1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2019 Andriy Gapon
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 #include <sys/param.h>
30 #include <sys/kernel.h>
31 #include <sys/bus.h>
32 #include <sys/eventhandler.h>
33 #include <sys/module.h>
34 #include <sys/rman.h>
35 #include <sys/systm.h>
36 #include <sys/watchdog.h>
37
38 #include <dev/superio/superio.h>
39
40 #include <machine/bus.h>
41 #include <machine/resource.h>
42
43
44 struct itwd_softc {
45 eventhandler_tag wd_ev;
46 void *intr_handle;
47 struct resource *intr_res;
48 int intr_rid;
49 };
50
51 static void
wd_func(void * priv,u_int cmd,int * error)52 wd_func(void *priv, u_int cmd, int *error)
53 {
54 device_t dev = priv;
55 uint64_t timeout;
56 uint8_t val;
57
58
59 if (cmd != 0) {
60 cmd &= WD_INTERVAL;
61
62 /*
63 * Convert the requested timeout to seconds.
64 * If the timeout is smaller than the minimal supported value
65 * then set it to the minimum.
66 * TODO This hardware actually supports 64ms resolution
67 * when bit 5 of 0x72 is set. Switch to that resolution when
68 * needed.
69 */
70 if (cmd >= WD_TO_1SEC)
71 timeout = (uint64_t)1 << (cmd - WD_TO_1SEC);
72 else
73 timeout = 1;
74
75 /* TODO If timeout is greater than maximum value
76 * that can be specified in seconds, we should
77 * switch the timer to minutes mode by clearing
78 * bit 7 of 0x72 (ensure that bit 5 is also cleared).
79 *
80 * For now, just disable the timer to honor the
81 * watchdog(9) protocol.
82 *
83 * XXX The timeout actually can be up to 65535 units
84 * as it is set via two registers 0x73, LSB, and 0x74,
85 * MSB. But it is not clear what the protocol for writing
86 * those two registers is.
87 */
88 if (timeout <= UINT8_MAX) {
89 val = timeout;
90 *error = 0;
91 } else {
92 /* error left unchanged */
93 val = 0;
94 }
95 } else {
96 val = 0;
97 }
98 #ifdef DIAGNOSTIC
99 if (bootverbose)
100 device_printf(dev, "setting timeout to %d\n", val);
101 #endif
102 superio_write(dev, 0x73, val);
103 if (superio_read(dev, 0x73) != val)
104 superio_write(dev, 0x73, val);
105 }
106
107 static void
itwd_intr(void * cookie)108 itwd_intr(void *cookie)
109 {
110 device_t dev = cookie;
111 uint8_t val;
112
113 val = superio_read(dev, 0x71);
114 if (bootverbose)
115 device_printf(dev, "got interrupt, wdt status = %d\n", val & 1);
116 superio_write(dev, 0x71, val & ~((uint8_t)0x01));
117 }
118
119 static int
itwd_probe(device_t dev)120 itwd_probe(device_t dev)
121 {
122
123 if (superio_vendor(dev) != SUPERIO_VENDOR_ITE)
124 return (ENXIO);
125 if (superio_get_type(dev) != SUPERIO_DEV_WDT)
126 return (ENXIO);
127 device_set_desc(dev, "Watchdog Timer on ITE SuperIO");
128 return (BUS_PROBE_DEFAULT);
129 }
130
131 static int
itwd_attach(device_t dev)132 itwd_attach(device_t dev)
133 {
134 struct itwd_softc *sc = device_get_softc(dev);
135 int irq = 0;
136 int nmi = 0;
137 int error;
138
139 /* First, reset the timeout, just in case. */
140 superio_write(dev, 0x74, 0);
141 superio_write(dev, 0x73, 0);
142
143 TUNABLE_INT_FETCH("dev.itwd.irq", &irq);
144 TUNABLE_INT_FETCH("dev.itwd.nmi", &nmi);
145 if (irq < 0 || irq > 15) {
146 device_printf(dev, "Ignoring invalid IRQ value %d\n", irq);
147 irq = 0;
148 }
149 if (irq == 0 && nmi) {
150 device_printf(dev, "Ignoring NMI mode if IRQ is not set\n");
151 nmi = 0;
152 }
153
154 /*
155 * NB: if the interrupt has been configured for the NMI delivery,
156 * then it is not available for the regular interrupt allocation.
157 * Thus, we configure the hardware to generate the interrupt,
158 * but do not attempt to allocate and setup it as a regular
159 * interrupt.
160 */
161 if (irq != 0 && !nmi) {
162 sc->intr_rid = 0;
163 bus_set_resource(dev, SYS_RES_IRQ, sc->intr_rid, irq, 1);
164
165 sc->intr_res = bus_alloc_resource_any(dev, SYS_RES_IRQ,
166 &sc->intr_rid, RF_ACTIVE);
167 if (sc->intr_res == NULL) {
168 device_printf(dev, "unable to map interrupt\n");
169 return (ENXIO);
170 }
171 error = bus_setup_intr(dev, sc->intr_res,
172 INTR_TYPE_MISC | INTR_MPSAFE, NULL, itwd_intr, dev,
173 &sc->intr_handle);
174 if (error != 0) {
175 bus_release_resource(dev, SYS_RES_IRQ,
176 sc->intr_rid, sc->intr_res);
177 device_printf(dev, "Unable to setup irq: error %d\n",
178 error);
179 return (ENXIO);
180 }
181 }
182 if (irq != 0) {
183 device_printf(dev, "Using IRQ%d to signal timeout\n", irq);
184 } else {
185 /* System reset via KBRST. */
186 irq = 0x40;
187 device_printf(dev, "Configured for system reset on timeout\n");
188 }
189
190 superio_write(dev, 0x71, 0);
191 superio_write(dev, 0x72, 0x80 | (uint8_t)irq);
192
193 sc->wd_ev = EVENTHANDLER_REGISTER(watchdog_list, wd_func, dev, 0);
194 return (0);
195 }
196
197 static int
itwd_detach(device_t dev)198 itwd_detach(device_t dev)
199 {
200 struct itwd_softc *sc = device_get_softc(dev);
201 int dummy;
202
203 if (sc->wd_ev != NULL)
204 EVENTHANDLER_DEREGISTER(watchdog_list, sc->wd_ev);
205 wd_func(dev, 0, &dummy);
206 if (sc->intr_handle)
207 bus_teardown_intr(dev, sc->intr_res, sc->intr_handle);
208 if (sc->intr_res)
209 bus_release_resource(dev, SYS_RES_IRQ, sc->intr_rid,
210 sc->intr_res);
211 return (0);
212 }
213
214 static device_method_t itwd_methods[] = {
215 /* Methods from the device interface */
216 DEVMETHOD(device_probe, itwd_probe),
217 DEVMETHOD(device_attach, itwd_attach),
218 DEVMETHOD(device_detach, itwd_detach),
219
220 /* Terminate method list */
221 { 0, 0 }
222 };
223
224 static driver_t itwd_driver = {
225 "itwd",
226 itwd_methods,
227 sizeof (struct itwd_softc)
228 };
229
230 DRIVER_MODULE(itwd, superio, itwd_driver, NULL, NULL);
231 MODULE_DEPEND(itwd, superio, 1, 1, 1);
232 MODULE_VERSION(itwd, 1);
233