Loading...
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/watchdog.h>
14#include <linux/of.h>
15#include <linux/of_device.h>
16#include <linux/io.h>
17#include <linux/uaccess.h>
18#include <linux/slab.h>
19
20
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
45MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
46MODULE_DESCRIPTION("Hardware watchdog driver for Sun RIO");
47MODULE_SUPPORTED_DEVICE("watchdog");
48MODULE_LICENSE("GPL");
49
50#define DRIVER_NAME "riowd"
51#define PFX DRIVER_NAME ": "
52
53struct riowd {
54 void __iomem *regs;
55 spinlock_t lock;
56};
57
58static struct riowd *riowd_device;
59
60#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
66static void riowd_writereg(struct riowd *p, u8 val, int index)
67{
68 unsigned long flags;
69
70 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);
74}
75
76static int riowd_open(struct inode *inode, struct file *filp)
77{
78 nonseekable_open(inode, filp);
79 return 0;
80}
81
82static int riowd_release(struct inode *inode, struct file *filp)
83{
84 return 0;
85}
86
87static long riowd_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
88{
89 static const struct watchdog_info info = {
90 .options = WDIOF_SETTIMEOUT,
91 .firmware_version = 1,
92 .identity = DRIVER_NAME,
93 };
94 void __user *argp = (void __user *)arg;
95 struct riowd *p = riowd_device;
96 unsigned int options;
97 int new_margin;
98
99 switch (cmd) {
100 case WDIOC_GETSUPPORT:
101 if (copy_to_user(argp, &info, sizeof(info)))
102 return -EFAULT;
103 break;
104
105 case WDIOC_GETSTATUS:
106 case WDIOC_GETBOOTSTATUS:
107 if (put_user(0, (int __user *)argp))
108 return -EFAULT;
109 break;
110
111 case WDIOC_KEEPALIVE:
112 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
113 break;
114
115 case WDIOC_SETOPTIONS:
116 if (copy_from_user(&options, argp, sizeof(options)))
117 return -EFAULT;
118
119 if (options & WDIOS_DISABLECARD)
120 riowd_writereg(p, 0, WDTO_INDEX);
121 else if (options & WDIOS_ENABLECARD)
122 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
123 else
124 return -EINVAL;
125
126 break;
127
128 case WDIOC_SETTIMEOUT:
129 if (get_user(new_margin, (int __user *)argp))
130 return -EFAULT;
131 if ((new_margin < 60) || (new_margin > (255 * 60)))
132 return -EINVAL;
133 riowd_timeout = (new_margin + 59) / 60;
134 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
135 /* Fall */
136
137 case WDIOC_GETTIMEOUT:
138 return put_user(riowd_timeout * 60, (int __user *)argp);
139
140 default:
141 return -EINVAL;
142 };
143
144 return 0;
145}
146
147static ssize_t riowd_write(struct file *file, const char __user *buf,
148 size_t count, loff_t *ppos)
149{
150 struct riowd *p = riowd_device;
151
152 if (count) {
153 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
154 return 1;
155 }
156
157 return 0;
158}
159
160static const struct file_operations riowd_fops = {
161 .owner = THIS_MODULE,
162 .llseek = no_llseek,
163 .unlocked_ioctl = riowd_ioctl,
164 .open = riowd_open,
165 .write = riowd_write,
166 .release = riowd_release,
167};
168
169static struct miscdevice riowd_miscdev = {
170 .minor = WATCHDOG_MINOR,
171 .name = "watchdog",
172 .fops = &riowd_fops
173};
174
175static int __devinit riowd_probe(struct platform_device *op)
176{
177 struct riowd *p;
178 int err = -EINVAL;
179
180 if (riowd_device)
181 goto out;
182
183 err = -ENOMEM;
184 p = kzalloc(sizeof(*p), GFP_KERNEL);
185 if (!p)
186 goto out;
187
188 spin_lock_init(&p->lock);
189
190 p->regs = of_ioremap(&op->resource[0], 0, 2, DRIVER_NAME);
191 if (!p->regs) {
192 printk(KERN_ERR PFX "Cannot map registers.\n");
193 goto out_free;
194 }
195 /* Make miscdev useable right away */
196 riowd_device = p;
197
198 err = misc_register(&riowd_miscdev);
199 if (err) {
200 printk(KERN_ERR PFX "Cannot register watchdog misc device.\n");
201 goto out_iounmap;
202 }
203
204 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 return 0;
209
210out_iounmap:
211 riowd_device = NULL;
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 platform_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);
228
229 return 0;
230}
231
232static const struct of_device_id riowd_match[] = {
233 {
234 .name = "pmc",
