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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Watchdog driver for the SA11x0/PXA2xx | |
3 | * | |
143a2e54 WVS |
4 | * (c) Copyright 2000 Oleg Drokin <green@crimea.edu> |
5 | * Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk> | |
1da177e4 LT |
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 | * | |
143a2e54 | 18 | * 27/11/2000 Initial release |
1da177e4 | 19 | */ |
27c766aa JP |
20 | |
21 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
22 | ||
1da177e4 LT |
23 | #include <linux/module.h> |
24 | #include <linux/moduleparam.h> | |
25 | #include <linux/types.h> | |
26 | #include <linux/kernel.h> | |
27 | #include <linux/fs.h> | |
28 | #include <linux/miscdevice.h> | |
29 | #include <linux/watchdog.h> | |
30 | #include <linux/init.h> | |
23019a73 | 31 | #include <linux/io.h> |
1977f032 | 32 | #include <linux/bitops.h> |
f19e0312 | 33 | #include <linux/uaccess.h> |
87c52578 | 34 | #include <linux/timex.h> |
1da177e4 LT |
35 | |
36 | #ifdef CONFIG_ARCH_PXA | |
5bf3df3f | 37 | #include <mach/regs-ost.h> |
1da177e4 LT |
38 | #endif |
39 | ||
afd2fc02 | 40 | #include <mach/reset.h> |
a09e64fb | 41 | #include <mach/hardware.h> |
1da177e4 | 42 | |
28a62385 | 43 | static unsigned long oscr_freq; |
1da177e4 | 44 | static unsigned long sa1100wdt_users; |
a6f052e3 | 45 | static unsigned int pre_margin; |
1da177e4 | 46 | static int boot_status; |
1da177e4 LT |
47 | |
48 | /* | |
49 | * Allow only one person to hold it open | |
50 | */ | |
51 | static int sa1100dog_open(struct inode *inode, struct file *file) | |
52 | { | |
f19e0312 | 53 | if (test_and_set_bit(1, &sa1100wdt_users)) |
1da177e4 LT |
54 | return -EBUSY; |
55 | ||
56 | /* Activate SA1100 Watchdog timer */ | |
57 | OSMR3 = OSCR + pre_margin; | |
58 | OSSR = OSSR_M3; | |
59 | OWER = OWER_WME; | |
60 | OIER |= OIER_E3; | |
6abe78bf | 61 | return nonseekable_open(inode, file); |
1da177e4 LT |
62 | } |
63 | ||
64 | /* | |
9bbd0375 IC |
65 | * The watchdog cannot be disabled. |
66 | * | |
67 | * Previous comments suggested that turning off the interrupt by | |
68 | * clearing OIER[E3] would prevent the watchdog timing out but this | |
69 | * does not appear to be true (at least on the PXA255). | |
1da177e4 LT |
70 | */ |
71 | static int sa1100dog_release(struct inode *inode, struct file *file) | |
72 | { | |
27c766aa | 73 | pr_crit("Device closed - timer will not stop\n"); |
1da177e4 | 74 | clear_bit(1, &sa1100wdt_users); |
1da177e4 LT |
75 | return 0; |
76 | } | |
77 | ||
f19e0312 AC |
78 | static ssize_t sa1100dog_write(struct file *file, const char __user *data, |
79 | size_t len, loff_t *ppos) | |
1da177e4 | 80 | { |
9bbd0375 | 81 | if (len) |
1da177e4 LT |
82 | /* Refresh OSMR3 timer. */ |
83 | OSMR3 = OSCR + pre_margin; | |
1da177e4 LT |
84 | return len; |
85 | } | |
86 | ||
f19e0312 AC |
87 | static const struct watchdog_info ident = { |
88 | .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT | |
89 | | WDIOF_KEEPALIVEPING, | |
9bbd0375 | 90 | .identity = "SA1100/PXA255 Watchdog", |
a6f052e3 | 91 | .firmware_version = 1, |
1da177e4 LT |
92 | }; |
93 | ||
f19e0312 AC |
94 | static long sa1100dog_ioctl(struct file *file, unsigned int cmd, |
95 | unsigned long arg) | |
1da177e4 | 96 | { |
795b89d2 | 97 | int ret = -ENOTTY; |
1da177e4 | 98 | int time; |
3a69e579 IC |
99 | void __user *argp = (void __user *)arg; |
100 | int __user *p = argp; | |
1da177e4 LT |
101 | |
102 | switch (cmd) { | |
103 | case WDIOC_GETSUPPORT: | |
3a69e579 | 104 | ret = copy_to_user(argp, &ident, |
1da177e4 LT |
105 | sizeof(ident)) ? -EFAULT : 0; |
106 | break; | |
107 | ||
108 | case WDIOC_GETSTATUS: | |
3a69e579 | 109 | ret = put_user(0, p); |
1da177e4 LT |
110 | break; |
111 | ||
112 | case WDIOC_GETBOOTSTATUS: | |
3a69e579 | 113 | ret = put_user(boot_status, p); |
1da177e4 LT |
114 | break; |
115 | ||
0c06090c WVS |
116 | case WDIOC_KEEPALIVE: |
117 | OSMR3 = OSCR + pre_margin; | |
118 | ret = 0; | |
119 | break; | |
120 | ||
1da177e4 | 121 | case WDIOC_SETTIMEOUT: |
3a69e579 | 122 | ret = get_user(time, p); |
1da177e4 LT |
123 | if (ret) |
124 | break; | |
125 | ||
a6f052e3 | 126 | if (time <= 0 || (oscr_freq * (long long)time >= 0xffffffff)) { |
1da177e4 LT |
127 | ret = -EINVAL; |
128 | break; | |
129 | } | |
130 | ||
28a62385 | 131 | pre_margin = oscr_freq * time; |
1da177e4 LT |
132 | OSMR3 = OSCR + pre_margin; |
133 | /*fall through*/ | |
134 | ||
135 | case WDIOC_GETTIMEOUT: | |
28a62385 | 136 | ret = put_user(pre_margin / oscr_freq, p); |
1da177e4 | 137 | break; |
1da177e4 LT |
138 | } |
139 | return ret; | |
140 | } | |
141 | ||
f19e0312 | 142 | static const struct file_operations sa1100dog_fops = { |
1da177e4 LT |
143 | .owner = THIS_MODULE, |
144 | .llseek = no_llseek, | |
145 | .write = sa1100dog_write, | |
f19e0312 | 146 | .unlocked_ioctl = sa1100dog_ioctl, |
1da177e4 LT |
147 | .open = sa1100dog_open, |
148 | .release = sa1100dog_release, | |
149 | }; | |
150 | ||
f19e0312 | 151 | static struct miscdevice sa1100dog_miscdev = { |
1da177e4 | 152 | .minor = WATCHDOG_MINOR, |
9bbd0375 | 153 | .name = "watchdog", |
1da177e4 LT |
154 | .fops = &sa1100dog_fops, |
155 | }; | |
156 | ||
157 | static int margin __initdata = 60; /* (secs) Default is 1 minute */ | |
158 | ||
159 | static int __init sa1100dog_init(void) | |
160 | { | |
161 | int ret; | |
162 | ||
28a62385 EM |
163 | oscr_freq = get_clock_tick_rate(); |
164 | ||
1da177e4 LT |
165 | /* |
166 | * Read the reset status, and save it for later. If | |
167 | * we suspend, RCSR will be cleared, and the watchdog | |
168 | * reset reason will be lost. | |
169 | */ | |
214c6a7e EM |
170 | boot_status = (reset_status & RESET_STATUS_WATCHDOG) ? |
171 | WDIOF_CARDRESET : 0; | |
28a62385 | 172 | pre_margin = oscr_freq * margin; |
1da177e4 LT |
173 | |
174 | ret = misc_register(&sa1100dog_miscdev); | |
175 | if (ret == 0) | |
27c766aa JP |
176 | pr_info("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n", |
177 | margin); | |
1da177e4 LT |
178 | return ret; |
179 | } | |
180 | ||
181 | static void __exit sa1100dog_exit(void) | |
182 | { | |
183 | misc_deregister(&sa1100dog_miscdev); | |
184 | } | |
185 | ||
186 | module_init(sa1100dog_init); | |
187 | module_exit(sa1100dog_exit); | |
188 | ||
189 | MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>"); | |
190 | MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog"); | |
191 | ||
192 | module_param(margin, int, 0); | |
193 | MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)"); | |
194 | ||
1da177e4 LT |
195 | MODULE_LICENSE("GPL"); |
196 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |