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pcf8563.c revision 1.1
      1 /*	$NetBSD: pcf8563.c,v 1.1 2011/01/21 19:11:47 jakllsch Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2011 Jonathan A. Kollasch
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
     20  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     21  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     22  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     23  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     24  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     25  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     26  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: pcf8563.c,v 1.1 2011/01/21 19:11:47 jakllsch Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/systm.h>
     34 #include <sys/device.h>
     35 #include <sys/kernel.h>
     36 
     37 #include <dev/clock_subr.h>
     38 
     39 #include <dev/i2c/i2cvar.h>
     40 #include <dev/i2c/pcf8563reg.h>
     41 
     42 struct pcf8563rtc_softc {
     43 	device_t sc_dev;
     44 	i2c_tag_t sc_tag;
     45 	int sc_addr;
     46 	struct todr_chip_handle sc_todr;
     47 };
     48 
     49 static int pcf8563rtc_match(device_t, cfdata_t, void *);
     50 static void pcf8563rtc_attach(device_t, device_t, void *);
     51 
     52 CFATTACH_DECL_NEW(pcf8563rtc, sizeof(struct pcf8563rtc_softc),
     53     pcf8563rtc_match, pcf8563rtc_attach, NULL, NULL);
     54 
     55 static int pcf8563rtc_clock_read(struct pcf8563rtc_softc *, struct clock_ymdhms *);
     56 static int pcf8563rtc_clock_write(struct pcf8563rtc_softc *, struct clock_ymdhms *);
     57 static int pcf8563rtc_gettime(struct todr_chip_handle *, struct timeval *);
     58 static int pcf8563rtc_settime(struct todr_chip_handle *, struct timeval *);
     59 
     60 static int
     61 pcf8563rtc_match(device_t parent, cfdata_t cf, void *aux)
     62 {
     63 	struct i2c_attach_args *ia = aux;
     64 
     65 	if (ia->ia_addr == PCF8563_ADDR)
     66 		return 1;
     67 
     68 	return 0;
     69 }
     70 
     71 static void
     72 pcf8563rtc_attach(device_t parent, device_t self, void *aux)
     73 {
     74 	struct pcf8563rtc_softc *sc = device_private(self);
     75 	struct i2c_attach_args *ia = aux;
     76 
     77 	aprint_naive(": Real-time Clock\n");
     78 	aprint_normal(": NXP PCF8563 Real-time Clock\n");
     79 
     80 	sc->sc_dev = self;
     81 	sc->sc_tag = ia->ia_tag;
     82 	sc->sc_addr = ia->ia_addr;
     83 	sc->sc_todr.cookie = sc;
     84 	sc->sc_todr.todr_gettime = pcf8563rtc_gettime;
     85 	sc->sc_todr.todr_settime = pcf8563rtc_settime;
     86 	sc->sc_todr.todr_setwen = NULL;
     87 
     88 	todr_attach(&sc->sc_todr);
     89 }
     90 
     91 static int
     92 pcf8563rtc_gettime(struct todr_chip_handle *ch, struct timeval *tv)
     93 {
     94 	struct pcf8563rtc_softc *sc = ch->cookie;
     95 	struct clock_ymdhms dt;
     96 
     97 	memset(&dt, 0, sizeof(dt));
     98 
     99 	if (pcf8563rtc_clock_read(sc, &dt) == 0)
    100 		return -1;
    101 
    102 	tv->tv_sec = clock_ymdhms_to_secs(&dt);
    103 	tv->tv_usec = 0;
    104 
    105 	return 0;
    106 }
    107 
    108 static int
    109 pcf8563rtc_settime(struct todr_chip_handle *ch, struct timeval *tv)
    110 {
    111         struct pcf8563rtc_softc *sc = ch->cookie;
    112 	struct clock_ymdhms dt;
    113 
    114 	clock_secs_to_ymdhms(tv->tv_sec, &dt);
    115 
    116 	if (pcf8563rtc_clock_write(sc, &dt) == 0)
    117 		return -1;
    118 
    119 	return 0;
    120 }
    121 
    122 static int
    123 pcf8563rtc_clock_read(struct pcf8563rtc_softc *sc, struct clock_ymdhms *dt)
    124 {
    125 	uint8_t bcd[PCF8563_NREGS];
    126 	uint8_t reg = PCF8563_R_CS1;
    127 
    128 	if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) {
    129 		device_printf(sc->sc_dev, "acquire bus for read failed\n");
    130 		return 0;
    131 	}
    132 
    133 	if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr, &reg, 1,
    134 		     &bcd[reg], PCF8563_R_YEAR - reg + 1, I2C_F_POLL)) {
    135 		iic_release_bus(sc->sc_tag, I2C_F_POLL);
    136 		device_printf(sc->sc_dev, "read failed\n");
    137 		return 0;
    138 	}
    139 
    140 	iic_release_bus(sc->sc_tag, I2C_F_POLL);
    141 
    142 	dt->dt_sec = FROMBCD(bcd[PCF8563_R_SECOND] & PCF8563_M_SECOND);
    143 	dt->dt_min = FROMBCD(bcd[PCF8563_R_MINUTE] & PCF8563_M_MINUTE);
    144 	dt->dt_hour = FROMBCD(bcd[PCF8563_R_HOUR] & PCF8563_M_HOUR);
    145 	dt->dt_day = FROMBCD(bcd[PCF8563_R_DAY] & PCF8563_M_DAY);
    146 	dt->dt_mon = FROMBCD(bcd[PCF8563_R_MONTH] & PCF8563_M_MONTH);
    147 	dt->dt_year = FROMBCD(bcd[PCF8563_R_YEAR] & PCF8563_M_YEAR);
    148 	dt->dt_year += 2000;
    149 
    150 	return 1;
    151 }
    152 
    153 static int
    154 pcf8563rtc_clock_write(struct pcf8563rtc_softc *sc, struct clock_ymdhms *dt)
    155 {
    156 	uint8_t bcd[PCF8563_NREGS];
    157 	uint8_t reg = PCF8563_R_SECOND;
    158 
    159 	bcd[PCF8563_R_SECOND] = TOBCD(dt->dt_sec);
    160 	bcd[PCF8563_R_MINUTE] = TOBCD(dt->dt_min);
    161 	bcd[PCF8563_R_HOUR] = TOBCD(dt->dt_hour);
    162 	bcd[PCF8563_R_DAY] = TOBCD(dt->dt_day);
    163 	bcd[PCF8563_R_WEEKDAY] = TOBCD(dt->dt_wday);
    164 	bcd[PCF8563_R_MONTH] = TOBCD(dt->dt_mon);
    165 	bcd[PCF8563_R_YEAR] = TOBCD(dt->dt_year % 100);
    166 
    167 	if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) {
    168 		device_printf(sc->sc_dev, "acquire bus for write failed\n");
    169 		return 0;
    170 	}
    171 
    172 	if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr, &reg, 1,
    173 		     &bcd[reg], PCF8563_R_YEAR - reg + 1, I2C_F_POLL)) {
    174 		iic_release_bus(sc->sc_tag, I2C_F_POLL);
    175 		device_printf(sc->sc_dev, "write failed\n");
    176 		return 0;
    177 	}
    178 
    179 	iic_release_bus(sc->sc_tag, I2C_F_POLL);
    180 
    181 	return 1;
    182 }
    183