/*- * Copyright (c) 2014-2015 Luiz Otavio O Souza * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __FBSDID("$FreeBSD: head/sys/dev/iicbus/ds3231.c 279399 2015-02-28 19:02:44Z loos $"); /* * Driver for Maxim DS3231[N] real-time clock/calendar. */ #include "opt_platform.h" #include #include #include #include #include #include #include #include #include #ifdef FDT #include #include #include #endif #include #include "clock_if.h" #include "iicbus_if.h" struct ds3231_softc { device_t sc_dev; int sc_last_c; int sc_year0; struct intr_config_hook enum_hook; uint16_t sc_addr; /* DS3231 slave address. */ uint8_t sc_ctrl; uint8_t sc_status; }; static int ds3231_sqw_freq[] = { 1, 1024, 4096, 8192 }; static void ds3231_start(void *); static int ds3231_read(device_t dev, uint16_t addr, uint8_t reg, uint8_t *data, size_t len) { struct iic_msg msg[2] = { { addr, IIC_M_WR | IIC_M_NOSTOP, 1, ® }, { addr, IIC_M_RD, len, data }, }; return (iicbus_transfer(dev, msg, nitems(msg))); } static int ds3231_write(device_t dev, uint16_t addr, uint8_t *data, size_t len) { struct iic_msg msg[1] = { { addr, IIC_M_WR, len, data }, }; return (iicbus_transfer(dev, msg, nitems(msg))); } static int ds3231_ctrl_read(struct ds3231_softc *sc) { int error; sc->sc_ctrl = 0; error = ds3231_read(sc->sc_dev, sc->sc_addr, DS3231_CONTROL, &sc->sc_ctrl, sizeof(sc->sc_ctrl)); if (error) { device_printf(sc->sc_dev, "cannot read from RTC.\n"); return (error); } return (0); } static int ds3231_ctrl_write(struct ds3231_softc *sc) { int error; uint8_t data[2]; data[0] = DS3231_CONTROL; /* Always enable the oscillator. Always disable both alarms. */ data[1] = sc->sc_ctrl & ~DS3231_CTRL_MASK; error = ds3231_write(sc->sc_dev, sc->sc_addr, data, sizeof(data)); if (error != 0) device_printf(sc->sc_dev, "cannot write to RTC.\n"); return (error); } static int ds3231_status_read(struct ds3231_softc *sc) { int error; sc->sc_status = 0; error = ds3231_read(sc->sc_dev, sc->sc_addr, DS3231_STATUS, &sc->sc_status, sizeof(sc->sc_status)); if (error) { device_printf(sc->sc_dev, "cannot read from RTC.\n"); return (error); } return (0); } static int ds3231_status_write(struct ds3231_softc *sc, int clear_a1, int clear_a2) { int error; uint8_t data[2]; data[0] = DS3231_STATUS; data[1] = sc->sc_status; if (clear_a1 == 0) data[1] |= DS3231_STATUS_A1F; if (clear_a2 == 0) data[1] |= DS3231_STATUS_A2F; error = ds3231_write(sc->sc_dev, sc->sc_addr, data, sizeof(data)); if (error != 0) device_printf(sc->sc_dev, "cannot write to RTC.\n"); return (error); } static int ds3231_set_24hrs_mode(struct ds3231_softc *sc) { int error; uint8_t data[2], hour; hour = 0; error = ds3231_read(sc->sc_dev, sc->sc_addr, DS3231_HOUR, &hour, sizeof(hour)); if (error) { device_printf(sc->sc_dev, "cannot read from RTC.\n"); return (error); } data[0] = DS3231_HOUR; data[1] = hour & ~DS3231_C_MASK; error = ds3231_write(sc->sc_dev, sc->sc_addr, data, sizeof(data)); if (error != 0) device_printf(sc->sc_dev, "cannot write to RTC.