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wdog.c revision 1.6 
      1 /* $NetBSD: wdog.c,v 1.6 2002/03/24 18:04:42 uch 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/param.h>
     30 #include <sys/buf.h>
     31 #include <sys/systm.h>
     32 #include <sys/kernel.h>
     33 #include <sys/uio.h>
     34 #include <sys/device.h>
     35 #include <sys/fcntl.h>
     36 #include <sys/ioctl.h>
     37 #include <sys/malloc.h>
     38 #include <sys/proc.h>
     39 #include <sys/syslog.h>
     40 
     41 #include <machine/cpu.h>
     42 #include <machine/conf.h>
     43 #include <machine/intr.h>
     44 
     45 #include <sh3/frame.h>
     46 #include <sh3/wdtreg.h>
     47 #include <sh3/wdogvar.h>
     48 #include <sh3/exception.h>
     49 
     50 struct wdog_softc {
     51 	struct device sc_dev;		/* generic device structures */
     52 	int flags;
     53 };
     54 
     55 static int wdogmatch(struct device *, struct cfdata *, void *);
     56 static void wdogattach(struct device *, struct device *, void *);
     57 static int wdogintr(void *);
     58 
     59 struct cfattach wdog_ca = {
     60 	sizeof(struct wdog_softc), wdogmatch, wdogattach
     61 };
     62 
     63 extern struct cfdriver wdog_cd;
     64 
     65 void
     66 wdog_wr_cnt(unsigned char x)
     67 {
     68 
     69 	SHREG_WTCNT_W = WTCNT_W_M | (unsigned short) x;
     70 }
     71 
     72 void
     73 wdog_wr_csr(unsigned char x)
     74 {
     75 
     76 	SHREG_WTCSR_W = WTCSR_W_M | (unsigned short) x;
     77 }
     78 
     79 static int
     80 wdogmatch(struct device *parent, struct cfdata *cfp, void *aux)
     81 {
     82 
     83 	if (strcmp(cfp->cf_driver->cd_name, "wdog"))
     84 		return (0);
     85 
     86 	return (1);
     87 }
     88 
     89 /*
     90  *  functions for probeing.
     91  */
     92 /* ARGSUSED */
     93 static void
     94 wdogattach(struct device *parent, struct device *self, void *aux)
     95 {
     96 	struct wdog_softc *sc = (struct wdog_softc *)self;
     97 
     98 	sc->flags = 0;
     99 
    100 	wdog_wr_csr(WTCSR_WT | WTCSR_CKS_4096);	/* default to wt mode */
    101 
    102 	intc_intr_establish(SH_INTEVT_WDT_ITI, IST_LEVEL, IPL_SOFTCLOCK,
    103 	    wdogintr, 0);
    104 
    105 	printf("\nwdog0: internal watchdog timer\n");
    106 }
    107 
    108 /*ARGSUSED*/
    109 int
    110 wdogopen(dev_t dev, int flag, int mode, struct proc *p)
    111 {
    112 	struct wdog_softc *sc = wdog_cd.cd_devs[0]; /* XXX */
    113 
    114 	if (minor(dev) != 0)
    115 		return (ENXIO);
    116 	if (sc->flags & WDOGF_OPEN)
    117 		return (EBUSY);
    118 	sc->flags |= WDOGF_OPEN;
    119 	return (0);
    120 }
    121 
    122 /*ARGSUSED*/
    123 int
    124 wdogclose(dev_t dev, int flag, int mode, struct proc *p)
    125 {
    126 	struct wdog_softc *sc = wdog_cd.cd_devs[0]; /* XXX */
    127 
    128 	if (sc->flags & WDOGF_OPEN)
    129 		sc->flags = 0;
    130 
    131 	return (0);
    132 }
    133 
    134 extern unsigned int maxwdog;
    135 
    136 /*ARGSUSED*/
    137 int
    138 wdogioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
    139 {
    140 	int error = 0;
    141 	int request;
    142 
    143 	switch (cmd) {
    144 	case SIOWDOGSETMODE:
    145 		request = *(int *)data;
    146 
    147 		switch (request) {
    148 		case WDOGM_RESET:
    149 			wdog_wr_csr(SHREG_WTCSR_R | WTCSR_WT);
    150 			break;
    151 		case WDOGM_INTR:
    152 			wdog_wr_csr(SHREG_WTCSR_R & ~WTCSR_WT);
    153 			break;
    154 		default:
    155 			error = EINVAL;
    156 			break;
    157 		}
    158 		break;
    159 	case SIORESETWDOG:
    160 		wdog_wr_cnt(0);		/* reset to zero */
    161 		break;
    162 	case SIOSTARTWDOG:
    163 		wdog_wr_csr(WTCSR_WT | WTCSR_CKS_4096);
    164 		wdog_wr_cnt(0);		/* reset to zero */
    165 		wdog_wr_csr(SHREG_WTCSR_R | WTCSR_TME);	/* start!!! */
    166 		break;
    167 	case SIOSTOPWDOG:
    168 		wdog_wr_csr(SHREG_WTCSR_R & ~WTCSR_TME); /* stop */
    169 		break;
    170 	case SIOSETWDOG:
    171 		request = *(int *)data;
    172 
    173 		if (request > 2) {
    174 			error = EINVAL;
    175 			break;
    176 		}
    177 		break;
    178 	default:
    179 		error = EINVAL;
    180 		break;
    181 	}
    182 
    183 	return (error);
    184 }
    185 
    186 int
    187 wdogintr(void *arg)
    188 {
    189 	struct trapframe *frame = arg;
    190 
    191 	wdog_wr_csr(SHREG_WTCSR_R & ~WTCSR_IOVF); /* clear overflow bit */
    192 	wdog_wr_cnt(0);			/* reset to zero */
    193 	printf("wdog trapped: spc = %x\n", frame->tf_spc);
    194 
    195 	return (0);
    196 }
    197