Commit | Line | Data |
---|---|---|
957183f3 | 1 | /* riowd.c - driver for hw watchdog inside Super I/O of RIO |
1da177e4 | 2 | * |
e42311d7 | 3 | * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net) |
1da177e4 LT |
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> | |
f29b889e | 13 | #include <linux/smp_lock.h> |
e42311d7 DM |
14 | #include <linux/watchdog.h> |
15 | #include <linux/of.h> | |
16 | #include <linux/of_device.h> | |
1da177e4 LT |
17 | |
18 | #include <asm/io.h> | |
1da177e4 LT |
19 | #include <asm/uaccess.h> |
20 | ||
1da177e4 LT |
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 | ||
e42311d7 | 46 | MODULE_AUTHOR("David S. Miller <davem@davemloft.net>"); |
1da177e4 LT |
47 | MODULE_DESCRIPTION("Hardware watchdog driver for Sun RIO"); |
48 | MODULE_SUPPORTED_DEVICE("watchdog"); | |
49 | MODULE_LICENSE("GPL"); | |
50 | ||
e25ecd08 DM |
51 | #define DRIVER_NAME "riowd" |
52 | #define PFX DRIVER_NAME ": " | |
1da177e4 | 53 | |
e42311d7 DM |
54 | struct riowd { |
55 | void __iomem *regs; | |
56 | spinlock_t lock; | |
57 | }; | |
58 | ||
59 | static struct riowd *riowd_device; | |
1da177e4 | 60 | |
1da177e4 LT |
61 | #define WDTO_INDEX 0x05 |
62 | ||
63 | static int riowd_timeout = 1; /* in minutes */ | |
64 | module_param(riowd_timeout, int, 0); | |
65 | MODULE_PARM_DESC(riowd_timeout, "Watchdog timeout in minutes"); | |
66 | ||
e42311d7 | 67 | static void riowd_writereg(struct riowd *p, u8 val, int index) |
1da177e4 LT |
68 | { |
69 | unsigned long flags; | |
1da177e4 | 70 | |
e42311d7 DM |
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); | |
1da177e4 LT |
75 | } |
76 | ||
77 | static int riowd_open(struct inode *inode, struct file *filp) | |
78 | { | |
f29b889e | 79 | cycle_kernel_lock(); |
1da177e4 LT |
80 | nonseekable_open(inode, filp); |
81 | return 0; | |
82 | } | |
83 | ||
84 | static int riowd_release(struct inode *inode, struct file *filp) | |
85 | { | |
86 | return 0; | |
87 | } | |
88 | ||
9626dd75 | 89 | static long riowd_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
90 | { |
91 | static struct watchdog_info info = { | |
e42311d7 DM |
92 | .options = WDIOF_SETTIMEOUT, |
93 | .firmware_version = 1, | |
e25ecd08 | 94 | .identity = DRIVER_NAME, |
1da177e4 LT |
95 | }; |
96 | void __user *argp = (void __user *)arg; | |
e42311d7 | 97 | struct riowd *p = riowd_device; |
1da177e4 LT |
98 | unsigned int options; |
99 | int new_margin; | |
100 | ||
101 | switch (cmd) { | |
102 | case WDIOC_GETSUPPORT: | |
103 | if (copy_to_user(argp, &info, sizeof(info))) | |
104 | return -EFAULT; | |
105 | break; | |
106 | ||
107 | case WDIOC_GETSTATUS: | |
108 | case WDIOC_GETBOOTSTATUS: | |
109 | if (put_user(0, (int __user *)argp)) | |
110 | return -EFAULT; | |
111 | break; | |
112 | ||
113 | case WDIOC_KEEPALIVE: | |
e42311d7 | 114 | riowd_writereg(p, riowd_timeout, WDTO_INDEX); |
1da177e4 LT |
115 | break; |
116 | ||
117 | case WDIOC_SETOPTIONS: | |
118 | if (copy_from_user(&options, argp, sizeof(options))) | |
119 | return -EFAULT; | |
120 | ||
121 | if (options & WDIOS_DISABLECARD) | |
e42311d7 | 122 | riowd_writereg(p, 0, WDTO_INDEX); |
1da177e4 | 123 | else if (options & WDIOS_ENABLECARD) |
e42311d7 | 124 | riowd_writereg(p, riowd_timeout, WDTO_INDEX); |
1da177e4 LT |
125 | else |
126 | return -EINVAL; | |
127 | ||
128 | break; | |
129 | ||
130 | case WDIOC_SETTIMEOUT: | |
131 | if (get_user(new_margin, (int __user *)argp)) | |
132 | return -EFAULT; | |
133 | if ((new_margin < 60) || (new_margin > (255 * 60))) | |
e42311d7 | 134 | return -EINVAL; |
1da177e4 | 135 | riowd_timeout = (new_margin + 59) / 60; |
e42311d7 | 136 | riowd_writereg(p, riowd_timeout, WDTO_INDEX); |
1da177e4 LT |
137 | /* Fall */ |
138 | ||
139 | case WDIOC_GETTIMEOUT: | |
140 | return put_user(riowd_timeout * 60, (int __user *)argp); | |
141 | ||
142 | default: | |
143 | return -EINVAL; | |
144 | }; | |
145 | ||
146 | return 0; | |
147 | } | |
148 | ||
149 | static ssize_t riowd_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | |
150 | { | |
e42311d7 DM |
151 | struct riowd *p = riowd_device; |
152 | ||
1da177e4 | 153 | if (count) { |
e42311d7 | 154 | riowd_writereg(p, riowd_timeout, WDTO_INDEX); |
1da177e4 LT |
155 | return 1; |
156 | } | |
157 | ||
158 | return 0; | |
159 | } | |
160 | ||
00977a59 | 161 | static const struct file_operations riowd_fops = { |
9626dd75 WVS |
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, | |
1da177e4 LT |
168 | }; |
169 | ||
e42311d7 DM |
170 | static struct miscdevice riowd_miscdev = { |
171 | .minor = WATCHDOG_MINOR, | |
172 | .name = "watchdog", | |
173 | .fops = &riowd_fops | |
174 | }; | |
1da177e4 | 175 | |
e42311d7 DM |
176 | static int __devinit riowd_probe(struct of_device *op, |
177 | const struct of_device_id *match) | |
1da177e4 | 178 | { |
e42311d7 DM |
179 | struct riowd *p; |
180 | int err = -EINVAL; | |
1da177e4 | 181 | |
e42311d7 DM |
182 | if (riowd_device) |
183 | goto out; | |
1da177e4 | 184 | |
e42311d7 DM |
185 | err = -ENOMEM; |
186 | p = kzalloc(sizeof(*p), GFP_KERNEL); | |
187 | if (!p) | |
188 | goto out; | |
1da177e4 | 189 | |
e42311d7 | 190 | spin_lock_init(&p->lock); |
1da177e4 | 191 | |
e25ecd08 | 192 | p->regs = of_ioremap(&op->resource[0], 0, 2, DRIVER_NAME); |
e42311d7 DM |
193 | if (!p->regs) { |
194 | printk(KERN_ERR PFX "Cannot map registers.\n"); | |
195 | goto out_free; | |
1da177e4 LT |
196 | } |
197 | ||
e42311d7 DM |
198 | err = misc_register(&riowd_miscdev); |
199 | if (err) { | |
200 | printk(KERN_ERR PFX "Cannot register watchdog misc device.\n"); | |
201 | goto out_iounmap; | |
1da177e4 LT |
202 | } |
203 | ||
e42311d7 DM |
204 | printk(KERN_INFO PFX "Hardware watchdog [%i minutes], " |
205 | "regs at %p\n", riowd_timeout, p->regs); | |
1da177e4 | 206 | |
e42311d7 DM |
207 | dev_set_drvdata(&op->dev, p); |
208 | riowd_device = p; | |
209 | err = 0; | |
1da177e4 | 210 | |
e42311d7 DM |
211 | out_iounmap: |
212 | of_iounmap(&op->resource[0], p->regs, 2); | |
1da177e4 | 213 | |
e42311d7 DM |
214 | out_free: |
215 | kfree(p); | |
1da177e4 | 216 | |
e42311d7 DM |
217 | out: |
218 | return err; | |
1da177e4 LT |
219 | } |
220 | ||
e42311d7 | 221 | static int __devexit riowd_remove(struct of_device *op) |
1da177e4 | 222 | { |
e42311d7 DM |
223 | struct riowd *p = dev_get_drvdata(&op->dev); |
224 | ||
1da177e4 | 225 | misc_deregister(&riowd_miscdev); |
e42311d7 DM |
226 | of_iounmap(&op->resource[0], p->regs, 2); |
227 | kfree(p); | |
228 | ||
229 | return 0; | |
230 | } | |
231 | ||
fd098316 | 232 | static const struct of_device_id riowd_match[] = { |
e42311d7 DM |
233 | { |
234 | .name = "pmc", | |
235 | }, | |
236 | {}, | |
237 | }; | |
238 | MODULE_DEVICE_TABLE(of, riowd_match); | |
239 | ||
240 | static struct of_platform_driver riowd_driver = { | |
e25ecd08 | 241 | .name = DRIVER_NAME, |
e42311d7 DM |
242 | .match_table = riowd_match, |
243 | .probe = riowd_probe, | |
244 | .remove = __devexit_p(riowd_remove), | |
245 | }; | |
246 | ||
247 | static int __init riowd_init(void) | |
248 | { | |
249 | return of_register_driver(&riowd_driver, &of_bus_type); | |
250 | } | |
251 | ||
252 | static void __exit riowd_exit(void) | |
253 | { | |
254 | of_unregister_driver(&riowd_driver); | |
1da177e4 LT |
255 | } |
256 | ||
257 | module_init(riowd_init); | |
e42311d7 | 258 | module_exit(riowd_exit); |