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> | |
e42311d7 DM |
13 | #include <linux/watchdog.h> |
14 | #include <linux/of.h> | |
15 | #include <linux/of_device.h> | |
278aefc5 WVS |
16 | #include <linux/io.h> |
17 | #include <linux/uaccess.h> | |
5a0e3ad6 | 18 | #include <linux/slab.h> |
1da177e4 | 19 | |
1da177e4 LT |
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 | ||
e42311d7 | 45 | MODULE_AUTHOR("David S. Miller <davem@davemloft.net>"); |
1da177e4 LT |
46 | MODULE_DESCRIPTION("Hardware watchdog driver for Sun RIO"); |
47 | MODULE_SUPPORTED_DEVICE("watchdog"); | |
48 | MODULE_LICENSE("GPL"); | |
49 | ||
e25ecd08 DM |
50 | #define DRIVER_NAME "riowd" |
51 | #define PFX DRIVER_NAME ": " | |
1da177e4 | 52 | |
e42311d7 DM |
53 | struct riowd { |
54 | void __iomem *regs; | |
55 | spinlock_t lock; | |
56 | }; | |
57 | ||
58 | static struct riowd *riowd_device; | |
1da177e4 | 59 | |
1da177e4 LT |
60 | #define WDTO_INDEX 0x05 |
61 | ||
62 | static int riowd_timeout = 1; /* in minutes */ | |
63 | module_param(riowd_timeout, int, 0); | |
64 | MODULE_PARM_DESC(riowd_timeout, "Watchdog timeout in minutes"); | |
65 | ||
e42311d7 | 66 | static void riowd_writereg(struct riowd *p, u8 val, int index) |
1da177e4 LT |
67 | { |
68 | unsigned long flags; | |
1da177e4 | 69 | |
e42311d7 DM |
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); | |
1da177e4 LT |
74 | } |
75 | ||
76 | static int riowd_open(struct inode *inode, struct file *filp) | |
77 | { | |
78 | nonseekable_open(inode, filp); | |
79 | return 0; | |
80 | } | |
81 | ||
82 | static int riowd_release(struct inode *inode, struct file *filp) | |
83 | { | |
84 | return 0; | |
85 | } | |
86 | ||
9626dd75 | 87 | static long riowd_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
1da177e4 | 88 | { |
42747d71 | 89 | static const struct watchdog_info info = { |
e42311d7 DM |
90 | .options = WDIOF_SETTIMEOUT, |
91 | .firmware_version = 1, | |
e25ecd08 | 92 | .identity = DRIVER_NAME, |
1da177e4 LT |
93 | }; |
94 | void __user *argp = (void __user *)arg; | |
e42311d7 | 95 | struct riowd *p = riowd_device; |
1da177e4 LT |
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: | |
e42311d7 | 112 | riowd_writereg(p, riowd_timeout, WDTO_INDEX); |
1da177e4 LT |
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) | |
e42311d7 | 120 | riowd_writereg(p, 0, WDTO_INDEX); |
1da177e4 | 121 | else if (options & WDIOS_ENABLECARD) |
e42311d7 | 122 | riowd_writereg(p, riowd_timeout, WDTO_INDEX); |
1da177e4 LT |
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))) | |
e42311d7 | 132 | return -EINVAL; |
1da177e4 | 133 | riowd_timeout = (new_margin + 59) / 60; |
e42311d7 | 134 | riowd_writereg(p, riowd_timeout, WDTO_INDEX); |
1da177e4 LT |
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 | ||
143a2e54 WVS |
147 | static ssize_t riowd_write(struct file *file, const char __user *buf, |
148 | size_t count, loff_t *ppos) | |
1da177e4 | 149 | { |
e42311d7 DM |
150 | struct riowd *p = riowd_device; |
151 | ||
1da177e4 | 152 | if (count) { |
e42311d7 | 153 | riowd_writereg(p, riowd_timeout, WDTO_INDEX); |
1da177e4 LT |
154 | return 1; |
155 | } | |
156 | ||
157 | return 0; | |
158 | } | |
159 | ||
00977a59 | 160 | static const struct file_operations riowd_fops = { |