\n"); return (error); } static int ds3231_temp_read(struct ds3231_softc *sc, int *temp) { int error, neg, t; uint8_t buf8[2]; uint16_t buf; error = ds3231_read(sc->sc_dev, sc->sc_addr, DS3231_TEMP, buf8, sizeof(buf8)); if (error != 0) return (error); buf = (buf8[0] << 8) | (buf8[1] & 0xff); neg = 0; if (buf & DS3231_NEG_BIT) { buf = ~(buf & DS3231_TEMP_MASK) + 1; neg = 1; } *temp = ((int16_t)buf >> 8) * 10; t = 0; if (buf & DS3231_0250C) t += 250; if (buf & DS3231_0500C) t += 500; t /= 100; *temp += t; if (neg) *temp = -(*temp); *temp += TZ_ZEROC; return (0); } static int ds3231_temp_sysctl(SYSCTL_HANDLER_ARGS) { int error, temp; struct ds3231_softc *sc; sc = (struct ds3231_softc *)arg1; if (ds3231_temp_read(sc, &temp) != 0) return (EIO); error = sysctl_handle_int(oidp, &temp, 0, req); return (error); } static int ds3231_conv_sysctl(SYSCTL_HANDLER_ARGS) { int error, conv, newc; struct ds3231_softc *sc; sc = (struct ds3231_softc *)arg1; error = ds3231_ctrl_read(sc); if (error != 0) return (error); newc = conv = (sc->sc_ctrl & DS3231_CTRL_CONV) ? 1 : 0; error = sysctl_handle_int(oidp, &newc, 0, req); if (error != 0 || req->newptr == NULL) return (error); if (conv == 0 && newc != 0) { error = ds3231_status_read(sc); if (error != 0) return (error); if (sc->sc_status & DS3231_STATUS_BUSY) return (0); sc->sc_ctrl |= DS3231_CTRL_CONV; error = ds3231_ctrl_write(sc); if (error != 0) return (error); } return (error); } static int ds3231_bbsqw_sysctl(SYSCTL_HANDLER_ARGS) { int bbsqw, error, newb; struct ds3231_softc *sc; sc = (struct ds3231_softc *)arg1; error = ds3231_ctrl_read(sc); if (error != 0) return (error); bbsqw = newb = (sc->sc_ctrl & DS3231_CTRL_BBSQW) ? 1 : 0; error = sysctl_handle_int(oidp, &newb, 0, req); if (error != 0 || req->newptr == NULL) return (error); if (bbsqw != newb) { sc->sc_ctrl &= ~DS3231_CTRL_BBSQW; if (newb) sc->sc_ctrl |= DS3231_CTRL_BBSQW; error = ds3231_ctrl_write(sc); if (error != 0) return (error); } return (error); } static int ds3231_sqw_freq_sysctl(SYSCTL_HANDLER_ARGS) { int error, freq, i, newf, tmp; struct ds3231_softc *sc; sc = (struct ds3231_softc *)arg1; error = ds3231_ctrl_read(sc); if (error != 0) return (error); tmp = (sc->sc_ctrl & DS3231_CTRL_RS_MASK) >> DS3231_CTRL_RS_SHIFT; if (tmp > nitems(ds3231_sqw_freq)) tmp = nitems(ds3231_sqw_freq); freq = ds3231_sqw_freq[tmp]; error = sysctl_handle_int(oidp, &freq, 0, req); if (error != 0 || req->newptr == NULL) return (error); if (freq != ds3231_sqw_freq[tmp]) { newf = 0; for (i = 0; i < nitems(ds3231_sqw_freq); i++) if (freq >= ds3231_sqw_freq[i]) newf = i; sc->sc_ctrl &= ~DS3231_CTRL_RS_MASK; sc->sc_ctrl |= newf << DS3231_CTRL_RS_SHIFT; error = ds3231_ctrl_write(sc); if (error != 0) return (error); } return (error); } static int ds3231_str_sqw_mode(char *buf) { int len, rtrn; rtrn = -1; len = strlen(buf); if ((len > 2 && strncasecmp("interrupt", buf, len) == 0) || (len > 2 && strncasecmp("int", buf, len) == 0)) { rtrn = 1; } else if ((len > 2 && strncasecmp("square-wave", buf, len) == 0) || (len > 2 && strncasecmp("sqw", buf, len) == 0)) { rtrn = 0; } return (rtrn); } static int ds3231_sqw_mode_sysctl(SYSCTL_HANDLER_ARGS) { char buf[16]; int error, mode, newm; struct ds3231_softc *sc; sc = (struct ds3231_softc *)arg1; error = ds3231_ctrl_read(sc); if (error != 0) return (error); if (sc->sc_ctrl & DS3231_CTRL_INTCN) { mode = 1; strlcpy(buf, "interrupt", sizeof(buf)); } else { mode = 0; strlcpy(buf, "square-wave", sizeof(buf)); } error = sysctl_handle_string(oidp, buf, sizeof(buf), req); if (error != 0 || req->newptr == NULL) return (error); newm = ds3231_str_sqw_mode(buf); if (newm != -1 && mode != newm) { sc->sc_ctrl &= ~DS3231_CTRL_INTCN; if (newm == 1) sc->sc_ctrl |= DS3231_CTRL_INTCN; error = ds3231_ctrl_write(sc); if (error != 0) return (error); } return (error); } static int ds3231_en32khz_sysctl(SYSCTL_HANDLER_ARGS) { int error, en32khz, tmp; struct ds3231_softc *sc; sc = (struct ds3231_softc *)arg1; error = ds3231_status_read(sc); if (error != 0) return (error); tmp = en32khz = (sc->sc_status & DS3231_STATUS_EN32KHZ) ? 1 : 0; error = sysctl_handle_int(oidp, &en32khz, 0, req); if (error != 0 || req->newptr == NULL) return (error); if (en32khz != tmp) { sc->sc_status &= ~DS3231_STATUS_EN32KHZ; if (en32khz) sc->sc_status |= DS3231_STATUS_EN32KHZ; error = ds3231_status_write(sc, 0, 0); if (error != 0) return (error); } return (error); } static int ds3231_probe(device_t dev) { #ifdef FDT if (!ofw_bus_status_okay(dev)) return (ENXIO); if (!ofw_bus_is_compatible(dev, "maxim,ds3231")) return (ENXIO); #endif device_set_desc(dev, "Maxim DS3231 RTC"); return (BUS_PROBE_DEFAULT); } static int ds3231_attach(device_t dev) { struct ds3231_softc *sc; sc = device_get_softc(dev); sc->sc_dev = dev; sc->sc_addr = iicbus_get_addr(dev); sc->sc_last_c = -1; sc->sc_year0 = 1900; sc->enum_hook.ich_func = ds3231_start; sc->enum_hook.ich_arg = dev; /* * We have to wait until interrupts are enabled. Usually I2C read * and write only works when the interrupts are available. */ if (config_intrhook_establish(&sc->enum_hook) != 0) return (ENOMEM); return (0); } static void ds3231_start(void *xdev) { device_t dev; struct ds3231_softc *sc; struct sysctl_ctx_list *ctx; struct sysctl_oid *tree_node; struct sysctl_oid_list *tree; dev = (device_t)xdev; sc = device_get_softc(dev); ctx = device_get_sysctl_ctx(dev); tree_node = device_get_sysctl_tree(dev); tree = SYSCTL_CHILDREN(tree_node); config_intrhook_disestablish(&sc->enum_hook); if (ds3231_ctrl_read(sc) != 0) return; if (ds3231_status_read(sc) != 0) return; /* Clear the OSF bit and ack any pending alarm interrupt. */ if (sc->sc_status & DS3231_STATUS_OSF) { device_printf(sc->sc_dev, "oscillator has stopped, check the battery.\n"); sc->sc_status &= ~DS3231_STATUS_OSF; } if (ds3231_status_write(sc, 1, 1) != 0) return; /* Always enable the oscillator. */ if (ds3231_ctrl_write(sc) != 0) return; /* Set the 24 hours mode. */ if (ds3231_set_24hrs_mode(sc) != 0) return; /* Temperature. */ SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "temperature", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, sc, 0, ds3231_temp_sysctl, "IK", "Current temperature"); /* Configuration parameters. */ SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "temp_conv", CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_MPSAFE, sc, 0, ds3231_conv_sysctl, "IU", "DS3231 start a new temperature converstion"); SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "bbsqw", CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_MPSAFE, sc, 0, ds3231_bbsqw_sysctl, "IU", "DS3231 battery-backed square-wave output enable"); SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "sqw_freq", CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_MPSAFE, sc, 0, ds3231_sqw_freq_sysctl, "IU", "DS3231 square-wave output frequency"); SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "sqw_mode", CTLFLAG_RW | CTLTYPE_STRING | CTLFLAG_MPSAFE, sc, 0, ds3231_sqw_mode_sysctl, "A", "DS3231 SQW output mode control"); SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "32khz_enable", CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_MPSAFE, sc, 0, ds3231_en32khz_sysctl, "IU", "DS3231 enable the 32kHz output"); /* 1 second resolution. */ clock_register(dev, 1000000); } static int ds3231_gettime(device_t dev, struct timespec *ts) { int c, error; struct clocktime ct; struct ds3231_softc *sc; uint8_t data[7]; sc = device_get_softc(dev); memset(data, 0, sizeof(data)); error = ds3231_read(sc->sc_dev, sc->sc_addr, DS3231_SECS, data, sizeof(data)); if (error != 0) { device_printf(dev, "cannot read from RTC.\n"); return (error); } ct.nsec = 0; ct.sec = FROMBCD(data[DS3231_SECS] & DS3231_SECS_MASK); ct.min = FROMBCD(data[DS3231_MINS] & DS3231_MINS_MASK); ct.hour = FROMBCD(data[DS3231_HOUR] & DS3231_HOUR_MASK); ct.day = FROMBCD(data[DS3231_DATE] & DS3231_DATE_MASK); ct.dow = data[DS3231_WEEKDAY] & DS3231_WEEKDAY_MASK; ct.mon = FROMBCD(data[DS3231_MONTH] & DS3231_MONTH_MASK); ct.year = FROMBCD(data[DS3231_YEAR] & DS3231_YEAR_MASK); c = (data[DS3231_MONTH] & DS3231_C_MASK) ? 1 : 0; if (sc->sc_last_c == -1) sc->sc_last_c = c; else if (c != sc->sc_last_c) { sc->sc_year0 += 100; sc->sc_last_c = c; } ct.year += sc->sc_year0; if (ct.year < POSIX_BASE_YEAR) ct.year += 100; /* assume [1970, 2069] */ return (clock_ct_to_ts(&ct, ts)); } static int ds3231_settime(device_t dev, struct timespec *ts) { int error; struct clocktime ct; struct ds3231_softc *sc; uint8_t data[8]; sc = device_get_softc(dev); /* Accuracy is only one second. */ if (ts->tv_nsec >= 500000000) ts->tv_sec++; ts->tv_nsec = 0; clock_ts_to_ct(ts, &ct); memset(data, 0, sizeof(data)); data[0] = DS3231_SECS; data[DS3231_SECS + 1] = TOBCD(ct.sec); data[DS3231_MINS + 1] = TOBCD(ct.min); data[DS3231_HOUR + 1] = TOBCD(ct.hour); data[DS3231_DATE + 1] = TOBCD(ct.day); data[DS3231_WEEKDAY + 1] = ct.dow; data[DS3231_MONTH + 1] = TOBCD(ct.mon); data[DS3231_YEAR + 1] = TOBCD(ct.year % 100); if (sc->sc_last_c) data[DS3231_MONTH] |= DS3231_C_MASK; /* Write the time back to RTC. */ error = ds3231_write(dev, sc->sc_addr, data, sizeof(data)); if (error != 0) device_printf(dev, "cannot write to RTC.\n"); return (error); } static device_method_t ds3231_methods[] = { DEVMETHOD(device_probe, ds3231_probe), DEVMETHOD(device_attach, ds3231_attach), DEVMETHOD(clock_gettime, ds3231_gettime), DEVMETHOD(clock_settime, ds3231_settime), DEVMETHOD_END }; static driver_t ds3231_driver = { "ds3231", ds3231_methods, sizeof(struct ds3231_softc), }; static devclass_t ds3231_devclass; DRIVER_MODULE(ds3231, iicbus, ds3231_driver, ds3231_devclass, NULL, NULL); MODULE_VERSION(ds3231, 1); MODULE_DEPEND(ds3231, iicbus, 1, 1, 1);