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      1 /*	$NetBSD: epwdog.c,v 1.6 2021/11/21 08:25:26 skrll Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2005 HAMAJIMA Katsuomi. All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * 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 copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     25  * SUCH DAMAGE.
     26  */
     27 
     28 #include <sys/cdefs.h>
     29 __KERNEL_RCSID(0, "$NetBSD: epwdog.c,v 1.6 2021/11/21 08:25:26 skrll Exp $");
     30 
     31 #include <sys/param.h>
     32 #include <sys/systm.h>
     33 #include <sys/kernel.h>
     34 #include <sys/device.h>
     35 #include <sys/bus.h>
     36 #include <arm/ep93xx/ep93xxvar.h>
     37 #include <arm/ep93xx/epsocvar.h>
     38 #include <arm/ep93xx/epwdogreg.h>
     39 #include <arm/ep93xx/epwdogvar.h>
     40 
     41 struct epwdog_softc {
     42 	bus_space_tag_t		sc_iot;
     43 	bus_space_handle_t	sc_ioh;
     44 };
     45 
     46 static int epwdog_match(device_t, cfdata_t, void *);
     47 static void epwdog_attach(device_t, device_t, void *);
     48 
     49 CFATTACH_DECL_NEW(epwdog, sizeof(struct epwdog_softc),
     50 	      epwdog_match, epwdog_attach, NULL, NULL);
     51 
     52 static struct epwdog_softc *the_epwdog_sc = 0;
     53 
     54 static int
     55 epwdog_match(device_t parent, cfdata_t match, void *aux)
     56 {
     57 	return 1;
     58 }
     59 
     60 static void
     61 epwdog_attach(device_t parent, device_t self, void *aux)
     62 {
     63 	struct epwdog_softc *sc = device_private(self);
     64 	struct epsoc_attach_args *sa = aux;
     65 
     66 	printf("\n");
     67 	sc->sc_iot = sa->sa_iot;
     68 
     69 	if (bus_space_map(sa->sa_iot, sa->sa_addr,
     70 			  sa->sa_size, 0, &sc->sc_ioh)) {
     71 		printf("%s: Cannot map registers", device_xname(self));
     72 		return;
     73 	}
     74 
     75 	if (!the_epwdog_sc)
     76 		the_epwdog_sc = sc;
     77 #ifdef DIAGNOSTIC
     78 	else
     79 		printf("%s is already configured\n", device_xname(self));
     80 #endif
     81 }
     82 
     83 int
     84 epwdog_reset(void)
     85 {
     86 	struct epwdog_softc *sc = the_epwdog_sc;
     87 
     88 #ifdef DIAGNOSTIC
     89 	if (!sc) {
     90 		printf("epwdog not configured\n");
     91 		return (ENXIO);
     92 	}
     93 #endif
     94 
     95 	bus_space_write_2(sc->sc_iot, sc->sc_ioh,
     96 			  EP93XX_WDOG_Ctrl, EP93XX_WDOG_DISABLE);
     97 	splhigh();
     98 	bus_space_write_2(sc->sc_iot, sc->sc_ioh,
     99 			  EP93XX_WDOG_Ctrl, EP93XX_WDOG_ENABLE);
    100 	while (1);
    101 
    102 	return 0; /* not reached */
    103 }
    104