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authorDavid S. Miller <davem@davemloft.net>2008-08-29 18:40:24 -0400
committerDavid S. Miller <davem@davemloft.net>2008-08-29 18:40:24 -0400
commit957183f32e136450eb9a4b8eed52dfac46834eed (patch)
tree8c0b70602f1c2043e5bab7337580ca666e70ca99 /drivers/watchdog/riowd.c
parente42311d75107ca78868ded0286b691aad2df1f29 (diff)
riowatchdog: Move under drivers/watchdog
The config stuff was already in drivers/watchdog/Kconfig Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/watchdog/riowd.c')
-rw-r--r--drivers/watchdog/riowd.c259
1 files changed, 259 insertions, 0 deletions
diff --git a/drivers/watchdog/riowd.c b/drivers/watchdog/riowd.c
new file mode 100644
index 000000000000..98bb60ff02f2
--- /dev/null
+++ b/drivers/watchdog/riowd.c
@@ -0,0 +1,259 @@
1/* riowd.c - driver for hw watchdog inside Super I/O of RIO
2 *
3 * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)
4 */
5
6#include <linux/kernel.h>
7#include <linux/module.h>
8#include <linux/types.h>
9#include <linux/fs.h>
10#include <linux/errno.h>
11#include <linux/init.h>
12#include <linux/miscdevice.h>
13#include <linux/smp_lock.h>
14#include <linux/watchdog.h>
15#include <linux/of.h>
16#include <linux/of_device.h>
17
18#include <asm/io.h>
19#include <asm/uaccess.h>
20
21
22/* RIO uses the NatSemi Super I/O power management logical device
23 * as its' watchdog.
24 *
25 * When the watchdog triggers, it asserts a line to the BBC (Boot Bus
26 * Controller) of the machine. The BBC can only be configured to
27 * trigger a power-on reset when the signal is asserted. The BBC
28 * can be configured to ignore the signal entirely as well.
29 *
30 * The only Super I/O device register we care about is at index
31 * 0x05 (WDTO_INDEX) which is the watchdog time-out in minutes (1-255).
32 * If set to zero, this disables the watchdog. When set, the system
33 * must periodically (before watchdog expires) clear (set to zero) and
34 * re-set the watchdog else it will trigger.
35 *
36 * There are two other indexed watchdog registers inside this Super I/O
37 * logical device, but they are unused. The first, at index 0x06 is
38 * the watchdog control and can be used to make the watchdog timer re-set
39 * when the PS/2 mouse or serial lines show activity. The second, at
40 * index 0x07 is merely a sampling of the line from the watchdog to the
41 * BBC.
42 *
43 * The watchdog device generates no interrupts.
44 */
45
46MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
47MODULE_DESCRIPTION("Hardware watchdog driver for Sun RIO");
48MODULE_SUPPORTED_DEVICE("watchdog");
49MODULE_LICENSE("GPL");
50
51#define RIOWD_NAME "pmc"
52#define PFX RIOWD_NAME ": "
53
54struct riowd {
55 void __iomem *regs;
56 spinlock_t lock;
57};
58
59static struct riowd *riowd_device;
60
61#define WDTO_INDEX 0x05
62
63static int riowd_timeout = 1; /* in minutes */
64module_param(riowd_timeout, int, 0);
65MODULE_PARM_DESC(riowd_timeout, "Watchdog timeout in minutes");
66
67static void riowd_writereg(struct riowd *p, u8 val, int index)
68{
69 unsigned long flags;
70
71 spin_lock_irqsave(&p->lock, flags);
72 writeb(index, p->regs + 0);
73 writeb(val, p->regs + 1);
74 spin_unlock_irqrestore(&p->lock, flags);
75}
76
77static int riowd_open(struct inode *inode, struct file *filp)
78{
79 cycle_kernel_lock();
80 nonseekable_open(inode, filp);
81 return 0;
82}
83
84static int riowd_release(struct inode *inode, struct file *filp)
85{
86 return 0;
87}
88
89static int riowd_ioctl(struct inode *inode, struct file *filp,
90 unsigned int cmd, unsigned long arg)
91{
92 static struct watchdog_info info = {
93 .options = WDIOF_SETTIMEOUT,
94 .firmware_version = 1,
95 .identity = "riowd",
96 };
97 void __user *argp = (void __user *)arg;
98 struct riowd *p = riowd_device;
99 unsigned int options;
100 int new_margin;
101
102 switch (cmd) {
103 case WDIOC_GETSUPPORT:
104 if (copy_to_user(argp, &info, sizeof(info)))
105 return -EFAULT;
106 break;
107
108 case WDIOC_GETSTATUS:
109 case WDIOC_GETBOOTSTATUS:
110 if (put_user(0, (int __user *)argp))
111 return -EFAULT;
112 break;
113
114 case WDIOC_KEEPALIVE:
115 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
116 break;
117
118 case WDIOC_SETOPTIONS:
119 if (copy_from_user(&options, argp, sizeof(options)))
120 return -EFAULT;
121
122 if (options & WDIOS_DISABLECARD)
123 riowd_writereg(p, 0, WDTO_INDEX);
124 else if (options & WDIOS_ENABLECARD)
125 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
126 else
127 return -EINVAL;
128
129 break;
130
131 case WDIOC_SETTIMEOUT:
132 if (get_user(new_margin, (int __user *)argp))
133 return -EFAULT;
134 if ((new_margin < 60) || (new_margin > (255 * 60)))
135 return -EINVAL;
136 riowd_timeout = (new_margin + 59) / 60;
137 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
138 /* Fall */
139
140 case WDIOC_GETTIMEOUT:
141 return put_user(riowd_timeout * 60, (int __user *)argp);
142
143 default:
144 return -EINVAL;
145 };
146
147 return 0;
148}
149
150static ssize_t riowd_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
151{
152 struct riowd *p = riowd_device;
153
154 if (count) {
155 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
156 return 1;
157 }
158
159 return 0;
160}
161
162static const struct file_operations riowd_fops = {
163 .owner = THIS_MODULE,
164 .llseek = no_llseek,
165 .ioctl = riowd_ioctl,
166 .open = riowd_open,
167 .write = riowd_write,
168 .release = riowd_release,
169};
170
171static struct miscdevice riowd_miscdev = {
172 .minor = WATCHDOG_MINOR,
173 .name = "watchdog",
174 .fops = &riowd_fops
175};
176
177static int __devinit riowd_probe(struct of_device *op,
178 const struct of_device_id *match)
179{
180 struct riowd *p;
181 int err = -EINVAL;
182
183 if (riowd_device)
184 goto out;
185
186 err = -ENOMEM;
187 p = kzalloc(sizeof(*p), GFP_KERNEL);
188 if (!p)
189 goto out;
190
191 spin_lock_init(&p->lock);
192
193 p->regs = of_ioremap(&op->resource[0], 0, 2, "riowd");
194 if (!p->regs) {
195 printk(KERN_ERR PFX "Cannot map registers.\n");
196 goto out_free;
197 }
198
199 err = misc_register(&riowd_miscdev);
200 if (err) {
201 printk(KERN_ERR PFX "Cannot register watchdog misc device.\n");
202 goto out_iounmap;
203 }
204
205 printk(KERN_INFO PFX "Hardware watchdog [%i minutes], "
206 "regs at %p\n", riowd_timeout, p->regs);
207
208 dev_set_drvdata(&op->dev, p);
209 riowd_device = p;
210 err = 0;
211
212out_iounmap:
213 of_iounmap(&op->resource[0], p->regs, 2);
214
215out_free:
216 kfree(p);
217
218out:
219 return err;
220}
221
222static int __devexit riowd_remove(struct of_device *op)
223{
224 struct riowd *p = dev_get_drvdata(&op->dev);
225
226 misc_deregister(&riowd_miscdev);
227 of_iounmap(&op->resource[0], p->regs, 2);
228 kfree(p);
229
230 return 0;
231}
232
233static struct of_device_id riowd_match[] = {
234 {
235 .name = "pmc",
236 },
237 {},
238};
239MODULE_DEVICE_TABLE(of, riowd_match);
240
241static struct of_platform_driver riowd_driver = {
242 .name = "riowd",
243 .match_table = riowd_match,
244 .probe = riowd_probe,
245 .remove = __devexit_p(riowd_remove),
246};
247
248static int __init riowd_init(void)
249{
250 return of_register_driver(&riowd_driver, &of_bus_type);
251}
252
253static void __exit riowd_exit(void)
254{
255 of_unregister_driver(&riowd_driver);
256}
257
258module_init(riowd_init);
259module_exit(riowd_exit);