Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Watchdog driver for the SA11x0/PXA2xx | |
3 | * | |
4 | * (c) Copyright 2000 Oleg Drokin <green@crimea.edu> | |
5 | * Based on SoftDog driver by Alan Cox <alan@redhat.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | * | |
12 | * Neither Oleg Drokin nor iXcelerator.com admit liability nor provide | |
13 | * warranty for any of this software. This material is provided | |
14 | * "AS-IS" and at no charge. | |
15 | * | |
16 | * (c) Copyright 2000 Oleg Drokin <green@crimea.edu> | |
17 | * | |
18 | * 27/11/2000 Initial release | |
19 | */ | |
1da177e4 LT |
20 | #include <linux/module.h> |
21 | #include <linux/moduleparam.h> | |
22 | #include <linux/types.h> | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/fs.h> | |
25 | #include <linux/miscdevice.h> | |
26 | #include <linux/watchdog.h> | |
27 | #include <linux/init.h> | |
1977f032 | 28 | #include <linux/bitops.h> |
1da177e4 LT |
29 | |
30 | #ifdef CONFIG_ARCH_PXA | |
31 | #include <asm/arch/pxa-regs.h> | |
32 | #endif | |
33 | ||
34 | #include <asm/hardware.h> | |
1da177e4 LT |
35 | #include <asm/uaccess.h> |
36 | ||
37 | #define OSCR_FREQ CLOCK_TICK_RATE | |
1da177e4 LT |
38 | |
39 | static unsigned long sa1100wdt_users; | |
1da177e4 LT |
40 | static int pre_margin; |
41 | static int boot_status; | |
1da177e4 LT |
42 | |
43 | /* | |
44 | * Allow only one person to hold it open | |
45 | */ | |
46 | static int sa1100dog_open(struct inode *inode, struct file *file) | |
47 | { | |
1da177e4 LT |
48 | if (test_and_set_bit(1,&sa1100wdt_users)) |
49 | return -EBUSY; | |
50 | ||
51 | /* Activate SA1100 Watchdog timer */ | |
52 | OSMR3 = OSCR + pre_margin; | |
53 | OSSR = OSSR_M3; | |
54 | OWER = OWER_WME; | |
55 | OIER |= OIER_E3; | |
6abe78bf | 56 | return nonseekable_open(inode, file); |
1da177e4 LT |
57 | } |
58 | ||
59 | /* | |
9bbd0375 IC |
60 | * The watchdog cannot be disabled. |
61 | * | |
62 | * Previous comments suggested that turning off the interrupt by | |
63 | * clearing OIER[E3] would prevent the watchdog timing out but this | |
64 | * does not appear to be true (at least on the PXA255). | |
1da177e4 LT |
65 | */ |
66 | static int sa1100dog_release(struct inode *inode, struct file *file) | |
67 | { | |
9bbd0375 | 68 | printk(KERN_CRIT "WATCHDOG: Device closed - timer will not stop\n"); |
1da177e4 LT |
69 | |
70 | clear_bit(1, &sa1100wdt_users); | |
1da177e4 LT |
71 | |
72 | return 0; | |
73 | } | |
74 | ||
a0734042 | 75 | static ssize_t sa1100dog_write(struct file *file, const char __user *data, size_t len, loff_t *ppos) |
1da177e4 | 76 | { |
9bbd0375 | 77 | if (len) |
1da177e4 LT |
78 | /* Refresh OSMR3 timer. */ |
79 | OSMR3 = OSCR + pre_margin; | |
1da177e4 LT |
80 | |
81 | return len; | |
82 | } | |
83 | ||
84 | static struct watchdog_info ident = { | |
9bbd0375 IC |
85 | .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, |
86 | .identity = "SA1100/PXA255 Watchdog", | |
1da177e4 LT |
87 | }; |
88 | ||
89 | static int sa1100dog_ioctl(struct inode *inode, struct file *file, | |
90 | unsigned int cmd, unsigned long arg) | |
