xref: /freebsd/sys/dev/ichwd/ichwd.c (revision 6af83ee0d2941d18880b6aaa2b4facd1d30c6106)
1 /*-
2  * Copyright (c) 2004 Texas A&M University
3  * All rights reserved.
4  *
5  * Developer: Wm. Daryl Hawkins
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * Intel ICH Watchdog Timer (WDT) driver
31  *
32  * Originally developed by Wm. Daryl Hawkins of Texas A&M
33  * Heavily modified by <des@FreeBSD.org>
34  *
35  * This is a tricky one.  The ICH WDT can't be treated as a regular PCI
36  * device as it's actually an integrated function of the ICH LPC interface
37  * bridge.  Detection is also awkward, because we can only infer the
38  * presence of the watchdog timer from the fact that the machine has an
39  * ICH chipset, or, on ACPI 2.x systems, by the presence of the 'WDDT'
40  * ACPI table (although this driver does not support the ACPI detection
41  * method).
42  *
43  * There is one slight problem on non-ACPI or ACPI 1.x systems: we have no
44  * way of knowing if the WDT is permanently disabled (either by the BIOS
45  * or in hardware).
46  *
47  * The WDT is programmed through I/O registers in the ACPI I/O space.
48  * Intel swears it's always at offset 0x60, so we use that.
49  *
50  * For details about the ICH WDT, see Intel Application Note AP-725
51  * (document no. 292273-001).  The WDT is also described in the individual
52  * chipset datasheets, e.g. Intel82801EB ICH5 / 82801ER ICH5R Datasheet
53  * (document no. 252516-001) sections 9.10 and 9.11.
54  */
55 
56 #include <sys/cdefs.h>
57 __FBSDID("$FreeBSD$");
58 
59 #include <sys/param.h>
60 #include <sys/kernel.h>
61 #include <sys/module.h>
62 #include <sys/systm.h>
63 #include <sys/bus.h>
64 #include <machine/bus.h>
65 #include <sys/rman.h>
66 #include <machine/resource.h>
67 #include <sys/watchdog.h>
68 
69 #include <dev/pci/pcivar.h>
70 
71 #include <dev/ichwd/ichwd.h>
72 
73 static struct ichwd_device ichwd_devices[] = {
74 	{ VENDORID_INTEL, DEVICEID_82801AA, "Intel 82801AA watchdog timer" },
75 	{ VENDORID_INTEL, DEVICEID_82801AB, "Intel 82801AB watchdog timer" },
76 	{ VENDORID_INTEL, DEVICEID_82801BA, "Intel 82801BA watchdog timer" },
77 	{ VENDORID_INTEL, DEVICEID_82801BAM, "Intel 82801BAM watchdog timer" },
78 	{ VENDORID_INTEL, DEVICEID_82801CA, "Intel 82801CA watchdog timer" },
79 	{ VENDORID_INTEL, DEVICEID_82801CAM, "Intel 82801CAM watchdog timer" },
80 	{ VENDORID_INTEL, DEVICEID_82801DB, "Intel 82801DB watchdog timer" },
81 	{ VENDORID_INTEL, DEVICEID_82801DBM, "Intel 82801DBM watchdog timer" },
82 	{ VENDORID_INTEL, DEVICEID_82801E, "Intel 82801E watchdog timer" },
83 	{ VENDORID_INTEL, DEVICEID_82801EBR, "Intel 82801EB/ER watchdog timer" },
84 	{ 0, 0, NULL },
85 };
86 
87 static devclass_t ichwd_devclass;
88 
89 #define ichwd_read_1(sc, off) \
90 	bus_space_read_1((sc)->smi_bst, (sc)->smi_bsh, (off))
91 #define ichwd_read_2(sc, off) \
92 	bus_space_read_2((sc)->smi_bst, (sc)->smi_bsh, (off))
93 #define ichwd_read_4(sc, off) \
94 	bus_space_read_4((sc)->smi_bst, (sc)->smi_bsh, (off))
95 
96 #define ichwd_write_1(sc, off, val) \
97 	bus_space_write_1((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
98 #define ichwd_write_2(sc, off, val) \
99 	bus_space_write_2((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
100 #define ichwd_write_4(sc, off, val) \
101 	bus_space_write_4((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
102 
103 static __inline void
104 ichwd_intr_enable(struct ichwd_softc *sc)
105 {
106 	ichwd_write_4(sc, SMI_EN, ichwd_read_4(sc, SMI_EN) | SMI_TCO_EN);
107 }
108 
109 static __inline void
110 ichwd_intr_disable(struct ichwd_softc *sc)
111 {
112 	ichwd_write_4(sc, SMI_EN, ichwd_read_4(sc, SMI_EN) & ~SMI_TCO_EN);
113 }
114 
115 static __inline void
116 ichwd_sts_reset(struct ichwd_softc *sc)
117 {
118 	ichwd_write_2(sc, TCO1_STS, TCO_TIMEOUT);
119 	ichwd_write_2(sc, TCO2_STS, TCO_BOOT_STS);
120 	ichwd_write_2(sc, TCO2_STS, TCO_SECOND_TO_STS);
121 }
122 
123 static __inline void
124 ichwd_tmr_enable(struct ichwd_softc *sc)
125 {
126 	uint16_t cnt;
127 
128 	cnt = ichwd_read_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
129 	ichwd_write_2(sc, TCO1_CNT, cnt & ~TCO_TMR_HALT);
130 	sc->active = 1;
131 	if (bootverbose)
132 		device_printf(sc->device, "timer enabled\n");
133 }
134 
135 static __inline void
136 ichwd_tmr_disable(struct ichwd_softc *sc)
137 {
138 	uint16_t cnt;
139 
140 	cnt = ichwd_read_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
141 	ichwd_write_2(sc, TCO1_CNT, cnt | TCO_TMR_HALT);
142 	sc->active = 0;
143 	if (bootverbose)
144 		device_printf(sc->device, "timer disabled\n");
145 }
146 
147 static __inline void
148 ichwd_tmr_reload(struct ichwd_softc *sc)
149 {
150 	ichwd_write_1(sc, TCO_RLD, 1);
151 	if (bootverbose)
152 		device_printf(sc->device, "timer reloaded\n");
153 }
154 
155 static __inline void
156 ichwd_tmr_set(struct ichwd_softc *sc, uint8_t timeout)
157 {
158 	ichwd_write_1(sc, TCO_TMR, timeout);
159 	sc->timeout = timeout;
160 	if (bootverbose)
161 		device_printf(sc->device, "timeout set to %u ticks\n", timeout);
162 }
163 
164 /*
165  * Watchdog event handler.
166  */
167 static void
168 ichwd_event(void *arg, unsigned int cmd, int *error)
169 {
170 	struct ichwd_softc *sc = arg;
171 	unsigned int timeout;
172 
173 	cmd &= WD_INTERVAL;
174 
175 	/* disable / enable */
176 	if (cmd == 0) {
177 		if (sc->active)
178 			ichwd_tmr_disable(sc);
179 		*error = 0;
180 		return;
181 	}
182 	if (!sc->active)
183 		ichwd_tmr_enable(sc);
184 
185 	/* convert from power-of-to-ns to WDT ticks */
186 	if (cmd >= 64) {
187 		*error = EINVAL;
188 		return;
189 	}
190 	timeout = ((uint64_t)1 << cmd) / ICHWD_TICK;
191 	if (timeout < ICHWD_MIN_TIMEOUT || timeout > ICHWD_MAX_TIMEOUT) {
192 		*error = EINVAL;
193 		return;
194 	}
195 
196 	/* set new initial value */
197 	if (timeout != sc->timeout)
198 		ichwd_tmr_set(sc, timeout);
199 
200 	/* reload */
201 	ichwd_tmr_reload(sc);
202 
203 	*error = 0;
204 	return;
205 }
206 
207 static unsigned long pmbase;
208 
209 /*
210  * Look for an ICH LPC interface bridge.  If one is found, register an
211  * ichwd device.  There can be only one.
212  */
213 static void
214 ichwd_identify(driver_t *driver, device_t parent)
215 {
216 	struct ichwd_device *id;
217 	device_t ich = NULL;
218 	device_t dev;
219 
220 	/* look for an ICH LPC interface bridge */
221 	for (id = ichwd_devices; id->desc != NULL; ++id)
222 		if ((ich = pci_find_device(id->vendor, id->device)) != NULL)
223 			break;
224 	if (ich == NULL)
225 		return;
226 
227 	if (bootverbose)
228 		printf("%s(): found ICH chipset: %s\n", __func__, id->desc);
229 
230 	/* get for ACPI base address */
231 	pmbase = pci_read_config(ich, ICH_PMBASE, 2) & ICH_PMBASE_MASK;
232 	if (pmbase == 0) {
233 		if (bootverbose)
234 			printf("%s(): ICH PMBASE register is empty\n",
235 			    __func__);
236 		return;
237 	}
238 
239 	/* try to clear the NO_REBOOT bit */
240 	pci_write_config(ich, ICH_GEN_STA, 0x00, 1);
241 	if (pci_read_config(ich, ICH_GEN_STA, 1) & ICH_GEN_STA_NO_REBOOT) {
242 		if (bootverbose)
243 			printf("%s(): ICH WDT present but disabled\n",
244 			    __func__);
245 		return;
246 	}
247 
248 	/* good, add child to bus */
249 	if ((dev = device_find_child(parent, driver->name, 0)) == NULL)
250 		dev = BUS_ADD_CHILD(parent, 0, driver->name, 0);
251 
252 	if (dev != NULL)
253 		device_set_desc_copy(dev, id->desc);
254 }
255 
256 static int
257 ichwd_probe(device_t dev)
258 {
259 	(void)dev;
260 	return (0);
261 }
262 
263 static int
264 ichwd_attach(device_t dev)
265 {
266 	struct ichwd_softc *sc;
267 
268 	sc = device_get_softc(dev);
269 	sc->device = dev;
270 
271 	/* allocate I/O register space */
272 	sc->smi_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->smi_rid,
273 	    pmbase + SMI_BASE, pmbase + SMI_BASE + SMI_LEN - 1, SMI_LEN,
274 	    RF_ACTIVE|RF_SHAREABLE);
275 	if (sc->smi_res == NULL) {
276 		device_printf(dev, "unable to reserve SMI registers\n");
277 		goto fail;
278 	}
279 	sc->smi_bst = rman_get_bustag(sc->smi_res);
280 	sc->smi_bsh = rman_get_bushandle(sc->smi_res);
281 	sc->tco_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->tco_rid,
282 	    pmbase + TCO_BASE, pmbase + TCO_BASE + TCO_LEN - 1, TCO_LEN,
283 	    RF_ACTIVE|RF_SHAREABLE);
284 	if (sc->tco_res == NULL) {
285 		device_printf(dev, "unable to reserve TCO registers\n");
286 		goto fail;
287 	}
288 	sc->tco_bst = rman_get_bustag(sc->tco_res);
289 	sc->tco_bsh = rman_get_bushandle(sc->tco_res);
290 
291 	/* reset the watchdog status registers */
292 	ichwd_sts_reset(sc);
293 
294 	/* make sure the WDT starts out inactive */
295 	ichwd_tmr_disable(sc);
296 
297 	/* register the watchdog event handler */
298 	sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, ichwd_event, sc, 0);
299 
300 	/* enable watchdog timeout interrupts */
301 	ichwd_intr_enable(sc);
302 
303 	return (0);
304  fail:
305 	sc = device_get_softc(dev);
306 	if (sc->tco_res != NULL)
307 		bus_release_resource(dev, SYS_RES_IOPORT,
308 		    sc->tco_rid, sc->tco_res);
309 	if (sc->smi_res != NULL)
310 		bus_release_resource(dev, SYS_RES_IOPORT,
311 		    sc->smi_rid, sc->smi_res);
312 	return (ENXIO);
313 }
314 
315 static int
316 ichwd_detach(device_t dev)
317 {
318 	struct ichwd_softc *sc;
319 
320 	device_printf(dev, "detaching\n");
321 
322 	sc = device_get_softc(dev);
323 
324 	/* halt the watchdog timer */
325 	if (sc->active)
326 		ichwd_tmr_disable(sc);
327 
328 	/* disable watchdog timeout interrupts */
329 	ichwd_intr_disable(sc);
330 
331 	/* deregister event handler */
332 	if (sc->ev_tag != NULL)
333 		EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
334 	sc->ev_tag = NULL;
335 
336 	/* reset the watchdog status registers */
337 	ichwd_sts_reset(sc);
338 
339 	/* deallocate I/O register space */
340 	bus_release_resource(dev, SYS_RES_IOPORT, sc->tco_rid, sc->tco_res);
341 	bus_release_resource(dev, SYS_RES_IOPORT, sc->smi_rid, sc->smi_res);
342 
343 	return (0);
344 }
345 
346 static device_method_t ichwd_methods[] = {
347 	DEVMETHOD(device_identify, ichwd_identify),
348 	DEVMETHOD(device_probe,	ichwd_probe),
349 	DEVMETHOD(device_attach, ichwd_attach),
350 	DEVMETHOD(device_detach, ichwd_detach),
351 	{0,0}
352 };
353 
354 static driver_t ichwd_driver = {
355 	"ichwd",
356 	ichwd_methods,
357 	sizeof(struct ichwd_softc),
358 };
359 
360 static int
361 ichwd_modevent(module_t mode, int type, void *data)
362 {
363 	int error = 0;
364 
365 	switch (type) {
366 	case MOD_LOAD:
367 		printf("ichwd module loaded\n");
368 		break;
369 	case MOD_UNLOAD:
370 		printf("ichwd module unloaded\n");
371 		break;
372 	case MOD_SHUTDOWN:
373 		printf("ichwd module shutting down\n");
374 		break;
375 	}
376 	return (error);
377 }
378 
379 DRIVER_MODULE(ichwd, nexus, ichwd_driver, ichwd_devclass, ichwd_modevent, NULL);
380 /*
381  * this doesn't seem to work, though I can't figure out why.
382  * currently not a big issue since watchdog is standard.
383 MODULE_DEPEND(ichwd, watchdog, 1, 1, 1);
384  */
385