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ds1743.c revision 1.3
      1 /*	$NetBSD: ds1743.c,v 1.3 2003/07/25 11:44:21 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/cdefs.h>
     41 __KERNEL_RCSID(0, "$NetBSD: ds1743.c,v 1.3 2003/07/25 11:44:21 scw 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(dsrtc, 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