1/* $NetBSD: wdog.c,v 1.11 2011/06/17 19:03:02 matt Exp $ */
2
3/*
4 * Copyright (c) 2002 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Jason R. Thorpe and Simon Burge 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 IBM 405GP processor.
40 */
41
42#include <sys/cdefs.h>
43__KERNEL_RCSID(0, "$NetBSD: wdog.c,v 1.11 2011/06/17 19:03:02 matt Exp $");
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/device.h>
48#include <sys/cpu.h>
49#include <sys/wdog.h>
50
51#include <prop/proplib.h>
52
53#include <powerpc/spr.h>
54#include <powerpc/ibm4xx/spr.h>
55#include <powerpc/ibm4xx/cpu.h>
56#include <powerpc/ibm4xx/dev/opbvar.h>
57
58#include <dev/sysmon/sysmonvar.h>
59
60static int wdog_match(device_t, cfdata_t, void *);
61static void wdog_attach(device_t, device_t, void *);
62static int wdog_tickle(struct sysmon_wdog *);
63static int wdog_setmode(struct sysmon_wdog *);
64
65struct wdog_softc {
66	device_t sc_dev;
67	struct sysmon_wdog sc_smw;
68	bool sc_wdog_armed;
69	int sc_wdog_period;
70};
71
72CFATTACH_DECL_NEW(wdog, sizeof(struct wdog_softc),
73    wdog_match, wdog_attach, NULL, NULL);
74
75static int
76wdog_match(device_t parent, cfdata_t cf, void *aux)
77{
78	struct opb_attach_args * const oaa = aux;
79
80	/* match only watchdog devices */
81	if (strcmp(oaa->opb_name, cf->cf_name) != 0)
82		return (0);
83
84	return (1);
85}
86
87static void
88wdog_attach(device_t parent, device_t self, void *aux)
89{
90	struct wdog_softc * const sc = device_private(self);
91	unsigned int processor_freq;
92	prop_number_t freq;
93
94	freq = prop_dictionary_get(board_properties, "processor-frequency");
95	KASSERT(freq != NULL);
96	processor_freq = (unsigned int) prop_number_integer_value(freq);
97
98	sc->sc_wdog_period = (2LL << 29) / processor_freq;
99	aprint_normal(": %d second period\n", sc->sc_wdog_period);
100
101	sc->sc_dev = self;
102	sc->sc_smw.smw_name = device_xname(self);
103	sc->sc_smw.smw_cookie = sc;
104	sc->sc_smw.smw_setmode = wdog_setmode;
105	sc->sc_smw.smw_tickle = wdog_tickle;
106	sc->sc_smw.smw_period = sc->sc_wdog_period;
107
108	if (sysmon_wdog_register(&sc->sc_smw) != 0)
109		aprint_error_dev(self, "unable to register with sysmon\n");
110}
111
112static int
113wdog_tickle(struct sysmon_wdog *smw)
114{
115	uint32_t tsr;
116
117	tsr = mfspr(SPR_TSR);
118	tsr |= TSR_ENW | TSR_WIS;
119	mtspr(SPR_TSR, tsr);
120	return (0);
121}
122
123static int
124wdog_setmode(struct sysmon_wdog *smw)
125{
126	struct wdog_softc * const sc = smw->smw_cookie;
127
128	if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
129		if (sc->sc_wdog_armed) {
130			uint32_t tsr = mfspr(SPR_TSR);
131			tsr &= ~(TSR_ENW | TSR_WIS);
132			mtspr(SPR_TSR, tsr);
133			sc->sc_wdog_armed = false;
134		}
135	} else {
136		if (smw->smw_period == WDOG_PERIOD_DEFAULT)
137			smw->smw_period = sc->sc_wdog_period;
138		else if (smw->smw_period != sc->sc_wdog_period) {
139			/*
140			 * There's 4 set watchdog periods on the 405GP,
141			 * but we only support the longest one (2.684
142			 * seconds).
143			 */
144			return (EOPNOTSUPP);
145		}
146		sc->sc_wdog_armed = true;
147
148		uint32_t tcr = mfspr(SPR_TCR);
149		tcr |= TCR_WP_2_29 | TCR_WRC_SYSTEM;
150		mtspr(SPR_TCR, tcr);
151
152		/* Arm the watchdog. */
153		wdog_tickle(smw);
154	}
155	return (0);
156}
157