9626dd75 WVS |
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, | |
1da177e4 LT |
167 | }; |
168 | ||
e42311d7 DM |
169 | static struct miscdevice riowd_miscdev = { |
170 | .minor = WATCHDOG_MINOR, | |
171 | .name = "watchdog", | |
172 | .fops = &riowd_fops | |
173 | }; | |
1da177e4 | 174 | |
2dc11581 | 175 | static int __devinit riowd_probe(struct platform_device *op, |
e42311d7 | 176 | const struct of_device_id *match) |
1da177e4 | 177 | { |
e42311d7 DM |
178 | struct riowd *p; |
179 | int err = -EINVAL; | |
1da177e4 | 180 | |
e42311d7 DM |
181 | if (riowd_device) |
182 | goto out; | |
1da177e4 | 183 | |
e42311d7 DM |
184 | err = -ENOMEM; |
185 | p = kzalloc(sizeof(*p), GFP_KERNEL); | |
186 | if (!p) | |
187 | goto out; | |
1da177e4 | 188 | |
e42311d7 | 189 | spin_lock_init(&p->lock); |
1da177e4 | 190 | |
e25ecd08 | 191 | p->regs = of_ioremap(&op->resource[0], 0, 2, DRIVER_NAME); |
e42311d7 DM |
192 | if (!p->regs) { |
193 | printk(KERN_ERR PFX "Cannot map registers.\n"); | |
194 | goto out_free; | |
1da177e4 | 195 | } |
462265bf TG |
196 | /* Make miscdev useable right away */ |
197 | riowd_device = p; | |
1da177e4 | 198 | |
e42311d7 DM |
199 | err = misc_register(&riowd_miscdev); |
200 | if (err) { | |
201 | printk(KERN_ERR PFX "Cannot register watchdog misc device.\n"); | |
202 | goto out_iounmap; | |
1da177e4 LT |
203 | } |
204 | ||
e42311d7 DM |
205 | printk(KERN_INFO PFX "Hardware watchdog [%i minutes], " |
206 | "regs at %p\n", riowd_timeout, p->regs); | |
1da177e4 | 207 | |
e42311d7 | 208 | dev_set_drvdata(&op->dev, p); |
03717e3d | 209 | return 0; |
1da177e4 | 210 | |
e42311d7 | 211 | out_iounmap: |
462265bf | 212 | riowd_device = NULL; |
e42311d7 | 213 | of_iounmap(&op->resource[0], p->regs, 2); |
1da177e4 | 214 | |
e42311d7 DM |
215 | out_free: |
216 | kfree(p); | |
1da177e4 | 217 | |
e42311d7 DM |
218 | out: |
219 | return err; | |
1da177e4 LT |
220 | } |
221 | ||
2dc11581 | 222 | static int __devexit riowd_remove(struct platform_device *op) |
1da177e4 | 223 | { |
e42311d7 DM |
224 | struct riowd *p = dev_get_drvdata(&op->dev); |
225 | ||
1da177e4 | 226 | misc_deregister(&riowd_miscdev); |
e42311d7 DM |
227 | of_iounmap(&op->resource[0], p->regs, 2); |
228 | kfree(p); | |
229 | ||
230 | return 0; | |
231 | } | |
232 | ||
fd098316 | 233 | static const struct of_device_id riowd_match[] = { |
e42311d7 DM |
234 | { |
235 | .name = "pmc", | |
236 | }, | |
237 | {}, | |
238 | }; | |
239 | MODULE_DEVICE_TABLE(of, riowd_match); | |
240 | ||
241 | static struct of_platform_driver riowd_driver = { | |
4018294b GL |
242 | .driver = { |
243 | .name = DRIVER_NAME, | |
244 | .owner = THIS_MODULE, | |
245 | .of_match_table = riowd_match, | |
246 | }, | |
e42311d7 DM |
247 | .probe = riowd_probe, |
248 | .remove = __devexit_p(riowd_remove), | |
249 | }; | |
250 | ||
251 | static int __init riowd_init(void) | |
252 | { | |
1ab1d63a | 253 | return of_register_platform_driver(&riowd_driver); |
e42311d7 DM |
254 | } |
255 | ||
256 | static void __exit riowd_exit(void) | |
257 | { | |
1ab1d63a | 258 | of_unregister_platform_driver(&riowd_driver); |
1da177e4 LT |
259 | } |
260 | ||
261 | module_init(riowd_init); | |
e42311d7 | 262 | module_exit(riowd_exit); |