91 | { | |
795b89d2 | 92 | int ret = -ENOTTY; |
1da177e4 | 93 | int time; |
3a69e579 IC |
94 | void __user *argp = (void __user *)arg; |
95 | int __user *p = argp; | |
1da177e4 LT |
96 | |
97 | switch (cmd) { | |
98 | case WDIOC_GETSUPPORT: | |
3a69e579 | 99 | ret = copy_to_user(argp, &ident, |
1da177e4 LT |
100 | sizeof(ident)) ? -EFAULT : 0; |
101 | break; | |
102 | ||
103 | case WDIOC_GETSTATUS: | |
3a69e579 | 104 | ret = put_user(0, p); |
1da177e4 LT |
105 | break; |
106 | ||
107 | case WDIOC_GETBOOTSTATUS: | |
3a69e579 | 108 | ret = put_user(boot_status, p); |
1da177e4 LT |
109 | break; |
110 | ||
111 | case WDIOC_SETTIMEOUT: | |
3a69e579 | 112 | ret = get_user(time, p); |
1da177e4 LT |
113 | if (ret) |
114 | break; | |
115 | ||
116 | if (time <= 0 || time > 255) { | |
117 | ret = -EINVAL; | |
118 | break; | |
119 | } | |
120 | ||
121 | pre_margin = OSCR_FREQ * time; | |
122 | OSMR3 = OSCR + pre_margin; | |
123 | /*fall through*/ | |
124 | ||
125 | case WDIOC_GETTIMEOUT: | |
3a69e579 | 126 | ret = put_user(pre_margin / OSCR_FREQ, p); |
1da177e4 LT |
127 | break; |
128 | ||
129 | case WDIOC_KEEPALIVE: | |
130 | OSMR3 = OSCR + pre_margin; | |
131 | ret = 0; | |
132 | break; | |
133 | } | |
134 | return ret; | |
135 | } | |
136 | ||
62322d25 | 137 | static const struct file_operations sa1100dog_fops = |
1da177e4 LT |
138 | { |
139 | .owner = THIS_MODULE, | |
140 | .llseek = no_llseek, | |
141 | .write = sa1100dog_write, | |
142 | .ioctl = sa1100dog_ioctl, | |
143 | .open = sa1100dog_open, | |
144 | .release = sa1100dog_release, | |
145 | }; | |
146 | ||
147 | static struct miscdevice sa1100dog_miscdev = | |
148 | { | |
149 | .minor = WATCHDOG_MINOR, | |
9bbd0375 | 150 | .name = "watchdog", |
1da177e4 LT |
151 | .fops = &sa1100dog_fops, |
152 | }; | |
153 | ||
154 | static int margin __initdata = 60; /* (secs) Default is 1 minute */ | |
155 | ||
156 | static int __init sa1100dog_init(void) | |
157 | { | |
158 | int ret; | |
159 | ||
160 | /* | |
161 | * Read the reset status, and save it for later. If | |
162 | * we suspend, RCSR will be cleared, and the watchdog | |
163 | * reset reason will be lost. | |
164 | */ | |
165 | boot_status = (RCSR & RCSR_WDR) ? WDIOF_CARDRESET : 0; | |
166 | pre_margin = OSCR_FREQ * margin; | |
167 | ||
168 | ret = misc_register(&sa1100dog_miscdev); | |
169 | if (ret == 0) | |
170 | printk("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n", | |
171 | margin); | |
1da177e4 LT |
172 | return ret; |
173 | } | |
174 | ||
175 | static void __exit sa1100dog_exit(void) | |
176 | { | |
177 | misc_deregister(&sa1100dog_miscdev); | |
178 | } | |
179 | ||
180 | module_init(sa1100dog_init); | |
181 | module_exit(sa1100dog_exit); | |
182 | ||
183 | MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>"); | |
184 | MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog"); | |
185 | ||
186 | module_param(margin, int, 0); | |
187 | MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)"); | |
188 | ||
1da177e4 LT |
189 | MODULE_LICENSE("GPL"); |
190 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |