blob: 1e8f02f440e6f5ee6db426f0e0d9863731b686b0 [file] [log] [blame]
David S. Miller957183f2008-08-29 15:40:24 -07001/* riowd.c - driver for hw watchdog inside Super I/O of RIO
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 *
David S. Millere42311d2008-08-29 15:35:59 -07003 * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 */
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>
Arnd Bergmannf29b8892008-05-20 19:16:35 +020013#include <linux/smp_lock.h>
David S. Millere42311d2008-08-29 15:35:59 -070014#include <linux/watchdog.h>
15#include <linux/of.h>
16#include <linux/of_device.h>
Wim Van Sebroeck278aefc2009-03-18 09:09:26 +000017#include <linux/io.h>
18#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
21/* RIO uses the NatSemi Super I/O power management logical device
22 * as its' watchdog.
23 *
24 * When the watchdog triggers, it asserts a line to the BBC (Boot Bus
25 * Controller) of the machine. The BBC can only be configured to
26 * trigger a power-on reset when the signal is asserted. The BBC
27 * can be configured to ignore the signal entirely as well.
28 *
29 * The only Super I/O device register we care about is at index
30 * 0x05 (WDTO_INDEX) which is the watchdog time-out in minutes (1-255).
31 * If set to zero, this disables the watchdog. When set, the system
32 * must periodically (before watchdog expires) clear (set to zero) and
33 * re-set the watchdog else it will trigger.
34 *
35 * There are two other indexed watchdog registers inside this Super I/O
36 * logical device, but they are unused. The first, at index 0x06 is
37 * the watchdog control and can be used to make the watchdog timer re-set
38 * when the PS/2 mouse or serial lines show activity. The second, at
39 * index 0x07 is merely a sampling of the line from the watchdog to the
40 * BBC.
41 *
42 * The watchdog device generates no interrupts.
43 */
44
David S. Millere42311d2008-08-29 15:35:59 -070045MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
Linus Torvalds1da177e2005-04-16 15:20:36 -070046MODULE_DESCRIPTION("Hardware watchdog driver for Sun RIO");
47MODULE_SUPPORTED_DEVICE("watchdog");
48MODULE_LICENSE("GPL");
49
David S. Millere25ecd02008-08-29 15:42:31 -070050#define DRIVER_NAME "riowd"
51#define PFX DRIVER_NAME ": "
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
David S. Millere42311d2008-08-29 15:35:59 -070053struct riowd {
54 void __iomem *regs;
55 spinlock_t lock;
56};
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
David S. Millere42311d2008-08-29 15:35:59 -070058static struct riowd *riowd_device;
59
Linus Torvalds1da177e2005-04-16 15:20:36 -070060#define WDTO_INDEX 0x05
61
62static int riowd_timeout = 1; /* in minutes */
63module_param(riowd_timeout, int, 0);
64MODULE_PARM_DESC(riowd_timeout, "Watchdog timeout in minutes");
65
David S. Millere42311d2008-08-29 15:35:59 -070066static void riowd_writereg(struct riowd *p, u8 val, int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067{
68 unsigned long flags;
69
David S. Millere42311d2008-08-29 15:35:59 -070070 spin_lock_irqsave(&p->lock, flags);
71 writeb(index, p->regs + 0);
72 writeb(val, p->regs + 1);
73 spin_unlock_irqrestore(&p->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074}
75
76static int riowd_open(struct inode *inode, struct file *filp)
77{
Arnd Bergmannf29b8892008-05-20 19:16:35 +020078 cycle_kernel_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 nonseekable_open(inode, filp);
80 return 0;
81}
82
83static int riowd_release(struct inode *inode, struct file *filp)
84{
85 return 0;
86}
87
Wim Van Sebroeck9626dd72009-01-21 11:13:11 +000088static long riowd_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -070089{
90 static struct watchdog_info info = {
David S. Millere42311d2008-08-29 15:35:59 -070091 .options = WDIOF_SETTIMEOUT,
92 .firmware_version = 1,
David S. Millere25ecd02008-08-29 15:42:31 -070093 .identity = DRIVER_NAME,
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 };
95 void __user *argp = (void __user *)arg;
David S. Millere42311d2008-08-29 15:35:59 -070096 struct riowd *p = riowd_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 unsigned int options;
98 int new_margin;
99
100 switch (cmd) {
101 case WDIOC_GETSUPPORT:
102 if (copy_to_user(argp, &info, sizeof(info)))
103 return -EFAULT;
104 break;
105
106 case WDIOC_GETSTATUS:
107 case WDIOC_GETBOOTSTATUS:
108 if (put_user(0, (int __user *)argp))
109 return -EFAULT;
110 break;
111
112 case WDIOC_KEEPALIVE:
David S. Millere42311d2008-08-29 15:35:59 -0700113 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 break;
115
116 case WDIOC_SETOPTIONS:
117 if (copy_from_user(&options, argp, sizeof(options)))
118 return -EFAULT;
119
120 if (options & WDIOS_DISABLECARD)
