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pcf8583.c revision 1.14.2.1
      1 /*	$NetBSD: pcf8583.c,v 1.14.2.1 2014/08/10 06:54:51 tls Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2003 Wasabi Systems, Inc.
      5  * All rights reserved.
      6  *
      7  * Written by Steve C. Woodford and Jason R. Thorpe for Wasabi Systems, Inc.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *      This product includes software developed for the NetBSD Project by
     20  *      Wasabi Systems, Inc.
     21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
     22  *    or promote products derived from this software without specific prior
     23  *    written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
     29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     35  * POSSIBILITY OF SUCH DAMAGE.
     36  */
     37 
     38 /*
     39  * Driver for the Philips PCF8583 Real Time Clock.
     40  *
     41  * This driver is partially derived from Ben Harris's PCF8583 driver
     42  * for NetBSD/acorn26.
     43  */
     44 
     45 #include <sys/cdefs.h>
     46 __KERNEL_RCSID(0, "$NetBSD: pcf8583.c,v 1.14.2.1 2014/08/10 06:54:51 tls Exp $");
     47 
     48 #include <sys/param.h>
     49 #include <sys/systm.h>
     50 #include <sys/device.h>
     51 #include <sys/kernel.h>
     52 #include <sys/fcntl.h>
     53 #include <sys/uio.h>
     54 #include <sys/conf.h>
     55 #include <sys/event.h>
     56 
     57 #include <dev/clock_subr.h>
     58 
     59 #include <dev/i2c/i2cvar.h>
     60 #include <dev/i2c/pcf8583reg.h>
     61 #include <dev/i2c/pcf8583var.h>
     62 
     63 struct pcfrtc_softc {
     64 	device_t sc_dev;
     65 	i2c_tag_t sc_tag;
     66 	int sc_address;
     67 	int sc_open;
     68 	struct todr_chip_handle sc_todr;
     69 };
     70 
     71 static int  pcfrtc_match(device_t, cfdata_t, void *);
     72 static void pcfrtc_attach(device_t, device_t, void *);
     73 
     74 CFATTACH_DECL_NEW(pcfrtc, sizeof(struct pcfrtc_softc),
     75 	pcfrtc_match, pcfrtc_attach, NULL, NULL);
     76 extern struct cfdriver pcfrtc_cd;
     77 
     78 dev_type_open(pcfrtc_open);
     79 dev_type_close(pcfrtc_close);
     80 dev_type_read(pcfrtc_read);
     81 dev_type_write(pcfrtc_write);
     82 
     83 const struct cdevsw pcfrtc_cdevsw = {
     84 	.d_open = pcfrtc_open,
     85 	.d_close = pcfrtc_close,
     86 	.d_read = pcfrtc_read,
     87 	.d_write = pcfrtc_write,
     88 	.d_ioctl = noioctl,
     89 	.d_stop = nostop,
     90 	.d_tty = notty,
     91 	.d_poll = nopoll,
     92 	.d_mmap = nommap,
     93 	.d_kqfilter = nokqfilter,
     94 	.d_discard = nodiscard,
     95 	.d_flag = D_OTHER
     96 };
     97 
     98 static int pcfrtc_clock_read(struct pcfrtc_softc *, struct clock_ymdhms *,
     99 			     uint8_t *);
    100 static int pcfrtc_clock_write(struct pcfrtc_softc *, struct clock_ymdhms *,
    101 			      uint8_t);
    102 static int pcfrtc_gettime(struct todr_chip_handle *, struct timeval *);
    103 static int pcfrtc_settime(struct todr_chip_handle *, struct timeval *);
    104 
    105 int
    106 pcfrtc_match(device_t parent, cfdata_t cf, void *aux)
    107 {
    108 	struct i2c_attach_args *ia = aux;
    109 
    110 	if ((ia->ia_addr & PCF8583_ADDRMASK) == PCF8583_ADDR)
    111 		return (1);
    112 
    113 	return (0);
    114 }
    115 
    116 void
    117 pcfrtc_attach(device_t parent, device_t self, void *aux)
    118 {
    119 	struct pcfrtc_softc *sc = device_private(self);
    120 	struct i2c_attach_args *ia = aux;
    121 	uint8_t cmdbuf[1], csr;
    122 
    123 	sc->sc_tag = ia->ia_tag;
    124 	sc->sc_address = ia->ia_addr;
    125 	sc->sc_dev = self;
    126 
    127 	aprint_naive(": Real-time Clock/NVRAM\n");
    128 	aprint_normal(": PCF8583 Real-time Clock/NVRAM\n");
    129 
    130 	cmdbuf[0] = PCF8583_REG_CSR;
    131 	if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address,
    132 	    cmdbuf, 1, &csr, 1, 0) != 0) {
    133 		aprint_error_dev(self, "unable to read CSR\n");
    134 		return;
    135 	}
    136 	aprint_normal_dev(sc->sc_dev, "");
    137 	switch (csr & PCF8583_CSR_FN_MASK) {
    138 	case PCF8583_CSR_FN_32768HZ:
    139 		aprint_normal(" 32.768 kHz clock");
    140 		break;
    141 
    142 	case PCF8583_CSR_FN_50HZ:
    143 		aprint_normal(" 50 Hz clock");
    144 		break;
    145 
    146 	case PCF8583_CSR_FN_EVENT:
    147 		aprint_normal(" event counter");
    148 		break;
    149 
    150 	case PCF8583_CSR_FN_TEST:
    151 		aprint_normal(" test mode");
    152 		break;
    153 	}
    154 	if (csr & PCF8583_CSR_STOP)
    155 		aprint_normal(", stopped");
    156 	if (csr & PCF8583_CSR_ALARMENABLE)
    157 		aprint_normal(", alarm enabled");
    158 	aprint_normal("\n");
    159 
    160 	sc->sc_open = 0;
    161 
    162 	sc->sc_todr.cookie = sc;
    163 	sc->sc_todr.todr_gettime = pcfrtc_gettime;
    164 	sc->sc_todr.todr_settime = pcfrtc_settime;
    165 	sc->sc_todr.todr_setwen = NULL;
    166 
    167 	todr_attach(&sc->sc_todr);
    168 }
    169 
    170 /*ARGSUSED*/
    171 int
    172 pcfrtc_open(dev_t dev, int flag, int fmt, struct lwp *l)
    173 {
    174 	struct pcfrtc_softc *sc;
    175 
    176 	if ((sc = device_lookup_private(&pcfrtc_cd, minor(dev))) == NULL)
    177 		return (ENXIO);
    178 
    179 	/* XXX: Locking */
    180 
    181 	if (sc->sc_open)
    182 		return (EBUSY);
    183 
    184 	sc->sc_open = 1;
    185 	return (0);
    186 }
    187 
    188 /*ARGSUSED*/
    189 int
    190 pcfrtc_close(dev_t dev, int flag, int fmt, struct lwp *l)
    191 {
    192 	struct pcfrtc_softc *sc;
    193 
    194 	if ((sc = device_lookup_private(&pcfrtc_cd, minor(dev))) == NULL)
    195 		return (ENXIO);
    196 
    197 	sc->sc_open = 0;
    198 	return (0);
    199 }
    200 
    201 /*ARGSUSED*/
    202 int
    203 pcfrtc_read(dev_t dev, struct uio *uio, int flags)
    204 {
    205 	struct pcfrtc_softc *sc;
    206 	u_int8_t ch, cmdbuf[1];
    207 	int a, error;
    208 
    209 	if ((sc = device_lookup_private(&pcfrtc_cd, minor(dev))) == NULL)
    210 		return (ENXIO);
    211 
    212 	if (uio->uio_offset >= PCF8583_NVRAM_SIZE)
    213 		return (EINVAL);
    214 
    215 	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
    216 		return (error);
    217 
    218 	while (uio->uio_resid && uio->uio_offset < PCF8583_NVRAM_SIZE) {
    219 		a = (int)uio->uio_offset;
    220 		cmdbuf[0] = a + PCF8583_NVRAM_START;
    221 		if ((error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
    222 				      sc->sc_address, cmdbuf, 1,
    223 				      &ch, 1, 0)) != 0) {
    224 			iic_release_bus(sc->sc_tag, 0);
    225 			aprint_error_dev(sc->sc_dev,
    226 			    "pcfrtc_read: read failed at 0x%x\n", a);
    227 			return (error);
    228 		}
    229 		if ((error = uiomove(&ch, 1, uio)) != 0) {
    230 			iic_release_bus(sc->sc_tag, 0);
    231 			return (error);
    232 		}
    233 	}
    234 
    235 	iic_release_bus(sc->sc_tag, 0);
    236 
    237 	return (0);
    238 }
    239 
    240 /*ARGSUSED*/
    241 int
    242 pcfrtc_write(dev_t dev, struct uio *uio, int flags)
    243 {
    244 	struct pcfrtc_softc *sc;
    245 	u_int8_t cmdbuf[2];
    246 	int a, error;
    247 
    248 	if ((sc = device_lookup_private(&pcfrtc_cd, minor(dev))) == NULL)
    249 		return (ENXIO);
    250 
    251 	if (uio->uio_offset >= PCF8583_NVRAM_SIZE)
    252 		return (EINVAL);
    253 
    254 	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
    255 		return (error);
    256 
    257 	while (uio->uio_resid && uio->uio_offset < PCF8583_NVRAM_SIZE) {
    258 		a = (int)uio->uio_offset;
    259 		cmdbuf[0] = a + PCF8583_NVRAM_START;
    260 		if ((error = uiomove(&cmdbuf[1], 1, uio)) != 0)
    261 			break;
    262 
    263 		if ((error = iic_exec(sc->sc_tag,
    264 		    uio->uio_resid ? I2C_OP_WRITE : I2C_OP_WRITE_WITH_STOP,
    265 		    sc->sc_address, cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
    266 			aprint_error_dev(sc->sc_dev,
    267 			    "pcfrtc_write: write failed at 0x%x\n", a);
    268 			return (error);
    269 		}
    270 	}
    271 
    272 	iic_release_bus(sc->sc_tag, 0);
    273 
    274 	return (error);
    275 }
    276 
    277 static int
    278 pcfrtc_gettime(struct todr_chip_handle *ch, struct timeval *tv)
    279 {
    280 	struct pcfrtc_softc *sc = ch->cookie;
    281 	struct clock_ymdhms dt;
    282 	int err;
    283 	uint8_t centi;
    284 
    285 	if ((err = pcfrtc_clock_read(sc, &dt, &centi)))
    286 		return err;
    287 
    288 	tv->tv_sec = clock_ymdhms_to_secs(&dt);
    289 	tv->tv_usec = centi * 10000;
    290 
    291 	return (0);
    292 }
    293 
    294 static int
    295 pcfrtc_settime(struct todr_chip_handle *ch, struct timeval *tv)
    296 {
    297 	struct pcfrtc_softc *sc = ch->cookie;
    298 	struct clock_ymdhms dt;
    299 	int err;
    300 
    301 	clock_secs_to_ymdhms(tv->tv_sec, &dt);
    302 
    303 	if ((err = pcfrtc_clock_write(sc, &dt, tv->tv_usec / 10000)) != 0)
    304 		return err;
    305 
    306 	return (0);
    307 }
    308 
    309 static const int pcf8583_rtc_offset[] = {
    310 	PCF8583_REG_CSR,
    311 	PCF8583_REG_CENTI,
    312 	PCF8583_REG_SEC,
    313 	PCF8583_REG_MIN,
    314 	PCF8583_REG_HOUR,
    315 	PCF8583_REG_YEARDATE,
    316 	PCF8583_REG_WKDYMON,
    317 	PCF8583_REG_TIMER,
    318 	0xc0,			/* NVRAM -- year stored here */
    319 	0xc1,			/* NVRAM -- century stored here */
    320 };
    321 
    322 static int
    323 pcfrtc_clock_read(struct pcfrtc_softc *sc, struct clock_ymdhms *dt,
    324     uint8_t *centi)
    325 {
    326 	u_int8_t bcd[10], cmdbuf[1];
    327 	int i, err;
    328 
    329 	if ((err = iic_acquire_bus(sc->sc_tag, I2C_F_POLL))) {
    330 		aprint_error_dev(sc->sc_dev,
    331 		    "pcfrtc_clock_read: failed to acquire I2C bus\n");
    332 		return err;
    333 	}
    334 
    335 	/* Read each timekeeping register in order. */
    336 	for (i = 0; i < 10; i++) {
    337 		cmdbuf[0] = pcf8583_rtc_offset[i];
    338 
    339 		if ((err = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
    340 			     sc->sc_address, cmdbuf, 1,
    341 			     &bcd[i], 1, I2C_F_POLL))) {
    342 			iic_release_bus(sc->sc_tag, I2C_F_POLL);
    343 			aprint_error_dev(sc->sc_dev,
    344 			    "pcfrtc_clock_read: failed to read rtc "
    345 			    "at 0x%x\n",
    346 			    pcf8583_rtc_offset[i]);
    347 			return err;
    348 		}
    349 	}
    350 
    351 	/* Done with I2C */
    352 	iic_release_bus(sc->sc_tag, I2C_F_POLL);
    353 
    354 	/*
    355 	 * Convert the PCF8583's register values into something useable
    356 	 */
    357 	*centi      = FROMBCD(bcd[PCF8583_REG_CENTI]);
    358 	dt->dt_sec  = FROMBCD(bcd[PCF8583_REG_SEC]);
    359 	dt->dt_min  = FROMBCD(bcd[PCF8583_REG_MIN]);
    360 	dt->dt_hour = FROMBCD(bcd[PCF8583_REG_HOUR] & PCF8583_HOUR_MASK);
    361 	if (bcd[PCF8583_REG_HOUR] & PCF8583_HOUR_12H) {
    362 		dt->dt_hour %= 12;	/* 12AM -> 0, 12PM -> 12 */
    363 		if (bcd[PCF8583_REG_HOUR] & PCF8583_HOUR_PM)
    364 			dt->dt_hour += 12;
    365 	}
    366 
    367 	dt->dt_day = FROMBCD(bcd[PCF8583_REG_YEARDATE] & PCF8583_DATE_MASK);
    368 	dt->dt_mon = FROMBCD(bcd[PCF8583_REG_WKDYMON] & PCF8583_MON_MASK);
    369 
    370 	dt->dt_year = bcd[8] + (bcd[9] * 100);
    371 	/* Try to notice if the year's rolled over. */
    372 	if (bcd[PCF8583_REG_CSR] & PCF8583_CSR_MASK)
    373 		aprint_error_dev(sc->sc_dev,
    374 		    "cannot check year in mask mode\n");
    375 	else {
    376 		while (dt->dt_year % 4 !=
    377 		       (bcd[PCF8583_REG_YEARDATE] &
    378 			PCF8583_YEAR_MASK) >> PCF8583_YEAR_SHIFT)
    379 			dt->dt_year++;
    380 	}
    381 
    382 	return 0;
    383 }
    384 
    385 static int
    386 pcfrtc_clock_write(struct pcfrtc_softc *sc, struct clock_ymdhms *dt,
    387     uint8_t centi)
    388 {
    389 	uint8_t bcd[10], cmdbuf[2];
    390 	int i, err;
    391 
    392 	/*
    393 	 * Convert our time representation into something the PCF8583
    394 	 * can understand.
    395 	 */
    396 	bcd[PCF8583_REG_CENTI]    = centi;
    397 	bcd[PCF8583_REG_SEC]      = TOBCD(dt->dt_sec);
    398 	bcd[PCF8583_REG_MIN]      = TOBCD(dt->dt_min);
    399 	bcd[PCF8583_REG_HOUR]     = TOBCD(dt->dt_hour) & PCF8583_HOUR_MASK;
    400 	bcd[PCF8583_REG_YEARDATE] = TOBCD(dt->dt_day) |
    401 	    ((dt->dt_year % 4) << PCF8583_YEAR_SHIFT);
    402 	bcd[PCF8583_REG_WKDYMON]  = TOBCD(dt->dt_mon) |
    403 	    ((dt->dt_wday % 4) << PCF8583_WKDY_SHIFT);
    404 	bcd[8]                    = dt->dt_year % 100;
    405 	bcd[9]                    = dt->dt_year / 100;
    406 
    407 	if ((err = iic_acquire_bus(sc->sc_tag, I2C_F_POLL))) {
    408 		aprint_error_dev(sc->sc_dev,
    409 		    "pcfrtc_clock_write: failed to acquire I2C bus\n");
    410 		return err;
    411 	}
    412 
    413 	for (i = 1; i < 10; i++) {
    414 		cmdbuf[0] = pcf8583_rtc_offset[i];
    415 		if ((err = iic_exec(sc->sc_tag,
    416 			     i != 9 ? I2C_OP_WRITE : I2C_OP_WRITE_WITH_STOP,
    417 			     sc->sc_address, cmdbuf, 1,
    418 			     &bcd[i], 1, I2C_F_POLL))) {
    419 			iic_release_bus(sc->sc_tag, I2C_F_POLL);
    420 			aprint_error_dev(sc->sc_dev,
    421 			    "pcfrtc_clock_write: failed to write rtc "
    422 			    " at 0x%x\n",
    423 			    pcf8583_rtc_offset[i]);
    424 			return err;
    425 		}
    426 	}
    427 
    428 	iic_release_bus(sc->sc_tag, I2C_F_POLL);
    429 
    430 	return 0;
    431 }
    432 
    433 int
    434 pcfrtc_bootstrap_read(i2c_tag_t tag, int i2caddr, int offset,
    435     u_int8_t *rvp, size_t len)
    436 {
    437 	u_int8_t cmdbuf[1];
    438 
    439 	/*
    440 	 * NOTE: "offset" is an absolute offset into the PCF8583
    441 	 * address space, not relative to the NVRAM.
    442 	 */
    443 
    444 	if (len == 0)
    445 		return (0);
    446 
    447 	if (iic_acquire_bus(tag, I2C_F_POLL) != 0)
    448 		return (-1);
    449 
    450 	while (len) {
    451 		/* Read a single byte. */
    452 		cmdbuf[0] = offset;
    453 		if (iic_exec(tag, I2C_OP_READ_WITH_STOP, i2caddr,
    454 			     cmdbuf, 1, rvp, 1, I2C_F_POLL)) {
    455 			iic_release_bus(tag, I2C_F_POLL);
    456 			return (-1);
    457 		}
    458 
    459 		len--;
    460 		rvp++;
    461 		offset++;
    462 	}
    463 
    464 	iic_release_bus(tag, I2C_F_POLL);
    465 	return (0);
    466 }
    467 
    468 int
    469 pcfrtc_bootstrap_write(i2c_tag_t tag, int i2caddr, int offset,
    470     u_int8_t *rvp, size_t len)
    471 {
    472 	u_int8_t cmdbuf[1];
    473 
    474 	/*
    475 	 * NOTE: "offset" is an absolute offset into the PCF8583
    476 	 * address space, not relative to the NVRAM.
    477 	 */
    478 
    479 	if (len == 0)
    480 		return (0);
    481 
    482 	if (iic_acquire_bus(tag, I2C_F_POLL) != 0)
    483 		return (-1);
    484 
    485 	while (len) {
    486 		/* Write a single byte. */
    487 		cmdbuf[0] = offset;
    488 		if (iic_exec(tag, I2C_OP_WRITE_WITH_STOP, i2caddr,
    489 			     cmdbuf, 1, rvp, 1, I2C_F_POLL)) {
    490 			iic_release_bus(tag, I2C_F_POLL);
    491 			return (-1);
    492 		}
    493 
    494 		len--;
    495 		rvp++;
    496 		offset++;
    497 	}
    498 
    499 	iic_release_bus(tag, I2C_F_POLL);
    500 	return (0);
    501 }
    502