Commit | Line | Data |
---|---|---|
33c050c5 DL |
1 | /* |
2 | * PNX833x Hardware Watchdog Driver | |
3 | * Copyright 2008 NXP Semiconductors | |
4 | * Daniel Laird <daniel.j.laird@nxp.com> | |
5 | * Andre McCurdy <andre.mccurdy@nxp.com> | |
6 | * | |
7 | * Heavily based upon - IndyDog 0.3 | |
8 | * A Hardware Watchdog Device for SGI IP22 | |
9 | * | |
10 | * (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, All Rights Reserved. | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License | |
14 | * as published by the Free Software Foundation; either version | |
15 | * 2 of the License, or (at your option) any later version. | |
16 | * | |
17 | * based on softdog.c by Alan Cox <alan@redhat.com> | |
18 | */ | |
19 | ||
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/mm.h> | |
26 | #include <linux/miscdevice.h> | |
27 | #include <linux/watchdog.h> | |
28 | #include <linux/notifier.h> | |
29 | #include <linux/reboot.h> | |
30 | #include <linux/init.h> | |
31 | #include <asm/mach-pnx833x/pnx833x.h> | |
32 | ||
33 | #define PFX "pnx833x: " | |
34 | #define WATCHDOG_TIMEOUT 30 /* 30 sec Maximum timeout */ | |
35 | #define WATCHDOG_COUNT_FREQUENCY 68000000U /* Watchdog counts at 68MHZ. */ | |
76550d32 RD |
36 | #define PNX_WATCHDOG_TIMEOUT (WATCHDOG_TIMEOUT * WATCHDOG_COUNT_FREQUENCY) |
37 | #define PNX_TIMEOUT_VALUE 2040000000U | |
33c050c5 DL |
38 | |
39 | /** CONFIG block */ | |
40 | #define PNX833X_CONFIG (0x07000U) | |
41 | #define PNX833X_CONFIG_CPU_WATCHDOG (0x54) | |
42 | #define PNX833X_CONFIG_CPU_WATCHDOG_COMPARE (0x58) | |
43 | #define PNX833X_CONFIG_CPU_COUNTERS_CONTROL (0x1c) | |
44 | ||
45 | /** RESET block */ | |
46 | #define PNX833X_RESET (0x08000U) | |
47 | #define PNX833X_RESET_CONFIG (0x08) | |
48 | ||
49 | static int pnx833x_wdt_alive; | |
50 | ||
51 | /* Set default timeout in MHZ.*/ | |
76550d32 | 52 | static int pnx833x_wdt_timeout = PNX_WATCHDOG_TIMEOUT; |
33c050c5 DL |
53 | module_param(pnx833x_wdt_timeout, int, 0); |
54 | MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default=" | |
76550d32 | 55 | __MODULE_STRING(PNX_TIMEOUT_VALUE) "(30 seconds)."); |
33c050c5 DL |
56 | |
57 | static int nowayout = WATCHDOG_NOWAYOUT; | |
58 | module_param(nowayout, int, 0); | |
59 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" | |
60 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
61 | ||
76550d32 RD |
62 | #define START_DEFAULT 1 |
63 | static int start_enabled = START_DEFAULT; | |
33c050c5 DL |
64 | module_param(start_enabled, int, 0); |
65 | MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion " | |
76550d32 | 66 | "(default=" __MODULE_STRING(START_DEFAULT) ")"); |
33c050c5 DL |
67 | |
68 | static void pnx833x_wdt_start(void) | |
69 | { | |
70 | /* Enable watchdog causing reset. */ | |
71 | PNX833X_REG(PNX833X_RESET + PNX833X_RESET_CONFIG) |= 0x1; | |
72 | /* Set timeout.*/ | |
73 | PNX833X_REG(PNX833X_CONFIG + | |
74 | PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout; | |
75 | /* Enable watchdog. */ | |
76 | PNX833X_REG(PNX833X_CONFIG + | |
77 | PNX833X_CONFIG_CPU_COUNTERS_CONTROL) |= 0x1; | |
78 | ||
79 | printk(KERN_INFO PFX "Started watchdog timer.\n"); | |
80 | } | |
81 | ||