David S. Millere42311d2008-08-29 15:35:59 -0700121 riowd_writereg(p, 0, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 else if (options & WDIOS_ENABLECARD)
David S. Millere42311d2008-08-29 15:35:59 -0700123 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 else
125 return -EINVAL;
126
127 break;
128
129 case WDIOC_SETTIMEOUT:
130 if (get_user(new_margin, (int __user *)argp))
131 return -EFAULT;
132 if ((new_margin < 60) || (new_margin > (255 * 60)))
David S. Millere42311d2008-08-29 15:35:59 -0700133 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 riowd_timeout = (new_margin + 59) / 60;
David S. Millere42311d2008-08-29 15:35:59 -0700135 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 /* Fall */
137
138 case WDIOC_GETTIMEOUT:
139 return put_user(riowd_timeout * 60, (int __user *)argp);
140
141 default:
142 return -EINVAL;
143 };
144
145 return 0;
146}
147
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000148static ssize_t riowd_write(struct file *file, const char __user *buf,
149 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150{
David S. Millere42311d2008-08-29 15:35:59 -0700151 struct riowd *p = riowd_device;
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 if (count) {
David S. Millere42311d2008-08-29 15:35:59 -0700154 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 return 1;
156 }
157
158 return 0;
159}
160
Arjan van de Ven00977a52007-02-12 00:55:34 -0800161static const struct file_operations riowd_fops = {
Wim Van Sebroeck9626dd72009-01-21 11:13:11 +0000162 .owner = THIS_MODULE,
163 .llseek = no_llseek,
164 .unlocked_ioctl = riowd_ioctl,
165 .open = riowd_open,
166 .write = riowd_write,
167 .release = riowd_release,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168};
169
David S. Millere42311d2008-08-29 15:35:59 -0700170static struct miscdevice riowd_miscdev = {
171 .minor = WATCHDOG_MINOR,
172 .name = "watchdog",
173 .fops = &riowd_fops
174};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
David S. Millere42311d2008-08-29 15:35:59 -0700176static int __devinit riowd_probe(struct of_device *op,
177 const struct of_device_id *match)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178{
David S. Millere42311d2008-08-29 15:35:59 -0700179 struct riowd *p;
180 int err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
David S. Millere42311d2008-08-29 15:35:59 -0700182 if (riowd_device)
183 goto out;
184
185 err = -ENOMEM;
186 p = kzalloc(sizeof(*p), GFP_KERNEL);
187 if (!p)
188 goto out;
189
190 spin_lock_init(&p->lock);
191
David S. Millere25ecd02008-08-29 15:42:31 -0700192 p->regs = of_ioremap(&op->resource[0], 0, 2, DRIVER_NAME);
David S. Millere42311d2008-08-29 15:35:59 -0700193 if (!p->regs) {
194 printk(KERN_ERR PFX "Cannot map registers.\n");
195 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 }
197
David S. Millere42311d2008-08-29 15:35:59 -0700198 err = misc_register(&riowd_miscdev);
199 if (err) {
200 printk(KERN_ERR PFX "Cannot register watchdog misc device.\n");
201 goto out_iounmap;
202 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
David S. Millere42311d2008-08-29 15:35:59 -0700204 printk(KERN_INFO PFX "Hardware watchdog [%i minutes], "
205 "regs at %p\n", riowd_timeout, p->regs);
206
207 dev_set_drvdata(&op->dev, p);
208 riowd_device = p;
209 err = 0;
210
211out_iounmap:
212 of_iounmap(&op->resource[0], p->regs, 2);
213
214out_free:
215 kfree(p);
216
217out:
218 return err;
219}
220
221static int __devexit riowd_remove(struct of_device *op)
222{
223 struct riowd *p = dev_get_drvdata(&op->dev);
224
225 misc_deregister(&riowd_miscdev);
226 of_iounmap(&op->resource[0], p->regs, 2);
227 kfree(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
229 return 0;
230}
231
David S. Millerfd098312008-08-31 01:23:17 -0700232static const struct of_device_id riowd_match[] = {
David S. Millere42311d2008-08-29 15:35:59 -0700233 {
234 .name = "pmc",
235 },
236 {},
237};
238MODULE_DEVICE_TABLE(of, riowd_match);
239
240static struct of_platform_driver riowd_driver = {
David S. Millere25ecd02008-08-29 15:42:31 -0700241 .name = DRIVER_NAME,
David S. Millere42311d2008-08-29 15:35:59 -0700242 .match_table = riowd_match,
243 .probe = riowd_probe,
244 .remove = __devexit_p(riowd_remove),
245};
246
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247static int __init riowd_init(void)
248{
David S. Millere42311d2008-08-29 15:35:59 -0700249 return of_register_driver(&riowd_driver, &of_bus_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250}
251
David S. Millere42311d2008-08-29 15:35:59 -0700252static void __exit riowd_exit(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253{
David S. Millere42311d2008-08-29 15:35:59 -0700254 of_unregister_driver(&riowd_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255}
256
257module_init(riowd_init);
David S. Millere42311d2008-08-29 15:35:59 -0700258module_exit(riowd_exit);