diff options
Diffstat (limited to 'drivers/char')
-rw-r--r-- | drivers/char/watchdog/Kconfig | 7 | ||||
-rw-r--r-- | drivers/char/watchdog/Makefile | 1 | ||||
-rw-r--r-- | drivers/char/watchdog/at91_wdt.c | 228 |
3 files changed, 236 insertions, 0 deletions
diff --git a/drivers/char/watchdog/Kconfig b/drivers/char/watchdog/Kconfig index 16e99db2e12d..d53f664a4dd8 100644 --- a/drivers/char/watchdog/Kconfig +++ b/drivers/char/watchdog/Kconfig | |||
@@ -60,6 +60,13 @@ config SOFT_WATCHDOG | |||
60 | 60 | ||
61 | # ARM Architecture | 61 | # ARM Architecture |
62 | 62 | ||
63 | config AT91_WATCHDOG | ||
64 | tristate "AT91RM9200 watchdog" | ||
65 | depends on WATCHDOG && ARCH_AT91RM9200 | ||
66 | help | ||
67 | Watchdog timer embedded into AT91RM9200 chips. This will reboot your | ||
68 | system when the timeout is reached. | ||
69 | |||
63 | config 21285_WATCHDOG | 70 | config 21285_WATCHDOG |
64 | tristate "DC21285 watchdog" | 71 | tristate "DC21285 watchdog" |
65 | depends on WATCHDOG && FOOTBRIDGE | 72 | depends on WATCHDOG && FOOTBRIDGE |
diff --git a/drivers/char/watchdog/Makefile b/drivers/char/watchdog/Makefile index d6f27fde9905..6ab77b61a643 100644 --- a/drivers/char/watchdog/Makefile +++ b/drivers/char/watchdog/Makefile | |||
@@ -23,6 +23,7 @@ obj-$(CONFIG_WDTPCI) += wdt_pci.o | |||
23 | obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb.o | 23 | obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb.o |
24 | 24 | ||
25 | # ARM Architecture | 25 | # ARM Architecture |
26 | obj-$(CONFIG_AT91_WATCHDOG) += at91_wdt.o | ||
26 | obj-$(CONFIG_21285_WATCHDOG) += wdt285.o | 27 | obj-$(CONFIG_21285_WATCHDOG) += wdt285.o |
27 | obj-$(CONFIG_977_WATCHDOG) += wdt977.o | 28 | obj-$(CONFIG_977_WATCHDOG) += wdt977.o |
28 | obj-$(CONFIG_IXP2000_WATCHDOG) += ixp2000_wdt.o | 29 | obj-$(CONFIG_IXP2000_WATCHDOG) += ixp2000_wdt.o |
diff --git a/drivers/char/watchdog/at91_wdt.c b/drivers/char/watchdog/at91_wdt.c new file mode 100644 index 000000000000..ac83bc4b019a --- /dev/null +++ b/drivers/char/watchdog/at91_wdt.c | |||
@@ -0,0 +1,228 @@ | |||
1 | /* | ||
2 | * Watchdog driver for Atmel AT91RM9200 (Thunder) | ||
3 | * | ||
4 | * Copyright (C) 2003 SAN People (Pty) Ltd | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or | ||
7 | * modify it under the terms of the GNU General Public License | ||
8 | * as published by the Free Software Foundation; either version | ||
9 | * 2 of the License, or (at your option) any later version. | ||
10 | */ | ||
11 | |||
12 | #include <linux/config.h> | ||
13 | #include <linux/errno.h> | ||
14 | #include <linux/fs.h> | ||
15 | #include <linux/init.h> | ||
16 | #include <linux/kernel.h> | ||
17 | #include <linux/miscdevice.h> | ||
18 | #include <linux/module.h> | ||
19 | #include <linux/moduleparam.h> | ||
20 | #include <linux/types.h> | ||
21 | #include <linux/watchdog.h> | ||
22 | #include <asm/bitops.h> | ||
23 | #include <asm/uaccess.h> | ||
24 | |||
25 | |||
26 | #define WDT_DEFAULT_TIME 5 /* 5 seconds */ | ||
27 | #define WDT_MAX_TIME 256 /* 256 seconds */ | ||
28 | |||
29 | static int wdt_time = WDT_DEFAULT_TIME; | ||
30 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
31 | |||