235 },
236 {},
237};
238MODULE_DEVICE_TABLE(of, riowd_match);
239
240static struct platform_driver riowd_driver = {
241 .driver = {
242 .name = DRIVER_NAME,
243 .owner = THIS_MODULE,
244 .of_match_table = riowd_match,
245 },
246 .probe = riowd_probe,
247 .remove = __devexit_p(riowd_remove),
248};
249
250static int __init riowd_init(void)
251{
252 return platform_driver_register(&riowd_driver);
253}
254
255static void __exit riowd_exit(void)
256{
257 platform_driver_unregister(&riowd_driver);
258}
259
260module_init(riowd_init);
261module_exit(riowd_exit);
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/types.h>
11#include <linux/fs.h>
12#include <linux/errno.h>
13#include <linux/miscdevice.h>
14#include <linux/watchdog.h>
15#include <linux/of.h>
16#include <linux/of_device.h>
17#include <linux/io.h>
18#include <linux/uaccess.h>
19#include <linux/slab.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 DRIVER_NAME "riowd"
52#define PFX DRIVER_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 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
88static long riowd_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
89{
90 static const struct watchdog_info info = {
91 .options = WDIOF_SETTIMEOUT,
92 .firmware_version = 1,
93 .identity = DRIVER_NAME,
94 };
95 void __user *argp = (void __user *)arg;
96 struct riowd *p = riowd_device;
97 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:
113 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
114 break;
115
116 case WDIOC_SETOPTIONS:
117 if (copy_from_user(&options, argp, sizeof(options)))
118 return -EFAULT;
119
120 if (options & WDIOS_DISABLECARD)
121 riowd_writereg(p, 0, WDTO_INDEX);
122 else if (options & WDIOS_ENABLECARD)
123 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
124 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)))
133 return -EINVAL;
134 riowd_timeout = (new_margin + 59) / 60;
135 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
136 /* 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
148static ssize_t riowd_write(struct file *file, const char __user *buf,
149 size_t count, loff_t *ppos)
150{
151 struct riowd *p = riowd_device;
152
153 if (count) {
154 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
155 return 1;
156 }
157
158 return 0;
159}
160
161static const struct file_operations riowd_fops = {
162 .owner = THIS_MODULE,
163 .llseek = no_llseek,
164 .unlocked_ioctl = riowd_ioctl,
165 .open = riowd_open,
166 .write = riowd_write,
167 .release = riowd_release,
168};
169
170static struct miscdevice riowd_miscdev = {
171 .minor = WATCHDOG_MINOR,
172 .name = "watchdog",
173 .fops = &riowd_fops
174};
175
176static int riowd_probe(struct platform_device *op)
177{
178 struct riowd *p;
179 int err = -EINVAL;
180
181 if (riowd_device)
182 goto out;
183
184 err = -ENOMEM;
185 p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL);
186 if (!p)
187 goto out;
188
189 spin_lock_init(&p->lock);
190
191 p->regs = of_ioremap(&op->resource[0], 0, 2, DRIVER_NAME);
192 if (!p->regs) {
193 pr_err("Cannot map registers\n");
194 goto out;
195 }
196 /* Make miscdev useable right away */
197 riowd_device = p;
198
199 err = misc_register(&riowd_miscdev);
200 if (err) {
201 pr_err("Cannot register watchdog misc device\n");
202 goto out_iounmap;
203 }
204
205 pr_info("Hardware watchdog [%i minutes], regs at %p\n",
206 riowd_timeout, p->regs);
207
208 platform_set_drvdata(op, p);
209 return 0;
210
211out_iounmap:
212 riowd_device = NULL;
213 of_iounmap(&op->resource[0], p->regs, 2);
214
215out:
216 return err;
217}
218
219static int riowd_remove(struct platform_device *op)
220{
221 struct riowd *p = platform_get_drvdata(op);
222
223 misc_deregister(&riowd_miscdev);
224 of_iounmap(&op->resource[0], p->regs, 2);
225
226 return 0;
227}
228
229static const struct of_device_id riowd_match[] = {
230 {
231 .name = "pmc",
232 },
233 {},
234};
235MODULE_DEVICE_TABLE(of, riowd_match);
236
237static struct platform_driver riowd_driver = {
238 .driver = {
239 .name = DRIVER_NAME,
240 .of_match_table = riowd_match,
241 },
242 .probe = riowd_probe,
243 .remove = riowd_remove,
244};
245
246module_platform_driver(riowd_driver);