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admwdog.c revision 1.1 
      1 /* $NetBSD: admwdog.c,v 1.1 2007/03/20 08:52:02 dyoung Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2007 David Young.  All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or
      7  * without modification, are permitted provided that the following
      8  * conditions are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above
     12  *    copyright notice, this list of conditions and the following
     13  *    disclaimer in the documentation and/or other materials provided
     14  *    with the distribution.
     15  * 3. The name of the author may not be used to endorse or promote
     16  *    products derived from this software without specific prior
     17  *    written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY
     20  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
     21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
     22  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
     24  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
     26  * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
     28  * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
     30  * OF SUCH DAMAGE.
     31  */
     32 
     33 #include <sys/cdefs.h>
     34 
     35 __KERNEL_RCSID(0, "$NetBSD: admwdog.c,v 1.1 2007/03/20 08:52:02 dyoung Exp $");
     36 
     37 #include <sys/param.h>
     38 #include <sys/systm.h>
     39 #include <sys/device.h>
     40 #include <sys/wdog.h>
     41 #include <sys/kernel.h>	/* for hz */
     42 
     43 #include <machine/bus.h>
     44 
     45 #include <dev/sysmon/sysmonvar.h>
     46 
     47 #include <mips/adm5120/include/adm5120reg.h>
     48 #include <mips/adm5120/include/adm5120var.h>
     49 #include <mips/adm5120/include/adm5120_obiovar.h>
     50 #include <mips/adm5120/dev/if_admswvar.h>
     51 
     52 /* maximum watchdog period, seconds */
     53 #define	ADMWDOG_MAX_PERIOD	(__SHIFTOUT_MASK(ADM5120_WDOG_WTS_MASK) / 100)
     54 
     55 static int admwdog_setmode(struct sysmon_wdog *smw);
     56 static int admwdog_tickle(struct sysmon_wdog *smw);
     57 
     58 static inline uint32_t
     59 admwdog_read(struct admsw_softc *sc)
     60 {
     61 	return bus_space_read_4(sc->sc_st, sc->sc_ioh, ADM5120_WDOG0);
     62 }
     63 
     64 static inline void
     65 admwdog_write(struct admsw_softc *sc, uint32_t val)
     66 {
     67 	bus_space_write_4(sc->sc_st, sc->sc_ioh, ADM5120_WDOG0, val);
     68 }
     69 
     70 static void
     71 admwdog_reset(struct admsw_softc *sc)
     72 {
     73 	int s;
     74 	uint32_t wdog0;
     75 
     76 	wdog0 = __SHIFTIN(sc->sc_smw.smw_period * 100, ADM5120_WDOG_WTS_MASK) |
     77 	    __SHIFTIN(1, ADM5120_WDOG_WT_MASK);
     78 
     79 	s = splhigh();
     80 
     81 	admwdog_write(sc, wdog0);
     82 	(void)admwdog_read(sc);
     83 	admwdog_write(sc, ADM5120_WDOG0_WTTR | wdog0);
     84 
     85 	splx(s);
     86 }
     87 
     88 static int
     89 admwdog_setmode(struct sysmon_wdog *smw)
     90 {
     91 	struct admsw_softc *sc = smw->smw_cookie;
     92 
     93 	if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
     94 		admwdog_write(sc, 0);
     95 		return 0;
     96 	}
     97 
     98 	if (smw->smw_period == WDOG_PERIOD_DEFAULT)
     99 		smw->smw_period = 32;
    100 	else if (smw->smw_period > ADMWDOG_MAX_PERIOD)
    101 		return EINVAL;
    102 
    103 	admwdog_reset(sc);
    104 
    105 	return 0;
    106 }
    107 
    108 static int
    109 admwdog_tickle(struct sysmon_wdog *smw)
    110 {
    111 	struct admsw_softc *sc = smw->smw_cookie;
    112 
    113 	(void)admwdog_read(sc);
    114 	return 0;
    115 }
    116 
    117 void
    118 admwdog_attach(struct admsw_softc *sc)
    119 {
    120 	struct sysmon_wdog *smw = &sc->sc_smw;
    121 
    122 	/* deactivate watchdog */
    123 	admwdog_write(sc, 0);
    124 
    125 	smw->smw_name = device_xname(&sc->sc_dev);
    126 	smw->smw_cookie = sc;
    127 	smw->smw_setmode = admwdog_setmode;
    128 	smw->smw_tickle = admwdog_tickle;
    129 	smw->smw_period = ADMWDOG_MAX_PERIOD;
    130 
    131 	sysmon_wdog_register(&sc->sc_smw);
    132 }
    133