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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
Joe Perches27c766a2012-02-15 15:06:19 -08006#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
Linus Torvalds1da177e2005-04-16 15:20:36 -07008#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/types.h>
11#include <linux/fs.h>
12#include <linux/errno.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/miscdevice.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>
Wim Van Sebroeck278aefc2009-03-18 09:09:26 +000017#include <linux/io.h>
18#include <linux/uaccess.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090019#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
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{
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
Wim Van Sebroeck9626dd72009-01-21 11:13:11 +000088static long riowd_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -070089{
Wim Van Sebroeck42747d72009-12-26 18:55:22 +000090 static const struct watchdog_info info = {
David S. Millere42311d2008-08-29 15:35:59 -070091 .options = WDIOF_SETTIMEOUT,
92 .firmware_version = 1,
David S. Millere25ecd02008-08-29 15:42:31 -070093 .identity = DRIVER_NAME,
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 };
95 void __user *argp = (void __user *)arg;
David S. Millere42311d2008-08-29 15:35:59 -070096 struct riowd *p = riowd_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 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:
David S. Millere42311d2008-08-29 15:35:59 -0700113 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 break;
115
116 case WDIOC_SETOPTIONS:
117 if (copy_from_user(&options, argp, sizeof(options)))
118 return -EFAULT;
119
120 if (options & WDIOS_DISABLECARD)
David S. Millere42311d2008-08-29 15:35:59 -0700121 riowd_writereg(p, 0, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 else if (options & WDIOS_ENABLECARD)
David S. Millere42311d2008-08-29 15:35:59 -0700123 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 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)))
David S. Millere42311d2008-08-29 15:35:59 -0700133 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 riowd_timeout = (new_margin + 59) / 60;
David S. Millere42311d2008-08-29 15:35:59 -0700135 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 /* 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
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000148static ssize_t riowd_write(struct file *file, const char __user *buf,
149 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150{
David S. Millere42311d2008-08-29 15:35:59 -0700151 struct riowd *p = riowd_device;
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 if (count) {
David S. Millere42311d2008-08-29 15:35:59 -0700154 riowd_writereg(p, riowd_timeout, WDTO_INDEX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 return 1;
156 }
157
158 return 0;
159}
160
Arjan van de Ven00977a52007-02-12 00:55:34 -0800161static const struct file_operations riowd_fops = {
Wim Van Sebroeck9626dd72009-01-21 11:13:11 +0000162 .owner = THIS_MODULE,
163 .llseek = no_llseek,
164 .unlocked_ioctl = riowd_ioctl,
165 .open = riowd_open,
166 .write = riowd_write,
167 .release = riowd_release,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168};
169
David S. Millere42311d2008-08-29 15:35:59 -0700170static struct miscdevice riowd_miscdev = {
171 .minor = WATCHDOG_MINOR,
172 .name = "watchdog",
173 .fops = &riowd_fops
174};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
Bill Pemberton2d991a12012-11-19 13:21:41 -0500176static int riowd_probe(struct platform_device *op)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177{
David S. Millere42311d2008-08-29 15:35:59 -0700178 struct riowd *p;
179 int err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
David S. Millere42311d2008-08-29 15:35:59 -0700181 if (riowd_device)
182 goto out;
183
184 err = -ENOMEM;
Jingoo Hana508e2e2013-04-30 14:01:59 +0900185 p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL);
David S. Millere42311d2008-08-29 15:35:59 -0700186 if (!p)
187 goto out;
188
189 spin_lock_init(&p->lock);
190
David S. Millere25ecd02008-08-29 15:42:31 -0700191 p->regs = of_ioremap(&op->resource[0], 0, 2, DRIVER_NAME);
David S. Millere42311d2008-08-29 15:35:59 -0700192 if (!p->regs) {
Joe Perches27c766a2012-02-15 15:06:19 -0800193 pr_err("Cannot map registers\n");
Jingoo Hana508e2e2013-04-30 14:01:59 +0900194 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 }
Thomas Gleixner462265b2009-11-02 21:16:28 -0800196 /* Make miscdev useable right away */
197 riowd_device = p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
David S. Millere42311d2008-08-29 15:35:59 -0700199 err = misc_register(&riowd_miscdev);
200 if (err) {
Joe Perches27c766a2012-02-15 15:06:19 -0800201 pr_err("Cannot register watchdog misc device\n");
David S. Millere42311d2008-08-29 15:35:59 -0700202 goto out_iounmap;
203 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
Joe Perches27c766a2012-02-15 15:06:19 -0800205 pr_info("Hardware watchdog [%i minutes], regs at %p\n",
206 riowd_timeout, p->regs);
David S. Millere42311d2008-08-29 15:35:59 -0700207
Jingoo Hanb94828f2013-05-23 19:44:38 +0900208 platform_set_drvdata(op, p);
Thomas Gleixner03717e32009-10-14 01:18:26 -0700209 return 0;
David S. Millere42311d2008-08-29 15:35:59 -0700210
211out_iounmap:
Thomas Gleixner462265b2009-11-02 21:16:28 -0800212 riowd_device = NULL;
David S. Millere42311d2008-08-29 15:35:59 -0700213 of_iounmap(&op->resource[0], p->regs, 2);
214
David S. Millere42311d2008-08-29 15:35:59 -0700215out:
216 return err;
217}
218
Bill Pemberton4b12b892012-11-19 13:26:24 -0500219static int riowd_remove(struct platform_device *op)
David S. Millere42311d2008-08-29 15:35:59 -0700220{
Jingoo Hanb94828f2013-05-23 19:44:38 +0900221 struct riowd *p = platform_get_drvdata(op);
David S. Millere42311d2008-08-29 15:35:59 -0700222
223 misc_deregister(&riowd_miscdev);
224 of_iounmap(&op->resource[0], p->regs, 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225
226 return 0;
227}
228
David S. Millerfd098312008-08-31 01:23:17 -0700229static const struct of_device_id riowd_match[] = {
David S. Millere42311d2008-08-29 15:35:59 -0700230 {
231 .name = "pmc",
232 },
233 {},
234};
235MODULE_DEVICE_TABLE(of, riowd_match);
236
Grant Likely1c48a5c2011-02-17 02:43:24 -0700237static struct platform_driver riowd_driver = {
Grant Likely40182942010-04-13 16:13:02 -0700238 .driver = {
239 .name = DRIVER_NAME,
240 .owner = THIS_MODULE,
241 .of_match_table = riowd_match,
242 },
David S. Millere42311d2008-08-29 15:35:59 -0700243 .probe = riowd_probe,
Bill Pemberton82268712012-11-19 13:21:12 -0500244 .remove = riowd_remove,
David S. Millere42311d2008-08-29 15:35:59 -0700245};
246
Axel Linb8ec6112011-11-29 13:56:27 +0800247module_platform_driver(riowd_driver);