diff options
author | Wim Van Sebroeck <wim@iguana.be> | 2007-08-17 04:38:02 -0400 |
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committer | Wim Van Sebroeck <wim@iguana.be> | 2007-10-18 06:39:03 -0400 |
commit | b7e04f8c61a46d742de23af5d7ca2b41b33e40ac (patch) | |
tree | c52a7ea568648e2d8ed0d423098b42298de2058b /drivers/watchdog/ep93xx_wdt.c | |
parent | d85714d81cc0408daddb68c10f7fd69eafe7c213 (diff) |
mv watchdog tree under drivers
move watchdog tree from drivers/char/watchdog to drivers/watchdog.
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/ep93xx_wdt.c')
-rw-r--r-- | drivers/watchdog/ep93xx_wdt.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/drivers/watchdog/ep93xx_wdt.c b/drivers/watchdog/ep93xx_wdt.c new file mode 100644 index 000000000000..0e4787a0bb87 --- /dev/null +++ b/drivers/watchdog/ep93xx_wdt.c | |||
@@ -0,0 +1,253 @@ | |||
1 | /* | ||
2 | * Watchdog driver for Cirrus Logic EP93xx family of devices. | ||
3 | * | ||
4 | * Copyright (c) 2004 Ray Lehtiniemi | ||
5 | * Copyright (c) 2006 Tower Technologies | ||
6 | * Based on ep93xx driver, bits from alim7101_wdt.c | ||
7 | * | ||
8 | * Authors: Ray Lehtiniemi <rayl@mail.com>, | ||
9 | * Alessandro Zummo <a.zummo@towertech.it> | ||
10 | * | ||
11 | * This file is licensed under the terms of the GNU General Public | ||
12 | * License version 2. This program is licensed "as is" without any | ||
13 | * warranty of any kind, whether express or implied. | ||
14 | * | ||
15 | * This watchdog fires after 250msec, which is a too short interval | ||
16 | * for us to rely on the user space daemon alone. So we ping the | ||
17 | * wdt each ~200msec and eventually stop doing it if the user space | ||
18 | * daemon dies. | ||
19 | * | ||
20 | * TODO: | ||
21 | * | ||
22 | * - Test last reset from watchdog status | ||
23 | * - Add a few missing ioctls | ||
24 | */ | ||
25 | |||
26 | #include <linux/module.h> | ||
27 | #include <linux/fs.h> | ||
28 | #include <linux/miscdevice.h> | ||
29 | #include <linux/watchdog.h> | ||
30 | #include <linux/timer.h> | ||
31 | |||
32 | #include <asm/hardware.h> | ||
33 | #include <asm/uaccess.h> | ||
34 | |||
35 | #define WDT_VERSION "0.3" | ||
36 | #define PFX "ep93xx_wdt: " | ||
37 | |||
38 | /* default timeout (secs) */ | ||
39 | #define WDT_TIMEOUT 30 | ||
40 | |||
41 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
42 | static int timeout = WDT_TIMEOUT; | ||
43 | |||
44 | static struct timer_list timer; | ||
45 | static unsigned long next_heartbeat; | ||
46 | static unsigned long wdt_status; | ||
47 | static unsigned long boot_status; | ||
48 | |||
49 | #define WDT_IN_USE 0 | ||
50 | #define WDT_OK_TO_CLOSE 1 | ||
51 | |||
52 | #define EP93XX_WDT_REG(x) (EP93XX_WATCHDOG_BASE + (x)) | ||
53 | #define EP93XX_WDT_WATCHDOG EP93XX_WDT_REG(0x00) | ||
54 | #define EP93XX_WDT_WDSTATUS EP93XX_WDT_REG(0x04) | ||
55 | |||
56 | /* reset the wdt every ~200ms */ | ||
57 | #define WDT_INTERVAL (HZ/5) | ||
58 | |||
59 | static void wdt_enable(void) | ||
60 | { | ||
61 | __raw_writew(0xaaaa, EP93XX_WDT_WATCHDOG); | ||
62 | } | ||
63 | |||
64 | static void wdt_disable(void) | ||
65 | { | ||
66 | __raw_writew(0xaa55, EP93XX_WDT_WATCHDOG); | ||
67 | } | ||
68 | |||
69 | static inline void wdt_ping(void) | ||
70 | { | ||
71 | __raw_writew(0x5555, EP93XX_WDT_WATCHDOG); | ||
72 | } | ||
73 | |||
74 | static void wdt_startup(void) | ||
75 | { | ||
76 | next_heartbeat = jiffies + (timeout * HZ); | ||
77 | |||
78 | wdt_enable(); | ||
79 | mod_timer(&timer, jiffies + WDT_INTERVAL); | ||
80 | } | ||
81 | |||
82 | static void wdt_shutdown(void) | ||
83 | { | ||
84 | del_timer_sync(&timer); | ||
85 | wdt_disable(); | ||
86 | } | ||
87 | |||
88 | static void wdt_keepalive(void) | ||
89 | { | ||
90 | /* user land ping */ | ||
91 | next_heartbeat = jiffies + (timeout * HZ); | ||
92 | } | ||
93 | |||
94 | static int ep93xx_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 | |||
101 | wdt_startup(); | ||
102 | |||
103 | return nonseekable_open(inode, file); | ||
104 | } | ||
105 | |||
106 | static ssize_t | ||
107 | ep93xx_wdt_write(struct file *file, const char __user *data, size_t len, | ||
108 | loff_t *ppos) | ||
109 | { | ||
110 | if (len) { | ||
111 | if (!nowayout) { | ||
112 | size_t i; | ||
113 | |||
114 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
115 | |||
116 | for (i = 0; i != len; i++) { | ||
117 | char c; | ||
118 | |||
119 | if (get_user(c, data + i)) | ||
120 | return -EFAULT; | ||
121 | |||
122 | if (c == 'V') | ||
123 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
124 | else | ||
125 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
126 | } | ||
127 | } | ||
128 | wdt_keepalive(); | ||
129 | } | ||
130 | |||
131 | return len; | ||
132 | } | ||
133 | |||
134 | static struct watchdog_info ident = { | ||
135 | .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE, | ||
136 | .identity = "EP93xx Watchdog", | ||
137 | }; | ||
138 | |||
139 | static int | ||
140 | ep93xx_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | ||
141 | unsigned long arg) | ||
142 | { | ||
143 | int ret = -ENOTTY; | ||
144 | |||
145 | switch (cmd) { | ||
146 | case WDIOC_GETSUPPORT: | ||
147 | ret = copy_to_user((struct watchdog_info __user *)arg, &ident, | ||
148 | sizeof(ident)) ? -EFAULT : 0; | ||
149 | break; | ||
150 | |||
151 | case WDIOC_GETSTATUS: | ||
152 | ret = put_user(0, (int __user *)arg); | ||
153 | break; | ||
154 | |||
155 | case WDIOC_GETBOOTSTATUS: | ||
156 | ret = put_user(boot_status, (int __user *)arg); | ||
157 | break; | ||
158 | |||
159 | case WDIOC_GETTIMEOUT: | ||
160 | /* actually, it is 0.250 seconds.... */ | ||
161 | ret = put_user(1, (int __user *)arg); | ||
162 | break; | ||
163 | |||
164 | case WDIOC_KEEPALIVE: | ||
165 | wdt_keepalive(); | ||
166 | ret = 0; | ||
167 | break; | ||
168 | } | ||
169 | return ret; | ||
170 | } | ||
171 | |||
172 | static int ep93xx_wdt_release(struct inode *inode, struct file *file) | ||
173 | { | ||
174 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) | ||
175 | wdt_shutdown(); | ||
176 | else | ||
177 | printk(KERN_CRIT PFX "Device closed unexpectedly - " | ||
178 | "timer will not stop\n"); | ||
179 | |||
180 | clear_bit(WDT_IN_USE, &wdt_status); | ||
181 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
182 | |||
183 | return 0; | ||
184 | } | ||
185 | |||
186 | static const struct file_operations ep93xx_wdt_fops = { | ||
187 | .owner = THIS_MODULE, | ||
188 | .write = ep93xx_wdt_write, | ||
189 | .ioctl = ep93xx_wdt_ioctl, | ||
190 | .open = ep93xx_wdt_open, | ||
191 | .release = ep93xx_wdt_release, | ||
192 | }; | ||
193 | |||
194 | static struct miscdevice ep93xx_wdt_miscdev = { | ||
195 | .minor = WATCHDOG_MINOR, | ||
196 | .name = "watchdog", | ||
197 | .fops = &ep93xx_wdt_fops, | ||
198 | }; | ||
199 | |||
200 | static void ep93xx_timer_ping(unsigned long data) | ||
201 | { | ||
202 | if (time_before(jiffies, next_heartbeat)) | ||
203 | wdt_ping(); | ||
204 | |||
205 | /* Re-set the timer interval */ | ||
206 | mod_timer(&timer, jiffies + WDT_INTERVAL); | ||
207 | } | ||
208 | |||
209 | static int __init ep93xx_wdt_init(void) | ||
210 | { | ||
211 | int err; | ||
212 | |||
213 | err = misc_register(&ep93xx_wdt_miscdev); | ||
214 | |||
215 | boot_status = __raw_readl(EP93XX_WDT_WATCHDOG) & 0x01 ? 1 : 0; | ||
216 | |||
217 | printk(KERN_INFO PFX "EP93XX watchdog, driver version " | ||
218 | WDT_VERSION "%s\n", | ||
219 | (__raw_readl(EP93XX_WDT_WATCHDOG) & 0x08) | ||
220 | ? " (nCS1 disable detected)" : ""); | ||
221 | |||
222 | if (timeout < 1 || timeout > 3600) { | ||
223 | timeout = WDT_TIMEOUT; | ||
224 | printk(KERN_INFO PFX | ||
225 | "timeout value must be 1<=x<=3600, using %d\n", | ||
226 | timeout); | ||
227 | } | ||
228 | |||
229 | setup_timer(&timer, ep93xx_timer_ping, 1); | ||
230 | return err; | ||
231 | } | ||
232 | |||
233 | static void __exit ep93xx_wdt_exit(void) | ||
234 | { | ||
235 | wdt_shutdown(); | ||
236 | misc_deregister(&ep93xx_wdt_miscdev); | ||
237 | } | ||
238 | |||
239 | module_init(ep93xx_wdt_init); | ||
240 | module_exit(ep93xx_wdt_exit); | ||
241 | |||
242 | module_param(nowayout, int, 0); | ||
243 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); | ||
244 | |||
245 | module_param(timeout, int, 0); | ||
246 | MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); | ||
247 | |||
248 | MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>," | ||
249 | "Alessandro Zummo <a.zummo@towertech.it>"); | ||
250 | MODULE_DESCRIPTION("EP93xx Watchdog"); | ||
251 | MODULE_LICENSE("GPL"); | ||
252 | MODULE_VERSION(WDT_VERSION); | ||
253 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||