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pcf8563.c revision 1.13
      1 /*	$NetBSD: pcf8563.c,v 1.13 2021/01/17 21:42:35 thorpej 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 /* XXX */
     30 #if defined(__arm__) || defined(__aarch64__)
     31 #include "opt_fdt.h"
     32 #endif
     33 
     34 #include <sys/cdefs.h>
     35 __KERNEL_RCSID(0, "$NetBSD: pcf8563.c,v 1.13 2021/01/17 21:42:35 thorpej Exp $");
     36 
     37 #include <sys/param.h>
     38 #include <sys/systm.h>
     39 #include <sys/device.h>
     40 #include <sys/kernel.h>
     41 
     42 #include <dev/clock_subr.h>
     43 
     44 #include <dev/i2c/i2cvar.h>
     45 #include <dev/i2c/pcf8563reg.h>
     46 
     47 #ifdef FDT
     48 #include <dev/fdt/fdtvar.h>
     49 #endif
     50 
     51 static const struct device_compatible_entry compat_data[] = {
     52 	{ .compat = "nxp,pcf8563" },
     53 	{ .compat = "pcf8563rtc" },
     54 
     55 	{ 0 }
     56 };
     57 
     58 struct pcf8563rtc_softc {
     59 	device_t sc_dev;
     60 	i2c_tag_t sc_tag;
     61 	int sc_addr;
     62 	struct todr_chip_handle sc_todr;
     63 };
     64 
     65 static int pcf8563rtc_match(device_t, cfdata_t, void *);
     66 static void pcf8563rtc_attach(device_t, device_t, void *);
     67 
     68 CFATTACH_DECL_NEW(pcf8563rtc, sizeof(struct pcf8563rtc_softc),
     69     pcf8563rtc_match, pcf8563rtc_attach, NULL, NULL);
     70 
     71 static int pcf8563rtc_clock_read(struct pcf8563rtc_softc *, struct clock_ymdhms *);
     72 static int pcf8563rtc_clock_write(struct pcf8563rtc_softc *, struct clock_ymdhms *);
     73 static int pcf8563rtc_gettime(struct todr_chip_handle *, struct clock_ymdhms *);
     74 static int pcf8563rtc_settime(struct todr_chip_handle *, struct clock_ymdhms *);
     75 
     76 static int
     77 pcf8563rtc_match(device_t parent, cfdata_t cf, void *aux)
     78 {
     79 	struct i2c_attach_args *ia = aux;
     80 	int match_result;
     81 
     82 	if (iic_use_direct_match(ia, cf, compat_data, &match_result))
     83 		return match_result;
     84 
     85 	/* indirect config - check typical address */
     86 	if (ia->ia_addr == PCF8563_ADDR)
     87 		return I2C_MATCH_ADDRESS_ONLY;
     88 
     89 	return 0;
     90 }
     91 
     92 static void
     93 pcf8563rtc_attach(device_t parent, device_t self, void *aux)
     94 {
     95 	struct pcf8563rtc_softc *sc = device_private(self);
     96 	struct i2c_attach_args *ia = aux;
     97 	int error;
     98 
     99 	aprint_naive(": Real-time Clock\n");
    100 	aprint_normal(": NXP PCF8563 Real-time Clock\n");
    101 
    102 	sc->sc_dev = self;
    103 	sc->sc_tag = ia->ia_tag;
    104 	sc->sc_addr = ia->ia_addr;
    105 	sc->sc_todr.cookie = sc;
    106 	sc->sc_todr.todr_gettime_ymdhms = pcf8563rtc_gettime;
    107 	sc->sc_todr.todr_settime_ymdhms = pcf8563rtc_settime;
    108 	sc->sc_todr.todr_setwen = NULL;
    109 
    110 	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
    111 		aprint_error_dev(sc->sc_dev,
    112 		    "failed to acquire bus for attach\n");
    113 		return;
    114 	}
    115 	if ((error = iic_smbus_write_byte(sc->sc_tag, sc->sc_addr,
    116 					  PCF8563_R_CS1, 0, 0)) == 0) {
    117 		error = iic_smbus_write_byte(sc->sc_tag, sc->sc_addr,
    118 					     PCF8563_R_CS2, 0, 0);
    119 	}
    120 	iic_release_bus(sc->sc_tag, 0);
    121 	if (error) {
    122 		aprint_error_dev(sc->sc_dev, "failed to initialize RTC\n");
    123 		return;
    124 	}
    125 
    126 #ifdef FDT
    127 	fdtbus_todr_attach(self, ia->ia_cookie, &sc->sc_todr);
    128 #else
    129 	todr_attach(&sc->sc_todr);
    130 #endif
    131 }
    132 
    133 static int
    134 pcf8563rtc_gettime(struct todr_chip_handle *ch, struct clock_ymdhms *dt)
    135 {
    136 	struct pcf8563rtc_softc *sc = ch->cookie;
    137 
    138 	return pcf8563rtc_clock_read(sc, dt);
    139 }
    140 
    141 static int
    142 pcf8563rtc_settime(struct todr_chip_handle *ch, struct clock_ymdhms *dt)
    143 {
    144         struct pcf8563rtc_softc *sc = ch->cookie;
    145 
    146 	return pcf8563rtc_clock_write(sc, dt);
    147 }
    148 
    149 static int
    150 pcf8563rtc_clock_read(struct pcf8563rtc_softc *sc, struct clock_ymdhms *dt)
    151 {
    152 	uint8_t bcd[PCF8563_NREGS];
    153 	uint8_t reg = PCF8563_R_SECOND;
    154 	int error;
    155 
    156 	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
    157 		device_printf(sc->sc_dev, "acquire bus for read failed\n");
    158 		return error;
    159 	}
    160 
    161 	if ((error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
    162 			      &reg, 1, &bcd[reg], PCF8563_R_YEAR - reg + 1,
    163 			      0)) != 0) {
    164 		iic_release_bus(sc->sc_tag, 0);
    165 		device_printf(sc->sc_dev, "read failed\n");
    166 		return error;
    167 	}
    168 
    169 	iic_release_bus(sc->sc_tag, 0);
    170 
    171 	if (bcd[PCF8563_R_SECOND] & PCF8563_M_VL)
    172 		return EIO;
    173 
    174 	dt->dt_sec = bcdtobin(bcd[PCF8563_R_SECOND] & PCF8563_M_SECOND);
    175 	dt->dt_min = bcdtobin(bcd[PCF8563_R_MINUTE] & PCF8563_M_MINUTE);
    176 	dt->dt_hour = bcdtobin(bcd[PCF8563_R_HOUR] & PCF8563_M_HOUR);
    177 	dt->dt_day = bcdtobin(bcd[PCF8563_R_DAY] & PCF8563_M_DAY);
    178 	dt->dt_wday = bcdtobin(bcd[PCF8563_R_WEEKDAY] & PCF8563_M_WEEKDAY);
    179 	dt->dt_mon = bcdtobin(bcd[PCF8563_R_MONTH] & PCF8563_M_MONTH);
    180 	dt->dt_year = 1900 +
    181 	    (bcdtobin(bcd[PCF8563_R_YEAR] & PCF8563_M_YEAR) % 100);
    182 	if ((bcd[PCF8563_R_MONTH] & PCF8563_M_CENTURY) == 0)
    183 		dt->dt_year += 100;
    184 
    185 	return error;
    186 }
    187 
    188 static int
    189 pcf8563rtc_clock_write(struct pcf8563rtc_softc *sc, struct clock_ymdhms *dt)
    190 {
    191 	uint8_t bcd[PCF8563_NREGS];
    192 	uint8_t reg = PCF8563_R_SECOND;
    193 	int error;
    194 
    195 	bcd[PCF8563_R_SECOND] = bintobcd(dt->dt_sec);
    196 	bcd[PCF8563_R_MINUTE] = bintobcd(dt->dt_min);
    197 	bcd[PCF8563_R_HOUR] = bintobcd(dt->dt_hour);
    198 	bcd[PCF8563_R_DAY] = bintobcd(dt->dt_day);
    199 	bcd[PCF8563_R_WEEKDAY] = bintobcd(dt->dt_wday);
    200 	bcd[PCF8563_R_MONTH] = bintobcd(dt->dt_mon);
    201 	bcd[PCF8563_R_YEAR] = bintobcd(dt->dt_year % 100);
    202 	if (dt->dt_year < 2000)
    203 		bcd[PCF8563_R_MONTH] |= PCF8563_M_CENTURY;
    204 
    205 	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
    206 		device_printf(sc->sc_dev, "acquire bus for write failed\n");
    207 		return error;
    208 	}
    209 
    210 	if ((error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr, &reg, 1, &bcd[reg], PCF8563_R_YEAR - reg + 1, 0)) != 0) {
    211 		iic_release_bus(sc->sc_tag, 0);
    212 		device_printf(sc->sc_dev, "write failed\n");
    213 		return error;
    214 	}
    215 
    216 	iic_release_bus(sc->sc_tag, 0);
    217 
    218 	return error;
    219 }
    220