xref: /netbsd-src/sys/arch/evbppc/walnut/dev/ds1743.c (revision e5548b402ae4c44fb816de42c7bba9581ce23ef5)
1 /*	$NetBSD: ds1743.c,v 1.6 2005/12/11 12:17:13 christos 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/cdefs.h>
41 __KERNEL_RCSID(0, "$NetBSD: ds1743.c,v 1.6 2005/12/11 12:17:13 christos Exp $");
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/device.h>
46 
47 #include <machine/rtc.h>
48 #include <machine/bus.h>
49 
50 #include <evbppc/walnut/dev/ds1743reg.h>
51 #include <evbppc/walnut/dev/todclockvar.h>
52 #include <evbppc/walnut/dev/pbusvar.h>
53 
54 struct dsrtc_softc {
55 	struct device	sc_dev;
56 	bus_space_tag_t	sc_iot;
57 	bus_space_handle_t sc_ioh;
58 };
59 
60 static void dsrtcattach(struct device *, struct device *, void *);
61 static int dsrtcmatch(struct device *, struct cfdata *, void *);
62 #if 0	/* Nothing uses these yet */
63 static int ds1743_ram_read(struct dsrtc_softc *, int);
64 static void ds1743_ram_write(struct dsrtc_softc *, int, int);
65 #endif
66 
67 static int dsrtc_read(void *, rtc_t *);
68 static int dsrtc_write(void *, rtc_t *);
69 static inline u_char ds1743_read(struct dsrtc_softc *, int);
70 static inline void ds1743_write(struct dsrtc_softc *, int, u_char);
71 static u_char ds1743_lock(struct dsrtc_softc *, u_char);
72 static void ds1743_unlock(struct dsrtc_softc *, u_char);
73 
74 /* device and attach structures */
75 CFATTACH_DECL(ds1743rtc, sizeof(struct dsrtc_softc),
76     dsrtcmatch, dsrtcattach, NULL, NULL);
77 
78 /*
79  * dsrtcmatch()
80  *
81  * Validate the IIC address to make sure its an RTC we understand
82  */
83 int ds1743found = 0;
84 
85 #define DS_SCRATCH_ADDR 0x1FF7
86 
87 static int
88 dsrtcmatch(struct device *parent, struct cfdata *cf, void *aux)
89 {
90 	struct pbus_attach_args *paa = aux;
91 	int retval = !ds1743found;
92 	bus_space_handle_t h;
93 	u_int8_t x;
94 
95 	/* match only RTC devices */
96 	if (strcmp(paa->pb_name, cf->cf_name) != 0)
97 		return 0;
98 
99 	if (bus_space_map(paa->pb_bt, paa->pb_addr, DS_SIZE, 0, &h)) {
100 		printf("%s: can't map i/o space\n", paa->pb_name);
101 		return 0;
102 	}
103 
104 	/* Read one byte of what's supposed to be NVRAM */
105 	x = bus_space_read_1(paa->pb_bt, h, DS_SCRATCH_ADDR);
106 	bus_space_write_1(paa->pb_bt, h, DS_SCRATCH_ADDR, 0xAA);
107 	if (bus_space_read_1(paa->pb_bt, h, DS_SCRATCH_ADDR) != 0xAA) {
108 		retval = 0;
109 		goto done;
110 	}
111 
112 	bus_space_write_1(paa->pb_bt, h, DS_SCRATCH_ADDR, 0x55);
113 	if (bus_space_read_1(paa->pb_bt, h, DS_SCRATCH_ADDR) != 0x55) {
114 		retval = 0;
115 		goto done;
116 	}
117 
118 	/* Restore scratch byte value */
119 	bus_space_write_1(paa->pb_bt, h, DS_SCRATCH_ADDR, x);
120   done:
121 	bus_space_unmap(paa->pb_bt, h, DS_SIZE);
122 
123 	return retval;
124 }
125 
126 /*
127  * dsrtcattach()
128  *
129  * Attach the rtc device
130  */
131 
132 static void
133 dsrtcattach(struct device *parent, struct device *self, void *aux)
134 {
135 	struct dsrtc_softc *sc = (struct dsrtc_softc *)self;
136 	struct pbus_attach_args *paa = aux;
137 	struct todclock_attach_args ta;
138 
139 	ds1743found = 1;
140 
141 	sc->sc_iot = paa->pb_bt;
142 	if (bus_space_map(sc->sc_iot, paa->pb_addr, DS_SIZE, 0, &sc->sc_ioh)) {
143 		printf(": can't map i/o space\n");
144 		return;
145 	}
146 
147 	ds1743_unlock(sc, 0);	/* Make sure the clock is running */
148 	if ((ds1743_read(sc, DS_DAY) & DS_CTL_BF) == 0)
