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Commit | Line | Data |
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3a5f9000 DT |
1 | /* |
2 | * Watchdog driver for SBC-FITPC2 board | |
3 | * | |
4 | * Author: Denis Turischev <denis@compulab.co.il> | |
5 | * | |
6 | * Adapted from the IXP2000 watchdog driver by Deepak Saxena. | |
7 | * | |
8 | * This file is licensed under the terms of the GNU General Public | |
9 | * License version 2. This program is licensed "as is" without any | |
10 | * warranty of any kind, whether express or implied. | |
11 | */ | |
12 | ||
13 | #define pr_fmt(fmt) KBUILD_MODNAME " WATCHDOG: " fmt | |
14 | ||
15 | #include <linux/module.h> | |
16 | #include <linux/types.h> | |
17 | #include <linux/miscdevice.h> | |
18 | #include <linux/watchdog.h> | |
19 | #include <linux/ioport.h> | |
20 | #include <linux/delay.h> | |
21 | #include <linux/fs.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/moduleparam.h> | |
24 | #include <linux/dmi.h> | |
25 | #include <linux/io.h> | |
26 | #include <linux/uaccess.h> | |
27 | ||
28 | #include <asm/system.h> | |
29 | ||
30 | static int nowayout = WATCHDOG_NOWAYOUT; | |
31 | static unsigned int margin = 60; /* (secs) Default is 1 minute */ | |
32 | static unsigned long wdt_status; | |
33 | static DEFINE_SPINLOCK(wdt_lock); | |
34 | ||
35 | #define WDT_IN_USE 0 | |
36 | #define WDT_OK_TO_CLOSE 1 | |
37 | ||
38 | #define COMMAND_PORT 0x4c | |
39 | #define DATA_PORT 0x48 | |
40 | ||
41 | #define IFACE_ON_COMMAND 1 | |
42 | #define REBOOT_COMMAND 2 | |
43 | ||
44 | #define WATCHDOG_NAME "SBC-FITPC2 Watchdog" | |
45 | ||
46 | static void wdt_send_data(unsigned char command, unsigned char data) | |
47 | { | |
48 | outb(command, COMMAND_PORT); | |
49 | mdelay(100); | |
50 | outb(data, DATA_PORT); | |
51 | mdelay(200); | |
52 | } | |
53 | ||
54 | static void wdt_enable(void) | |
55 | { | |
56 | spin_lock(&wdt_lock); | |
57 | wdt_send_data(IFACE_ON_COMMAND, 1); | |
58 | wdt_send_data(REBOOT_COMMAND, margin); | |
59 | spin_unlock(&wdt_lock); | |
60 | } | |
61 | ||
62 | static void wdt_disable(void) | |
63 | { | |
64 | spin_lock(&wdt_lock); | |
65 | wdt_send_data(IFACE_ON_COMMAND, 0); | |
66 | wdt_send_data(REBOOT_COMMAND, 0); | |
67 | spin_unlock(&wdt_lock); | |
68 | } | |
69 | ||
70 | static int fitpc2_wdt_open(struct inode *inode, struct file *file) | |
71 | { | |
72 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | |
73 | return -EBUSY; | |
74 | ||
75 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
76 | ||
77 | wdt_enable(); | |
78 | ||
79 | return nonseekable_open(inode, file); | |
80 | } | |
81 | ||
82 | static ssize_t fitpc2_wdt_write(struct file *file, const char *data, | |
83 | size_t len, loff_t *ppos) | |
84 | { | |
85 | size_t i; | |
86 | ||
87 | if (!len) | |
88 | return 0; | |
89 | ||
90 | if (nowayout) { | |
91 | len = 0; | |
92 | goto out; | |
93 | } | |
94 | ||
95 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
96 | ||
97 | for (i = 0; i != len; i++) { | |
98 | char c; | |
99 | ||
100 | if (get_user(c, data + i)) | |
101 | return -EFAULT; | |
102 | ||
103 | if (c == 'V') | |
104 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
105 | } | |
106 | ||
107 | out: | |
108 | wdt_enable(); | |
109 | ||
110 | return len; | |
111 | } | |
112 | ||
113 | ||
114 | static struct watchdog_info ident = { | |
115 | .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | | |
116 | WDIOF_KEEPALIVEPING, | |
117 | .identity = WATCHDOG_NAME, | |
118 | }; | |
119 | ||
120 | ||
121 | static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd, | |
122 | unsigned long arg) | |
123 | { | |
124 | int ret = -ENOTTY; | |
125 | int time; | |
126 | ||
127 | switch (cmd) { | |
128 | case WDIOC_GETSUPPORT: | |
129 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | |
130 | sizeof(ident)) ? -EFAULT : 0; | |
131 | break; | |
132 | ||
133 | case WDIOC_GETSTATUS: | |
134 | ret = put_user(0, (int *)arg); | |
135 | break; | |
136 | ||
137 | case WDIOC_GETBOOTSTATUS: | |
138 | ret = put_user(0, (int *)arg); | |
139 | break; | |
140 | ||
141 | case WDIOC_KEEPALIVE: | |
142 | wdt_enable(); | |
143 | ret = 0; | |
144 | break; | |
145 | ||
146 | case WDIOC_SETTIMEOUT: | |
147 | ret = get_user(time, (int *)arg); | |
148 | if (ret) | |
149 | break; | |
150 | ||
151 | if (time < 31 || time > 255) { | |
152 | ret = -EINVAL; | |
153 | break; | |
154 | } | |
155 | ||
156 | margin = time; | |
157 | wdt_enable(); | |
158 | /* Fall through */ | |
159 | ||
160 | case WDIOC_GETTIMEOUT: | |
161 | ret = put_user(margin, (int *)arg); | |
162 | break; | |
163 | } | |
164 | ||
165 | return ret; | |
166 | } | |
167 | ||
168 | static int fitpc2_wdt_release(struct inode *inode, struct file *file) | |
169 | { | |
170 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) { | |
171 | wdt_disable(); | |
172 | pr_info("Device disabled\n"); | |
173 | } else { | |
174 | pr_warning("Device closed unexpectedly -" | |
175 | " timer will not stop\n"); | |
176 | wdt_enable(); | |
177 | } | |
178 | ||
179 | clear_bit(WDT_IN_USE, &wdt_status); | |
180 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
181 | ||
182 | return 0; | |
183 | } | |
184 | ||
185 | ||
186 | static const struct file_operations fitpc2_wdt_fops = { | |
187 | .owner = THIS_MODULE, | |
188 | .llseek = no_llseek, | |
189 | .write = fitpc2_wdt_write, | |
190 | .unlocked_ioctl = fitpc2_wdt_ioctl, | |
191 | .open = fitpc2_wdt_open, | |
192 | .release = fitpc2_wdt_release, | |
193 | }; | |
194 | ||
195 | static struct miscdevice fitpc2_wdt_miscdev = { | |
196 | .minor = WATCHDOG_MINOR, | |
197 | .name = "watchdog", | |
198 | .fops = &fitpc2_wdt_fops, | |
199 | }; | |
200 | ||
201 | static int __init fitpc2_wdt_init(void) | |
202 | { | |
203 | int err; | |
204 | ||
205 | if (strcmp("SBC-FITPC2", dmi_get_system_info(DMI_BOARD_NAME))) { | |
206 | pr_info("board name is: %s. Should be SBC-FITPC2\n", | |
207 | dmi_get_system_info(DMI_BOARD_NAME)); | |
208 | return -ENODEV; | |
209 | } | |
210 | ||
211 | if (!request_region(COMMAND_PORT, 1, WATCHDOG_NAME)) { | |
212 | pr_err("I/O address 0x%04x already in use\n", COMMAND_PORT); | |
213 | return -EIO; | |
214 | } | |
215 | ||
216 | if (!request_region(DATA_PORT, 1, WATCHDOG_NAME)) { | |
217 | pr_err("I/O address 0x%04x already in use\n", DATA_PORT); | |
218 | err = -EIO; | |
219 | goto err_data_port; | |
220 | } | |
221 | ||
222 | if (margin < 31 || margin > 255) { | |
223 | pr_err("margin must be in range 31 - 255" | |
224 | " seconds, you tried to set %d\n", margin); | |
225 | err = -EINVAL; | |
226 | goto err_margin; | |
227 | } | |
228 | ||
229 | err = misc_register(&fitpc2_wdt_miscdev); | |
230 | if (!err) { | |
231 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", | |
232 | WATCHDOG_MINOR, err); | |
233 | goto err_margin; | |
234 | } | |
235 | ||
236 | return 0; | |
237 | ||
238 | err_margin: | |
239 | release_region(DATA_PORT, 1); | |
240 | err_data_port: | |
241 | release_region(COMMAND_PORT, 1); | |
242 | ||
243 | return err; | |
244 | } | |
245 | ||
246 | static void __exit fitpc2_wdt_exit(void) | |
247 | { | |
248 | misc_deregister(&fitpc2_wdt_miscdev); | |
249 | release_region(DATA_PORT, 1); | |
250 | release_region(COMMAND_PORT, 1); | |
251 | } | |
252 | ||
253 | module_init(fitpc2_wdt_init); | |
254 | module_exit(fitpc2_wdt_exit); | |
255 | ||
256 | MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>"); | |
257 | MODULE_DESCRIPTION("SBC-FITPC2 Watchdog"); | |
258 | ||
259 | module_param(margin, int, 0); | |
260 | MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)"); | |
261 | ||
262 | module_param(nowayout, int, 0); | |
263 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); | |
264 | ||
265 | MODULE_LICENSE("GPL"); | |
266 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
267 |