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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 | ||
27c766aa JP |
20 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
21 | ||
33c050c5 DL |
22 | #include <linux/module.h> |
23 | #include <linux/moduleparam.h> | |
24 | #include <linux/types.h> | |
25 | #include <linux/kernel.h> | |
26 | #include <linux/fs.h> | |
27 | #include <linux/mm.h> | |
28 | #include <linux/miscdevice.h> | |
29 | #include <linux/watchdog.h> | |
30 | #include <linux/notifier.h> | |
31 | #include <linux/reboot.h> | |
32 | #include <linux/init.h> | |
33 | #include <asm/mach-pnx833x/pnx833x.h> | |
34 | ||
33c050c5 DL |
35 | #define WATCHDOG_TIMEOUT 30 /* 30 sec Maximum timeout */ |
36 | #define WATCHDOG_COUNT_FREQUENCY 68000000U /* Watchdog counts at 68MHZ. */ | |
76550d32 RD |
37 | #define PNX_WATCHDOG_TIMEOUT (WATCHDOG_TIMEOUT * WATCHDOG_COUNT_FREQUENCY) |
38 | #define PNX_TIMEOUT_VALUE 2040000000U | |
33c050c5 DL |
39 | |
40 | /** CONFIG block */ | |
41 | #define PNX833X_CONFIG (0x07000U) | |
42 | #define PNX833X_CONFIG_CPU_WATCHDOG (0x54) | |
43 | #define PNX833X_CONFIG_CPU_WATCHDOG_COMPARE (0x58) | |
44 | #define PNX833X_CONFIG_CPU_COUNTERS_CONTROL (0x1c) | |
45 | ||
46 | /** RESET block */ | |
47 | #define PNX833X_RESET (0x08000U) | |
48 | #define PNX833X_RESET_CONFIG (0x08) | |
49 | ||
50 | static int pnx833x_wdt_alive; | |
51 | ||
52 | /* Set default timeout in MHZ.*/ | |
76550d32 | 53 | static int pnx833x_wdt_timeout = PNX_WATCHDOG_TIMEOUT; |
33c050c5 DL |
54 | module_param(pnx833x_wdt_timeout, int, 0); |
55 | MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default=" | |
76550d32 | 56 | __MODULE_STRING(PNX_TIMEOUT_VALUE) "(30 seconds)."); |
33c050c5 | 57 | |
86a1e189 WVS |
58 | static bool nowayout = WATCHDOG_NOWAYOUT; |
59 | module_param(nowayout, bool, 0); | |
33c050c5 DL |
60 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
61 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
62 | ||
76550d32 RD |
63 | #define START_DEFAULT 1 |
64 | static int start_enabled = START_DEFAULT; | |
33c050c5 DL |
65 | module_param(start_enabled, int, 0); |
66 | MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion " | |
76550d32 | 67 | "(default=" __MODULE_STRING(START_DEFAULT) ")"); |
33c050c5 DL |
68 | |
69 | static void pnx833x_wdt_start(void) | |
70 | { | |
71 | /* Enable watchdog causing reset. */ | |
72 | PNX833X_REG(PNX833X_RESET + PNX833X_RESET_CONFIG) |= 0x1; | |
73 | /* Set timeout.*/ | |
74 | PNX833X_REG(PNX833X_CONFIG + | |
75 | PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout; | |
76 | /* Enable watchdog. */ | |
77 | PNX833X_REG(PNX833X_CONFIG + | |
78 | PNX833X_CONFIG_CPU_COUNTERS_CONTROL) |= 0x1; | |
79 | ||
27c766aa | 80 | pr_info("Started watchdog timer\n"); |
33c050c5 DL |
81 | } |
82 | ||
83 | static void pnx833x_wdt_stop(void) | |
84 | { | |
85 | /* Disable watchdog causing reset. */ | |
86 | PNX833X_REG(PNX833X_RESET + PNX833X_CONFIG) &= 0xFFFFFFFE; | |
87 | /* Disable watchdog.*/ | |
88 | PNX833X_REG(PNX833X_CONFIG + | |
89 | PNX833X_CONFIG_CPU_COUNTERS_CONTROL) &= 0xFFFFFFFE; | |
90 | ||
27c766aa | 91 | pr_info("Stopped watchdog timer\n"); |
33c050c5 DL |
92 | } |
93 | ||
94 | static void pnx833x_wdt_ping(void) | |
95 | { | |
96 | PNX833X_REG(PNX833X_CONFIG + | |
97 | PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout; | |
98 | } | |
99 | ||
100 | /* | |
101 | * Allow only one person to hold it open | |
102 | */ | |
103 | static int pnx833x_wdt_open(struct inode *inode, struct file *file) | |
104 | { | |
105 | if (test_and_set_bit(0, &pnx833x_wdt_alive)) | |
106 | return -EBUSY; | |
107 | ||
108 | if (nowayout) | |
109 | __module_get(THIS_MODULE); | |
110 | ||
111 | /* Activate timer */ | |
112 | if (!start_enabled) | |
113 | pnx833x_wdt_start(); | |
114 | ||
115 | pnx833x_wdt_ping(); | |
116 | ||
27c766aa | 117 | pr_info("Started watchdog timer\n"); |
33c050c5 DL |
118 | |
119 | return nonseekable_open(inode, file); | |
120 | } | |
121 | ||
122 | static int pnx833x_wdt_release(struct inode *inode, struct file *file) | |
123 | { | |
124 | /* Shut off the timer. | |
125 | * Lock it in if it's a module and we defined ...NOWAYOUT */ | |
126 | if (!nowayout) | |
127 | pnx833x_wdt_stop(); /* Turn the WDT off */ | |
128 | ||
129 | clear_bit(0, &pnx833x_wdt_alive); | |
130 | return 0; | |
131 | } | |
132 | ||
133 | static ssize_t pnx833x_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) | |
134 | { | |
135 | /* Refresh the timer. */ | |
136 | if (len) | |
137 | pnx833x_wdt_ping(); | |
138 | ||
139 | return len; | |
140 | } | |
141 | ||
142 | static long pnx833x_wdt_ioctl(struct file *file, unsigned int cmd, | |
143 | unsigned long arg) | |
144 | { | |
145 | int options, new_timeout = 0; | |
146 | uint32_t timeout, timeout_left = 0; | |
147 | ||
42747d71 | 148 | static const struct watchdog_info ident = { |
33c050c5 DL |
149 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, |
150 | .firmware_version = 0, | |
151 | .identity = "Hardware Watchdog for PNX833x", | |
152 | }; | |
153 | ||
154 | switch (cmd) { | |
155 | default: | |
156 | return -ENOTTY; | |
157 | ||
158 | case WDIOC_GETSUPPORT: | |
159 | if (copy_to_user((struct watchdog_info *)arg, | |
160 | &ident, sizeof(ident))) | |
161 | return -EFAULT; | |
162 | return 0; | |
163 | ||
164 | case WDIOC_GETSTATUS: | |
165 | case WDIOC_GETBOOTSTATUS: | |
166 | return put_user(0, (int *)arg); | |
167 | ||
168 | case WDIOC_SETOPTIONS: | |
169 | if (get_user(options, (int *)arg)) | |
170 | return -EFAULT; | |
171 | ||
172 | if (options & WDIOS_DISABLECARD) | |
173 | pnx833x_wdt_stop(); | |
174 | ||
175 | if (options & WDIOS_ENABLECARD) | |
176 | pnx833x_wdt_start(); | |
177 | ||
178 | return 0; | |
179 | ||
180 | case WDIOC_KEEPALIVE: | |
181 | pnx833x_wdt_ping(); | |
182 | return 0; | |
183 | ||
184 | case WDIOC_SETTIMEOUT: | |
185 | { | |
186 | if (get_user(new_timeout, (int *)arg)) | |
187 | return -EFAULT; | |
188 | ||
189 | pnx833x_wdt_timeout = new_timeout; | |
190 | PNX833X_REG(PNX833X_CONFIG + | |
191 | PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = new_timeout; | |
192 | return put_user(new_timeout, (int *)arg); | |
193 | } | |
194 | ||
195 | case WDIOC_GETTIMEOUT: | |
196 | timeout = PNX833X_REG(PNX833X_CONFIG + | |
197 | PNX833X_CONFIG_CPU_WATCHDOG_COMPARE); | |
198 | return put_user(timeout, (int *)arg); | |
199 | ||
200 | case WDIOC_GETTIMELEFT: | |
201 | timeout_left = PNX833X_REG(PNX833X_CONFIG + | |
202 | PNX833X_CONFIG_CPU_WATCHDOG); | |
203 | return put_user(timeout_left, (int *)arg); | |
204 | ||
205 | } | |
206 | } | |
207 | ||
208 | static int pnx833x_wdt_notify_sys(struct notifier_block *this, | |
209 | unsigned long code, void *unused) | |
210 | { | |
211 | if (code == SYS_DOWN || code == SYS_HALT) | |
212 | pnx833x_wdt_stop(); /* Turn the WDT off */ | |
213 | ||
214 | return NOTIFY_DONE; | |
215 | } | |
216 | ||
217 | static const struct file_operations pnx833x_wdt_fops = { | |
218 | .owner = THIS_MODULE, | |
219 | .llseek = no_llseek, | |
220 | .write = pnx833x_wdt_write, | |
221 | .unlocked_ioctl = pnx833x_wdt_ioctl, | |
222 | .open = pnx833x_wdt_open, | |
223 | .release = pnx833x_wdt_release, | |
224 | }; | |
225 | ||
226 | static struct miscdevice pnx833x_wdt_miscdev = { | |
227 | .minor = WATCHDOG_MINOR, | |
228 | .name = "watchdog", | |
229 | .fops = &pnx833x_wdt_fops, | |
230 | }; | |
231 | ||
232 | static struct notifier_block pnx833x_wdt_notifier = { | |
233 | .notifier_call = pnx833x_wdt_notify_sys, | |
234 | }; | |
235 | ||
33c050c5 DL |
236 | static int __init watchdog_init(void) |
237 | { | |
238 | int ret, cause; | |
239 | ||
240 | /* Lets check the reason for the reset.*/ | |
241 | cause = PNX833X_REG(PNX833X_RESET); | |
242 | /*If bit 31 is set then watchdog was cause of reset.*/ | |
243 | if (cause & 0x80000000) { | |
27c766aa | 244 | pr_info("The system was previously reset due to the watchdog firing - please investigate...\n"); |
33c050c5 DL |
245 | } |
246 | ||
247 | ret = register_reboot_notifier(&pnx833x_wdt_notifier); | |
248 | if (ret) { | |
27c766aa | 249 | pr_err("cannot register reboot notifier (err=%d)\n", ret); |
33c050c5 DL |
250 | return ret; |
251 | } | |
252 | ||
253 | ret = misc_register(&pnx833x_wdt_miscdev); | |
254 | if (ret) { | |
27c766aa JP |
255 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
256 | WATCHDOG_MINOR, ret); | |
33c050c5 DL |
257 | unregister_reboot_notifier(&pnx833x_wdt_notifier); |
258 | return ret; | |
259 | } | |
260 | ||
27c766aa JP |
261 | pr_info("Hardware Watchdog Timer for PNX833x: Version 0.1\n"); |
262 | ||
33c050c5 DL |
263 | if (start_enabled) |
264 | pnx833x_wdt_start(); | |
265 | ||
266 | return 0; | |
267 | } | |
268 | ||
269 | static void __exit watchdog_exit(void) | |
270 | { | |
271 | misc_deregister(&pnx833x_wdt_miscdev); | |
272 | unregister_reboot_notifier(&pnx833x_wdt_notifier); | |
273 | } | |
274 | ||
275 | module_init(watchdog_init); | |
276 | module_exit(watchdog_exit); | |
277 | ||
278 | MODULE_AUTHOR("Daniel Laird/Andre McCurdy"); | |
279 | MODULE_DESCRIPTION("Hardware Watchdog Device for PNX833x"); | |
280 | MODULE_LICENSE("GPL"); |