[WATCHDOG] Coding style - Indentation - part 2
[linux-2.6.git] / drivers / watchdog / iop_wdt.c
1 /*
2  * drivers/char/watchdog/iop_wdt.c
3  *
4  * WDT driver for Intel I/O Processors
5  * Copyright (C) 2005, Intel Corporation.
6  *
7  * Based on ixp4xx driver, Copyright 2004 (c) MontaVista, Software, Inc.
8  *
9  * This program is free software; you can redistribute it and/or modify it
10  * under the terms and conditions of the GNU General Public License,
11  * version 2, as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope it will be useful, but WITHOUT
14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16  * more details.
17  *
18  * You should have received a copy of the GNU General Public License along with
19  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
20  * Place - Suite 330, Boston, MA 02111-1307 USA.
21  *
22  *      Curt E Bruns <curt.e.bruns@intel.com>
23  *      Peter Milne <peter.milne@d-tacq.com>
24  *      Dan Williams <dan.j.williams@intel.com>
25  */
26
27 #include <linux/module.h>
28 #include <linux/kernel.h>
29 #include <linux/fs.h>
30 #include <linux/init.h>
31 #include <linux/device.h>
32 #include <linux/miscdevice.h>
33 #include <linux/watchdog.h>
34 #include <linux/uaccess.h>
35 #include <asm/hardware.h>
36
37 static int nowayout = WATCHDOG_NOWAYOUT;
38 static unsigned long wdt_status;
39 static unsigned long boot_status;
40 static spinlock_t wdt_lock;
41
42 #define WDT_IN_USE              0
43 #define WDT_OK_TO_CLOSE         1
44 #define WDT_ENABLED             2
45
46 static unsigned long iop_watchdog_timeout(void)
47 {
48         return (0xffffffffUL / get_iop_tick_rate());
49 }
50
51 /**
52  * wdt_supports_disable - determine if we are accessing a iop13xx watchdog
53  * or iop3xx by whether it has a disable command
54  */
55 static int wdt_supports_disable(void)
56 {
57         int can_disable;
58
59         if (IOP_WDTCR_EN_ARM != IOP_WDTCR_DIS_ARM)
60                 can_disable = 1;
61         else
62                 can_disable = 0;
63
64         return can_disable;
65 }
66
67 static void wdt_enable(void)
68 {
69         /* Arm and enable the Timer to starting counting down from 0xFFFF.FFFF
70          * Takes approx. 10.7s to timeout
71          */
72         spin_lock(&wdt_lock);
73         write_wdtcr(IOP_WDTCR_EN_ARM);
74         write_wdtcr(IOP_WDTCR_EN);
75         spin_unlock(&wdt_lock);
76 }
77
78 /* returns 0 if the timer was successfully disabled */
79 static int wdt_disable(void)
80 {
81         /* Stop Counting */
82         if (wdt_supports_disable()) {
83                 spin_lock(&wdt_lock);
84                 write_wdtcr(IOP_WDTCR_DIS_ARM);
85                 write_wdtcr(IOP_WDTCR_DIS);
86                 clear_bit(WDT_ENABLED, &wdt_status);
87                 spin_unlock(&wdt_lock);
88                 printk(KERN_INFO "WATCHDOG: Disabled\n");
89                 return 0;
90         } else
91                 return 1;
92 }
93
94 static int iop_wdt_open(struct inode *inode, struct file *file)
95 {
96         if (test_and_set_bit(WDT_IN_USE, &wdt_status))
97                 return -EBUSY;
98
99         clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
100         wdt_enable();
101         set_bit(WDT_ENABLED, &wdt_status);
102         return nonseekable_open(inode, file);
103 }
104
105 static ssize_t iop_wdt_write(struct file *file, const char *data, size_t len,
106                   loff_t *ppos)
107 {
108         if (len) {
109                 if (!nowayout) {
110                         size_t i;
111
112                         clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
113
114                         for (i = 0; i != len; i++) {
115                                 char c;
116
117                                 if (get_user(c, data + i))
118                                         return -EFAULT;
119                                 if (c == 'V')
120                                         set_bit(WDT_OK_TO_CLOSE, &wdt_status);
121                         }
122                 }
123                 wdt_enable();
124         }
125         return len;
126 }
127
128 static const struct watchdog_info ident = {
129         .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
130         .identity = "iop watchdog",
131 };
132
133 static long iop_wdt_ioctl(struct file *file,
134                                 unsigned int cmd, unsigned long arg)
135 {
136         int options;
137         int ret = -ENOTTY;
138         int __user *argp = (int __user *)arg;
139
140         switch (cmd) {
141         case WDIOC_GETSUPPORT:
142                 if (copy_to_user(argp, &ident, sizeof ident))
143                         ret = -EFAULT;
144                 else
145                         ret = 0;
146                 break;
147
148         case WDIOC_GETSTATUS:
149                 ret = put_user(0, argp);
150                 break;
151
152         case WDIOC_GETBOOTSTATUS:
153                 ret = put_user(boot_status, argp);
154                 break;
155
156         case WDIOC_SETOPTIONS:
157                 if (get_user(options, (int *)arg))
158                         return -EFAULT;
159
160                 if (options & WDIOS_DISABLECARD) {
161                         if (!nowayout) {
162                                 if (wdt_disable() == 0) {
163                                         set_bit(WDT_OK_TO_CLOSE, &wdt_status);
164                                         ret = 0;
165                                 } else
166                                         ret = -ENXIO;
167                         } else
168                                 ret = 0;
169                 }
170                 if (options & WDIOS_ENABLECARD) {
171                         wdt_enable();
172                         ret = 0;
173                 }
174                 break;
175
176         case WDIOC_KEEPALIVE:
177                 wdt_enable();
178                 ret = 0;
179                 break;
180
181         case WDIOC_GETTIMEOUT:
182                 ret = put_user(iop_watchdog_timeout(), argp);
183                 break;
184         }
185         return ret;
186 }
187
188 static int iop_wdt_release(struct inode *inode, struct file *file)
189 {
190         int state = 1;
191         if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
192                 if (test_bit(WDT_ENABLED, &wdt_status))
193                         state = wdt_disable();
194
195         /* if the timer is not disbaled reload and notify that we are still
196          * going down
197          */
198         if (state != 0) {
199                 wdt_enable();
200                 printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
201                        "reset in %lu seconds\n", iop_watchdog_timeout());
202         }
203
204         clear_bit(WDT_IN_USE, &wdt_status);
205         clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
206
207         return 0;
208 }
209
210 static const struct file_operations iop_wdt_fops = {
211         .owner = THIS_MODULE,
212         .llseek = no_llseek,
213         .write = iop_wdt_write,
214         .unlocked_ioctl = iop_wdt_ioctl,
215         .open = iop_wdt_open,
216         .release = iop_wdt_release,
217 };
218
219 static struct miscdevice iop_wdt_miscdev = {
220         .minor = WATCHDOG_MINOR,
221         .name = "watchdog",
222         .fops = &iop_wdt_fops,
223 };
224
225 static int __init iop_wdt_init(void)
226 {
227         int ret;
228
229         spin_lock_init(&wdt_lock);
230
231
232         /* check if the reset was caused by the watchdog timer */
233         boot_status = (read_rcsr() & IOP_RCSR_WDT) ? WDIOF_CARDRESET : 0;
234
235         /* Configure Watchdog Timeout to cause an Internal Bus (IB) Reset
236          * NOTE: An IB Reset will Reset both cores in the IOP342
237          */
238         write_wdtsr(IOP13XX_WDTCR_IB_RESET);
239
240         /* Register after we have the device set up so we cannot race
241            with an open */
242         ret = misc_register(&iop_wdt_miscdev);
243         if (ret == 0)
244                 printk("iop watchdog timer: timeout %lu sec\n",
245                        iop_watchdog_timeout());
246
247         return ret;
248 }
249
250 static void __exit iop_wdt_exit(void)
251 {
252         misc_deregister(&iop_wdt_miscdev);
253 }
254
255 module_init(iop_wdt_init);
256 module_exit(iop_wdt_exit);
257
258 module_param(nowayout, int, 0);
259 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
260
261 MODULE_AUTHOR("Curt E Bruns <curt.e.bruns@intel.com>");
262 MODULE_DESCRIPTION("iop watchdog timer driver");
263 MODULE_LICENSE("GPL");
264 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);