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/param.h>
29 #include <sys/kernel.h>
30 #include <sys/bus.h>
31 #include <sys/eventhandler.h>
32 #include <sys/module.h>
33 #include <sys/rman.h>
34 #include <sys/systm.h>
35 #include <sys/watchdog.h>
36
37 #include <dev/superio/superio.h>
38
39 #include <machine/bus.h>
40 #include <machine/resource.h>
41
42
43 struct itwd_softc {
44 eventhandler_tag wd_ev;
45 void *intr_handle;
46 struct resource *intr_res;
47 int intr_rid;
48 };
49
50 static void
wd_func(void * priv,u_int cmd,int * error)51 wd_func(void *priv, u_int cmd, int *error)
52 {
53 device_t dev = priv;
54 uint64_t timeout;
55 uint8_t val;
56
57
58 if (cmd != 0) {
59 cmd &= WD_INTERVAL;
60
61 /*
62 * Convert the requested timeout to seconds.
63 * If the timeout is smaller than the minimal supported value
64 * then set it to the minimum.
65 * TODO This hardware actually supports 64ms resolution
66 * when bit 5 of 0x72 is set. Switch to that resolution when
67 * needed.
68 */
69 if (cmd >= WD_TO_1SEC)
70 timeout = (uint64_t)1 << (cmd - WD_TO_1SEC);
71 else
72 timeout = 1;
73
74 /* TODO If timeout is greater than maximum value
75 * that can be specified in seconds, we should
76 * switch the timer to minutes mode by clearing
77 * bit 7 of 0x72 (ensure that bit 5 is also cleared).
78 *
79 * For now, just disable the timer to honor the
80 * watchdog(9) protocol.
81 *
82 * XXX The timeout actually can be up to 65535 units
83 * as it is set via two registers 0x73, LSB, and 0x74,
84 * MSB. But it is not clear what the protocol for writing
85 * those two registers is.
86 */
87 if (timeout <= UINT8_MAX) {
88 val = timeout;
89 *error = 0;
90 } else {
91 /* error left unchanged */
92 val = 0;
93 }
94 } else {
95 val = 0;
96 }
97 #ifdef DIAGNOSTIC
98 if (bootverbose)
99 device_printf(dev, "setting timeout to %d\n", val);
100 #endif
101 superio_write(dev, 0x73, val);
102 if (superio_read(dev, 0x73) != val)
103 superio_write(dev, 0x73, val);
104 }
105
106 static void
itwd_intr(void * cookie)107 itwd_intr(void *cookie)
108 {
109 device_t dev = cookie;
110 uint8_t val;
111
112 val = superio_read(dev, 0x71);
113 if (bootverbose)
114 device_printf(dev, "got interrupt, wdt status = %d\n", val & 1);
115 superio_write(dev, 0x71, val & ~((uint8_t)0x01));
116 }
117
118 static int
itwd_probe(device_t dev)119 itwd_probe(device_t dev)
120 {
121
122 if (superio_vendor(dev) != SUPERIO_VENDOR_ITE)
123 return (ENXIO);
124 if (superio_get_type(dev) != SUPERIO_DEV_WDT)
125 return (ENXIO);
126 device_set_desc(dev, "Watchdog Timer on ITE SuperIO");
127 return (BUS_PROBE_DEFAULT);
128 }
129
130 static int
itwd_attach(device_t dev)131 itwd_attach(device_t dev)
132 {
133 struct itwd_softc *sc = device_get_softc(dev);
134 int irq = 0;
135 int nmi = 0;
136 int error;
137
138 /* First, reset the timeout, just in case. */
139 superio_write(dev, 0x74, 0);
140 superio_write(dev, 0x73, 0);
141
142 TUNABLE_INT_FETCH("dev.itwd.irq", &irq);
143 TUNABLE_INT_FETCH("dev.itwd.nmi", &nmi);
144 if (irq < 0 || irq > 15) {
145 device_printf(dev, "Ignoring invalid IRQ value %d\n", irq);
146 irq = 0;
147 }
148 if (irq == 0 && nmi) {
149 device_printf(dev, "Ignoring NMI mode if IRQ is not set\n");
150 nmi = 0;
151 }
152
153 /*
154 * NB: if the interrupt has been configured for the NMI delivery,
155 * then it is not available for the regular interrupt allocation.
156 * Thus, we configure the hardware to generate the interrupt,
157 * but do not attempt to allocate and setup it as a regular
158 * interrupt.
159 */
160 if (irq != 0 && !nmi) {
161 sc->intr_rid = 0;
162 bus_set_resource(dev, SYS_RES_IRQ, sc->intr_rid, irq, 1);
163
164 sc->intr_res = bus_alloc_resource_any(dev, SYS_RES_IRQ,
165 &sc->intr_rid, RF_ACTIVE);
166 if (sc->intr_res == NULL) {
167 device_printf(dev, "unable to map interrupt\n");
168 return (ENXIO);
169 }
170 error = bus_setup_intr(dev, sc->intr_res,
171 INTR_TYPE_MISC | INTR_MPSAFE, NULL, itwd_intr, dev,
172 &sc->intr_handle);
173 if (error != 0) {
174 bus_release_resource(dev, SYS_RES_IRQ,
175 sc->intr_rid, sc->intr_res);
176 device_printf(dev, "Unable to setup irq: error %d\n",
177 error);
178 return (ENXIO);
179 }
180 }
181 if (irq != 0) {
182 device_printf(dev, "Using IRQ%d to signal timeout\n", irq);
183 } else {
184 /* System reset via KBRST. */
185 irq = 0x40;
186 device_printf(dev, "Configured for system reset on timeout\n");
187 }
188
189 superio_write(dev, 0x71, 0);
190 superio_write(dev, 0x72, 0x80 | (uint8_t)irq);
191
192 sc->wd_ev = EVENTHANDLER_REGISTER(watchdog_list, wd_func, dev, 0);
193 return (0);
194 }
195
196 static int
itwd_detach(device_t dev)197 itwd_detach(device_t dev)
198 {
199 struct itwd_softc *sc = device_get_softc(dev);
200 int dummy;
201
202 if (sc->wd_ev != NULL)
203 EVENTHANDLER_DEREGISTER(watchdog_list, sc->wd_ev);
204 wd_func(dev, 0, &dummy);
205 if (sc->intr_handle)
206 bus_teardown_intr(dev, sc->intr_res, sc->intr_handle);
207 if (sc->intr_res)
208 bus_release_resource(dev, SYS_RES_IRQ, sc->intr_rid,
209 sc->intr_res);
210 return (0);
211 }
212
213 static device_method_t itwd_methods[] = {
214 /* Methods from the device interface */
215 DEVMETHOD(device_probe, itwd_probe),
216 DEVMETHOD(device_attach, itwd_attach),
217 DEVMETHOD(device_detach, itwd_detach),
218
219 /* Terminate method list */
220 { 0, 0 }
221 };
222
223 static driver_t itwd_driver = {
224 "itwd",
225 itwd_methods,
226 sizeof (struct itwd_softc)
227 };
228
229 DRIVER_MODULE(itwd, superio, itwd_driver, NULL, NULL);
230 MODULE_DEPEND(itwd, superio, 1, 1, 1);
231 MODULE_VERSION(itwd, 1);
232