blob: 09cb1833ea27a754be67934c98d12396f3f623a7 [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017
18#include <asm/io.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <asm/uaccess.h>
20
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
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
David S. Millere42311d2008-08-29 15:35:59 -070046MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
Linus Torvalds1da177e2005-04-16 15:20:36 -070047MODULE_DESCRIPTION("Hardware watchdog driver for Sun RIO");
48MODULE_SUPPORTED_DEVICE("watchdog");
49MODULE_LICENSE("GPL");
50
David S. Millere25ecd02008-08-29 15:42:31 -070051#define DRIVER_NAME "riowd"
52#define PFX DRIVER_NAME ": "
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
David S. Millere42311d2008-08-29 15:35:59 -070054struct riowd {
55 void __iomem *regs;
56 spinlock_t lock;
57};
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
David S. Millere42311d2008-08-29 15:35:59 -070059static struct riowd *riowd_device;
60
Linus Torvalds1da177e2005-04-16 15:20:36 -070061#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
David S. Millere42311d2008-08-29 15:35:59 -070067static void riowd_writereg(struct riowd *p, u8 val, int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -070068{
69 unsigned long flags;
70
David S. Millere42311d2008-08-29 15:35:59 -070071 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075}
76
77static int riowd_open(struct inode *inode, struct file *filp)
78{
Arnd Bergmannf29b8892008-05-20 19:16:35 +020079 cycle_kernel_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 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 = {
David S. Millere42311d2008-08-29 15:35:59 -070093 .options = WDIOF_SETTIMEOUT,
94 .firmware_version = 1,
David S. Millere25ecd02008-08-29 15:42:31 -070095 .identity = DRIVER_NAME,
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 };
97 void __user *argp = (void __user *)arg;
David S. Millere42311d2008-08-29 15:35:59 -070098 struct riowd *p = riowd_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 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:
David S. Millere42311d2008-08-29 15:35:59 -0700115 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 break;
117
118 case WDIOC_SETOPTIONS:
119 if (copy_from_user(&options, argp, sizeof(options)))
120 return -EFAULT;
121
122 if (options & WDIOS_DISABLECARD)
David S. Millere42311d2008-08-29 15:35:59 -0700123 riowd_writereg(p, 0, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 else if (options & WDIOS_ENABLECARD)
David S. Millere42311d2008-08-29 15:35:59 -0700125 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 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)))
David S. Millere42311d2008-08-29 15:35:59 -0700135 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 riowd_timeout = (new_margin + 59) / 60;
David S. Millere42311d2008-08-29 15:35:59 -0700137 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 /* 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{
David S. Millere42311d2008-08-29 15:35:59 -0700152 struct riowd *p = riowd_device;
153
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 if (count) {
David S. Millere42311d2008-08-29 15:35:59 -0700155 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 return 1;
157 }
158
159 return 0;
160}
161
Arjan van de Ven00977a52007-02-12 00:55:34 -0800162static const struct file_operations riowd_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 .owner = THIS_MODULE,
David S. Millere42311d2008-08-29 15:35:59 -0700164 .llseek = no_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 .ioctl = riowd_ioctl,
166 .open = riowd_open,
167 .write = riowd_write,
168 .release = riowd_release,
169};
170
David S. Millere42311d2008-08-29 15:35:59 -0700171static struct miscdevice riowd_miscdev = {
172 .minor = WATCHDOG_MINOR,
173 .name = "watchdog",
174 .fops = &riowd_fops
175};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
David S. Millere42311d2008-08-29 15:35:59 -0700177static int __devinit riowd_probe(struct of_device *op,
178 const struct of_device_id *match)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179{
David S. Millere42311d2008-08-29 15:35:59 -0700180 struct riowd *p;
181 int err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
David S. Millere42311d2008-08-29 15:35:59 -0700183 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
David S. Millere25ecd02008-08-29 15:42:31 -0700193 p->regs = of_ioremap(&op->resource[0], 0, 2, DRIVER_NAME);
David S. Millere42311d2008-08-29 15:35:59 -0700194 if (!p->regs) {
195 printk(KERN_ERR PFX "Cannot map registers.\n");
196 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 }
198
David S. Millere42311d2008-08-29 15:35:59 -0700199 err = misc_register(&riowd_miscdev);
200 if (err) {
201 printk(KERN_ERR PFX "Cannot register watchdog misc device.\n");
202 goto out_iounmap;
203 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
David S. Millere42311d2008-08-29 15:35:59 -0700205 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
230 return 0;
231}
232
David S. Millerfd098312008-08-31 01:23:17 -0700233static const struct of_device_id riowd_match[] = {
David S. Millere42311d2008-08-29 15:35:59 -0700234 {
235 .name = "pmc",
236 },
237 {},
238};
239MODULE_DEVICE_TABLE(of, riowd_match);
240
241static struct of_platform_driver riowd_driver = {
David S. Millere25ecd02008-08-29 15:42:31 -0700242 .name = DRIVER_NAME,
David S. Millere42311d2008-08-29 15:35:59 -0700243 .match_table = riowd_match,
244 .probe = riowd_probe,
245 .remove = __devexit_p(riowd_remove),
246};
247
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248static int __init riowd_init(void)
249{
David S. Millere42311d2008-08-29 15:35:59 -0700250 return of_register_driver(&riowd_driver, &of_bus_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251}
252
David S. Millere42311d2008-08-29 15:35:59 -0700253static void __exit riowd_exit(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254{
David S. Millere42311d2008-08-29 15:35:59 -0700255 of_unregister_driver(&riowd_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256}
257
258module_init(riowd_init);
David S. Millere42311d2008-08-29 15:35:59 -0700259module_exit(riowd_exit);