/*- * 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 /* * 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; bool sc_use_ampm; }; static void ds3231_start(void *); static int ds3231_read1(device_t dev, uint8_t reg, uint8_t *data) { return (iicdev_readfrom(dev, reg, data, 1, IIC_INTRWAIT)); } static int ds3231_write1(device_t dev, uint8_t reg, uint8_t data) { return (iicdev_writeto(dev, reg, &data, 1, IIC_INTRWAIT)); } static int ds3231_ctrl_read(struct ds3231_softc *sc) { int error; error = ds3231_read1(sc->sc_dev, DS3231_CONTROL, &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; /* Always enable the oscillator. Always disable both alarms. */ data = sc->sc_ctrl & ~DS3231_CTRL_MASK; error = ds3231_write1(sc->sc_dev, DS3231_CONTROL, 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; error = ds3231_read1(sc->sc_dev, DS3231_STATUS, &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; data = sc->sc_status; if (clear_a1 == 0) data |= DS3231_STATUS_A1F; if (clear_a2 == 0) data |= DS3231_STATUS_A2F; error = ds3231_write1(sc->sc_dev, DS3231_STATUS, 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 = iicdev_readfrom(sc->sc_dev, DS3231_TEMP, buf8, sizeof(buf8), IIC_INTRWAIT); 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 ds3231_sqw_freq[] = { 1, 1024, 4096, 8192 }; 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) - 1; 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) { int rc; #ifdef FDT if (!ofw_bus_status_okay(dev)) return (ENXIO); if (ofw_bus_is_compatible(dev, "maxim,ds3231")) rc = BUS_PROBE_DEFAULT; else #endif rc = BUS_PROBE_NOWILDCARD; device_set_desc(dev, "Maxim DS3231 RTC"); return (rc); } 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 = 0; 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 int ds3231_detach(device_t dev) { clock_unregister(dev); 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; /* * Warn if the clock stopped, but don't restart it until the first * clock_settime() call. */ if (sc->sc_status & DS3231_STATUS_OSF) { device_printf(sc->sc_dev, "WARNING: RTC clock stopped, check the battery.\n"); } /* * Ack any pending alarm interrupts and clear the EOSC bit to ensure the * clock runs even when on battery power. Do not give up if these * writes fail, because a factory-fresh chip is in a special mode that * disables much of the chip to save battery power, and the only thing * that gets it out of that mode is writing to the time registers. In * these pristine chips, the EOSC and alarm bits are zero already, so * the first valid write of time will get everything running properly. */ ds3231_status_write(sc, 1, 1); ds3231_ctrl_write(sc); /* 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 conversion"); 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"); /* * Register as a clock with 1 second resolution. Schedule the * clock_settime() method to be called just after top-of-second; * resetting the time resets top-of-second in the hardware. */ clock_register_flags(dev, 1000000, CLOCKF_SETTIME_NO_ADJ); clock_schedule(dev, 1); } static int ds3231_gettime(device_t dev, struct timespec *ts) { int c, error; struct bcd_clocktime bct; struct ds3231_softc *sc; uint8_t data[7], hourmask; sc = device_get_softc(dev); /* If the clock halted, we don't have good data. */ if ((error = ds3231_status_read(sc)) != 0) { device_printf(dev, "cannot read from RTC.\n"); return (error); } if (sc->sc_status & DS3231_STATUS_OSF) return (EINVAL); error = iicdev_readfrom(sc->sc_dev, DS3231_SECS, data, sizeof(data), IIC_INTRWAIT); if (error != 0) { device_printf(dev, "cannot read from RTC.\n"); return (error); } /* If chip is in AM/PM mode remember that. */ if (data[DS3231_HOUR] & DS3231_HOUR_USE_AMPM) { sc->sc_use_ampm = true; hourmask = DS3231_HOUR_MASK_12HR; } else hourmask = DS3231_HOUR_MASK_24HR; bct.nsec = 0; bct.sec = data[DS3231_SECS] & DS3231_SECS_MASK; bct.min = data[DS3231_MINS] & DS3231_MINS_MASK; bct.hour = data[DS3231_HOUR] & hourmask; bct.day = data[DS3231_DATE] & DS3231_DATE_MASK; bct.mon = data[DS3231_MONTH] & DS3231_MONTH_MASK; bct.year = data[DS3231_YEAR] & DS3231_YEAR_MASK; bct.ispm = data[DS3231_HOUR] & DS3231_HOUR_IS_PM; /* * If the century flag has toggled since we last saw it, there has been * a century rollover. If this is the first time we're seeing it, * remember the state so we can preserve its polarity on writes. */ 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 += 0x100; sc->sc_last_c = c; } bct.year |= sc->sc_year0; clock_dbgprint_bcd(sc->sc_dev, CLOCK_DBG_READ, &bct); return (clock_bcd_to_ts(&bct, ts, sc->sc_use_ampm)); } static int ds3231_settime(device_t dev, struct timespec *ts) { int error; struct bcd_clocktime bct; struct ds3231_softc *sc; uint8_t data[7]; uint8_t pmflags; sc = device_get_softc(dev); /* * We request a timespec with no resolution-adjustment. That also * disables utc adjustment, so apply that ourselves. */ ts->tv_sec -= utc_offset(); clock_ts_to_bcd(ts, &bct, sc->sc_use_ampm); clock_dbgprint_bcd(sc->sc_dev, CLOCK_DBG_WRITE, &bct); /* If the chip is in AM/PM mode, adjust hour and set flags as needed. */ if (sc->sc_use_ampm) { pmflags = DS3231_HOUR_USE_AMPM; if (bct.ispm) pmflags |= DS3231_HOUR_IS_PM; } else pmflags = 0; data[DS3231_SECS] = bct.sec; data[DS3231_MINS] = bct.min; data[DS3231_HOUR] = bct.hour | pmflags; data[DS3231_DATE] = bct.day; data[DS3231_WEEKDAY] = bct.dow + 1; data[DS3231_MONTH] = bct.mon; data[DS3231_YEAR] = bct.year & 0xff; if (sc->sc_last_c) data[DS3231_MONTH] |= DS3231_C_MASK; /* Write the time back to RTC. */ error = iicdev_writeto(dev, DS3231_SECS, data, sizeof(data), IIC_INTRWAIT); if (error != 0) { device_printf(dev, "cannot write to RTC.\n"); return (error); } /* * Unlike most hardware, the osc-was-stopped bit does not clear itself * after setting the time, it has to be manually written to zero. */ if (sc->sc_status & DS3231_STATUS_OSF) { if ((error = ds3231_status_read(sc)) != 0) { device_printf(dev, "cannot read from RTC.\n"); return (error); } sc->sc_status &= ~DS3231_STATUS_OSF; if ((error = ds3231_status_write(sc, 0, 0)) != 0) { device_printf(dev, "cannot write to RTC.\n"); return (error); } } return (error); } static device_method_t ds3231_methods[] = { DEVMETHOD(device_probe, ds3231_probe), DEVMETHOD(device_attach, ds3231_attach), DEVMETHOD(device_detach, ds3231_detach), DEVMETHOD(clock_gettime, ds3231_gettime), DEVMETHOD(clock_settime, ds3231_settime), DEVMETHOD_END }; static driver_t ds3231_driver = { "ds3231", ds3231_methods, sizeof(struct ds3231_softc), }; DRIVER_MODULE(ds3231, iicbus, ds3231_driver, NULL, NULL); MODULE_VERSION(ds3231, 1); MODULE_DEPEND(ds3231, iicbus, 1, 1, 1);