Commit | Line | Data |
---|---|---|
fabbfb9e | 1 | /* |
0d7b1014 | 2 | * mpc8xxx_wdt.c - MPC8xx/MPC83xx/MPC86xx watchdog userspace interface |
fabbfb9e KG |
3 | * |
4 | * Authors: Dave Updegraff <dave@cray.org> | |
5f3b2756 WVS |
5 | * Kumar Gala <galak@kernel.crashing.org> |
6 | * Attribution: from 83xx_wst: Florian Schirmer <jolt@tuxbox.org> | |
7 | * ..and from sc520_wdt | |
500c919e AV |
8 | * Copyright (c) 2008 MontaVista Software, Inc. |
9 | * Anton Vorontsov <avorontsov@ru.mvista.com> | |
fabbfb9e KG |
10 | * |
11 | * Note: it appears that you can only actually ENABLE or DISABLE the thing | |
12 | * once after POR. Once enabled, you cannot disable, and vice versa. | |
13 | * | |
14 | * This program is free software; you can redistribute it and/or modify it | |
15 | * under the terms of the GNU General Public License as published by the | |
16 | * Free Software Foundation; either version 2 of the License, or (at your | |
17 | * option) any later version. | |
18 | */ | |
19 | ||
27c766aa JP |
20 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
21 | ||
fabbfb9e KG |
22 | #include <linux/fs.h> |
23 | #include <linux/init.h> | |
24 | #include <linux/kernel.h> | |
500c919e | 25 | #include <linux/timer.h> |
fabbfb9e | 26 | #include <linux/miscdevice.h> |
ef8ab12e | 27 | #include <linux/of_platform.h> |
fabbfb9e KG |
28 | #include <linux/module.h> |
29 | #include <linux/watchdog.h> | |
f26ef3dc AC |
30 | #include <linux/io.h> |
31 | #include <linux/uaccess.h> | |
ef8ab12e | 32 | #include <sysdev/fsl_soc.h> |
fabbfb9e | 33 | |
59ca1b0d | 34 | struct mpc8xxx_wdt { |
fabbfb9e KG |
35 | __be32 res0; |
36 | __be32 swcrr; /* System watchdog control register */ | |
37 | #define SWCRR_SWTC 0xFFFF0000 /* Software Watchdog Time Count. */ | |
38 | #define SWCRR_SWEN 0x00000004 /* Watchdog Enable bit. */ | |
39 | #define SWCRR_SWRI 0x00000002 /* Software Watchdog Reset/Interrupt Select bit.*/ | |
40 | #define SWCRR_SWPR 0x00000001 /* Software Watchdog Counter Prescale bit. */ | |
41 | __be32 swcnr; /* System watchdog count register */ | |
42 | u8 res1[2]; | |
43 | __be16 swsrr; /* System watchdog service register */ | |
44 | u8 res2[0xF0]; | |
45 | }; | |
46 | ||
59ca1b0d | 47 | struct mpc8xxx_wdt_type { |
500c919e AV |
48 | int prescaler; |
49 | bool hw_enabled; | |
50 | }; | |
51 | ||
59ca1b0d | 52 | static struct mpc8xxx_wdt __iomem *wd_base; |
593fc178 | 53 | static int mpc8xxx_wdt_init_late(void); |
fabbfb9e KG |
54 | |
55 | static u16 timeout = 0xffff; | |
56 | module_param(timeout, ushort, 0); | |
f26ef3dc | 57 | MODULE_PARM_DESC(timeout, |
76550d32 | 58 | "Watchdog timeout in ticks. (0<timeout<65536, default=65535)"); |
fabbfb9e | 59 | |
90ab5ee9 | 60 | static bool reset = 1; |
fabbfb9e | 61 | module_param(reset, bool, 0); |
f26ef3dc AC |
62 | MODULE_PARM_DESC(reset, |
63 | "Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset"); | |
fabbfb9e | 64 | |
86a1e189 WVS |
65 | static bool nowayout = WATCHDOG_NOWAYOUT; |
66 | module_param(nowayout, bool, 0); | |
500c919e AV |
67 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " |
68 | "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
69 | ||
fabbfb9e KG |
70 | /* |
