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wdog.c revision 1.9 
      1 /* $NetBSD: wdog.c,v 1.9 2006/05/05 18:04:42 thorpej Exp $ */
      2 
      3 /*
      4  * Copyright (c) 2002 Wasabi Systems, Inc.
      5  * All rights reserved.
      6  *
      7  * Written by Jason R. Thorpe and Simon Burge for Wasabi Systems, Inc.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *	This product includes software developed for the NetBSD Project by
     20  *	Wasabi Systems, Inc.
     21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
     22  *    or promote products derived from this software without specific prior
     23  *    written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
     29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     35  * POSSIBILITY OF SUCH DAMAGE.
     36  */
     37 
     38 /*
     39  * Watchdog timer support for the IBM 405GP processor.
     40  */
     41 
     42 #include <sys/cdefs.h>
     43 __KERNEL_RCSID(0, "$NetBSD: wdog.c,v 1.9 2006/05/05 18:04:42 thorpej Exp $");
     44 
     45 #include <sys/param.h>
     46 #include <sys/systm.h>
     47 #include <sys/device.h>
     48 #include <sys/wdog.h>
     49 
     50 #include <prop/proplib.h>
     51 
     52 #include <powerpc/spr.h>
     53 #include <powerpc/ibm4xx/dev/opbvar.h>
     54 
     55 #include <dev/sysmon/sysmonvar.h>
     56 
     57 static int wdog_match(struct device *, struct cfdata *, void *);
     58 static void wdog_attach(struct device *, struct device *, void *);
     59 static int wdog_tickle(struct sysmon_wdog *);
     60 static int wdog_setmode(struct sysmon_wdog *);
     61 
     62 struct wdog_softc {
     63 	struct device sc_dev;
     64 	struct sysmon_wdog sc_smw;
     65 	int sc_wdog_armed;
     66 	int sc_wdog_period;
     67 };
     68 
     69 CFATTACH_DECL(wdog, sizeof(struct wdog_softc),
     70     wdog_match, wdog_attach, NULL, NULL);
     71 
     72 static int
     73 wdog_match(struct device *parent, struct cfdata *cf, void *aux)
     74 {
     75 	struct opb_attach_args *oaa = aux;
     76 
     77 	/* match only watchdog devices */
     78 	if (strcmp(oaa->opb_name, cf->cf_name) != 0)
     79 		return (0);
     80 
     81 	return (1);
     82 }
     83 
     84 static void
     85 wdog_attach(struct device *parent, struct device *self, void *aux)
     86 {
     87 	struct wdog_softc *sc = (void *)self;
     88 	unsigned int processor_freq;
     89 	prop_number_t freq;
     90 
     91 	freq = prop_dictionary_get(board_properties, "processor-frequency");
     92 	KASSERT(freq != NULL);
     93 	processor_freq = (unsigned int) prop_number_integer_value(freq);
     94 
     95 	sc->sc_wdog_period = (2LL << 29) / processor_freq;
     96 	printf(": %d second period\n", sc->sc_wdog_period);
     97 
     98 	sc->sc_smw.smw_name = sc->sc_dev.dv_xname;
     99 	sc->sc_smw.smw_cookie = sc;
    100 	sc->sc_smw.smw_setmode = wdog_setmode;
    101 	sc->sc_smw.smw_tickle = wdog_tickle;
    102 	sc->sc_smw.smw_period = sc->sc_wdog_period;
    103 
    104 	if (sysmon_wdog_register(&sc->sc_smw) != 0)
    105 		printf("%s: unable to register with sysmon\n",
    106 		    sc->sc_dev.dv_xname);
    107 
    108 }
    109 
    110 static int
    111 wdog_tickle(struct sysmon_wdog *smw)
    112 {
    113 	uint32_t tsr;
    114 
    115 	tsr = mfspr(SPR_TSR);
    116 	tsr |= TSR_ENW | TSR_WIS;
    117 	mtspr(SPR_TSR, tsr);
    118 	return (0);
    119 }
    120 
    121 static int
    122 wdog_setmode(struct sysmon_wdog *smw)
    123 {
    124 	struct wdog_softc *sc = smw->smw_cookie;
    125 	uint32_t tcr, tsr;
    126 
    127 	if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
    128 		if (sc->sc_wdog_armed) {
    129 			tsr = mfspr(SPR_TSR);
    130 			tsr &= ~(TSR_ENW | TSR_WIS);
    131 			mtspr(SPR_TSR, tsr);
    132 		}
    133 	} else {
    134 		if (smw->smw_period == WDOG_PERIOD_DEFAULT)
    135 			smw->smw_period = sc->sc_wdog_period;
    136 		else if (smw->smw_period != sc->sc_wdog_period) {
    137 			/*
    138 			 * There's 4 set watchdog periods on the 405GP,
    139 			 * but we only support the longest one (2.684
    140 			 * seconds).
    141 			 */
    142 			return (EOPNOTSUPP);
    143 		}
    144 		sc->sc_wdog_armed = 1;
    145 
    146 		tcr = mfspr(SPR_TCR);
    147 		tcr |= TCR_WP_2_29 | TCR_WRC_SYSTEM;
    148 		mtspr(SPR_TCR, tcr);
    149 
    150 		/* Arm the watchdog. */
    151 		wdog_tickle(smw);
    152 	}
    153 	return (0);
    154 }
    155