/* $OpenBSD: gpiodcf.c,v 1.7 2019/08/10 18:18:27 cheloha Exp $ */ /* * Copyright (c) 2008 Marc Balmer * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef GPIODCF_DEBUG #define DPRINTFN(n, x) do { if (gpiodcfdebug > (n)) printf x; } while (0) int gpiodcfdebug = 0; #else #define DPRINTFN(n, x) #endif #define DPRINTF(x) DPRINTFN(0, x) /* max. skew of received time diff vs. measured time diff in percent. */ #define MAX_SKEW 5 #define GPIODCF_NPINS 1 #define GPIODCF_PIN_DATA 0 struct gpiodcf_softc { struct device sc_dev; /* base device */ void *sc_gpio; struct gpio_pinmap sc_map; int __map[GPIODCF_NPINS]; u_char sc_dying; /* disconnecting */ int sc_data; struct timeout sc_to; struct timeout sc_bv_to; /* bit-value detect */ struct timeout sc_db_to; /* debounce */ struct timeout sc_mg_to; /* minute-gap detect */ struct timeout sc_sl_to; /* signal-loss detect */ struct timeout sc_it_to; /* invalidate time */ int sc_sync; /* 1 during sync */ u_int64_t sc_mask; /* 64 bit mask */ u_int64_t sc_tbits; /* Time bits */ int sc_minute; int sc_level; time_t sc_last_mg; time_t sc_current; /* current time */ time_t sc_next; /* time to become valid next */ time_t sc_last; int sc_nrecv; /* consecutive valid times */ struct timeval sc_last_tv; /* uptime of last valid time */ struct ksensor sc_sensor; #ifdef GPIODCF_DEBUG struct ksensor sc_skew; /* recv vs local skew */ #endif struct ksensordev sc_sensordev; }; /* * timeouts used: */ #define T_BV 150 /* bit value detection (150ms) */ #define T_SYNC 950 /* sync (950ms) */ #define T_MG 1500 /* minute gap detection (1500ms) */ #define T_MGSYNC 450 /* resync after a minute gap (450ms) */ #define T_SL 3000 /* detect signal loss (3sec) */ #define T_WAIT 5000 /* wait (5sec) */ #define T_WARN 300000 /* degrade sensor status to warning (5min) #define T_CRIT 900000 /* degrade sensor status to critical (15min) */ void gpiodcf_intr(void *); void gpiodcf_probe(void *); void gpiodcf_bv_probe(void *); void gpiodcf_mg_probe(void *); void gpiodcf_sl_probe(void *); void gpiodcf_invalidate(void *); int gpiodcf_match(struct device *, void *, void *); void gpiodcf_attach(struct device *, struct device *, void *); int gpiodcf_detach(struct device *, int); int gpiodcf_activate(struct device *, int); int gpiodcf_signal(struct gpiodcf_softc *); struct cfdriver gpiodcf_cd = { NULL, "gpiodcf", DV_DULL }; const struct cfattach gpiodcf_ca = { sizeof(struct gpiodcf_softc), gpiodcf_match, gpiodcf_attach, gpiodcf_detach, gpiodcf_activate }; int gpiodcf_match(struct device *parent, void *match, void *aux) { struct cfdata *cf = match; struct gpio_attach_args *ga = aux; if (ga->ga_offset == -1) return 0; return (strcmp(cf->cf_driver->cd_name, "gpiodcf") == 0); } void gpiodcf_attach(struct device *parent, struct device *self, void *aux) { struct gpiodcf_softc *sc = (struct gpiodcf_softc *)self; struct gpio_attach_args *ga = aux; int caps; if (gpio_npins(ga->ga_mask) != GPIODCF_NPINS) { printf(": invalid pin mask\n"); return; } sc->sc_gpio = ga->ga_gpio; sc->sc_map.pm_map = sc->__map; if (gpio_pin_map(sc->sc_gpio, ga->ga_offset, ga->ga_mask, &sc->sc_map)) { printf(": can't map pins\n"); return; } caps = gpio_pin_caps(sc->sc_gpio, &sc->sc_map, GPIODCF_PIN_DATA); if (!