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Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
957183f3 | 2 | /* riowd.c - driver for hw watchdog inside Super I/O of RIO |
1da177e4 | 3 | * |
e42311d7 | 4 | * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net) |
1da177e4 LT |
5 | */ |
6 | ||
27c766aa JP |
7 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
8 | ||
1da177e4 LT |
9 | #include <linux/kernel.h> |
10 | #include <linux/module.h> | |
11 | #include <linux/types.h> | |
12 | #include <linux/fs.h> | |
13 | #include <linux/errno.h> | |
1da177e4 | 14 | #include <linux/miscdevice.h> |
e42311d7 DM |
15 | #include <linux/watchdog.h> |
16 | #include <linux/of.h> | |
17 | #include <linux/of_device.h> | |
278aefc5 WVS |
18 | #include <linux/io.h> |
19 | #include <linux/uaccess.h> | |
5a0e3ad6 | 20 | #include <linux/slab.h> |
1da177e4 | 21 | |
1da177e4 LT |
22 | |
23 | /* RIO uses the NatSemi Super I/O power management logical device | |
24 | * as its' watchdog. | |
25 | * | |
26 | * When the watchdog triggers, it asserts a line to the BBC (Boot Bus | |
27 | * Controller) of the machine. The BBC can only be configured to | |
28 | * trigger a power-on reset when the signal is asserted. The BBC | |
29 | * can be configured to ignore the signal entirely as well. | |
30 | * | |
31 | * The only Super I/O device register we care about is at index | |
32 | * 0x05 (WDTO_INDEX) which is the watchdog time-out in minutes (1-255). | |
33 | * If set to zero, this disables the watchdog. When set, the system | |
34 | * must periodically (before watchdog expires) clear (set to zero) and | |
35 | * re-set the watchdog else it will trigger. | |
36 | * | |
37 | * There are two other indexed watchdog registers inside this Super I/O | |
38 | * logical device, but they are unused. The first, at index 0x06 is | |
39 | * the watchdog control and can be used to make the watchdog timer re-set | |
40 | * when the PS/2 mouse or serial lines show activity. The second, at | |
41 | * index 0x07 is merely a sampling of the line from the watchdog to the | |
42 | * BBC. | |
43 | * | |
44 | * The watchdog device generates no interrupts. | |
45 | */ | |
46 | ||
e42311d7 | 47 | MODULE_AUTHOR("David S. Miller <davem@davemloft.net>"); |
1da177e4 LT |
48 | MODULE_DESCRIPTION("Hardware watchdog driver for Sun RIO"); |
49 | MODULE_SUPPORTED_DEVICE("watchdog"); | |
50 | MODULE_LICENSE("GPL"); | |
51 | ||
e25ecd08 DM |
52 | #define DRIVER_NAME "riowd" |
53 | #define PFX DRIVER_NAME ": " | |
1da177e4 | 54 | |
e42311d7 DM |
55 | struct riowd { |
56 | void __iomem *regs; | |
57 | spinlock_t lock; | |
58 | }; | |
59 | ||
60 | static struct riowd *riowd_device; | |
1da177e4 | 61 | |
1da177e4 LT |
62 | #define WDTO_INDEX 0x05 |
63 | ||
64 | static int riowd_timeout = 1; /* in minutes */ | |
65 | module_param(riowd_timeout, int, 0); | |
66 | MODULE_PARM_DESC(riowd_timeout, "Watchdog timeout in minutes"); | |
67 | ||
e42311d7 | 68 | static void riowd_writereg(struct riowd *p, u8 val, int index) |
1da177e4 LT |
69 | { |
70 | unsigned long flags; | |
1da177e4 | 71 | |
e42311d7 DM |
72 | spin_lock_irqsave(&p->lock, flags); |
73 | writeb(index, p->regs + 0); | |
74 | writeb(val, p->regs + 1); | |
75 | spin_unlock_irqrestore(&p->lock, flags); | |
1da177e4 LT |
76 | } |
77 | ||
78 | static int riowd_open(struct inode *inode, struct file *filp) | |
79 | { | |
c5bf68fe | 80 | stream_open(inode, filp); |
1da177e4 LT |
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 | 90 | { |
42747d71 | 91 | static const 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); |
bd490f82 | 137 | fallthrough; |
1da177e4 LT |
138 | |
139 | case WDIOC_GETTIMEOUT: | |
140 | return put_user(riowd_timeout * 60, (int __user *)argp); | |
141 | ||
142 | default: | |
143 | return -EINVAL; | |
5e31896a | 144 | } |
1da177e4 LT |
145 | |
146 | return 0; | |
147 | } | |
148 | ||
143a2e54 WVS |
149 | static ssize_t riowd_write(struct file *file, const char __user *buf, |
150 | size_t count, loff_t *ppos) | |
1da177e4 | 151 | { |
e42311d7 DM |
152 | struct riowd *p = riowd_device; |
153 | ||
1da177e4 | 154 | if (count) { |
e42311d7 | 155 | riowd_writereg(p, riowd_timeout, WDTO_INDEX); |
1da177e4 LT |
156 | return 1; |
157 | } | |
158 | ||
159 | return 0; | |
160 | } | |
161 | ||
00977a59 | 162 | static const struct file_operations riowd_fops = { |
9626dd75 WVS |
163 | .owner = THIS_MODULE, |
164 | .llseek = no_llseek, | |
165 | .unlocked_ioctl = riowd_ioctl, | |
b6dfb247 | 166 | .compat_ioctl = compat_ptr_ioctl, |
9626dd75 WVS |
167 | .open = riowd_open, |
168 | .write = riowd_write, | |
169 | .release = riowd_release, | |
1da177e4 LT |
170 | }; |
171 | ||
e42311d7 DM |
172 | static struct miscdevice riowd_miscdev = { |
173 | .minor = WATCHDOG_MINOR, | |
174 | .name = "watchdog", | |
175 | .fops = &riowd_fops | |
176 | }; | |
1da177e4 | 177 | |
2d991a16 | 178 | static int riowd_probe(struct platform_device *op) |
1da177e4 | 179 | { |
e42311d7 DM |
180 | struct riowd *p; |
181 | int err = -EINVAL; | |
1da177e4 | 182 | |
e42311d7 DM |
183 | if (riowd_device) |
184 | goto out; | |
1da177e4 | 185 | |
e42311d7 | 186 | err = -ENOMEM; |
a508e2e6 | 187 | p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL); |
e42311d7 DM |
188 | if (!p) |
189 | goto out; | |
1da177e4 | 190 | |
e42311d7 | 191 | spin_lock_init(&p->lock); |
1da177e4 | 192 | |
e25ecd08 | 193 | p->regs = of_ioremap(&op->resource[0], 0, 2, DRIVER_NAME); |
e42311d7 | 194 | if (!p->regs) { |
27c766aa | 195 | pr_err("Cannot map registers\n"); |
a508e2e6 | 196 | goto out; |
1da177e4 | 197 | } |
462265bf TG |
198 | /* Make miscdev useable right away */ |
199 | riowd_device = p; | |
1da177e4 | 200 | |
e42311d7 DM |
201 | err = misc_register(&riowd_miscdev); |
202 | if (err) { | |
27c766aa | 203 | pr_err("Cannot register watchdog misc device\n"); |
e42311d7 | 204 | goto out_iounmap; |
1da177e4 LT |
205 | } |
206 | ||
27c766aa JP |
207 | pr_info("Hardware watchdog [%i minutes], regs at %p\n", |
208 | riowd_timeout, p->regs); | |
1da177e4 | 209 | |
b94828ff | 210 | platform_set_drvdata(op, p); |
03717e3d | 211 | return 0; |
1da177e4 | 212 | |
e42311d7 | 213 | out_iounmap: |
462265bf | 214 | riowd_device = NULL; |
e42311d7 | 215 | of_iounmap(&op->resource[0], p->regs, 2); |
1da177e4 | 216 | |
e42311d7 DM |
217 | out: |
218 | return err; | |
1da177e4 LT |
219 | } |
220 | ||
4b12b896 | 221 | static int riowd_remove(struct platform_device *op) |
1da177e4 | 222 | { |
b94828ff | 223 | struct riowd *p = platform_get_drvdata(op); |
e42311d7 | 224 | |
1da177e4 | 225 | misc_deregister(&riowd_miscdev); |
e42311d7 | 226 | of_iounmap(&op->resource[0], p->regs, 2); |
e42311d7 DM |
227 | |
228 | return 0; | |
229 | } | |
230 | ||
fd098316 | 231 | static const struct of_device_id riowd_match[] = { |
e42311d7 DM |
232 | { |
233 | .name = "pmc", | |
234 | }, | |
235 | {}, | |
236 | }; | |
237 | MODULE_DEVICE_TABLE(of, riowd_match); | |
238 | ||
1c48a5c9 | 239 | static struct platform_driver riowd_driver = { |
4018294b GL |
240 | .driver = { |
241 | .name = DRIVER_NAME, | |
4018294b GL |
242 | .of_match_table = riowd_match, |
243 | }, | |
e42311d7 | 244 | .probe = riowd_probe, |
82268714 | 245 | .remove = riowd_remove, |
e42311d7 DM |
246 | }; |
247 | ||
b8ec6118 | 248 | module_platform_driver(riowd_driver); |