1 /* $NetBSD: wdog.c,v 1.18 2014/07/25 08:10:34 dholland Exp $ */
2
3 /*-
4 * Copyright (C) 2000 SAITOH Masanobu. All rights reserved.
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 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: wdog.c,v 1.18 2014/07/25 08:10:34 dholland Exp $");
31
32 #include <sys/param.h>
33 #include <sys/buf.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/uio.h>
37 #include <sys/device.h>
38 #include <sys/fcntl.h>
39 #include <sys/ioctl.h>
40 #include <sys/malloc.h>
41 #include <sys/proc.h>
42 #include <sys/syslog.h>
43 #include <sys/conf.h>
44
45 #include <machine/cpu.h>
46 #include <machine/intr.h>
47
48 #include <sh3/frame.h>
49 #include <sh3/wdtreg.h>
50 #include <sh3/wdogvar.h>
51 #include <sh3/exception.h>
52
53 struct wdog_softc {
54 device_t sc_dev;
55 int flags;
56 };
57
58 static int wdogmatch(device_t, cfdata_t, void *);
59 static void wdogattach(device_t, device_t, void *);
60 static int wdogintr(void *);
61
62 CFATTACH_DECL_NEW(wdog, sizeof(struct wdog_softc),
63 wdogmatch, wdogattach, NULL, NULL);
64
65 extern struct cfdriver wdog_cd;
66
67 dev_type_open(wdogopen);
68 dev_type_close(wdogclose);
69 dev_type_ioctl(wdogioctl);
70
71 const struct cdevsw wdog_cdevsw = {
72 .d_open = wdogopen,
73 .d_close = wdogclose,
74 .d_read = noread,
75 .d_write = nowrite,
76 .d_ioctl = wdogioctl,
77 .d_stop = nostop,
78 .d_tty = notty,
79 .d_poll = nopoll,
80 .d_mmap = nommap,
81 .d_kqfilter = nokqfilter,
82 .d_discard = nodiscard,
83 .d_flag = 0
84 };
85
86 void
wdog_wr_cnt(unsigned char x)87 wdog_wr_cnt(unsigned char x)
88 {
89
90 SHREG_WTCNT_W = WTCNT_W_M | (unsigned short) x;
91 }
92
93 void
wdog_wr_csr(unsigned char x)94 wdog_wr_csr(unsigned char x)
95 {
96
97 SHREG_WTCSR_W = WTCSR_W_M | (unsigned short) x;
98 }
99
100 static int
wdogmatch(device_t parent,cfdata_t cfp,void * aux)101 wdogmatch(device_t parent, cfdata_t cfp, void *aux)
102 {
103
104 if (strcmp(cfp->cf_name, "wdog"))
105 return (0);
106
107 return (1);
108 }
109
110 /*
111 * functions for probeing.
112 */
113 /* ARGSUSED */
114 static void
wdogattach(device_t parent,device_t self,void * aux)115 wdogattach(device_t parent, device_t self, void *aux)
116 {
117 struct wdog_softc *sc;
118
119 sc = device_private(self);
120 sc->sc_dev = self;
121
122 aprint_naive("\n");
123 aprint_normal(": internal watchdog timer\n");
124
125 wdog_wr_csr(WTCSR_WT | WTCSR_CKS_4096); /* default to wt mode */
126
127 intc_intr_establish(SH_INTEVT_WDT_ITI, IST_LEVEL, IPL_SOFTCLOCK,
128 wdogintr, 0);
129 }
130
131 /*ARGSUSED*/
132 int
wdogopen(dev_t dev,int flag,int mode,struct lwp * l)133 wdogopen(dev_t dev, int flag, int mode, struct lwp *l)
134 {
135 struct wdog_softc *sc;
136
137 sc = device_lookup_private(&wdog_cd, minor(dev));
138 if (sc == NULL)
139 return (ENXIO);
140
141 if (sc->flags & WDOGF_OPEN)
142 return (EBUSY);
143 sc->flags |= WDOGF_OPEN;
144 return (0);
145 }
146
147 /*ARGSUSED*/
148 int
wdogclose(dev_t dev,int flag,int mode,struct lwp * l)149 wdogclose(dev_t dev, int flag, int mode, struct lwp *l)
150 {
151 struct wdog_softc *sc;
152
153 sc = device_lookup_private(&wdog_cd, minor(dev));
154
155 if (sc->flags & WDOGF_OPEN)
156 sc->flags = 0;
157
158 return (0);
159 }
160
161 extern unsigned int maxwdog;
162
163 /*ARGSUSED*/
164 int
wdogioctl(dev_t dev,u_long cmd,void * data,int flag,struct lwp * l)165 wdogioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
166 {
167 int error = 0;
168 int request;
169
170 switch (cmd) {
171 case SIOWDOGSETMODE:
172 request = *(int *)data;
173
174 switch (request) {
175 case WDOGM_RESET:
176 wdog_wr_csr(SHREG_WTCSR_R | WTCSR_WT);
177 break;
178 case WDOGM_INTR:
179 wdog_wr_csr(SHREG_WTCSR_R & ~WTCSR_WT);
180 break;
181 default:
182 error = EINVAL;
183 break;
184 }
185 break;
186 case SIORESETWDOG:
187 wdog_wr_cnt(0); /* reset to zero */
188 break;
189 case SIOSTARTWDOG:
190 wdog_wr_csr(WTCSR_WT | WTCSR_CKS_4096);
191 wdog_wr_cnt(0); /* reset to zero */
192 wdog_wr_csr(SHREG_WTCSR_R | WTCSR_TME); /* start!!! */
193 break;
194 case SIOSTOPWDOG:
195 wdog_wr_csr(SHREG_WTCSR_R & ~WTCSR_TME); /* stop */
196 break;
197 case SIOSETWDOG:
198 request = *(int *)data;
199
200 if (request > 2) {
201 error = EINVAL;
202 break;
203 }
204 break;
205 default:
206 error = EINVAL;
207 break;
208 }
209
210 return (error);
211 }
212
213 int
wdogintr(void * arg)214 wdogintr(void *arg)
215 {
216 struct trapframe *frame = arg;
217
218 wdog_wr_csr(SHREG_WTCSR_R & ~WTCSR_IOVF); /* clear overflow bit */
219 wdog_wr_cnt(0); /* reset to zero */
220 printf("wdog trapped: spc = %x\n", frame->tf_spc);
221
222 return (0);
223 }
224