(caps & GPIO_PIN_INPUT)) { printf(": data pin is unable to receive input\n"); goto fishy; } printf(": DATA[%d]", sc->sc_map.pm_map[GPIODCF_PIN_DATA]); sc->sc_data = GPIO_PIN_INPUT; gpio_pin_ctl(sc->sc_gpio, &sc->sc_map, GPIODCF_PIN_DATA, sc->sc_data); printf("\n"); strlcpy(sc->sc_sensor.desc, "DCF77", sizeof(sc->sc_sensor.desc)); timeout_set(&sc->sc_to, gpiodcf_probe, sc); timeout_set(&sc->sc_bv_to, gpiodcf_bv_probe, sc); timeout_set(&sc->sc_mg_to, gpiodcf_mg_probe, sc); timeout_set(&sc->sc_sl_to, gpiodcf_sl_probe, sc); timeout_set(&sc->sc_it_to, gpiodcf_invalidate, sc); strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname, sizeof(sc->sc_sensordev.xname)); sc->sc_sensor.type = SENSOR_TIMEDELTA; sc->sc_sensor.status = SENSOR_S_UNKNOWN; sensor_attach(&sc->sc_sensordev, &sc->sc_sensor); #ifdef GPIODCF_DEBUG sc->sc_skew.type = SENSOR_TIMEDELTA; sc->sc_skew.status = SENSOR_S_UNKNOWN; strlcpy(sc->sc_skew.desc, "local clock skew", sizeof(sc->sc_skew.desc)); sensor_attach(&sc->sc_sensordev, &sc->sc_skew); #endif sensordev_install(&sc->sc_sensordev); sc->sc_level = 0; sc->sc_minute = 0; sc->sc_last_mg = 0L; sc->sc_sync = 1; sc->sc_current = 0L; sc->sc_next = 0L; sc->sc_nrecv = 0; sc->sc_last = 0L; sc->sc_last_tv.tv_sec = 0L; /* Give the receiver some slack to stabilize */ timeout_add_msec(&sc->sc_to, T_WAIT); /* Detect signal loss */ timeout_add_msec(&sc->sc_sl_to, T_WAIT + T_SL); DPRINTF(("synchronizing\n")); return; fishy: DPRINTF(("gpiodcf_attach failed\n")); gpio_pin_unmap(sc->sc_gpio, &sc->sc_map); sc->sc_dying = 1; } int gpiodcf_detach(struct device *self, int flags) { struct gpiodcf_softc *sc = (struct gpiodcf_softc *)self; sc->sc_dying = 1; timeout_del(&sc->sc_to); timeout_del(&sc->sc_bv_to); timeout_del(&sc->sc_mg_to); timeout_del(&sc->sc_sl_to); timeout_del(&sc->sc_it_to); /* Unregister the clock with the kernel */ sensordev_deinstall(&sc->sc_sensordev); /* Finally unmap the GPIO pin */ gpio_pin_unmap(sc->sc_gpio, &sc->sc_map); return 0; } /* * return 1 during high-power-, 0 during low-power-emission * If bit 0 is set, the transmitter emits at full power. * During the low-power emission we decode a zero bit. */ int gpiodcf_signal(struct gpiodcf_softc *sc) { return (gpio_pin_read(sc->sc_gpio, &sc->sc_map, GPIODCF_PIN_DATA) == GPIO_PIN_HIGH ? 1 : 0); } /* gpiodcf_probe runs in a process context. */ void gpiodcf_probe(void *xsc) { struct gpiodcf_softc *sc = xsc; struct timespec now; int data; if (sc->sc_dying) return; data = gpiodcf_signal(sc); if (data == -1) return; if (data) { sc->sc_level = 1; timeout_add(&sc->sc_to, 1); return; } if (sc->sc_level == 0) return; /* the beginning of a second */ sc->sc_level = 0; if (sc->sc_minute == 1) { if (sc->sc_sync) { DPRINTF(("start collecting bits\n")); sc->sc_sync = 0; } else { /* provide the timedelta */ microtime(&sc->sc_sensor.tv); nanotime(&now); sc->sc_current = sc->sc_next; sc->sc_sensor.value = (int64_t)(now.tv_sec - sc->sc_current) * 1000000000LL + now.tv_nsec; sc->sc_sensor.status = SENSOR_S_OK; /* * if no valid time information is received * during the next 5 minutes, the sensor state * will be degraded to SENSOR_S_WARN */ timeout_add_msec(&sc->sc_it_to, T_WARN); } sc->sc_minute = 0; } timeout_add_msec(&sc->sc_to, T_SYNC); /* resync in 950 ms */ /* no clock and bit detection during sync */ if (!sc->sc_sync) { /* detect bit value */ timeout_add_msec(&sc->sc_bv_to, T_BV); } timeout_add_msec(&sc->sc_mg_to, T_MG); /* detect minute gap */ timeout_add_msec(&sc->sc_sl_to, T_SL); /* detect signal loss */ } /* detect the bit value */ void gpiodcf_bv_probe(void *xsc) { struct gpiodcf_softc *sc = xsc; int data; if (sc->sc_dying) return; data = gpiodcf_signal(sc); if (data == -1) { DPRINTF(("bit detection failed\n")); return; } DPRINTFN(1, (data ? "0" : "1")); if (!(data)) sc->sc_tbits |= sc->sc_mask; sc->sc_mask <<= 1; } /* detect the minute gap */ void gpiodcf_mg_probe(void *xsc) { struct gpiodcf_softc *sc = xsc; struct clock_ymdhms ymdhm; struct timeval monotime; int tdiff_recv, tdiff_local; int skew; int minute_bits, hour_bits, day_bits; int month_bits, year_bits, wday; int p1, p2, p3; int p1_bit, p2_bit, p3_bit; int r_bit, a1_bit, a2_bit, z1_bit, z2_bit; int s_bit, m_bit; u_int32_t parity = 0x6996; if (sc->sc_sync) { sc->sc_minute = 1; goto cleanbits; } if (time_second - sc->sc_last_mg < 57) { DPRINTF(("\nunexpected gap, resync\n")); sc->sc_sync = sc->sc_minute = 1; goto cleanbits; } /* extract bits w/o parity */ m_bit = sc->sc_tbits & 1; r_bit = sc->sc_tbits >> 15 & 1; a1_bit = sc->sc_tbits >> 16 & 1; z1_bit = sc->sc_tbits >> 17 & 1; z2_bit = sc->sc_tbits >> 18 & 1; a2_bit = sc->sc_tbits >> 19 & 1; s_bit = sc->sc_tbits >> 20 & 1; p1_bit = sc->sc_tbits >> 28 & 1; p2_bit = sc->sc_tbits >> 35 & 1; p3_bit = sc->sc_tbits >> 58 & 1; minute_bits = sc->sc_tbits >> 21 & 0x7f; hour_bits = sc->sc_tbits >> 29 & 0x3f; day_bits = sc->sc_tbits >> 36 & 0x3f; wday = (sc->sc_tbits >> 42) & 0x07; month_bits = sc->sc_tbits >> 45 & 0x1f; year_bits = sc->sc_tbits >> 50 & 0xff; /* validate time information */ p1 = (parity >> (minute_bits & 0x0f) & 1) ^ (parity >> (minute_bits >> 4) & 1); p2 = (parity >> (hour_bits & 0x0f) & 1) ^ (parity >> (hour_bits >> 4) & 1); p3 = (parity >> (day_bits & 0x0f) & 1) ^ (parity >> (day_bits >> 4) & 1) ^ ((parity >> wday) & 1) ^ (parity >> (month_bits & 0x0f) & 1) ^ (parity >> (month_bits >> 4) & 1) ^ (parity >> (year_bits & 0x0f) & 1) ^ (parity >> (year_bits >> 4) & 1); if (m_bit == 0 && s_bit == 1 && p1 == p1_bit && p2 == p2_bit && p3 == p3_bit && (z1_bit ^ z2_bit)) { /* Decode time */ if ((ymdhm.dt_year = 2000 + FROMBCD(year_bits)) > 2037) { DPRINTF(("year out of range, resync\n")); sc->sc_sync = 1; goto cleanbits; } ymdhm.dt_min = FROMBCD(minute_bits); ymdhm.dt_hour = FROMBCD(hour_bits); ymdhm.dt_day = FROMBCD(day_bits); ymdhm.dt_mon = FROMBCD(month_bits); ymdhm.dt_sec = 0; sc->sc_next = clock_ymdhms_to_secs(&ymdhm); getmicrouptime(&monotime); /* convert to coordinated universal time */ sc->sc_next -= z1_bit ? 7200 : 3600; DPRINTF(("\n%02d.%02d.%04d %02d:%02d:00 %s", ymdhm.dt_day, ymdhm.dt_mon, ymdhm.dt_year, ymdhm.dt_hour, ymdhm.dt_min, z1_bit ? "CEST" : "CET")); DPRINTF((r_bit ? ", call bit" : "")); DPRINTF((a1_bit ? ", dst chg ann." : "")); DPRINTF((a2_bit ? ", leap sec ann." : "")); DPRINTF(("\n")); if (sc->sc_last) { tdiff_recv = sc->sc_next - sc->sc_last; tdiff_local = monotime.tv_sec - sc->sc_last_tv.tv_sec; skew = abs(tdiff_local - tdiff_recv); #ifdef GPIODCF_DEBUG if (sc->sc_skew.status == SENSOR_S_UNKNOWN) sc->sc_skew.status = SENSOR_S_CRIT; sc->sc_skew.value = skew * 1000000000LL; getmicrotime(&sc->sc_skew.tv); #endif DPRINTF(("local = %d, recv = %d, skew = %d\n", tdiff_local, tdiff_recv, skew)); if (skew && skew * 100LL / tdiff_local > MAX_SKEW) { DPRINTF(("skew out of tolerated range\n")); goto cleanbits; } else { if (sc->sc_nrecv < 2) { sc->sc_nrecv++; DPRINTF(("got frame %d\n", sc->sc_nrecv)); } else { DPRINTF(("data is valid\n")); sc->sc_minute = 1; } } } else { DPRINTF(("received the first frame\n")); sc->sc_nrecv = 1; } /* record the time received and when it was received */ sc->sc_last = sc->sc_next; sc->sc_last_tv.tv_sec = monotime.tv_sec; } else { DPRINTF(("\nparity error, resync\n")); sc->sc_sync = sc->sc_minute = 1; } cleanbits: timeout_add_msec(&sc->sc_to, T_MGSYNC); /* re-sync in 450 ms */ sc->sc_last_mg = time_second; sc->sc_tbits = 0LL; sc->sc_mask = 1LL; } /* detect signal loss */ void gpiodcf_sl_probe(void *xsc) { struct gpiodcf_softc *sc = xsc; if (sc->sc_dying) return; DPRINTF(("no signal\n")); sc->sc_sync = 1; timeout_add_msec(&sc->sc_to, T_WAIT); timeout_add_msec(&sc->sc_sl_to, T_WAIT + T_SL); } /* invalidate timedelta (called in an interrupt context) */ void gpiodcf_invalidate(void *xsc) { struct gpiodcf_softc *sc = xsc; if (sc->sc_dying) return; if (sc->sc_sensor.status == SENSOR_S_OK) { sc->sc_sensor.status = SENSOR_S_WARN; /* * further degrade in 15 minutes if we dont receive any new * time information */ timeout_add_msec(&sc->sc_it_to, T_CRIT); } else { sc->sc_sensor.status = SENSOR_S_CRIT; sc->sc_nrecv = 0; } } int gpiodcf_activate(struct device *self, int act) { struct gpiodcf_softc *sc = (struct gpiodcf_softc *)self; switch (act) { case DVACT_DEACTIVATE: sc->sc_dying = 1; break; } return 0; }