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      1 /*	$NetBSD: i80321_wdog.c,v 1.10 2012/02/12 16:31:01 matt 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/cdefs.h>
     43 __KERNEL_RCSID(0, "$NetBSD: i80321_wdog.c,v 1.10 2012/02/12 16:31:01 matt 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 <sys/bus.h>
     51 #include <arm/cpufunc.h>
     52 
     53 #include <arm/xscale/i80321reg.h>
     54 #include <arm/xscale/i80321var.h>
     55 
     56 #include <dev/sysmon/sysmonvar.h>
     57 
     58 struct iopwdog_softc {
     59 	device_t sc_dev;
     60 	struct sysmon_wdog sc_smw;
     61 	int sc_wdog_armed;
     62 	int sc_wdog_period;
     63 };
     64 
     65 static inline void
     66 wdtcr_write(uint32_t val)
     67 {
     68 
     69 	__asm volatile("mcr p6, 0, %0, c7, c1, 0"
     70 		:
     71 		: "r" (val));
     72 }
     73 
     74 static int
     75 iopwdog_tickle(struct sysmon_wdog *smw)
     76 {
     77 
     78 	wdtcr_write(WDTCR_ENABLE1);
     79 	wdtcr_write(WDTCR_ENABLE2);
     80 	return (0);
     81 }
     82 
     83 static int
     84 iopwdog_setmode(struct sysmon_wdog *smw)
     85 {
     86 	struct iopwdog_softc *sc = smw->smw_cookie;
     87 
     88 	if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
     89 		/* The i80321 watchdog can't be disarmed once armed. */
     90 		if (sc->sc_wdog_armed)
     91 			return (EOPNOTSUPP);
     92 	} else {
     93 		if (smw->smw_period == WDOG_PERIOD_DEFAULT)
     94 			smw->smw_period = sc->sc_wdog_period;
     95 		else if (smw->smw_period != sc->sc_wdog_period) {
     96 			/* Can't change the i80321 watchdog period. */
     97 			return (EOPNOTSUPP);
     98 		}
     99 		sc->sc_wdog_armed = 1;
    100 		/* Watchdog is armed by tickling it. */
    101 		iopwdog_tickle(smw);
    102 	}
    103 	return (0);
    104 }
    105 
    106 static int
    107 iopwdog_match(device_t parent, cfdata_t cf, void *aux)
    108 {
    109 	struct iopxs_attach_args *ia = aux;
    110 
    111 	if (strcmp(cf->cf_name, ia->ia_name) == 0)
    112 		return (1);
    113 
    114 	return (0);
    115 }
    116 
    117 static void
    118 iopwdog_attach(device_t parent, device_t self, void *aux)
    119 {
    120 	struct iopwdog_softc *sc = device_private(self);
    121 	const char *xname = device_xname(self);
    122 
    123 	sc->sc_dev = self;
    124 	/*
    125 	 * XXX Should compute the period based on processor speed.
    126 	 * For a 600MHz XScale core, the wdog must be tickled approx.
    127 	 * every 7 seconds.
    128 	 */
    129 	sc->sc_wdog_period = 7;
    130 
    131 	aprint_naive(": Watchdog timer\n");
    132 	aprint_normal(": %d second period\n", sc->sc_wdog_period);
    133 
    134 	sc->sc_smw.smw_name = xname;
    135 	sc->sc_smw.smw_cookie = sc;
    136 	sc->sc_smw.smw_setmode = iopwdog_setmode;
    137 	sc->sc_smw.smw_tickle = iopwdog_tickle;
    138 	sc->sc_smw.smw_period = sc->sc_wdog_period;
    139 
    140 	if (sysmon_wdog_register(&sc->sc_smw) != 0)
    141 		aprint_error_dev(sc->sc_dev,
    142 		    "unable to register with sysmon\n");
    143 }
    144 
    145 CFATTACH_DECL_NEW(iopwdog, sizeof(struct iopwdog_softc),
    146     iopwdog_match, iopwdog_attach, NULL, NULL);
    147