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i80321_wdog.c revision 1.5 
      1 /*	$NetBSD: i80321_wdog.c,v 1.5 2003/04/29 01:07:31 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2002 Wasabi Systems, Inc.
      5  * All rights reserved.
      6  *
      7  * Written by Jason R. Thorpe 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 Intel i80321 I/O processor.
     40  */
     41 
     42 #include <sys/param.h>
     43 #include <sys/systm.h>
     44 #include <sys/device.h>
     45 #include <sys/wdog.h>
     46 
     47 #include <machine/bus.h>
     48 #include <arm/cpufunc.h>
     49 
     50 #include <arm/xscale/i80321reg.h>
     51 #include <arm/xscale/i80321var.h>
     52 
     53 #include <dev/sysmon/sysmonvar.h>
     54 
     55 struct iopwdog_softc {
     56 	struct device sc_dev;
     57 	struct sysmon_wdog sc_smw;
     58 	int sc_wdog_armed;
     59 	int sc_wdog_period;
     60 };
     61 
     62 static __inline void
     63 wdtcr_write(uint32_t val)
     64 {
     65 
     66 	__asm __volatile("mcr p6, 0, %0, c7, c1, 0"
     67 		:
     68 		: "r" (val));
     69 }
     70 
     71 static int
     72 iopwdog_tickle(struct sysmon_wdog *smw)
     73 {
     74 
     75 	wdtcr_write(WDTCR_ENABLE1);
     76 	wdtcr_write(WDTCR_ENABLE2);
     77 	return (0);
     78 }
     79 
     80 static int
     81 iopwdog_setmode(struct sysmon_wdog *smw)
     82 {
     83 	struct iopwdog_softc *sc = smw->smw_cookie;
     84 
     85 	if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
     86 		/* The i80321 watchdog can't be disarmed once armed. */
     87 		if (sc->sc_wdog_armed)
     88 			return (EOPNOTSUPP);
     89 	} else {
     90 		if (smw->smw_period == WDOG_PERIOD_DEFAULT)
     91 			smw->smw_period = sc->sc_wdog_period;
     92 		else if (smw->smw_period != sc->sc_wdog_period) {
     93 			/* Can't change the i80321 watchdog period. */
     94 			return (EOPNOTSUPP);
     95 		}
     96 		sc->sc_wdog_armed = 1;
     97 		/* Watchdog is armed by tickling it. */
     98 		iopwdog_tickle(smw);
     99 	}
    100 	return (0);
    101 }
    102 
    103 static int
    104 iopwdog_match(struct device *parent, struct cfdata *cf, void *aux)
    105 {
    106 	struct iopxs_attach_args *ia = aux;
    107 
    108 	if (strcmp(cf->cf_name, ia->ia_name) == 0)
    109 		return (1);
    110 
    111 	return (0);
    112 }
    113 
    114 static void
    115 iopwdog_attach(struct device *parent, struct device *self, void *aux)
    116 {
    117 	struct iopwdog_softc *sc = (void *) self;
    118 
    119 	/*
    120 	 * XXX Should compute the period based on processor speed.
    121 	 * For a 600MHz XScale core, the wdog must be tickled approx.
    122 	 * every 7 seconds.
    123 	 */
    124 	sc->sc_wdog_period = 7;
    125 
    126 	aprint_naive(": Watchdog timer\n");
    127 	aprint_normal(": %d second period\n", sc->sc_wdog_period);
    128 
    129 	sc->sc_smw.smw_name = sc->sc_dev.dv_xname;
    130 	sc->sc_smw.smw_cookie = sc;
    131 	sc->sc_smw.smw_setmode = iopwdog_setmode;
    132 	sc->sc_smw.smw_tickle = iopwdog_tickle;
    133 	sc->sc_smw.smw_period = sc->sc_wdog_period;
    134 
    135 	if (sysmon_wdog_register(&sc->sc_smw) != 0)
    136 		aprint_error("%s: unable to register with sysmon\n",
    137 		    sc->sc_dev.dv_xname);
    138 }
    139 
    140 CFATTACH_DECL(iopwdog, sizeof(struct iopwdog_softc),
    141     iopwdog_match, iopwdog_attach, NULL, NULL);
    142