32 | module_param(wdt_time, int, 0); | ||
33 | MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="__MODULE_STRING(WDT_DEFAULT_TIME) ")"); | ||
34 | |||
35 | module_param(nowayout, int, 0); | ||
36 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | ||
37 | |||
38 | |||
39 | static unsigned long at91wdt_busy; | ||
40 | |||
41 | /* ......................................................................... */ | ||
42 | |||
43 | /* | ||
44 | * Disable the watchdog. | ||
45 | */ | ||
46 | static void inline at91_wdt_stop(void) | ||
47 | { | ||
48 | at91_sys_write(AT91_ST_WDMR, AT91_ST_EXTEN); | ||
49 | } | ||
50 | |||
51 | /* | ||
52 | * Enable and reset the watchdog. | ||
53 | */ | ||
54 | static void inline at91_wdt_start(void) | ||
55 | { | ||
56 | at91_sys_write(AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN | (((65536 * wdt_time) >> 8) & AT91_ST_WDV)); | ||
57 | at91_sys_write(AT91_ST_CR, AT91_ST_WDRST); | ||
58 | } | ||
59 | |||
60 | /* | ||
61 | * Reload the watchdog timer. (ie, pat the watchdog) | ||
62 | */ | ||
63 | static void inline at91_wdt_reload(void) | ||
64 | { | ||
65 | at91_sys_write(AT91_ST_CR, AT91_ST_WDRST); | ||
66 | } | ||
67 | |||
68 | /* ......................................................................... */ | ||
69 | |||
70 | /* | ||
71 | * Watchdog device is opened, and watchdog starts running. | ||
72 | */ | ||
73 | static int at91_wdt_open(struct inode *inode, struct file *file) | ||
74 | { | ||
75 | if (test_and_set_bit(0, &at91wdt_busy)) | ||
76 | return -EBUSY; | ||
77 | |||
78 | at91_wdt_start(); | ||
79 | return nonseekable_open(inode, file); | ||
80 | } | ||
81 | |||
82 | /* | ||
83 | * Close the watchdog device. | ||
84 | * If CONFIG_WATCHDOG_NOWAYOUT is NOT defined then the watchdog is also | ||
85 | * disabled. | ||
86 | */ | ||
87 | static int at91_wdt_close(struct inode *inode, struct file *file) | ||
88 | { | ||
89 | if (!nowayout) | ||
90 | at91_wdt_stop(); /* Disable the watchdog when file is closed */ | ||
91 | |||
92 | clear_bit(0, &at91wdt_busy); | ||
93 | return 0; | ||
94 | } | ||
95 | |||
96 | /* | ||
97 | * Change the watchdog time interval. | ||
98 | */ | ||
99 | static int at91_wdt_settimeout(int new_time) | ||
100 | { | ||
101 | /* | ||
102 | * All counting occurs at SLOW_CLOCK / 128 = 0.256 Hz | ||
103 | * | ||
104 | * Since WDV is a 16-bit counter, the maximum period is | ||
105 | * 65536 / 0.256 = 256 seconds. | ||
106 | */ | ||
107 | if ((new_time <= 0) || (new_time > WDT_MAX_TIME)) | ||
108 | return -EINVAL; | ||
109 | |||
110 | /* Set new watchdog time. It will be used when at91_wdt_start() is called. */ | ||
111 | wdt_time = new_time; | ||
112 | return 0; | ||
113 | } | ||
114 | |||
115 | static struct watchdog_info at91_wdt_info = { | ||
116 | .identity = "at91 watchdog", | ||
117 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | ||
118 | }; | ||
119 | |||
120 | /* | ||
121 | * Handle commands from user-space. | ||
122 | */ | ||
123 | static int at91_wdt_ioctl(struct inode *inode, struct file *file, | ||
124 | unsigned int cmd, unsigned long arg) | ||
125 | { | ||
126 | void __user *argp = (void __user *)arg; | ||
127 | int __user *p = argp; | ||
128 | int new_value; | ||
129 | |||
130 | switch(cmd) { | ||
131 | case WDIOC_KEEPALIVE: | ||
132 | at91_wdt_reload(); /* pat the watchdog */ | ||
133 | return 0; | ||
134 | |||
135 | case WDIOC_GETSUPPORT: | ||
136 | return copy_to_user(argp, &at91_wdt_info, sizeof(at91_wdt_info)) ? -EFAULT : 0; | ||
137 | |||
138 | case WDIOC_SETTIMEOUT: | ||
139 | if (get_user(new_value, p)) | ||
140 | return -EFAULT; | ||
141 | |||
142 | if (at91_wdt_settimeout(new_value)) | ||
143 | return -EINVAL; | ||
144 | |||
145 | /* Enable new time value */ | ||
146 | at91_wdt_start(); | ||
147 | |||
148 | /* Return current value */ | ||
149 | return put_user(wdt_time, p); | ||
150 | |||
151 | case WDIOC_GETTIMEOUT: | ||
152 | return put_user(wdt_time, p); | ||
153 | |||
154 | case WDIOC_GETSTATUS: | ||
155 | case WDIOC_GETBOOTSTATUS: | ||
156 | return put_user(0, p); | ||
157 | |||
158 | case WDIOC_SETOPTIONS: | ||
159 | if (get_user(new_value, p)) | ||
160 | return -EFAULT; | ||
161 | |||
162 | if (new_value & WDIOS_DISABLECARD) | ||
163 | at91_wdt_stop(); | ||
164 | if (new_value & WDIOS_ENABLECARD) | ||
165 | at91_wdt_start(); | ||
166 | return 0; | ||
167 | |||
168 | default: | ||
169 | return -ENOIOCTLCMD; | ||
170 | } | ||
171 | } | ||
172 | |||
173 | /* | ||
174 | * Pat the watchdog whenever device is written to. | ||
175 | */ | ||
176 | static ssize_t at91_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) | ||
177 | { | ||
178 | at91_wdt_reload(); /* pat the watchdog */ | ||
179 | return len; | ||
180 | } | ||
181 | |||
182 | /* ......................................................................... */ | ||
183 | |||
184 | static struct file_operations at91wdt_fops = { | ||
185 | .owner = THIS_MODULE, | ||
186 | .llseek = no_llseek, | ||
187 | .ioctl = at91_wdt_ioctl, | ||
188 | .open = at91_wdt_open, | ||
189 | .release = at91_wdt_close, | ||
190 | .write = at91_wdt_write, | ||
191 | }; | ||
192 | |||
193 | static struct miscdevice at91wdt_miscdev = { | ||
194 | .minor = WATCHDOG_MINOR, | ||
195 | .name = "watchdog", | ||
196 | .fops = &at91wdt_fops, | ||
197 | }; | ||
198 | |||
199 | static int __init at91_wdt_init(void) | ||
200 | { | ||
201 | int res; | ||
202 | |||
203 | /* Check that the heartbeat value is within range; if not reset to the default */ | ||
204 | if (at91_wdt_settimeout(wdt_time)) { | ||
205 | at91_wdt_settimeout(WDT_DEFAULT_TIME); | ||
206 | printk(KERN_INFO "at91_wdt: wdt_time value must be 1 <= wdt_time <= 256, using %d\n", wdt_time); | ||
207 | } | ||
208 | |||
209 | res = misc_register(&at91wdt_miscdev); | ||
210 | if (res) | ||
211 | return res; | ||
212 | |||
213 | printk("AT91 Watchdog Timer enabled (%d seconds, nowayout=%d)\n", wdt_time, nowayout); | ||
214 | return 0; | ||
215 | } | ||
216 | |||
217 | static void __exit at91_wdt_exit(void) | ||
218 | { | ||
219 | misc_deregister(&at91wdt_miscdev); | ||
220 | } | ||
221 | |||
222 | module_init(at91_wdt_init); | ||
223 | module_exit(at91_wdt_exit); | ||
224 | |||
225 | MODULE_AUTHOR("Andrew Victor"); | ||
226 | MODULE_DESCRIPTION("Watchdog driver for Atmel AT91RM9200"); | ||
227 | MODULE_LICENSE("GPL"); | ||
228 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||