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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/sbus/char/riowatchdog.c
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/sbus/char/riowatchdog.c')
-rw-r--r--drivers/sbus/char/riowatchdog.c293
1 files changed, 293 insertions, 0 deletions
diff --git a/drivers/sbus/char/riowatchdog.c b/drivers/sbus/char/riowatchdog.c
new file mode 100644
index 00000000000..d1babff6a53
--- /dev/null
+++ b/drivers/sbus/char/riowatchdog.c
@@ -0,0 +1,293 @@
1/* $Id: riowatchdog.c,v 1.3.2.2 2002/01/23 18:48:02 davem Exp $
2 * riowatchdog.c - driver for hw watchdog inside Super I/O of RIO
3 *
4 * Copyright (C) 2001 David S. Miller (davem@redhat.com)
5 */
6
7#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/types.h>
10#include <linux/fs.h>
11#include <linux/errno.h>
12#include <linux/init.h>
13#include <linux/miscdevice.h>
14
15#include <asm/io.h>
16#include <asm/ebus.h>
17#include <asm/bbc.h>
18#include <asm/oplib.h>
19#include <asm/uaccess.h>
20
21#include <asm/watchdog.h>
22
23/* RIO uses the NatSemi Super I/O power management logical device
24 * as its' watchdog.
25 *
26 * When the watchdog triggers, it asserts a line to the BBC (Boot Bus
27 * Controller) of the machine. The BBC can only be configured to
28 * trigger a power-on reset when the signal is asserted. The BBC
29 * can be configured to ignore the signal entirely as well.
30 *
31 * The only Super I/O device register we care about is at index
32 * 0x05 (WDTO_INDEX) which is the watchdog time-out in minutes (1-255).
33 * If set to zero, this disables the watchdog. When set, the system
34 * must periodically (before watchdog expires) clear (set to zero) and
35 * re-set the watchdog else it will trigger.
36 *
37 * There are two other indexed watchdog registers inside this Super I/O
38 * logical device, but they are unused. The first, at index 0x06 is
39 * the watchdog control and can be used to make the watchdog timer re-set
40 * when the PS/2 mouse or serial lines show activity. The second, at
41 * index 0x07 is merely a sampling of the line from the watchdog to the
42 * BBC.
43 *
44 * The watchdog device generates no interrupts.
45 */
46
47MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
48MODULE_DESCRIPTION("Hardware watchdog driver for Sun RIO");
49MODULE_SUPPORTED_DEVICE("watchdog");
50MODULE_LICENSE("GPL");
51
52#define RIOWD_NAME "pmc"
53#define RIOWD_MINOR 215
54
55static DEFINE_SPINLOCK(riowd_lock);
56
57static void __iomem *bbc_regs;
58static void __iomem *riowd_regs;
59#define WDTO_INDEX 0x05
60
61static int riowd_timeout = 1; /* in minutes */
62module_param(riowd_timeout, int, 0);
63MODULE_PARM_DESC(riowd_timeout, "Watchdog timeout in minutes");
64
65#if 0 /* Currently unused. */
66static u8 riowd_readreg(int index)
67{
68 unsigned long flags;
69 u8 ret;
70
71 spin_lock_irqsave(&riowd_lock, flags);
72 writeb(index, riowd_regs + 0);
73 ret = readb(riowd_regs + 1);
74 spin_unlock_irqrestore(&riowd_lock, flags);
75
76 return ret;
77}
78#endif
79
80static void riowd_writereg(u8 val, int index)
81{
82 unsigned long flags;
83
84 spin_lock_irqsave(&riowd_lock, flags);
85 writeb(index, riowd_regs + 0);
86 writeb(val, riowd_regs + 1);
87 spin_unlock_irqrestore(&riowd_lock, flags);
88}
89
90static void riowd_pingtimer(void)
91{
92 riowd_writereg(riowd_timeout, WDTO_INDEX);
93}
94
95static void riowd_stoptimer(void)
96{
97 u8 val;
98
99 riowd_writereg(0, WDTO_INDEX);
100
101 val = readb(bbc_regs + BBC_WDACTION);
102 val &= ~BBC_WDACTION_RST;
103 writeb(val, bbc_regs + BBC_WDACTION);
104}
105
106static void riowd_starttimer(void)
107{
108 u8 val;
109
110 riowd_writereg(riowd_timeout, WDTO_INDEX);
111
112 val = readb(bbc_regs + BBC_WDACTION);
113 val |= BBC_WDACTION_RST;
114 writeb(val, bbc_regs + BBC_WDACTION);
115}
116
117static int riowd_open(struct inode *inode, struct file *filp)
118{
119 nonseekable_open(inode, filp);
120 return 0;
121}
122
123static int riowd_release(struct inode *inode, struct file *filp)
124{
125 return 0;
126}
127
128static int riowd_ioctl(struct inode *inode, struct file *filp,
129 unsigned int cmd, unsigned long arg)
130{
131 static struct watchdog_info info = {
132 WDIOF_SETTIMEOUT, 0, "Natl. Semiconductor PC97317"
133 };
134 void __user *argp = (void __user *)arg;
135 unsigned int options;
136 int new_margin;
137
138 switch (cmd) {
139 case WDIOC_GETSUPPORT:
140 if (copy_to_user(argp, &info, sizeof(info)))
141 return -EFAULT;
142 break;
143
144 case WDIOC_GETSTATUS:
145 case WDIOC_GETBOOTSTATUS:
146 if (put_user(0, (int __user *)argp))
147 return -EFAULT;
148 break;
149
150 case WDIOC_KEEPALIVE:
151 riowd_pingtimer();
152 break;
153
154 case WDIOC_SETOPTIONS:
155 if (copy_from_user(&options, argp, sizeof(options)))
156 return -EFAULT;
157
158 if (options & WDIOS_DISABLECARD)
159 riowd_stoptimer();
160 else if (options & WDIOS_ENABLECARD)
161 riowd_starttimer();
162 else
163 return -EINVAL;
164
165 break;
166
167 case WDIOC_SETTIMEOUT:
168 if (get_user(new_margin, (int __user *)argp))
169 return -EFAULT;
170 if ((new_margin < 60) || (new_margin > (255 * 60)))
171 return -EINVAL;
172 riowd_timeout = (new_margin + 59) / 60;
173 riowd_pingtimer();
174 /* Fall */
175
176 case WDIOC_GETTIMEOUT:
177 return put_user(riowd_timeout * 60, (int __user *)argp);
178
179 default:
180 return -EINVAL;
181 };
182
183 return 0;
184}
185
186static ssize_t riowd_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
187{
188 if (count) {
189 riowd_pingtimer();
190 return 1;
191 }
192
193 return 0;
194}
195
196static struct file_operations riowd_fops = {
197 .owner = THIS_MODULE,
198 .ioctl = riowd_ioctl,
199 .open = riowd_open,
200 .write = riowd_write,
201 .release = riowd_release,
202};
203
204static struct miscdevice riowd_miscdev = { RIOWD_MINOR, RIOWD_NAME, &riowd_fops };
205
206static int __init riowd_bbc_init(void)
207{
208 struct linux_ebus *ebus = NULL;
209 struct linux_ebus_device *edev = NULL;
210 u8 val;
211
212 for_each_ebus(ebus) {
213 for_each_ebusdev(edev, ebus) {
214 if (!strcmp(edev->prom_name, "bbc"))
215 goto found_bbc;
216 }
217 }
218
219found_bbc:
220 if (!edev)
221 return -ENODEV;
222 bbc_regs = ioremap(edev->resource[0].start, BBC_REGS_SIZE);
223 if (!bbc_regs)
224 return -ENODEV;
225
226 /* Turn it off. */
227 val = readb(bbc_regs + BBC_WDACTION);
228 val &= ~BBC_WDACTION_RST;
229 writeb(val, bbc_regs + BBC_WDACTION);
230
231 return 0;
232}
233
234static int __init riowd_init(void)
235{
236 struct linux_ebus *ebus = NULL;
237 struct linux_ebus_device *edev = NULL;
238
239 for_each_ebus(ebus) {
240 for_each_ebusdev(edev, ebus) {
241 if (!strcmp(edev->prom_name, RIOWD_NAME))
242 goto ebus_done;
243 }
244 }
245
246ebus_done:
247 if (!edev)
248 goto fail;
249
250 riowd_regs = ioremap(edev->resource[0].start, 2);
251 if (riowd_regs == NULL) {
252 printk(KERN_ERR "pmc: Cannot map registers.\n");
253 return -ENODEV;
254 }
255
256 if (riowd_bbc_init()) {
257 printk(KERN_ERR "pmc: Failure initializing BBC config.\n");
258 goto fail;
259 }
260
261 if (misc_register(&riowd_miscdev)) {
262 printk(KERN_ERR "pmc: Cannot register watchdog misc device.\n");
263 goto fail;
264 }
265
266 printk(KERN_INFO "pmc: Hardware watchdog [%i minutes], "
267 "regs at %p\n", riowd_timeout, riowd_regs);
268
269 return 0;
270
271fail:
272 if (riowd_regs) {
273 iounmap(riowd_regs);
274 riowd_regs = NULL;
275 }
276 if (bbc_regs) {
277 iounmap(bbc_regs);
278 bbc_regs = NULL;
279 }
280 return -ENODEV;
281}
282
283static void __exit riowd_cleanup(void)
284{
285 misc_deregister(&riowd_miscdev);
286 iounmap(riowd_regs);
287 riowd_regs = NULL;
288 iounmap(bbc_regs);
289 bbc_regs = NULL;
290}
291
292module_init(riowd_init);
293module_exit(riowd_cleanup);