diff options
Diffstat (limited to 'drivers/watchdog/iop_wdt.c')
-rw-r--r-- | drivers/watchdog/iop_wdt.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/drivers/watchdog/iop_wdt.c b/drivers/watchdog/iop_wdt.c new file mode 100644 index 000000000000..bbbd91af754d --- /dev/null +++ b/drivers/watchdog/iop_wdt.c | |||
@@ -0,0 +1,262 @@ | |||
1 | /* | ||
2 | * drivers/char/watchdog/iop_wdt.c | ||
3 | * | ||
4 | * WDT driver for Intel I/O Processors | ||
5 | * Copyright (C) 2005, Intel Corporation. | ||
6 | * | ||
7 | * Based on ixp4xx driver, Copyright 2004 (c) MontaVista, Software, Inc. | ||
8 | * | ||
9 | * This program is free software; you can redistribute it and/or modify it | ||
10 | * under the terms and conditions of the GNU General Public License, | ||
11 | * version 2, as published by the Free Software Foundation. | ||
12 | * | ||
13 | * This program is distributed in the hope it will be useful, but WITHOUT | ||
14 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
15 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | ||
16 | * more details. | ||
17 | * | ||
18 | * You should have received a copy of the GNU General Public License along with | ||
19 | * this program; if not, write to the Free Software Foundation, Inc., 59 Temple | ||
20 | * Place - Suite 330, Boston, MA 02111-1307 USA. | ||
21 | * | ||
22 | * Curt E Bruns <curt.e.bruns@intel.com> | ||
23 | * Peter Milne <peter.milne@d-tacq.com> | ||
24 | * Dan Williams <dan.j.williams@intel.com> | ||
25 | */ | ||
26 | |||
27 | #include <linux/module.h> | ||
28 | #include <linux/kernel.h> | ||
29 | #include <linux/fs.h> | ||
30 | #include <linux/init.h> | ||
31 | #include <linux/device.h> | ||
32 | #include <linux/miscdevice.h> | ||
33 | #include <linux/watchdog.h> | ||
34 | #include <linux/uaccess.h> | ||
35 | #include <asm/hardware.h> | ||
36 | |||
37 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
38 | static unsigned long wdt_status; | ||
39 | static unsigned long boot_status; | ||
40 | |||
41 | #define WDT_IN_USE 0 | ||
42 | #define WDT_OK_TO_CLOSE 1 | ||
43 | #define WDT_ENABLED 2 | ||
44 | |||
45 | static unsigned long iop_watchdog_timeout(void) | ||
46 | { | ||
47 | return (0xffffffffUL / get_iop_tick_rate()); | ||
48 | } | ||
49 | |||
50 | /** | ||
51 | * wdt_supports_disable - determine if we are accessing a iop13xx watchdog | ||
52 | * or iop3xx by whether it has a disable command | ||
53 | */ | ||
54 | static int wdt_supports_disable(void) | ||
55 | { | ||
56 | int can_disable; | ||
57 | |||
58 | if (IOP_WDTCR_EN_ARM != IOP_WDTCR_DIS_ARM) | ||
59 | can_disable = 1; | ||
60 | else | ||
61 | can_disable = 0; | ||
62 | |||
63 | return can_disable; | ||
64 | } | ||
65 | |||
66 | static void wdt_enable(void) | ||
67 | { | ||
68 | /* Arm and enable the Timer to starting counting down from 0xFFFF.FFFF | ||
69 | * Takes approx. 10.7s to timeout | ||
70 | */ | ||
71 | write_wdtcr(IOP_WDTCR_EN_ARM); | ||
72 | write_wdtcr(IOP_WDTCR_EN); | ||
73 | } | ||
74 | |||
75 | /* returns 0 if the timer was successfully disabled */ | ||
76 | static int wdt_disable(void) | ||
77 | { | ||
78 | /* Stop Counting */ | ||
79 | if (wdt_supports_disable()) { | ||
80 | write_wdtcr(IOP_WDTCR_DIS_ARM); | ||
81 | write_wdtcr(IOP_WDTCR_DIS); | ||
82 | clear_bit(WDT_ENABLED, &wdt_status); | ||
83 | printk(KERN_INFO "WATCHDOG: Disabled\n"); | ||
84 | return 0; | ||
85 | } else | ||
86 | return 1; | ||
87 | } | ||
88 | |||
89 | static int iop_wdt_open(struct inode *inode, struct file *file) | ||
90 | { | ||
91 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | ||
92 | return -EBUSY; | ||
93 | |||
94 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
95 | |||
96 | wdt_enable(); | ||
97 | |||
98 | set_bit(WDT_ENABLED, &wdt_status); | ||
99 | |||
100 | return nonseekable_open(inode, file); | ||
101 | } | ||
102 | |||
103 | static ssize_t | ||
104 | iop_wdt_write(struct file *file, const char *data, size_t len, | ||
105 | loff_t *ppos) | ||
106 | { | ||
107 | if (len) { | ||
108 | if (!nowayout) { | ||
109 | size_t i; | ||
110 | |||
111 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
112 | |||
113 | for (i = 0; i != len; i++) { | ||
114 | char c; | ||
115 | |||
116 | if (get_user(c, data + i)) | ||
117 | return -EFAULT; | ||
118 | if (c == 'V') | ||
119 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
120 | } | ||
121 | } | ||
122 | wdt_enable(); | ||
123 | } | ||
124 | |||
125 | return len; | ||
126 | } | ||
127 | |||
128 | static struct watchdog_info ident = { | ||
129 | .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, | ||
130 | .identity = "iop watchdog", | ||
131 | }; | ||
132 | |||
133 | static int | ||
134 | iop_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | ||
135 | unsigned long arg) | ||
136 | { | ||
137 | int options; | ||
138 | int ret = -ENOTTY; | ||
139 | |||
140 | switch (cmd) { | ||
141 | case WDIOC_GETSUPPORT: | ||
142 | if (copy_to_user | ||
143 | ((struct watchdog_info *)arg, &ident, sizeof ident)) | ||
144 | ret = -EFAULT; | ||
145 | else | ||
146 | ret = 0; | ||
147 | break; | ||
148 | |||
149 | case WDIOC_GETSTATUS: | ||
150 | ret = put_user(0, (int *)arg); | ||
151 | break; | ||
152 | |||
153 | case WDIOC_GETBOOTSTATUS: | ||
154 | ret = put_user(boot_status, (int *)arg); | ||
155 | break; | ||
156 | |||
157 | case WDIOC_GETTIMEOUT: | ||
158 | ret = put_user(iop_watchdog_timeout(), (int *)arg); | ||
159 | break; | ||
160 | |||
161 | case WDIOC_KEEPALIVE: | ||
162 | wdt_enable(); | ||
163 | ret = 0; | ||
164 | break; | ||
165 | |||
166 | case WDIOC_SETOPTIONS: | ||
167 | if (get_user(options, (int *)arg)) | ||
168 | return -EFAULT; | ||
169 | |||
170 | if (options & WDIOS_DISABLECARD) { | ||
171 | if (!nowayout) { | ||
172 | if (wdt_disable() == 0) { | ||
173 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
174 | ret = 0; | ||
175 | } else | ||
176 | ret = -ENXIO; | ||
177 | } else | ||
178 | ret = 0; | ||
179 | } | ||
180 | |||
181 | if (options & WDIOS_ENABLECARD) { | ||
182 | wdt_enable(); | ||
183 | ret = 0; | ||
184 | } | ||
185 | break; | ||
186 | } | ||
187 | |||
188 | return ret; | ||
189 | } | ||
190 | |||
191 | static int iop_wdt_release(struct inode *inode, struct file *file) | ||
192 | { | ||
193 | int state = 1; | ||
194 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) | ||
195 | if (test_bit(WDT_ENABLED, &wdt_status)) | ||
196 | state = wdt_disable(); | ||
197 | |||
198 | /* if the timer is not disbaled reload and notify that we are still | ||
199 | * going down | ||
200 | */ | ||
201 | if (state != 0) { | ||
202 | wdt_enable(); | ||
203 | printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - " | ||
204 | "reset in %lu seconds\n", iop_watchdog_timeout()); | ||
205 | } | ||
206 | |||
207 | clear_bit(WDT_IN_USE, &wdt_status); | ||
208 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
209 | |||
210 | return 0; | ||
211 | } | ||
212 | |||
213 | static const struct file_operations iop_wdt_fops = { | ||
214 | .owner = THIS_MODULE, | ||
215 | .llseek = no_llseek, | ||
216 | .write = iop_wdt_write, | ||
217 | .ioctl = iop_wdt_ioctl, | ||
218 | .open = iop_wdt_open, | ||
219 | .release = iop_wdt_release, | ||
220 | }; | ||
221 | |||
222 | static struct miscdevice iop_wdt_miscdev = { | ||
223 | .minor = WATCHDOG_MINOR, | ||
224 | .name = "watchdog", | ||
225 | .fops = &iop_wdt_fops, | ||
226 | }; | ||
227 | |||
228 | static int __init iop_wdt_init(void) | ||
229 | { | ||
230 | int ret; | ||
231 | |||
232 | ret = misc_register(&iop_wdt_miscdev); | ||
233 | if (ret == 0) | ||
234 | printk("iop watchdog timer: timeout %lu sec\n", | ||
235 | iop_watchdog_timeout()); | ||
236 | |||
237 | /* check if the reset was caused by the watchdog timer */ | ||
238 | boot_status = (read_rcsr() & IOP_RCSR_WDT) ? WDIOF_CARDRESET : 0; | ||
239 | |||
240 | /* Configure Watchdog Timeout to cause an Internal Bus (IB) Reset | ||
241 | * NOTE: An IB Reset will Reset both cores in the IOP342 | ||
242 | */ | ||
243 | write_wdtsr(IOP13XX_WDTCR_IB_RESET); | ||
244 | |||
245 | return ret; | ||
246 | } | ||
247 | |||
248 | static void __exit iop_wdt_exit(void) | ||
249 | { | ||
250 | misc_deregister(&iop_wdt_miscdev); | ||
251 | } | ||
252 | |||
253 | module_init(iop_wdt_init); | ||
254 | module_exit(iop_wdt_exit); | ||
255 | |||
256 | module_param(nowayout, int, 0); | ||
257 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); | ||
258 | |||
259 | MODULE_AUTHOR("Curt E Bruns <curt.e.bruns@intel.com>"); | ||
260 | MODULE_DESCRIPTION("iop watchdog timer driver"); | ||
261 | MODULE_LICENSE("GPL"); | ||
262 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||