82 | static void pnx833x_wdt_stop(void) | |
83 | { | |
84 | /* Disable watchdog causing reset. */ | |
85 | PNX833X_REG(PNX833X_RESET + PNX833X_CONFIG) &= 0xFFFFFFFE; | |
86 | /* Disable watchdog.*/ | |
87 | PNX833X_REG(PNX833X_CONFIG + | |
88 | PNX833X_CONFIG_CPU_COUNTERS_CONTROL) &= 0xFFFFFFFE; | |
89 | ||
90 | printk(KERN_INFO PFX "Stopped watchdog timer.\n"); | |
91 | } | |
92 | ||
93 | static void pnx833x_wdt_ping(void) | |
94 | { | |
95 | PNX833X_REG(PNX833X_CONFIG + | |
96 | PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout; | |
97 | } | |
98 | ||
99 | /* | |
100 | * Allow only one person to hold it open | |
101 | */ | |
102 | static int pnx833x_wdt_open(struct inode *inode, struct file *file) | |
103 | { | |
104 | if (test_and_set_bit(0, &pnx833x_wdt_alive)) | |
105 | return -EBUSY; | |
106 | ||
107 | if (nowayout) | |
108 | __module_get(THIS_MODULE); | |
109 | ||
110 | /* Activate timer */ | |
111 | if (!start_enabled) | |
112 | pnx833x_wdt_start(); | |
113 | ||
114 | pnx833x_wdt_ping(); | |
115 | ||
116 | printk(KERN_INFO "Started watchdog timer.\n"); | |
117 | ||
118 | return nonseekable_open(inode, file); | |
119 | } | |
120 | ||
121 | static int pnx833x_wdt_release(struct inode *inode, struct file *file) | |
122 | { | |
123 | /* Shut off the timer. | |
124 | * Lock it in if it's a module and we defined ...NOWAYOUT */ | |
125 | if (!nowayout) | |
126 | pnx833x_wdt_stop(); /* Turn the WDT off */ | |
127 | ||
128 | clear_bit(0, &pnx833x_wdt_alive); | |
129 | return 0; | |
130 | } | |
131 | ||
132 | static ssize_t pnx833x_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) | |
133 | { | |
134 | /* Refresh the timer. */ | |
135 | if (len) | |
136 | pnx833x_wdt_ping(); | |
137 | ||
138 | return len; | |
139 | } | |
140 | ||
141 | static long pnx833x_wdt_ioctl(struct file *file, unsigned int cmd, | |
142 | unsigned long arg) | |
143 | { | |
144 | int options, new_timeout = 0; | |
145 | uint32_t timeout, timeout_left = 0; | |
146 | ||
42747d71 | 147 | static const struct watchdog_info ident = { |
33c050c5 DL |
148 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, |
149 | .firmware_version = 0, | |
150 | .identity = "Hardware Watchdog for PNX833x", | |
151 | }; | |
152 | ||
153 | switch (cmd) { | |
154 | default: | |
155 | return -ENOTTY; | |
156 | ||
157 | case WDIOC_GETSUPPORT: | |
158 | if (copy_to_user((struct watchdog_info *)arg, | |
159 | &ident, sizeof(ident))) | |
160 | return -EFAULT; | |
161 | return 0; | |
162 | ||
163 | case WDIOC_GETSTATUS: | |
164 | case WDIOC_GETBOOTSTATUS: | |
165 | return put_user(0, (int *)arg); | |
166 | ||
167 | case WDIOC_SETOPTIONS: | |
168 | if (get_user(options, (int *)arg)) | |
169 | return -EFAULT; | |
170 | ||
171 | if (options & WDIOS_DISABLECARD) | |
172 | pnx833x_wdt_stop(); | |
173 | ||
174 | if (options & WDIOS_ENABLECARD) | |
175 | pnx833x_wdt_start(); | |
176 | ||
177 | return 0; | |
178 | ||
179 | case WDIOC_KEEPALIVE: | |
180 | pnx833x_wdt_ping(); | |
181 | return 0; | |
182 | ||
183 | case WDIOC_SETTIMEOUT: | |
184 | { | |
185 | if (get_user(new_timeout, (int *)arg)) | |
186 | return -EFAULT; | |
187 | ||
188 | pnx833x_wdt_timeout = new_timeout; | |
189 | PNX833X_REG(PNX833X_CONFIG + | |
190 | PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = new_timeout; | |
191 | return put_user(new_timeout, (int *)arg); | |
192 | } | |
193 | ||
194 | case WDIOC_GETTIMEOUT: | |
195 | timeout = PNX833X_REG(PNX833X_CONFIG + | |
196 | PNX833X_CONFIG_CPU_WATCHDOG_COMPARE); | |
197 | return put_user(timeout, (int *)arg); | |
198 | ||
199 | case WDIOC_GETTIMELEFT: | |
200 | timeout_left = PNX833X_REG(PNX833X_CONFIG + | |
201 | PNX833X_CONFIG_CPU_WATCHDOG); | |
202 | return put_user(timeout_left, (int *)arg); | |
203 | ||
204 | } | |
205 | } | |
206 | ||
207 | static int pnx833x_wdt_notify_sys(struct notifier_block *this, | |
208 | unsigned long code, void *unused) | |
209 | { | |
210 | if (code == SYS_DOWN || code == SYS_HALT) | |
211 | pnx833x_wdt_stop(); /* Turn the WDT off */ | |
212 | ||
213 | return NOTIFY_DONE; | |
214 | } | |
215 | ||
216 | static const struct file_operations pnx833x_wdt_fops = { | |
217 | .owner = THIS_MODULE, | |
218 | .llseek = no_llseek, | |
219 | .write = pnx833x_wdt_write, | |
220 | .unlocked_ioctl = pnx833x_wdt_ioctl, | |
221 | .open = pnx833x_wdt_open, | |
222 | .release = pnx833x_wdt_release, | |
223 | }; | |
224 | ||
225 | static struct miscdevice pnx833x_wdt_miscdev = { | |
226 | .minor = WATCHDOG_MINOR, | |
227 | .name = "watchdog", | |
228 | .fops = &pnx833x_wdt_fops, | |
229 | }; | |
230 | ||
231 | static struct notifier_block pnx833x_wdt_notifier = { | |
232 | .notifier_call = pnx833x_wdt_notify_sys, | |
233 | }; | |
234 | ||
235 | static char banner[] __initdata = | |
236 | KERN_INFO PFX "Hardware Watchdog Timer for PNX833x: Version 0.1\n"; | |
237 | ||
238 | static int __init watchdog_init(void) | |
239 | { | |
240 | int ret, cause; | |
241 | ||
242 | /* Lets check the reason for the reset.*/ | |
243 | cause = PNX833X_REG(PNX833X_RESET); | |
244 | /*If bit 31 is set then watchdog was cause of reset.*/ | |
245 | if (cause & 0x80000000) { | |
246 | printk(KERN_INFO PFX "The system was previously reset due to " | |
247 | "the watchdog firing - please investigate...\n"); | |
248 | } | |
249 | ||
250 | ret = register_reboot_notifier(&pnx833x_wdt_notifier); | |
251 | if (ret) { | |
252 | printk(KERN_ERR PFX | |
253 | "cannot register reboot notifier (err=%d)\n", ret); | |
254 | return ret; | |
255 | } | |
256 | ||
257 | ret = misc_register(&pnx833x_wdt_miscdev); | |
258 | if (ret) { | |
259 | printk(KERN_ERR PFX | |
260 | "cannot register miscdev on minor=%d (err=%d)\n", | |
261 | WATCHDOG_MINOR, ret); | |
262 | unregister_reboot_notifier(&pnx833x_wdt_notifier); | |
263 | return ret; | |
264 | } | |
265 | ||
266 | printk(banner); | |
267 | if (start_enabled) | |
268 | pnx833x_wdt_start(); | |
269 | ||
270 | return 0; | |
271 | } | |
272 | ||
273 | static void __exit watchdog_exit(void) | |
274 | { | |
275 | misc_deregister(&pnx833x_wdt_miscdev); | |
276 | unregister_reboot_notifier(&pnx833x_wdt_notifier); | |
277 | } | |
278 | ||
279 | module_init(watchdog_init); | |
280 | module_exit(watchdog_exit); | |
281 | ||
282 | MODULE_AUTHOR("Daniel Laird/Andre McCurdy"); | |
283 | MODULE_DESCRIPTION("Hardware Watchdog Device for PNX833x"); | |
284 | MODULE_LICENSE("GPL"); | |
285 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |