ichwd.c revision 129124 
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: head/sys/dev/ichwd/ichwd.c 129124 2004-05-11 18:21:38Z des $");
58
59#include <sys/param.h>
60#include <sys/kernel.h>
61#include <sys/systm.h>
62#include <sys/bus.h>
63#include <machine/bus.h>
64#include <sys/rman.h>
65#include <machine/resource.h>
66#include <sys/watchdog.h>
67
68#include <dev/pci/pcivar.h>
69
70#include <dev/ichwd/ichwd.h>
71
72static struct ichwd_device ichwd_devices[] = {
73	{ VENDORID_INTEL, DEVICEID_82801AA, "Intel 82801AA watchdog timer" },
74	{ VENDORID_INTEL, DEVICEID_82801AB, "Intel 82801AB watchdog timer" },
75	{ VENDORID_INTEL, DEVICEID_82801BA, "Intel 82801BA watchdog timer" },
76	{ VENDORID_INTEL, DEVICEID_82801BAM, "Intel 82801BAM watchdog timer" },
77	{ VENDORID_INTEL, DEVICEID_82801CA, "Intel 82801CA watchdog timer" },
78	{ VENDORID_INTEL, DEVICEID_82801CAM, "Intel 82801CAM watchdog timer" },
79	{ VENDORID_INTEL, DEVICEID_82801DB, "Intel 82801DB watchdog timer" },
80	{ VENDORID_INTEL, DEVICEID_82801DBM, "Intel 82801DBM watchdog timer" },
81	{ VENDORID_INTEL, DEVICEID_82801E, "Intel 82801E watchdog timer" },
82	{ VENDORID_INTEL, DEVICEID_82801EBR, "Intel 82801EB/ER watchdog timer" },
83	{ 0, 0, NULL },
84};
85
86static devclass_t ichwd_devclass;
87
88#define ichwd_read_1(sc, off) \
89	bus_space_read_1((sc)->smi_bst, (sc)->smi_bsh, (off))
90#define ichwd_read_2(sc, off) \
91	bus_space_read_2((sc)->smi_bst, (sc)->smi_bsh, (off))
92#define ichwd_read_4(sc, off) \
93	bus_space_read_4((sc)->smi_bst, (sc)->smi_bsh, (off))
94
95#define ichwd_write_1(sc, off, val) \
96	bus_space_write_1((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
97#define ichwd_write_2(sc, off, val) \
98	bus_space_write_2((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
99#define ichwd_write_4(sc, off, val) \
100	bus_space_write_4((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
101
102static __inline void
103ichwd_intr_enable(struct ichwd_softc *sc)
104{
105	ichwd_write_4(sc, SMI_EN, ichwd_read_4(sc, SMI_EN) | SMI_TCO_EN);
106}
107
108static __inline void
109ichwd_intr_disable(struct ichwd_softc *sc)
110{
111	ichwd_write_4(sc, SMI_EN, ichwd_read_4(sc, SMI_EN) & ~SMI_TCO_EN);
112}
113
114static __inline void
115ichwd_sts_reset(struct ichwd_softc *sc)
116{
117	ichwd_write_2(sc, TCO1_STS, TCO_TIMEOUT);
118	ichwd_write_2(sc, TCO2_STS, TCO_BOOT_STS);
119	ichwd_write_2(sc, TCO2_STS, TCO_SECOND_TO_STS);
120}
121
122static __inline void
123ichwd_tmr_enable(struct ichwd_softc *sc)
124{
125	uint16_t cnt;
126
127	cnt = ichwd_read_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
128	ichwd_write_2(sc, TCO1_CNT, cnt & ~TCO_TMR_HALT);
129	sc->active = 1;
130	if (bootverbose)
131		device_printf(sc->device, "timer enabled\n");
132}
133
134static __inline void
135ichwd_tmr_disable(struct ichwd_softc *sc)
136{
137	uint16_t cnt;
138
139	cnt = ichwd_read_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
140	ichwd_write_2(sc, TCO1_CNT, cnt | TCO_TMR_HALT);
141	sc->active = 0;
142	if (bootverbose)
143		device_printf(sc->device, "timer disabled\n");
144}
145
146static __inline void
147ichwd_tmr_reload(struct ichwd_softc *sc)
148{
149	ichwd_write_1(sc, TCO_RLD, 1);
150	if (bootverbose)
151		device_printf(sc->device, "timer reloaded\n");
152}
153
154static __inline void
155ichwd_tmr_set(struct ichwd_softc *sc, uint8_t timeout)
156{
157	ichwd_write_1(sc, TCO_TMR, timeout);
158	sc->timeout = timeout;
159	if (bootverbose)
160		device_printf(sc->device, "timeout set to %u ticks\n", timeout);
161}
162
163/*
164 * Watchdog event handler.
165 */
166static void
167ichwd_event(void *arg, unsigned int cmd, int *error)
168{
169	struct ichwd_softc *sc = arg;
170	unsigned int timeout;
171
172	cmd &= WD_INTERVAL;
173
174	/* disable / enable */
175	if (cmd == 0) {
176		if (sc->active)
177			ichwd_tmr_disable(sc);
178		*error = 0;
179		return;
180	}
181	if (!sc->active)
182		ichwd_tmr_enable(sc);
183
184	/* convert from power-of-to-ns to WDT ticks */
185	if (cmd >= 64) {
186		*error = EINVAL;
187		return;
188	}
189	timeout = ((uint64_t)1 << cmd) / ICHWD_TICK;
190	if (timeout < ICHWD_MIN_TIMEOUT || timeout > ICHWD_MAX_TIMEOUT) {
191		*error = EINVAL;
192		return;
193	}
194
195	/* set new initial value */
196	if (timeout != sc->timeout)
197		ichwd_tmr_set(sc, timeout);
198
199	/* reload */
200	ichwd_tmr_reload(sc);
201
202	*error = 0;
203	return;
204}
205
206static int
207ichwd_probe(device_t dev)
208{
209	(void)dev;
210	return (0);
211}
212
213static unsigned long pmbase;
214
215/*
216 * Look for an ICH LPC interface bridge.  If one is found, register an
217 * ichwd device.  There can be only one.
218 */
219static void
220ichwd_identify(driver_t *driver, device_t parent)
221{
222	struct ichwd_device *id;
223	device_t ich = NULL;
224	device_t dev;
225
226	printf("%s()\n", __func__);
227
228	/* look for an ICH LPC interface bridge */
229	for (id = ichwd_devices; id->desc != NULL; ++id)
230		if ((ich = pci_find_device(id->vendor, id->device)) != NULL)
231			break;
232	if (ich == NULL)
233		return;
234
235	if (bootverbose)
236		printf("%s(): found ICH chipset: %s\n", __func__, id->desc);
237
238	/* get for ACPI base address */
239	pmbase = pci_read_config(ich, ICH_PMBASE, 2) & ICH_PMBASE_MASK;
240	if (pmbase == 0) {
241		if (bootverbose)
242			printf("%s(): ICH PMBASE register is empty\n",
243			    __func__);
244		return;
245	}
246
247	/* try to clear the NO_REBOOT bit */
248	pci_write_config(ich, ICH_GEN_STA, 0x00, 1);
249	if (pci_read_config(ich, ICH_GEN_STA, 1) & ICH_GEN_STA_NO_REBOOT) {
250		if (bootverbose)
251			printf("%s(): ICH WDT present but disabled\n",
252			    __func__);
253		return;
254	}
255
256	/* good, add child to bus */
257	if ((dev = device_find_child(parent, driver->name, 0)) == NULL)
258		dev = BUS_ADD_CHILD(parent, 0, driver->name, -1);
259	device_set_desc_copy(dev, id->desc);
260	device_set_driver(dev, driver);
261}
262
263static int
264ichwd_attach(device_t dev)
265{
266	struct ichwd_softc *sc;
267
268	device_printf(dev, "attaching\n");
269
270	sc = device_get_softc(dev);
271	sc->device = dev;
272
273	/* allocate I/O register space */
274	sc->smi_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->smi_rid,
275	    pmbase + SMI_BASE, pmbase + SMI_BASE + SMI_LEN - 1, SMI_LEN,
276	    RF_ACTIVE|RF_SHAREABLE);
277	if (sc->smi_res == NULL) {
278		device_printf(dev, "unable to reserve SMI registers\n");
279		goto fail;
280	}
281	sc->smi_bst = rman_get_bustag(sc->smi_res);
282	sc->smi_bsh = rman_get_bushandle(sc->smi_res);
283	sc->tco_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->tco_rid,
284	    pmbase + TCO_BASE, pmbase + TCO_BASE + TCO_LEN - 1, TCO_LEN,
285	    RF_ACTIVE|RF_SHAREABLE);
286	if (sc->tco_res == NULL) {
287		device_printf(dev, "unable to reserve TCO registers\n");
288		goto fail;
289	}
290	sc->tco_bst = rman_get_bustag(sc->tco_res);
291	sc->tco_bsh = rman_get_bushandle(sc->tco_res);
292
293	/* reset the watchdog status registers */
294	ichwd_sts_reset(sc);
295
296	/* make sure the WDT starts out inactive */
297	ichwd_tmr_disable(sc);
298
299	/* register the watchdog event handler */
300	sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, ichwd_event, sc, 0);
301
302	/* enable watchdog timeout interrupts */
303	ichwd_intr_enable(sc);
304
305	return (0);
306 fail:
307	sc = device_get_softc(dev);
308	if (sc->tco_res != NULL)
309		bus_release_resource(dev, SYS_RES_IOPORT,
310		    sc->tco_rid, sc->tco_res);
311	if (sc->smi_res != NULL)
312		bus_release_resource(dev, SYS_RES_IOPORT,
313		    sc->smi_rid, sc->smi_res);
314	return (ENXIO);
315}
316
317static int
318ichwd_detach(device_t dev)
319{
320	struct ichwd_softc *sc;
321
322	device_printf(dev, "detaching\n");
323
324	sc = device_get_softc(dev);
325
326	/* halt the watchdog timer */
327	if (sc->active)
328		ichwd_tmr_disable(sc);
329
330	/* disable watchdog timeout interrupts */
331	ichwd_intr_disable(sc);
332
333	/* deregister event handler */
334	if (sc->ev_tag != NULL)
335		EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
336	sc->ev_tag = NULL;
337
338	/* reset the watchdog status registers */
339	ichwd_sts_reset(sc);
340
341	/* deallocate I/O register space */
342	bus_release_resource(dev, SYS_RES_IOPORT, sc->tco_rid, sc->tco_res);
343	bus_release_resource(dev, SYS_RES_IOPORT, sc->smi_rid, sc->smi_res);
344
345	return (0);
346}
347
348static device_method_t ichwd_methods[] = {
349	DEVMETHOD(device_identify, ichwd_identify),
350	DEVMETHOD(device_probe,	ichwd_probe),
351	DEVMETHOD(device_attach, ichwd_attach),
352	DEVMETHOD(device_detach, ichwd_detach),
353	{0,0}
354};
355
356static driver_t ichwd_driver = {
357	"ichwd",
358	ichwd_methods,
359	sizeof(struct ichwd_softc),
360};
361
362static int
363ichwd_modevent(module_t mode, int type, void *data)
364{
365	int error = 0;
366
367	switch (type) {
368	case MOD_LOAD:
369		printf("ichwd module loaded\n");
370		break;
371	case MOD_UNLOAD:
372		printf("ichwd module unloaded\n");
373		break;
374	case MOD_SHUTDOWN:
375		printf("ichwd module shutting down\n");
376		break;
377	}
378	return (error);
379}
380
381DRIVER_MODULE(ichwd, nexus, ichwd_driver, ichwd_devclass, ichwd_modevent, NULL);
382/*
383 * this doesn't seem to work, though I can't figure out why.
384 * currently not a big issue since watchdog is standard.
385MODULE_DEPEND(ichwd, watchdog, 1, 1, 1);
386 */
387