xref: /netbsd/sys/arch/arm/xscale/i80321_wdog.c (revision c4a72b64)
1 /*	$NetBSD: i80321_wdog.c,v 1.4 2002/10/02 05:02:29 thorpej 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/param.h>
43 #include <sys/systm.h>
44 #include <sys/device.h>
45 #include <sys/wdog.h>
46 
47 #include <machine/bus.h>
48 #include <arm/cpufunc.h>
49 
50 #include <arm/xscale/i80321reg.h>
51 #include <arm/xscale/i80321var.h>
52 
53 #include <dev/sysmon/sysmonvar.h>
54 
55 struct iopwdog_softc {
56 	struct device sc_dev;
57 	struct sysmon_wdog sc_smw;
58 	int sc_wdog_armed;
59 	int sc_wdog_period;
60 };
61 
62 static __inline void
63 wdtcr_write(uint32_t val)
64 {
65 
66 	__asm __volatile("mcr p6, 0, %0, c7, c1, 0"
67 		:
68 		: "r" (val));
69 }
70 
71 static int
72 iopwdog_tickle(struct sysmon_wdog *smw)
73 {
74 
75 	wdtcr_write(WDTCR_ENABLE1);
76 	wdtcr_write(WDTCR_ENABLE2);
77 	return (0);
78 }
79 
80 static int
81 iopwdog_setmode(struct sysmon_wdog *smw)
82 {
83 	struct iopwdog_softc *sc = smw->smw_cookie;
84 
85 	if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
86 		/* The i80321 watchdog can't be disarmed once armed. */
87 		if (sc->sc_wdog_armed)
88 			return (EOPNOTSUPP);
89 	} else {
90 		if (smw->smw_period == WDOG_PERIOD_DEFAULT)
91 			smw->smw_period = sc->sc_wdog_period;
92 		else if (smw->smw_period != sc->sc_wdog_period) {
93 			/* Can't change the i80321 watchdog period. */
94 			return (EOPNOTSUPP);
95 		}
96 		sc->sc_wdog_armed = 1;
97 		/* Watchdog is armed by tickling it. */
98 		iopwdog_tickle(smw);
99 	}
100 	return (0);
101 }
102 
103 static int
104 iopwdog_match(struct device *parent, struct cfdata *cf, void *aux)
105 {
106 	struct iopxs_attach_args *ia = aux;
107 
108 	if (strcmp(cf->cf_name, ia->ia_name) == 0)
109 		return (1);
110 
111 	return (0);
112 }
113 
114 static void
115 iopwdog_attach(struct device *parent, struct device *self, void *aux)
116 {
117 	struct iopwdog_softc *sc = (void *) self;
118 
119 	/*
120 	 * XXX Should compute the period based on processor speed.
121 	 * For a 600MHz XScale core, the wdog must be tickled approx.
122 	 * every 7 seconds.
123 	 */
124 	sc->sc_wdog_period = 7;
125 
126 	printf(": %d second period\n", sc->sc_wdog_period);
127 
128 	sc->sc_smw.smw_name = sc->sc_dev.dv_xname;
129 	sc->sc_smw.smw_cookie = sc;
130 	sc->sc_smw.smw_setmode = iopwdog_setmode;
131 	sc->sc_smw.smw_tickle = iopwdog_tickle;
132 	sc->sc_smw.smw_period = sc->sc_wdog_period;
133 
134 	if (sysmon_wdog_register(&sc->sc_smw) != 0)
135 		printf("%s: unable to register with sysmon\n",
136 		    sc->sc_dev.dv_xname);
137 }
138 
139 CFATTACH_DECL(iopwdog, sizeof(struct iopwdog_softc),
140     iopwdog_match, iopwdog_attach, NULL, NULL);
141