/* $OpenBSD: wdt.c,v 1.7 2006/03/15 20:03:07 miod Exp $ */ /*- * Copyright (c) 1998,1999 Alex Nash * 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 #include #include #include #include #include #include #include #include #include #include #include #include struct wdt_softc { /* wdt_dev must be the first item in the struct */ struct device wdt_dev; /* feature set: 0 = none 1 = temp, buzzer, etc. */ int features; /* unit number (unlikely more than one would be present though) */ int unit; /* how many processes are in WIOCSCHED */ unsigned procs; /* watchdog timeout */ unsigned timeout_secs; struct timeout timeout; /* device access through bus space */ bus_space_tag_t iot; bus_space_handle_t ioh; }; /* externally visible functions */ int wdtprobe(struct device *, void *, void *); void wdtattach(struct device *, struct device *, void *); int wdtopen(dev_t, int, int, struct proc *); int wdtclose(dev_t, int, int, struct proc *); int wdtioctl(dev_t, u_long, caddr_t, int, struct proc *); /* static functions */ static int wdt_is501(struct wdt_softc *wdt); static void wdt_8254_count(struct wdt_softc *wdt, int counter, u_int16_t v); static void wdt_8254_mode(struct wdt_softc *wdt, int counter, int mode); static void wdt_set_timeout(struct wdt_softc *wdt, unsigned seconds); static void wdt_timeout(void *arg); static void wdt_init_timer(struct wdt_softc *wdt); static void wdt_buzzer_off(struct wdt_softc *wdt); static int wdt_read_temperature(struct wdt_softc *wdt); static int wdt_read_status(struct wdt_softc *wdt); static void wdt_display_status(struct wdt_softc *wdt); static int wdt_get_state(struct wdt_softc *wdt, struct wdt_state *state); static void wdt_shutdown(void *arg); static int wdt_sched(struct wdt_softc *wdt, struct proc *p); static void wdt_timer_disable(struct wdt_softc *wdt); static void wdt_timer_enable(struct wdt_softc *wdt, unsigned seconds); #if WDT_DISABLE_BUZZER static void wdt_buzzer_disable(struct wdt_softc *wdt); #else static void wdt_buzzer_enable(struct wdt_softc *wdt); #endif struct cfattach wdt_ca = { sizeof(struct wdt_softc), wdtprobe, wdtattach }; struct cfdriver wdt_cd = { NULL, "wdt", DV_DULL }; /* * 8254 counter mappings */ #define WDT_8254_TC_LO 0 /* low 16 bits of timeout counter */ #define WDT_8254_TC_HI 1 /* high 16 bits of timeout counter */ #define WDT_8254_BUZZER 2 /* * WDT500/501 ports */ #define WDT_8254_BASE 0 #define WDT_8254_CTL (WDT_8254_BASE + 3) #define WDT_DISABLE_TIMER 7 #define WDT_ENABLE_TIMER 7 /* * WDT501 specific ports */ #define WDT_STATUS_REG 4 #define WDT_START_BUZZER 4 #define WDT_TEMPERATURE 5 #define WDT_STOP_BUZZER 5 #define UNIT(dev) (minor(dev)) int wdtprobe (parent, match, aux) struct device *parent; void *match, *aux; { struct pci_attach_args *const pa = (struct pci_attach_args *)aux; if (PCI_VENDOR(pa->pa_id) != PCI_VENDOR_INDCOMPSRC || PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_INDCOMPSRC_WDT50x) return(0); return(1); } void wdtattach (parent, self, aux) struct device *parent, *self; void *aux; { struct wdt_softc *wdt = (struct wdt_softc *)self; struct pci_attach_args *const pa = (struct pci_attach_args *)aux; bus_size_t iosize; int unit; unit = wdt->wdt_dev.dv_unit; /* retrieve the I/O region (BAR2) */ if (pci_mapreg_map(pa, 0x18, PCI_MAPREG_TYPE_IO, 0, &wdt->iot, &wdt->ioh, NULL, &iosize, 0) != 0) { printf("wdt%d: couldn't find PCI I/O region\n", unit); return; } /* sanity check I/O size */ if (iosize != (bus_size_t)16) { printf("wdt%d: invalid I/O region size\n", unit); return; } /* initialize the watchdog timer structure */ wdt->unit = unit; wdt->procs = 0; /* check the feature set available */ if (wdt_is501(wdt)) wdt->features = 1; else wdt->features = 0; /* * register a callback for system shutdown * (we need to disable the watchdog timer during shutdown) */ if (shutdownhook_establish(wdt_shutdown, wdt) == NULL) return; if (wdt->features) { /* * turn off the buzzer, it may have been activated * by a previous timeout */ wdt_buzzer_off(wdt); #ifdef WDT_DISABLE_BUZZER wdt_buzzer_disable(wdt); #else wdt_buzzer_enable(wdt); #endif } /* initialize the timer modes and the lower 16-bit counter */ wdt_init_timer(wdt); /* * it appears the timeout queue isn't processed until the * kernel has fully booted, so we set the first timeout * far in advance, and subsequent timeouts at the normal * 30 second interval */ wdt_timer_enable(wdt, 90/*seconds*/); wdt->timeout_secs = 30; printf("\n"); wdt_display_status(wdt); } int wdtopen (dev_t dev, int flags, int fmt, struct proc *p) { if (UNIT(dev) >= wdt_cd.cd_ndevs || wdt_cd.cd_devs[UNIT(dev)] == NULL) return (ENXIO); return(0); } int wdtclose (dev_t dev, int flags, int fmt, struct proc *p) { return(0); } int wdtioctl (dev_t dev, u_long cmd, caddr_t arg, int flag, struct proc *p) { struct wdt_softc *wdt = wdt_cd.cd_devs[UNIT(dev)]; int error; switch (cmd) { case WIOCSCHED: error = wdt_sched(wdt, p); break; case WIOCGETSTATE: if (wdt->features) error = wdt_get_state(wdt, (struct wdt_state *)arg); else error = ENXIO; break; default: error = ENXIO; break; } return(error); } /* * wdt_is501 * * Returns non-zero if the card is a 501 model. */ static int wdt_is501 (struct wdt_softc *wdt) { /* * It makes too much sense to detect the card type * by the device ID, so we have to resort to testing * the presence of a register to determine the type. */ int v = bus_space_read_1(wdt->iot, wdt->ioh, WDT_TEMPERATURE); /* XXX may not be reliable */ if (v == 0 || v == 0xFF) return(0); return(1); } /* * wdt_8254_count * * Loads the specified counter with the 16-bit value 'v'. */ static void wdt_8254_count (struct wdt_softc *wdt, int counter, u_int16_t v) { bus_space_write_1(wdt->iot, wdt->ioh, WDT_8254_BASE + counter, v & 0xFF); bus_space_write_1(wdt->iot, wdt->ioh, WDT_8254_BASE + counter, v >> 8); } /* * wdt_8254_mode * * Sets the mode of the specified counter. */ static void wdt_8254_mode (struct wdt_softc *wdt, int counter, int mode) { bus_space_write_1(wdt->iot, wdt->ioh, WDT_8254_CTL, (counter << 6) | 0x30 | (mode << 1)); } /* * wdt_set_timeout * * Load the watchdog timer with the specified number of seconds. */ static void wdt_set_timeout (struct wdt_softc *wdt, unsigned seconds) { /* 8254 has been programmed with a 2ms period */ u_int16_t v = (u_int16_t)seconds * 50; /* disable the timer */ (void)bus_space_read_1(wdt->iot, wdt->ioh, WDT_DISABLE_TIMER); /* load the new timeout count */ wdt_8254_count(wdt, WDT_8254_TC_HI, v); /* enable the timer */ bus_space_write_1(wdt->iot, wdt->ioh, WDT_ENABLE_TIMER, 0); } /* * wdt_timeout * * Kernel timeout handler. This function is called every * wdt->timeout_secs / 2 seconds. It reloads the watchdog * counters in one of two ways: * * - If there are one or more processes sleeping in a * WIOCSCHED ioctl(), they are woken up to perform * the counter reload. * - If no processes are sleeping in WIOCSCHED, the * counters are reloaded from here. * * Finally, another timeout is scheduled for wdt->timeout_secs * from now. */ static void wdt_timeout (void *arg) { struct wdt_softc *wdt = (struct wdt_softc *)arg; /* reload counters from proc in WIOCSCHED ioctl()? */ if (wdt->procs) wakeup(wdt); else wdt_set_timeout(wdt, wdt->timeout_secs); /* schedule another timeout in half the countdown time */ timeout_add(&wdt->timeout, wdt->timeout_secs * hz / 2); } /* * wdt_timer_disable * * Disables the watchdog timer and cancels the scheduled (if any) * kernel timeout. */ static void wdt_timer_disable (struct wdt_softc *wdt) { (void)bus_space_read_1(wdt->iot, wdt->ioh, WDT_DISABLE_TIMER); timeout_del(&wdt->timeout); } /* * wdt_timer_enable * * Enables the watchdog timer to expire in the specified number * of seconds. If 'seconds' is outside the range 2-1800, it * is silently clamped to be within range. */ static void wdt_timer_enable (struct wdt_softc *wdt, unsigned seconds) { int s; /* clamp range */ if (seconds < 2) seconds = 2; if (seconds > 1800) seconds = 1800; /* block out the timeout handler */ s = splclock(); wdt_timer_disable(wdt); wdt->timeout_secs = seconds; timeout_set(&wdt->timeout, wdt_timeout, wdt); timeout_add(&wdt->timeout, hz * seconds / 2); wdt_set_timeout(wdt, seconds); /* re-enable clock interrupts */ splx(s); } /* * wdt_init_timer * * Configure the modes for the watchdog counters and initialize * the low 16-bits of the watchdog counter to have a period of * approximately 1/50th of a second. */ static void wdt_init_timer (struct wdt_softc *wdt) { wdt_8254_mode(wdt, WDT_8254_TC_LO, 3); wdt_8254_mode(wdt, WDT_8254_TC_HI, 2); wdt_8254_count(wdt, WDT_8254_TC_LO, 41666); } /******************************************************************* * WDT501 specific functions *******************************************************************/ /* * wdt_buzzer_off * * Turns the buzzer off. */ static void wdt_buzzer_off (struct wdt_softc *wdt) { bus_space_write_1(wdt->iot, wdt->ioh, WDT_STOP_BUZZER, 0); } #ifndef WDT_DISABLE_BUZZER /* * wdt_buzzer_enable * * Enables the buzzer when the watchdog counter expires. */ static void wdt_buzzer_enable (struct wdt_softc *wdt) { bus_space_write_1(wdt->iot, wdt->ioh, WDT_8254_BUZZER, 1); wdt_8254_mode(wdt, WDT_8254_BUZZER, 1); } #else /* * wdt_buzzer_disable * * Disables the buzzer from sounding when the watchdog counter * expires. */ static void wdt_buzzer_disable (struct wdt_softc *wdt) { wdt_8254_mode(wdt, WDT_8254_BUZZER, 0); } #endif /* * wdt_read_temperature * * Returns the temperature (in Fahrenheit) from the board. */ static int wdt_read_temperature (struct wdt_softc *wdt) { unsigned v = bus_space_read_1(wdt->iot, wdt->ioh, WDT_TEMPERATURE); return((v * 11) / 15 + 7); } /* * wdt_read_status * * Returns the status register bits minus the counter refresh * and IRQ generated bits. */ static int wdt_read_status (struct wdt_softc *wdt) { /* mask off counter refresh & IRQ generated bits */ return(bus_space_read_1(wdt->iot, wdt->ioh, WDT_STATUS_REG) & 0x7E); } /* * wdt_display_status * * Displays the current timeout, temperature, and power supply * over/undervoltages to the console. */ static void wdt_display_status (struct wdt_softc *wdt) { if (wdt->features) { int status = wdt_read_status(wdt); int temp = wdt_read_temperature(wdt); printf("wdt%d: WDT501 timeout %d secs, temp %d F", wdt->unit, wdt->timeout_secs, temp); /* overvoltage bit is active low */ if ((status & WDT_SR_PS_OVER) == 0) printf(" "); /* undervoltage bit is active low */ if ((status & WDT_SR_PS_UNDER) == 0) printf(" "); } else { printf("wdt%d: WDT500 timeout %d secs", wdt->unit, wdt->timeout_secs); } printf("\n"); } /* * wdt_get_state * * Returns the temperature and status bits. */ static int wdt_get_state (struct wdt_softc *wdt, struct wdt_state *state) { state->temperature = wdt_read_temperature(wdt); state->status = wdt_read_status(wdt); return(0); } /* * wdt_shutdown * * Disables the watchdog timer at system shutdown time. */ static void wdt_shutdown (void *arg) { struct wdt_softc *wdt = (struct wdt_softc *)arg; wdt_timer_disable(wdt); } /* * wdt_sched * * Put the process into an infinite loop in which: * * - The process sleeps, waiting for a wakeup() from the tsleep() * handler. * - When awakened, the process reloads the watchdog counter and * repeats the loop. * * The only way the loop can be broken is if the process is interrupted * via a signal. * * The whole point of this is to cause a watchdog timeout to be * generated if processes are no longer being scheduled. */ static int wdt_sched (struct wdt_softc *wdt, struct proc *p) { int error; int s; /* * Regardless of the device permissions, you must be * root to do this -- a process which is STOPPED * while in this function can cause a reboot to occur * if the counters aren't reloaded within wdt->timeout_secs * seconds. */ if ((error = suser(p, 0))) return(error); /* block out the timeout handler */ s = splclock(); /* indicate that we are sleeping */ ++wdt->procs; /* loop until the process is signaled */ while (1) { error = tsleep(wdt, PCATCH | PSWP, "wdtsch", 0); wdt_set_timeout(wdt, wdt->timeout_secs); if (error != 0) break; } /* remove sleeping indication */ --wdt->procs; /* re-enable timeout handler */ splx(s); return(error); }