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wdog.c revision 1.2 
      1 /* $NetBSD: wdog.c,v 1.2 2002/08/12 02:06:21 simonb 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/param.h>
     43 #include <sys/systm.h>
     44 #include <sys/device.h>
     45 #include <sys/properties.h>
     46 #include <sys/wdog.h>
     47 
     48 #include <powerpc/spr.h>
     49 #include <powerpc/ibm4xx/dev/opbvar.h>
     50 
     51 #include <dev/sysmon/sysmonvar.h>
     52 
     53 static int wdog_match(struct device *, struct cfdata *, void *);
     54 static void wdog_attach(struct device *, struct device *, void *);
     55 static int wdog_tickle(struct sysmon_wdog *);
     56 static int wdog_setmode(struct sysmon_wdog *);
     57 
     58 struct wdog_softc {
     59 	struct device sc_dev;
     60 	struct sysmon_wdog sc_smw;
     61 	int sc_wdog_armed;
     62 	int sc_wdog_period;
     63 };
     64 
     65 struct cfattach wdog_ca = {
     66 	sizeof(struct wdog_softc), wdog_match, wdog_attach,
     67 };
     68 
     69 static int
     70 wdog_match(struct device *parent, struct cfdata *cf, void *aux)
     71 {
     72 	struct opb_attach_args *oaa = aux;
     73 
     74 	/* match only watchdog devices */
     75 	if (strcmp(oaa->opb_name, cf->cf_driver->cd_name) != 0)
     76 		return (0);
     77 
     78 	return (1);
     79 }
     80 
     81 static void
     82 wdog_attach(struct device *parent, struct device *self, void *aux)
     83 {
     84 	struct wdog_softc *sc = (void *)self;
     85 	unsigned int processor_freq;
     86 
     87 	if (board_info_get("processor-frequency",
     88 	    &processor_freq, sizeof(processor_freq)) == -1)
     89 		processor_freq = 200 * 1000 * 1000;	/* assume 200MHz */
     90 
     91 	sc->sc_wdog_period = (2LL << 29) / processor_freq;
     92 	printf(": %d second period\n", sc->sc_wdog_period);
     93 
     94 	sc->sc_smw.smw_name = sc->sc_dev.dv_xname;
     95 	sc->sc_smw.smw_cookie = sc;
     96 	sc->sc_smw.smw_setmode = wdog_setmode;
     97 	sc->sc_smw.smw_tickle = wdog_tickle;
     98 	sc->sc_smw.smw_period = sc->sc_wdog_period;
     99 
    100 	if (sysmon_wdog_register(&sc->sc_smw) != 0)
    101 		printf("%s: unable to register with sysmon\n",
    102 		    sc->sc_dev.dv_xname);
    103 
    104 }
    105 
    106 static int
    107 wdog_tickle(struct sysmon_wdog *smw)
    108 {
    109 	uint32_t tsr;
    110 
    111 	tsr = mfspr(SPR_TSR);
    112 	tsr |= TSR_ENW | TSR_WIS;
    113 	mtspr(SPR_TSR, tsr);
    114 	return (0);
    115 }
    116 
    117 static int
    118 wdog_setmode(struct sysmon_wdog *smw)
    119 {
    120 	struct wdog_softc *sc = smw->smw_cookie;
    121 	uint32_t tcr, tsr;
    122 
    123 	if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
    124 		if (sc->sc_wdog_armed) {
    125 			tsr = mfspr(SPR_TSR);
    126 			tsr &= ~(TSR_ENW | TSR_WIS);
    127 			mtspr(SPR_TSR, tsr);
    128 		}
    129 	} else {
    130 		if (smw->smw_period == WDOG_PERIOD_DEFAULT)
    131 			smw->smw_period = sc->sc_wdog_period;
    132 		else if (smw->smw_period != sc->sc_wdog_period) {
    133 			/*
    134 			 * There's 4 set watchdog periods on the 405GP,
    135 			 * but we only support the longest one (2.684
    136 			 * seconds).
    137 			 */
    138 			return (EOPNOTSUPP);
    139 		}
    140 		sc->sc_wdog_armed = 1;
    141 
    142 		tcr = mfspr(SPR_TCR);
    143 		tcr |= TCR_WP_2_29 | TCR_WRC_SYSTEM;
    144 		mtspr(SPR_TCR, tcr);
    145 
    146 		/* Arm the watchdog. */
    147 		wdog_tickle(smw);
    148 	}
    149 	return (0);
    150 }
    151