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wdog.c revision 1.9.66.1 
      1 /* $NetBSD: wdog.c,v 1.9.66.1 2010/03/11 15:02:50 yamt 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 1.9.66.1 2010/03/11 15:02:50 yamt 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/spr.h>
     54 #include <powerpc/ibm4xx/dev/opbvar.h>
     55 
     56 #include <dev/sysmon/sysmonvar.h>
     57 
     58 static int wdog_match(struct device *, struct cfdata *, void *);
     59 static void wdog_attach(struct device *, struct device *, void *);
     60 static int wdog_tickle(struct sysmon_wdog *);
     61 static int wdog_setmode(struct sysmon_wdog *);
     62 
     63 struct wdog_softc {
     64 	struct device sc_dev;
     65 	struct sysmon_wdog sc_smw;
     66 	int sc_wdog_armed;
     67 	int sc_wdog_period;
     68 };
     69 
     70 CFATTACH_DECL(wdog, sizeof(struct wdog_softc),
     71     wdog_match, wdog_attach, NULL, NULL);
     72 
     73 static int
     74 wdog_match(struct device *parent, struct cfdata *cf, void *aux)
     75 {
     76 	struct opb_attach_args *oaa = aux;
     77 
     78 	/* match only watchdog devices */
     79 	if (strcmp(oaa->opb_name, cf->cf_name) != 0)
     80 		return (0);
     81 
     82 	return (1);
     83 }
     84 
     85 static void
     86 wdog_attach(struct device *parent, struct device *self, void *aux)
     87 {
     88 	struct wdog_softc *sc = (void *)self;
     89 	unsigned int processor_freq;
     90 	prop_number_t freq;
     91 
     92 	freq = prop_dictionary_get(board_properties, "processor-frequency");
     93 	KASSERT(freq != NULL);
     94 	processor_freq = (unsigned int) prop_number_integer_value(freq);
     95 
     96 	sc->sc_wdog_period = (2LL << 29) / processor_freq;
     97 	printf(": %d second period\n", sc->sc_wdog_period);
     98 
     99 	sc->sc_smw.smw_name = sc->sc_dev.dv_xname;
    100 	sc->sc_smw.smw_cookie = sc;
    101 	sc->sc_smw.smw_setmode = wdog_setmode;
    102 	sc->sc_smw.smw_tickle = wdog_tickle;
    103 	sc->sc_smw.smw_period = sc->sc_wdog_period;
    104 
    105 	if (sysmon_wdog_register(&sc->sc_smw) != 0)
    106 		printf("%s: unable to register with sysmon\n",
    107 		    sc->sc_dev.dv_xname);
    108 
    109 }
    110 
    111 static int
    112 wdog_tickle(struct sysmon_wdog *smw)
    113 {
    114 	uint32_t tsr;
    115 
    116 	tsr = mfspr(SPR_TSR);
    117 	tsr |= TSR_ENW | TSR_WIS;
    118 	mtspr(SPR_TSR, tsr);
    119 	return (0);
    120 }
    121 
    122 static int
    123 wdog_setmode(struct sysmon_wdog *smw)
    124 {
    125 	struct wdog_softc *sc = smw->smw_cookie;
    126 	uint32_t tcr, tsr;
    127 
    128 	if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
    129 		if (sc->sc_wdog_armed) {
    130 			tsr = mfspr(SPR_TSR);
    131 			tsr &= ~(TSR_ENW | TSR_WIS);
    132 			mtspr(SPR_TSR, tsr);
    133 		}
    134 	} else {
    135 		if (smw->smw_period == WDOG_PERIOD_DEFAULT)
    136 			smw->smw_period = sc->sc_wdog_period;
    137 		else if (smw->smw_period != sc->sc_wdog_period) {
    138 			/*
    139 			 * There's 4 set watchdog periods on the 405GP,
    140 			 * but we only support the longest one (2.684
    141 			 * seconds).
    142 			 */
    143 			return (EOPNOTSUPP);
    144 		}
    145 		sc->sc_wdog_armed = 1;
    146 
    147 		tcr = mfspr(SPR_TCR);
    148 		tcr |= TCR_WP_2_29 | TCR_WRC_SYSTEM;
    149 		mtspr(SPR_TCR, tcr);
    150 
    151 		/* Arm the watchdog. */
    152 		wdog_tickle(smw);
    153 	}
    154 	return (0);
    155 }
    156