1/*	$NetBSD: e500wdog.c,v 1.4 2020/07/06 09:34:16 rin Exp $	*/
2/*-
3 * Copyright (c) 2010, 2011 The NetBSD Foundation, Inc.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Raytheon BBN Technologies Corp and Defense Advanced Research Projects
8 * Agency and which was developed by Matt Thomas of 3am Software Foundry.
9 *
10 * This material is based upon work supported by the Defense Advanced Research
11 * Projects Agency and Space and Naval Warfare Systems Center, Pacific, under
12 * Contract No. N66001-09-C-2073.
13 * Approved for Public Release, Distribution Unlimited
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 *    notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 *    notice, this list of conditions and the following disclaimer in the
22 *    documentation and/or other materials provided with the distribution.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
26 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
27 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
28 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37#include <sys/cdefs.h>
38__KERNEL_RCSID(0, "$NetBSD: e500wdog.c,v 1.4 2020/07/06 09:34:16 rin Exp $");
39
40#include "ioconf.h"
41
42#include <sys/param.h>
43#include <sys/cpu.h>
44#include <sys/device.h>
45#include <sys/wdog.h>
46
47#include <dev/sysmon/sysmonvar.h>
48
49#include <sys/intr.h>
50
51#include <powerpc/spr.h>
52#include <powerpc/booke/spr.h>
53
54#include <powerpc/booke/cpuvar.h>
55
56struct e500wdog_softc {
57	device_t sc_dev;
58	struct sysmon_wdog sc_smw;
59	u_int sc_wdog_period;
60	bool sc_wdog_armed;
61	uint64_t sc_timebase;
62};
63#ifndef	PQ3WDOG_PERIOD_DEFAULT
64#define	PQ3WDOG_PERIOD_DEFAULT	10
65#endif
66
67static int e500wdog_match(device_t, cfdata_t, void *);
68static void e500wdog_attach(device_t, device_t, void *);
69
70CFATTACH_DECL_NEW(e500wdog, sizeof(struct e500wdog_softc),
71    e500wdog_match, e500wdog_attach, NULL, NULL);
72
73static int
74e500wdog_match(device_t parent, cfdata_t cf, void *aux)
75{
76	struct cpunode_softc * const psc = device_private(parent);
77	struct cpunode_attach_args * const cna = aux;
78	struct cpunode_locators * const cnl = &cna->cna_locs;
79
80	if (!board_info_get_bool("pq3")
81	    || cnl->cnl_instance != 0
82	    || (psc->sc_children & cna->cna_childmask)
83	    || strcmp(cnl->cnl_name, "wdog") != 0)
84		return 0;
85
86	return 1;
87}
88
89static int
90e500wdog_tickle(struct sysmon_wdog *smw)
91{
92	mtspr(SPR_TSR, TSR_ENW);
93	return 0;
94}
95
96static int
97e500wdog_setmode(struct sysmon_wdog *smw)
98{
99	struct e500wdog_softc * const sc = smw->smw_cookie;
100
101	if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
102		/*
103		 * We can't disarm the watchdog.
104		 */
105		if (sc->sc_wdog_armed)
106			return EBUSY;
107	} else {
108		/*
109		 * If no changes, don't do anything.
110		 */
111		if (sc->sc_wdog_armed
112		    && smw->smw_period == sc->sc_wdog_period) {
113			mtspr(SPR_TSR, TSR_ENW);
114			return 0;
115		}
116		printf("%s:%d %u %u\n", __func__, __LINE__,
117		    sc->sc_wdog_period, smw->smw_period);
118		if (smw->smw_period == WDOG_PERIOD_DEFAULT) {
119			sc->sc_wdog_period = PQ3WDOG_PERIOD_DEFAULT;
120			smw->smw_period = PQ3WDOG_PERIOD_DEFAULT;
121		}
122		mtspr(SPR_TSR, TSR_ENW);
123		uint32_t tcr = mfspr(SPR_TCR);
124		if (!sc->sc_wdog_armed)
125			tcr = (tcr & ~TCR_WRC) | TCR_WRC_RESET | TCR_WIE;
126		const uint64_t period = sc->sc_wdog_period * sc->sc_timebase / 3;
127		const u_int wp = __builtin_clz(period) + 1;
128		tcr &= ~(TCR_WP|TCR_WPEXT);
129		tcr |= __SHIFTIN(wp, TCR_WP) | __SHIFTIN(wp >> 2, TCR_WPEXT);
130		mtspr(SPR_TCR, tcr);
131		sc->sc_wdog_period =
132		     ((1ULL << (63 - wp)) + sc->sc_timebase - 1)
133			/ sc->sc_timebase;
134		sc->sc_wdog_armed = true;
135	}
136	return 0;
137}
138
139static void
140e500wdog_attach(device_t parent, device_t self, void *aux)
141{
142	struct cpunode_softc * const psc = device_private(parent);
143	struct e500wdog_softc * const sc = device_private(self);
144	struct cpunode_attach_args * const cna = aux;
145
146	psc->sc_children |= cna->cna_childmask;
147	sc->sc_dev = self;
148
149	sc->sc_timebase = board_info_get_number("timebase-frequency");
150	const uint32_t tcr = mfspr(SPR_TCR);
151	u_int wp = __SHIFTOUT(tcr, TCR_WP) | (__SHIFTOUT(tcr, TCR_WPEXT) << 2);
152
153#if DEBUG > 1
154	printf(" tcr=%#x wp=%u", tcr, wp);
155	printf(" timebase=%"PRIu64, sc->sc_timebase);
156#endif
157	sc->sc_wdog_armed = (tcr & TCR_WRC) != 0;
158	if (sc->sc_wdog_armed)
159		sc->sc_wdog_period = ((1ULL << (63 - wp)) + sc->sc_timebase - 1)
160		    / sc->sc_timebase;
161	else
162		sc->sc_wdog_period = PQ3WDOG_PERIOD_DEFAULT;
163
164	aprint_normal(": default period is %u seconds%s\n",
165	    sc->sc_wdog_period,
166	    sc->sc_wdog_armed ? " (wdog is active)" : "");
167
168	sc->sc_smw.smw_name = device_xname(sc->sc_dev);
169	sc->sc_smw.smw_cookie = sc;
170	sc->sc_smw.smw_setmode = e500wdog_setmode;
171	sc->sc_smw.smw_tickle = e500wdog_tickle;
172	sc->sc_smw.smw_period = sc->sc_wdog_period;
173
174	if (sysmon_wdog_register(&sc->sc_smw) != 0)
175		aprint_error_dev(self, "unable to register with sysmon\n");
176
177#if 1
178	if (sc->sc_wdog_armed) {
179		int error = sysmon_wdog_setmode(&sc->sc_smw, WDOG_MODE_KTICKLE,
180		    sc->sc_wdog_period);
181		if (error)
182			aprint_error_dev(self,
183			    "failed to start kernel tickler: %d\n", error);
184	}
185#else
186	//mtspr(SPR_TSR, TSR_ENW);
187#endif
188}
189