149 		printf(": lithium cell is dead, RTC unreliable");
150 	printf("\n");
151 
152 #ifdef DEBUG
153 	{
154 		rtc_t rtc;
155 		dsrtc_read(sc, &rtc);
156 		printf("RTC: %d/%d/%02d%02d %d:%02d:%02d\n",
157 			rtc.rtc_mon, rtc.rtc_day, rtc.rtc_cen, rtc.rtc_year,
158 			rtc.rtc_hour, rtc.rtc_min, rtc.rtc_sec);
159 	}
160 #endif
161 
162 
163 	ta.ta_name = "todclock";
164 	ta.ta_rtc_arg = sc;
165 	ta.ta_rtc_write = dsrtc_write;
166 	ta.ta_rtc_read = dsrtc_read;
167 	ta.ta_flags = 0;
168 	config_found(self, &ta, NULL);
169 }
170 
171 static inline u_char
172 ds1743_read(struct dsrtc_softc *sc, int addr)
173 {
174 
175 	return(bus_space_read_1(sc->sc_iot, sc->sc_ioh, addr));
176 }
177 
178 static inline void
179 ds1743_write(struct dsrtc_softc *sc, int addr, u_char data)
180 {
181 
182 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, addr, data);
183 }
184 
185 
186 #if 0	/* Nothing uses these yet */
187 static u_char
188 ds1743_ram_read(struct dsrtc_softc *sc, int addr)
189 {
190 
191 	if (addr >= DS_RAM_SIZE)
192 		return(-1);
193 	return(ds1743_read(sc, addr));
194 }
195 
196 static void
197 ds1743_ram_write(struct dsrtc_softc *sc, int addr, u_char val)
198 {
199 
200 	if (addr >= DS_RAM_SIZE)
201 		return (-1);
202 	ds1743_write(sc, addr, val);
203 }
204 #endif
205 
206 #define BCD(x)		((((x) / 10) << 4) | (x % 10))
207 #define unBCD(v, x)	v = x; v = ((v >> 4) & 0xf) * 10 + (v & 0xf)
208 
209 static u_char
210 ds1743_lock(struct dsrtc_softc *sc, u_char mode)
211 {
212 	u_char octl, ctl;
213 
214 	octl = ds1743_read(sc, DS_CENTURY);
215 	ctl = octl | (mode & DS_CTL_RW);
216 	ds1743_write(sc, DS_CENTURY, ctl);	/* Lock RTC for both reading and writing */
217 	return octl;
218 }
219 
220 static void
221 ds1743_unlock(struct dsrtc_softc *sc, u_char key)
222 {
223 	int ctl;
224 
225 	ctl = ds1743_read(sc, DS_CENTURY);
226 	ctl = (ctl & 0x3f) | (key & DS_CTL_RW);
227 	ds1743_write(sc, DS_CENTURY, ctl);	/* Enable updates */
228 }
229 
230 static int
231 dsrtc_write(void * arg, rtc_t * rtc)
232 {
233 	struct dsrtc_softc *sc = arg;
234 	u_char key;
235 
236 	key = ds1743_lock(sc, DS_CTL_W);
237 
238 	ds1743_write(sc, DS_SECONDS, BCD(rtc->rtc_sec) & 0x7f);
239 	ds1743_write(sc, DS_MINUTES, BCD(rtc->rtc_min) & 0x7f);
240 	ds1743_write(sc, DS_HOURS, BCD(rtc->rtc_hour)  & 0x3f);
241 	ds1743_write(sc, DS_DATE, BCD(rtc->rtc_day)    & 0x3f);
242 	ds1743_write(sc, DS_MONTH, BCD(rtc->rtc_mon)   & 0x1f);
243 	ds1743_write(sc, DS_YEAR, BCD(rtc->rtc_year));
244 	ds1743_write(sc, DS_CENTURY, ((ds1743_read(sc, DS_CENTURY) & DS_CTL_RW)
245 				      | BCD(rtc->rtc_cen)));
246 
247 	ds1743_unlock(sc, key);
248 	dsrtc_read(arg, rtc);
249 	return(1);
250 }
251 
252 static int
253 dsrtc_read(void *arg, rtc_t *rtc)
254 {
255 	struct dsrtc_softc *sc = arg;
256 	u_char key;
257 
258 	key = ds1743_lock(sc, DS_CTL_R);
259 	rtc->rtc_micro = 0;
260 	rtc->rtc_centi = 0;
261 	unBCD(rtc->rtc_sec, ds1743_read(sc, DS_SECONDS) & 0x7f);
262 	unBCD(rtc->rtc_min, ds1743_read(sc, DS_MINUTES) & 0x7f);
263 	unBCD(rtc->rtc_hour, ds1743_read(sc, DS_HOURS) & 0x3f);
264 	unBCD(rtc->rtc_day, ds1743_read(sc, DS_DATE)   & 0x3f);
265 	unBCD(rtc->rtc_mon, ds1743_read(sc, DS_MONTH)   & 0x1f);
266 	unBCD(rtc->rtc_year, ds1743_read(sc, DS_YEAR));
267 	unBCD(rtc->rtc_cen, ds1743_read(sc, DS_CENTURY) & ~DS_CTL_RW);
268 
269 	ds1743_unlock(sc, key);
270 	return(1);
271 }
272