rtc_sec,ds1743_read(sc, DS_SECONDS) & 0x7f);
260 	unBCD(rtc->rtc_min,ds1743_read(sc, DS_MINUTES) & 0x7f);
261 	unBCD(rtc->rtc_hour, ds1743_read(sc, DS_HOURS) & 0x3f);
262 	unBCD(rtc->rtc_day, ds1743_read(sc, DS_DATE)   & 0x3f);
263 	unBCD(rtc->rtc_mon,ds1743_read(sc, DS_MONTH)   & 0x1f);
264 	unBCD(rtc->rtc_year, ds1743_read(sc, DS_YEAR));
265 	unBCD(rtc->rtc_cen, ds1743_read(sc, DS_CENTURY) & ~DS_CTL_RW);
266 
267 	ds1743_unlock(sc,key);
268 	return(1);
269 }
270