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      1 /*	$NetBSD: geodewdg.c,v 1.12 2016/07/11 11:31:49 msaitoh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2005 David Young.  All rights reserved.
      5  *
      6  * This code was written by David Young.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY DAVID YOUNG ``AS IS'' AND ANY
     18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
     19  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
     20  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL DAVID
     21  * YOUNG BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     22  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
     23  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
     28  * OF SUCH DAMAGE.
     29  */
     30 /*-
     31  * Copyright (c) 2002 The NetBSD Foundation, Inc.
     32  * All rights reserved.
     33  *
     34  * This code is derived from software contributed to The NetBSD Foundation
     35  * by Jason R. Thorpe.
     36  *
     37  * Redistribution and use in source and binary forms, with or without
     38  * modification, are permitted provided that the following conditions
     39  * are met:
     40  * 1. Redistributions of source code must retain the above copyright
     41  *    notice, this list of conditions and the following disclaimer.
     42  * 2. Redistributions in binary form must reproduce the above copyright
     43  *    notice, this list of conditions and the following disclaimer in the
     44  *    documentation and/or other materials provided with the distribution.
     45  *
     46  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     47  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     48  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     49  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     50  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     51  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     52  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     53  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     54  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     55  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     56  * POSSIBILITY OF SUCH DAMAGE.
     57  */
     58 
     59 /*
     60  * Device driver for the watchdog timer built into the
     61  * AMD Geode SC1100 processor.
     62  */
     63 
     64 #include <sys/cdefs.h>
     65 
     66 __KERNEL_RCSID(0, "$NetBSD: geodewdg.c,v 1.12 2016/07/11 11:31:49 msaitoh Exp $");
     67 
     68 #include <sys/param.h>
     69 #include <sys/systm.h>
     70 #include <sys/device.h>
     71 #include <sys/wdog.h>
     72 #include <uvm/uvm_extern.h>
     73 #include <sys/bus.h>
     74 #include <dev/pci/pcivar.h>
     75 #include <dev/pci/pcidevs.h>
     76 #include <arch/i386/pci/geodevar.h>
     77 #include <arch/i386/pci/geodereg.h>
     78 #include <dev/sysmon/sysmonvar.h>
     79 
     80 #ifdef GEODE_DEBUG
     81 #define	GEODE_DPRINTF(__x) printf __x
     82 #else /* GEODE_DEBUG */
     83 #define	GEODE_DPRINTF(__x) /* nothing */
     84 #endif
     85 
     86 struct geode_wdog_softc {
     87 	struct geode_gcb_softc *sc_gcb_dev;
     88 
     89 	uint16_t		sc_countdown;
     90 	uint8_t			sc_prescale;
     91 	struct sysmon_wdog      sc_smw;
     92 };
     93 
     94 static int attached = 0;
     95 
     96 static void
     97 geode_wdog_disable(struct geode_wdog_softc *sc)
     98 {
     99 	uint16_t wdcnfg;
    100 
    101 	/* cancel any pending countdown */
    102 	sc->sc_countdown = 0;
    103 	bus_space_write_2(sc->sc_gcb_dev->sc_iot, sc->sc_gcb_dev->sc_ioh,
    104 	    SC1100_GCB_WDTO, 0);
    105 	/* power-down clock */
    106 	wdcnfg = bus_space_read_2(sc->sc_gcb_dev->sc_iot,
    107 	    sc->sc_gcb_dev->sc_ioh, SC1100_GCB_WDCNFG);
    108 
    109 	GEODE_DPRINTF(("%s: wdcnfg %#04" PRIx16 " -> ", __func__, wdcnfg));
    110 
    111 	wdcnfg |= SC1100_WDCNFG_WD32KPD;
    112 	wdcnfg &= ~(SC1100_WDCNFG_WDTYPE2_MASK | SC1100_WDCNFG_WDTYPE1_MASK);
    113 	/* This no-op is for the reader's benefit. */
    114         wdcnfg |= SC1100_WDCNFG_WDTYPE1_NOACTION |
    115                   SC1100_WDCNFG_WDTYPE2_NOACTION;
    116 	bus_space_write_2(sc->sc_gcb_dev->sc_iot, sc->sc_gcb_dev->sc_ioh,
    117 	    SC1100_GCB_WDCNFG, wdcnfg);
    118 
    119 	GEODE_DPRINTF(("%#04" PRIx16 "\n", wdcnfg));
    120 }
    121 
    122 static void
    123 geode_wdog_enable(struct geode_wdog_softc *sc)
    124 {
    125 	uint16_t wdcnfg;
    126 
    127 	/* power-up clock and set prescale */
    128 	wdcnfg = bus_space_read_2(sc->sc_gcb_dev->sc_iot,
    129 	    sc->sc_gcb_dev->sc_ioh, SC1100_GCB_WDCNFG);
    130 
    131 	GEODE_DPRINTF(("%s: wdcnfg %#04" PRIx16 " -> ", __func__, wdcnfg));
    132 
    133 	wdcnfg &= ~(SC1100_WDCNFG_WD32KPD | SC1100_WDCNFG_WDPRES_MASK |
    134 	            SC1100_WDCNFG_WDTYPE1_MASK | SC1100_WDCNFG_WDTYPE2_MASK);
    135 	wdcnfg |= __SHIFTIN(sc->sc_prescale, SC1100_WDCNFG_WDPRES_MASK);
    136         wdcnfg |= SC1100_WDCNFG_WDTYPE1_RESET | SC1100_WDCNFG_WDTYPE2_NOACTION;
    137 
    138 	bus_space_write_2(sc->sc_gcb_dev->sc_iot, sc->sc_gcb_dev->sc_ioh,
    139 	    SC1100_GCB_WDCNFG, wdcnfg);
    140 
    141 	GEODE_DPRINTF(("%#04" PRIx16 "\n", wdcnfg));
    142 }
    143 
    144 static void
    145 geode_wdog_reset(struct geode_wdog_softc *sc)
    146 {
    147 	/* set countdown */
    148 	bus_space_write_2(sc->sc_gcb_dev->sc_iot, sc->sc_gcb_dev->sc_ioh,
    149 	    SC1100_GCB_WDTO, sc->sc_countdown);
    150 }
    151 
    152 static int
    153 geode_wdog_tickle(struct sysmon_wdog *smw)
    154 {
    155 	int s;
    156 	struct geode_wdog_softc *sc = smw->smw_cookie;
    157 
    158 	s = splhigh();
    159 	geode_wdog_reset(sc);
    160 	splx(s);
    161 	return 0;
    162 }
    163 
    164 static int
    165 geode_wdog_setmode(struct sysmon_wdog *smw)
    166 {
    167 	struct geode_wdog_softc *sc = smw->smw_cookie;
    168 	uint32_t ticks;
    169 	int prescale, s;
    170 
    171 	if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
    172 		s = splhigh();
    173 		geode_wdog_disable(sc);
    174 		splx(s);
    175 		return 0;
    176 	}
    177 	if (smw->smw_period == WDOG_PERIOD_DEFAULT)
    178 		smw->smw_period = 32;
    179 	else if (smw->smw_period > SC1100_WDIVL_MAX) /* too big? */
    180 		return EINVAL;
    181 
    182 	GEODE_DPRINTF(("%s: period %u\n", __func__, smw->smw_period));
    183 
    184 	ticks = smw->smw_period * SC1100_WDCLK_HZ;
    185 
    186 	GEODE_DPRINTF(("%s: ticks0 %" PRIu32 "\n", __func__, ticks));
    187 
    188 	for (prescale = 0; ticks > UINT16_MAX; prescale++)
    189 		ticks /= 2;
    190 
    191 	GEODE_DPRINTF(("%s: ticks %" PRIu32 "\n", __func__, ticks));
    192 	GEODE_DPRINTF(("%s: prescale %d\n", __func__, prescale));
    193 
    194 	KASSERT(prescale <= SC1100_WDCNFG_WDPRES_MAX);
    195 	KASSERT(ticks <= UINT16_MAX);
    196 
    197 	s = splhigh();
    198 
    199 	sc->sc_prescale = (uint8_t)prescale;
    200 	sc->sc_countdown = (uint16_t)ticks;
    201 
    202 	geode_wdog_enable(sc);
    203 
    204 	geode_wdog_reset(sc);
    205 
    206 	splx(s);
    207 	return 0;
    208 }
    209 
    210 static int
    211 geode_wdog_match(device_t parent, cfdata_t match, void *aux)
    212 {
    213 	return !attached;
    214 }
    215 
    216 static void
    217 geode_wdog_attach(device_t parent, device_t self, void *aux)
    218 {
    219 	struct geode_wdog_softc *sc = device_private(self);
    220 	uint8_t wdsts;
    221 
    222 	aprint_naive(": Watchdog Timer\n");
    223 	aprint_normal(": AMD Geode SC1100 Watchdog Timer\n");
    224 
    225 
    226 	/*
    227 	 * Hook up the watchdog timer.
    228 	 */
    229 	sc->sc_gcb_dev = device_private(parent);
    230 	sc->sc_smw.smw_name = device_xname(self);
    231 	sc->sc_smw.smw_cookie = sc;
    232 	sc->sc_smw.smw_setmode = geode_wdog_setmode;
    233 	sc->sc_smw.smw_tickle = geode_wdog_tickle;
    234 	sc->sc_smw.smw_period = 32;
    235 
    236 	/*
    237 	 * Determine cause of the last reset, and issue a warning if it
    238 	 * was due to watchdog expiry.
    239 	 */
    240 	wdsts = bus_space_read_1(sc->sc_gcb_dev->sc_iot,
    241 	    sc->sc_gcb_dev->sc_ioh, SC1100_GCB_WDSTS);
    242 
    243 	GEODE_DPRINTF(("%s: status %#02" PRIx8 "\n", device_xname(self),
    244 	    wdsts));
    245 
    246 	if (wdsts & SC1100_WDSTS_WDRST)
    247 		aprint_error(
    248 		    "%s: WARNING: LAST RESET DUE TO WATCHDOG EXPIRATION!\n",
    249 		    device_xname(self));
    250 
    251 	/* reset WDOVF by writing 1 to it */
    252 	bus_space_write_1(sc->sc_gcb_dev->sc_iot, sc->sc_gcb_dev->sc_ioh,
    253 	    SC1100_GCB_WDSTS, wdsts & SC1100_WDSTS_WDOVF);
    254 
    255 	if (sysmon_wdog_register(&sc->sc_smw) != 0)
    256 		aprint_error("%s: unable to register watchdog with sysmon\n",
    257 		    device_xname(self));
    258 
    259 	/* cancel any pending countdown */
    260 	geode_wdog_disable(sc);
    261 
    262 	attached = 1;
    263 }
    264 
    265 static int
    266 geode_wdog_detach(device_t self, int flags)
    267 {
    268 	int rc;
    269 	struct geode_wdog_softc *sc = device_private(self);
    270 
    271 	if ((rc = sysmon_wdog_unregister(&sc->sc_smw)) != 0) {
    272 		if (rc == ERESTART)
    273 			rc = EINTR;
    274 		return rc;
    275 	}
    276 
    277 	/* cancel any pending countdown */
    278 	geode_wdog_disable(sc);
    279 
    280 	attached = 0;
    281 
    282 	return 0;
    283 }
    284 
    285 CFATTACH_DECL_NEW(geodewdog, sizeof(struct geode_wdog_softc),
    286 	      geode_wdog_match, geode_wdog_attach, geode_wdog_detach, NULL);
    287