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wdog.c revision 1.14
      1 /* $NetBSD: wdog.c,v 1.14 2005/12/11 12:18:58 christos Exp $ */
      2 
      3 /*-
      4  * Copyright (C) 2000 SAITOH Masanobu.  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  * 3. The name of the author may not be used to endorse or promote products
     15  *    derived from this software without specific prior written permission.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: wdog.c,v 1.14 2005/12/11 12:18:58 christos Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/buf.h>
     34 #include <sys/systm.h>
     35 #include <sys/kernel.h>
     36 #include <sys/uio.h>
     37 #include <sys/device.h>
     38 #include <sys/fcntl.h>
     39 #include <sys/ioctl.h>
     40 #include <sys/malloc.h>
     41 #include <sys/proc.h>
     42 #include <sys/syslog.h>
     43 #include <sys/conf.h>
     44 
     45 #include <machine/cpu.h>
     46 #include <machine/intr.h>
     47 
     48 #include <sh3/frame.h>
     49 #include <sh3/wdtreg.h>
     50 #include <sh3/wdogvar.h>
     51 #include <sh3/exception.h>
     52 
     53 struct wdog_softc {
     54 	struct device sc_dev;		/* generic device structures */
     55 	int flags;
     56 };
     57 
     58 static int wdogmatch(struct device *, struct cfdata *, void *);
     59 static void wdogattach(struct device *, struct device *, void *);
     60 static int wdogintr(void *);
     61 
     62 CFATTACH_DECL(wdog, sizeof(struct wdog_softc),
     63     wdogmatch, wdogattach, NULL, NULL);
     64 
     65 extern struct cfdriver wdog_cd;
     66 
     67 dev_type_open(wdogopen);
     68 dev_type_close(wdogclose);
     69 dev_type_ioctl(wdogioctl);
     70 
     71 const struct cdevsw wdog_cdevsw = {
     72 	wdogopen, wdogclose, noread, nowrite, wdogioctl,
     73 	nostop, notty, nopoll, nommap, nokqfilter,
     74 };
     75 
     76 void
     77 wdog_wr_cnt(unsigned char x)
     78 {
     79 
     80 	SHREG_WTCNT_W = WTCNT_W_M | (unsigned short) x;
     81 }
     82 
     83 void
     84 wdog_wr_csr(unsigned char x)
     85 {
     86 
     87 	SHREG_WTCSR_W = WTCSR_W_M | (unsigned short) x;
     88 }
     89 
     90 static int
     91 wdogmatch(struct device *parent, struct cfdata *cfp, void *aux)
     92 {
     93 
     94 	if (strcmp(cfp->cf_name, "wdog"))
     95 		return (0);
     96 
     97 	return (1);
     98 }
     99 
    100 /*
    101  *  functions for probeing.
    102  */
    103 /* ARGSUSED */
    104 static void
    105 wdogattach(struct device *parent, struct device *self, void *aux)
    106 {
    107 	struct wdog_softc *sc = (struct wdog_softc *)self;
    108 
    109 	sc->flags = 0;
    110 
    111 	wdog_wr_csr(WTCSR_WT | WTCSR_CKS_4096);	/* default to wt mode */
    112 
    113 	intc_intr_establish(SH_INTEVT_WDT_ITI, IST_LEVEL, IPL_SOFTCLOCK,
    114 	    wdogintr, 0);
    115 
    116 	printf("\nwdog0: internal watchdog timer\n");
    117 }
    118 
    119 /*ARGSUSED*/
    120 int
    121 wdogopen(dev_t dev, int flag, int mode, struct lwp *l)
    122 {
    123 	struct wdog_softc *sc = wdog_cd.cd_devs[0]; /* XXX */
    124 
    125 	if (minor(dev) != 0)
    126 		return (ENXIO);
    127 	if (sc->flags & WDOGF_OPEN)
    128 		return (EBUSY);
    129 	sc->flags |= WDOGF_OPEN;
    130 	return (0);
    131 }
    132 
    133 /*ARGSUSED*/
    134 int
    135 wdogclose(dev_t dev, int flag, int mode, struct lwp *l)
    136 {
    137 	struct wdog_softc *sc = wdog_cd.cd_devs[0]; /* XXX */
    138 
    139 	if (sc->flags & WDOGF_OPEN)
    140 		sc->flags = 0;
    141 
    142 	return (0);
    143 }
    144 
    145 extern unsigned int maxwdog;
    146 
    147 /*ARGSUSED*/
    148 int
    149 wdogioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct lwp *l)
    150 {
    151 	int error = 0;
    152 	int request;
    153 
    154 	switch (cmd) {
    155 	case SIOWDOGSETMODE:
    156 		request = *(int *)data;
    157 
    158 		switch (request) {
    159 		case WDOGM_RESET:
    160 			wdog_wr_csr(SHREG_WTCSR_R | WTCSR_WT);
    161 			break;
    162 		case WDOGM_INTR:
    163 			wdog_wr_csr(SHREG_WTCSR_R & ~WTCSR_WT);
    164 			break;
    165 		default:
    166 			error = EINVAL;
    167 			break;
    168 		}
    169 		break;
    170 	case SIORESETWDOG:
    171 		wdog_wr_cnt(0);		/* reset to zero */
    172 		break;
    173 	case SIOSTARTWDOG:
    174 		wdog_wr_csr(WTCSR_WT | WTCSR_CKS_4096);
    175 		wdog_wr_cnt(0);		/* reset to zero */
    176 		wdog_wr_csr(SHREG_WTCSR_R | WTCSR_TME);	/* start!!! */
    177 		break;
    178 	case SIOSTOPWDOG:
    179 		wdog_wr_csr(SHREG_WTCSR_R & ~WTCSR_TME); /* stop */
    180 		break;
    181 	case SIOSETWDOG:
    182 		request = *(int *)data;
    183 
    184 		if (request > 2) {
    185 			error = EINVAL;
    186 			break;
    187 		}
    188 		break;
    189 	default:
    190 		error = EINVAL;
    191 		break;
    192 	}
    193 
    194 	return (error);
    195 }
    196 
    197 int
    198 wdogintr(void *arg)
    199 {
    200 	struct trapframe *frame = arg;
    201 
    202 	wdog_wr_csr(SHREG_WTCSR_R & ~WTCSR_IOVF); /* clear overflow bit */
    203 	wdog_wr_cnt(0);			/* reset to zero */
    204 	printf("wdog trapped: spc = %x\n", frame->tf_spc);
    205 
    206 	return (0);
    207 }
    208