71 | * We always prescale, but if someone really doesn't want to they can set this | |
72 | * to 0 | |
73 | */ | |
74 | static int prescale = 1; | |
75 | static unsigned int timeout_sec; | |
76 | ||
77 | static unsigned long wdt_is_open; | |
c7dfd0cc | 78 | static DEFINE_SPINLOCK(wdt_spinlock); |
fabbfb9e | 79 | |
59ca1b0d | 80 | static void mpc8xxx_wdt_keepalive(void) |
fabbfb9e KG |
81 | { |
82 | /* Ping the WDT */ | |
83 | spin_lock(&wdt_spinlock); | |
84 | out_be16(&wd_base->swsrr, 0x556c); | |
85 | out_be16(&wd_base->swsrr, 0xaa39); | |
86 | spin_unlock(&wdt_spinlock); | |
87 | } | |
88 | ||
59ca1b0d AV |
89 | static void mpc8xxx_wdt_timer_ping(unsigned long arg); |
90 | static DEFINE_TIMER(wdt_timer, mpc8xxx_wdt_timer_ping, 0, 0); | |
500c919e | 91 | |
59ca1b0d | 92 | static void mpc8xxx_wdt_timer_ping(unsigned long arg) |
500c919e | 93 | { |
59ca1b0d | 94 | mpc8xxx_wdt_keepalive(); |
500c919e AV |
95 | /* We're pinging it twice faster than needed, just to be sure. */ |
96 | mod_timer(&wdt_timer, jiffies + HZ * timeout_sec / 2); | |
97 | } | |
98 | ||
59ca1b0d | 99 | static void mpc8xxx_wdt_pr_warn(const char *msg) |
500c919e | 100 | { |
27c766aa | 101 | pr_crit("%s, expect the %s soon!\n", msg, |
500c919e AV |
102 | reset ? "reset" : "machine check exception"); |
103 | } | |
104 | ||
59ca1b0d | 105 | static ssize_t mpc8xxx_wdt_write(struct file *file, const char __user *buf, |
fabbfb9e KG |
106 | size_t count, loff_t *ppos) |
107 | { | |
108 | if (count) | |
59ca1b0d | 109 | mpc8xxx_wdt_keepalive(); |
fabbfb9e KG |
110 | return count; |
111 | } | |
112 | ||
59ca1b0d | 113 | static int mpc8xxx_wdt_open(struct inode *inode, struct file *file) |
fabbfb9e KG |
114 | { |
115 | u32 tmp = SWCRR_SWEN; | |
116 | if (test_and_set_bit(0, &wdt_is_open)) | |
117 | return -EBUSY; | |
118 | ||
119 | /* Once we start the watchdog we can't stop it */ | |
500c919e AV |
120 | if (nowayout) |
121 | __module_get(THIS_MODULE); | |
fabbfb9e KG |
122 | |
123 | /* Good, fire up the show */ | |
124 | if (prescale) | |
125 | tmp |= SWCRR_SWPR; | |
126 | if (reset) | |
127 | tmp |= SWCRR_SWRI; | |
128 | ||
129 | tmp |= timeout << 16; | |
130 | ||
131 | out_be32(&wd_base->swcrr, tmp); | |
132 | ||
500c919e AV |
133 | del_timer_sync(&wdt_timer); |
134 | ||
fabbfb9e KG |
135 | return nonseekable_open(inode, file); |
136 | } | |
137 | ||
59ca1b0d | 138 | static int mpc8xxx_wdt_release(struct inode *inode, struct file *file) |
fabbfb9e | 139 | { |
500c919e | 140 | if (!nowayout) |
59ca1b0d | 141 | mpc8xxx_wdt_timer_ping(0); |
500c919e | 142 | else |
59ca1b0d | 143 | mpc8xxx_wdt_pr_warn("watchdog closed"); |
fabbfb9e KG |
144 | clear_bit(0, &wdt_is_open); |
145 | return 0; | |
146 | } | |
147 | ||
cb55d282 | 148 | static long mpc8xxx_wdt_ioctl(struct file *file, unsigned int cmd, |
f26ef3dc | 149 | unsigned long arg) |
fabbfb9e KG |
150 | { |
151 | void __user *argp = (void __user *)arg; | |
152 | int __user *p = argp; | |
42747d71 | 153 | static const struct watchdog_info ident = { |
fabbfb9e KG |
154 | .options = WDIOF_KEEPALIVEPING, |
155 | .firmware_version = 1, | |
59ca1b0d | 156 | .identity = "MPC8xxx", |
fabbfb9e KG |
157 | }; |
158 | ||
159 | switch (cmd) { | |
160 | case WDIOC_GETSUPPORT: | |
161 | return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; | |
5c4eb61b WVS |
162 | case WDIOC_GETSTATUS: |
163 | case WDIOC_GETBOOTSTATUS: | |
164 | return put_user(0, p); | |
fabbfb9e | 165 | case WDIOC_KEEPALIVE: |
59ca1b0d | 166 | mpc8xxx_wdt_keepalive(); |
fabbfb9e KG |
167 | return 0; |
168 | case WDIOC_GETTIMEOUT: | |
169 | return put_user(timeout_sec, p); | |
170 | default: | |
795b89d2 | 171 | return -ENOTTY; |
fabbfb9e KG |
172 | } |
173 | } | |
174 | ||
59ca1b0d | 175 | static const struct file_operations mpc8xxx_wdt_fops = { |
fabbfb9e KG |
176 | .owner = THIS_MODULE, |
177 | .llseek = no_llseek, | |
59ca1b0d AV |
178 | .write = mpc8xxx_wdt_write, |
179 | .unlocked_ioctl = mpc8xxx_wdt_ioctl, | |
180 | .open = mpc8xxx_wdt_open, | |
181 | .release = mpc8xxx_wdt_release, | |
fabbfb9e KG |
182 | }; |
183 | ||
59ca1b0d | 184 | static struct miscdevice mpc8xxx_wdt_miscdev = { |
fabbfb9e KG |
185 | .minor = WATCHDOG_MINOR, |
186 | .name = "watchdog", | |
59ca1b0d | 187 | .fops = &mpc8xxx_wdt_fops, |
fabbfb9e KG |
188 | }; |
189 | ||
b1608d69 | 190 | static const struct of_device_id mpc8xxx_wdt_match[]; |
1c48a5c9 | 191 | static int __devinit mpc8xxx_wdt_probe(struct platform_device *ofdev) |
fabbfb9e | 192 | { |
fabbfb9e | 193 | int ret; |
b1608d69 | 194 | const struct of_device_id *match; |
de2b606c | 195 | struct device_node *np = ofdev->dev.of_node; |
639397e4 | 196 | const struct mpc8xxx_wdt_type *wdt_type; |
ef8ab12e | 197 | u32 freq = fsl_get_sys_freq(); |
500c919e | 198 | bool enabled; |
fabbfb9e | 199 | |
b1608d69 GL |
200 | match = of_match_device(mpc8xxx_wdt_match, &ofdev->dev); |
201 | if (!match) | |
1c48a5c9 | 202 | return -EINVAL; |
b1608d69 | 203 | wdt_type = match->data; |
1c48a5c9 | 204 | |
ef8ab12e AV |
205 | if (!freq || freq == -1) |
206 | return -EINVAL; | |
fabbfb9e | 207 | |
500c919e | 208 | wd_base = of_iomap(np, 0); |
ef8ab12e AV |
209 | if (!wd_base) |
210 | return -ENOMEM; | |
fabbfb9e | 211 | |
500c919e AV |
212 | enabled = in_be32(&wd_base->swcrr) & SWCRR_SWEN; |
213 | if (!enabled && wdt_type->hw_enabled) { | |
27c766aa | 214 | pr_info("could not be enabled in software\n"); |
500c919e AV |
215 | ret = -ENOSYS; |
216 | goto err_unmap; | |
217 | } | |
218 | ||
fabbfb9e KG |
219 | /* Calculate the timeout in seconds */ |
220 | if (prescale) | |
500c919e | 221 | timeout_sec = (timeout * wdt_type->prescaler) / freq; |
fabbfb9e | 222 | else |
ef8ab12e | 223 | timeout_sec = timeout / freq; |
fabbfb9e | 224 | |
593fc178 AV |
225 | #ifdef MODULE |
226 | ret = mpc8xxx_wdt_init_late(); | |
227 | if (ret) | |
228 | goto err_unmap; | |
229 | #endif | |
230 | ||
27c766aa JP |
231 | pr_info("WDT driver for MPC8xxx initialized. mode:%s timeout=%d (%d seconds)\n", |
232 | reset ? "reset" : "interrupt", timeout, timeout_sec); | |
500c919e AV |
233 | |
234 | /* | |
235 | * If the watchdog was previously enabled or we're running on | |
59ca1b0d | 236 | * MPC8xxx, we should ping the wdt from the kernel until the |
500c919e AV |
237 | * userspace handles it. |
238 | */ | |
239 | if (enabled) | |
59ca1b0d | 240 | mpc8xxx_wdt_timer_ping(0); |
fabbfb9e | 241 | return 0; |
fabbfb9e KG |
242 | err_unmap: |
243 | iounmap(wd_base); | |
0d7b1014 | 244 | wd_base = NULL; |
fabbfb9e KG |
245 | return ret; |
246 | } | |
247 | ||
2dc11581 | 248 | static int __devexit mpc8xxx_wdt_remove(struct platform_device *ofdev) |
fabbfb9e | 249 | { |
59ca1b0d | 250 | mpc8xxx_wdt_pr_warn("watchdog removed"); |
500c919e | 251 | del_timer_sync(&wdt_timer); |
59ca1b0d | 252 | misc_deregister(&mpc8xxx_wdt_miscdev); |
fabbfb9e KG |
253 | iounmap(wd_base); |
254 | ||
255 | return 0; | |
256 | } | |
257 | ||
59ca1b0d | 258 | static const struct of_device_id mpc8xxx_wdt_match[] = { |
ef8ab12e AV |
259 | { |
260 | .compatible = "mpc83xx_wdt", | |
59ca1b0d | 261 | .data = &(struct mpc8xxx_wdt_type) { |
500c919e AV |
262 | .prescaler = 0x10000, |
263 | }, | |
264 | }, | |
265 | { | |
266 | .compatible = "fsl,mpc8610-wdt", | |
59ca1b0d | 267 | .data = &(struct mpc8xxx_wdt_type) { |
500c919e AV |
268 | .prescaler = 0x10000, |
269 | .hw_enabled = true, | |
270 | }, | |
ef8ab12e | 271 | }, |
0d7b1014 AV |
272 | { |
273 | .compatible = "fsl,mpc823-wdt", | |
274 | .data = &(struct mpc8xxx_wdt_type) { | |
275 | .prescaler = 0x800, | |
276 | }, | |
277 | }, | |
ef8ab12e AV |
278 | {}, |
279 | }; | |
59ca1b0d | 280 | MODULE_DEVICE_TABLE(of, mpc8xxx_wdt_match); |
ef8ab12e | 281 | |
1c48a5c9 | 282 | static struct platform_driver mpc8xxx_wdt_driver = { |
59ca1b0d | 283 | .probe = mpc8xxx_wdt_probe, |
82268714 | 284 | .remove = mpc8xxx_wdt_remove, |
4018294b GL |
285 | .driver = { |
286 | .name = "mpc8xxx_wdt", | |
287 | .owner = THIS_MODULE, | |
288 | .of_match_table = mpc8xxx_wdt_match, | |
fabbfb9e KG |
289 | }, |
290 | }; | |
291 | ||
0d7b1014 AV |
292 | /* |
293 | * We do wdt initialization in two steps: arch_initcall probes the wdt | |
294 | * very early to start pinging the watchdog (misc devices are not yet | |
295 | * available), and later module_init() just registers the misc device. | |
296 | */ | |
593fc178 | 297 | static int mpc8xxx_wdt_init_late(void) |
0d7b1014 AV |
298 | { |
299 | int ret; | |
300 | ||
301 | if (!wd_base) | |
302 | return -ENODEV; | |
303 | ||
304 | ret = misc_register(&mpc8xxx_wdt_miscdev); | |
305 | if (ret) { | |
306 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", | |
27c766aa | 307 | WATCHDOG_MINOR, ret); |
0d7b1014 AV |
308 | return ret; |
309 | } | |
310 | return 0; | |
311 | } | |
593fc178 | 312 | #ifndef MODULE |
0d7b1014 | 313 | module_init(mpc8xxx_wdt_init_late); |
593fc178 | 314 | #endif |
0d7b1014 | 315 | |
59ca1b0d | 316 | static int __init mpc8xxx_wdt_init(void) |
fabbfb9e | 317 | { |
1c48a5c9 | 318 | return platform_driver_register(&mpc8xxx_wdt_driver); |
fabbfb9e | 319 | } |
0d7b1014 | 320 | arch_initcall(mpc8xxx_wdt_init); |
fabbfb9e | 321 | |
59ca1b0d | 322 | static void __exit mpc8xxx_wdt_exit(void) |
fabbfb9e | 323 | { |
1c48a5c9 | 324 | platform_driver_unregister(&mpc8xxx_wdt_driver); |
fabbfb9e | 325 | } |
59ca1b0d | 326 | module_exit(mpc8xxx_wdt_exit); |
fabbfb9e KG |
327 | |
328 | MODULE_AUTHOR("Dave Updegraff, Kumar Gala"); | |
0d7b1014 AV |
329 | MODULE_DESCRIPTION("Driver for watchdog timer in MPC8xx/MPC83xx/MPC86xx " |
330 | "uProcessors"); | |
fabbfb9e KG |
331 | MODULE_LICENSE("GPL"); |
332 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |