blob: e6a038ae8dc28bf6c64a6311e886b6afa8853db8 [file] [log] [blame]
Kumar Galafabbfb92006-01-14 13:20:50 -08001/*
Anton Vorontsov0d7b1012008-07-03 23:51:36 -07002 * mpc8xxx_wdt.c - MPC8xx/MPC83xx/MPC86xx watchdog userspace interface
Kumar Galafabbfb92006-01-14 13:20:50 -08003 *
4 * Authors: Dave Updegraff <dave@cray.org>
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +00005 * Kumar Gala <galak@kernel.crashing.org>
6 * Attribution: from 83xx_wst: Florian Schirmer <jolt@tuxbox.org>
7 * ..and from sc520_wdt
Anton Vorontsov500c9192008-07-03 23:51:34 -07008 * Copyright (c) 2008 MontaVista Software, Inc.
9 * Anton Vorontsov <avorontsov@ru.mvista.com>
Kumar Galafabbfb92006-01-14 13:20:50 -080010 *
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
Joe Perches27c766a2012-02-15 15:06:19 -080020#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
Kumar Galafabbfb92006-01-14 13:20:50 -080022#include <linux/fs.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
Anton Vorontsov500c9192008-07-03 23:51:34 -070025#include <linux/timer.h>
Kumar Galafabbfb92006-01-14 13:20:50 -080026#include <linux/miscdevice.h>
Anton Vorontsovef8ab122008-07-03 23:51:32 -070027#include <linux/of_platform.h>
Kumar Galafabbfb92006-01-14 13:20:50 -080028#include <linux/module.h>
29#include <linux/watchdog.h>
Alan Coxf26ef3d2008-05-19 14:07:09 +010030#include <linux/io.h>
31#include <linux/uaccess.h>
Anton Vorontsovef8ab122008-07-03 23:51:32 -070032#include <sysdev/fsl_soc.h>
Kumar Galafabbfb92006-01-14 13:20:50 -080033
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070034struct mpc8xxx_wdt {
Kumar Galafabbfb92006-01-14 13:20:50 -080035 __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
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070047struct mpc8xxx_wdt_type {
Anton Vorontsov500c9192008-07-03 23:51:34 -070048 int prescaler;
49 bool hw_enabled;
50};
51
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070052static struct mpc8xxx_wdt __iomem *wd_base;
Anton Vorontsov593fc172008-08-20 16:38:36 -070053static int mpc8xxx_wdt_init_late(void);
Kumar Galafabbfb92006-01-14 13:20:50 -080054
55static u16 timeout = 0xffff;
56module_param(timeout, ushort, 0);
Alan Coxf26ef3d2008-05-19 14:07:09 +010057MODULE_PARM_DESC(timeout,
Randy Dunlap76550d32010-05-01 09:46:15 -070058 "Watchdog timeout in ticks. (0<timeout<65536, default=65535)");
Kumar Galafabbfb92006-01-14 13:20:50 -080059
Rusty Russell90ab5ee2012-01-13 09:32:20 +103060static bool reset = 1;
Kumar Galafabbfb92006-01-14 13:20:50 -080061module_param(reset, bool, 0);
Alan Coxf26ef3d2008-05-19 14:07:09 +010062MODULE_PARM_DESC(reset,
63 "Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset");
Kumar Galafabbfb92006-01-14 13:20:50 -080064
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010065static bool nowayout = WATCHDOG_NOWAYOUT;
66module_param(nowayout, bool, 0);
Anton Vorontsov500c9192008-07-03 23:51:34 -070067MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
68 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
69
Kumar Galafabbfb92006-01-14 13:20:50 -080070/*
71 * We always prescale, but if someone really doesn't want to they can set this
72 * to 0
73 */
74static int prescale = 1;
75static unsigned int timeout_sec;
76
77static unsigned long wdt_is_open;
Alexey Dobriyanc7dfd0c2007-11-01 16:27:08 -070078static DEFINE_SPINLOCK(wdt_spinlock);
Kumar Galafabbfb92006-01-14 13:20:50 -080079
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070080static void mpc8xxx_wdt_keepalive(void)
Kumar Galafabbfb92006-01-14 13:20:50 -080081{
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
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070089static void mpc8xxx_wdt_timer_ping(unsigned long arg);
90static DEFINE_TIMER(wdt_timer, mpc8xxx_wdt_timer_ping, 0, 0);
Anton Vorontsov500c9192008-07-03 23:51:34 -070091
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070092static void mpc8xxx_wdt_timer_ping(unsigned long arg)
Anton Vorontsov500c9192008-07-03 23:51:34 -070093{
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070094 mpc8xxx_wdt_keepalive();
Anton Vorontsov500c9192008-07-03 23:51:34 -070095 /* We're pinging it twice faster than needed, just to be sure. */
96 mod_timer(&wdt_timer, jiffies + HZ * timeout_sec / 2);
97}
98
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070099static void mpc8xxx_wdt_pr_warn(const char *msg)
Anton Vorontsov500c9192008-07-03 23:51:34 -0700100{
Joe Perches27c766a2012-02-15 15:06:19 -0800101 pr_crit("%s, expect the %s soon!\n", msg,
Anton Vorontsov500c9192008-07-03 23:51:34 -0700102 reset ? "reset" : "machine check exception");
103}
104
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700105static ssize_t mpc8xxx_wdt_write(struct file *file, const char __user *buf,
Kumar Galafabbfb92006-01-14 13:20:50 -0800106 size_t count, loff_t *ppos)
107{
108 if (count)
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700109 mpc8xxx_wdt_keepalive();
Kumar Galafabbfb92006-01-14 13:20:50 -0800110 return count;
111}
112
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700113static int mpc8xxx_wdt_open(struct inode *inode, struct file *file)
Kumar Galafabbfb92006-01-14 13:20:50 -0800114{
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 */
Anton Vorontsov500c9192008-07-03 23:51:34 -0700120 if (nowayout)
121 __module_get(THIS_MODULE);
Kumar Galafabbfb92006-01-14 13:20:50 -0800122
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
Anton Vorontsov500c9192008-07-03 23:51:34 -0700133 del_timer_sync(&wdt_timer);
134
Kumar Galafabbfb92006-01-14 13:20:50 -0800135 return nonseekable_open(inode, file);
136}
137
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700138static int mpc8xxx_wdt_release(struct inode *inode, struct file *file)
Kumar Galafabbfb92006-01-14 13:20:50 -0800139{
Anton Vorontsov500c9192008-07-03 23:51:34 -0700140 if (!nowayout)
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700141 mpc8xxx_wdt_timer_ping(0);
Anton Vorontsov500c9192008-07-03 23:51:34 -0700142 else
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700143 mpc8xxx_wdt_pr_warn("watchdog closed");
Kumar Galafabbfb92006-01-14 13:20:50 -0800144 clear_bit(0, &wdt_is_open);
145 return 0;
146}
147
Anton Vorontsovcb55d282008-07-03 23:51:36 -0700148static long mpc8xxx_wdt_ioctl(struct file *file, unsigned int cmd,
Alan Coxf26ef3d2008-05-19 14:07:09 +0100149 unsigned long arg)
Kumar Galafabbfb92006-01-14 13:20:50 -0800150{
151 void __user *argp = (void __user *)arg;
152 int __user *p = argp;
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000153 static const struct watchdog_info ident = {
Kumar Galafabbfb92006-01-14 13:20:50 -0800154 .options = WDIOF_KEEPALIVEPING,
155 .firmware_version = 1,
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700156 .identity = "MPC8xxx",
Kumar Galafabbfb92006-01-14 13:20:50 -0800157 };
158
159 switch (cmd) {
160 case WDIOC_GETSUPPORT:
161 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
Wim Van Sebroeck5c4eb612007-07-21 13:42:18 +0000162 case WDIOC_GETSTATUS:
163 case WDIOC_GETBOOTSTATUS:
164 return put_user(0, p);
Kumar Galafabbfb92006-01-14 13:20:50 -0800165 case WDIOC_KEEPALIVE:
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700166 mpc8xxx_wdt_keepalive();
Kumar Galafabbfb92006-01-14 13:20:50 -0800167 return 0;
168 case WDIOC_GETTIMEOUT:
169 return put_user(timeout_sec, p);
170 default:
Samuel Tardieu795b89d2006-09-09 17:34:31 +0200171 return -ENOTTY;
Kumar Galafabbfb92006-01-14 13:20:50 -0800172 }
173}
174
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700175static const struct file_operations mpc8xxx_wdt_fops = {
Kumar Galafabbfb92006-01-14 13:20:50 -0800176 .owner = THIS_MODULE,
177 .llseek = no_llseek,
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700178 .write = mpc8xxx_wdt_write,
179 .unlocked_ioctl = mpc8xxx_wdt_ioctl,
180 .open = mpc8xxx_wdt_open,
181 .release = mpc8xxx_wdt_release,
Kumar Galafabbfb92006-01-14 13:20:50 -0800182};
183
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700184static struct miscdevice mpc8xxx_wdt_miscdev = {
Kumar Galafabbfb92006-01-14 13:20:50 -0800185 .minor = WATCHDOG_MINOR,
186 .name = "watchdog",
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700187 .fops = &mpc8xxx_wdt_fops,
Kumar Galafabbfb92006-01-14 13:20:50 -0800188};
189
Grant Likelyb1608d62011-05-18 11:19:24 -0600190static const struct of_device_id mpc8xxx_wdt_match[];
Grant Likely1c48a5c2011-02-17 02:43:24 -0700191static int __devinit mpc8xxx_wdt_probe(struct platform_device *ofdev)
Kumar Galafabbfb92006-01-14 13:20:50 -0800192{
Kumar Galafabbfb92006-01-14 13:20:50 -0800193 int ret;
Grant Likelyb1608d62011-05-18 11:19:24 -0600194 const struct of_device_id *match;
Michael Guntschede2b6062010-06-02 02:25:52 -0600195 struct device_node *np = ofdev->dev.of_node;
Arnd Bergmann639397e2012-05-21 21:57:39 +0200196 const struct mpc8xxx_wdt_type *wdt_type;
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700197 u32 freq = fsl_get_sys_freq();
Anton Vorontsov500c9192008-07-03 23:51:34 -0700198 bool enabled;
Kumar Galafabbfb92006-01-14 13:20:50 -0800199
Grant Likelyb1608d62011-05-18 11:19:24 -0600200 match = of_match_device(mpc8xxx_wdt_match, &ofdev->dev);
201 if (!match)
Grant Likely1c48a5c2011-02-17 02:43:24 -0700202 return -EINVAL;
Grant Likelyb1608d62011-05-18 11:19:24 -0600203 wdt_type = match->data;
Grant Likely1c48a5c2011-02-17 02:43:24 -0700204
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700205 if (!freq || freq == -1)
206 return -EINVAL;
Kumar Galafabbfb92006-01-14 13:20:50 -0800207
Anton Vorontsov500c9192008-07-03 23:51:34 -0700208 wd_base = of_iomap(np, 0);
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700209 if (!wd_base)
210 return -ENOMEM;
Kumar Galafabbfb92006-01-14 13:20:50 -0800211
Anton Vorontsov500c9192008-07-03 23:51:34 -0700212 enabled = in_be32(&wd_base->swcrr) & SWCRR_SWEN;
213 if (!enabled && wdt_type->hw_enabled) {
Joe Perches27c766a2012-02-15 15:06:19 -0800214 pr_info("could not be enabled in software\n");
Anton Vorontsov500c9192008-07-03 23:51:34 -0700215 ret = -ENOSYS;
216 goto err_unmap;
217 }
218
Kumar Galafabbfb92006-01-14 13:20:50 -0800219 /* Calculate the timeout in seconds */
220 if (prescale)
Anton Vorontsov500c9192008-07-03 23:51:34 -0700221 timeout_sec = (timeout * wdt_type->prescaler) / freq;
Kumar Galafabbfb92006-01-14 13:20:50 -0800222 else
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700223 timeout_sec = timeout / freq;
Kumar Galafabbfb92006-01-14 13:20:50 -0800224
Anton Vorontsov593fc172008-08-20 16:38:36 -0700225#ifdef MODULE
226 ret = mpc8xxx_wdt_init_late();
227 if (ret)
228 goto err_unmap;
229#endif
230
Joe Perches27c766a2012-02-15 15:06:19 -0800231 pr_info("WDT driver for MPC8xxx initialized. mode:%s timeout=%d (%d seconds)\n",
232 reset ? "reset" : "interrupt", timeout, timeout_sec);
Anton Vorontsov500c9192008-07-03 23:51:34 -0700233
234 /*
235 * If the watchdog was previously enabled or we're running on
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700236 * MPC8xxx, we should ping the wdt from the kernel until the
Anton Vorontsov500c9192008-07-03 23:51:34 -0700237 * userspace handles it.
238 */
239 if (enabled)
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700240 mpc8xxx_wdt_timer_ping(0);
Kumar Galafabbfb92006-01-14 13:20:50 -0800241 return 0;
Kumar Galafabbfb92006-01-14 13:20:50 -0800242err_unmap:
243 iounmap(wd_base);
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700244 wd_base = NULL;
Kumar Galafabbfb92006-01-14 13:20:50 -0800245 return ret;
246}
247
Grant Likely2dc11582010-08-06 09:25:50 -0600248static int __devexit mpc8xxx_wdt_remove(struct platform_device *ofdev)
Kumar Galafabbfb92006-01-14 13:20:50 -0800249{
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700250 mpc8xxx_wdt_pr_warn("watchdog removed");
Anton Vorontsov500c9192008-07-03 23:51:34 -0700251 del_timer_sync(&wdt_timer);
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700252 misc_deregister(&mpc8xxx_wdt_miscdev);
Kumar Galafabbfb92006-01-14 13:20:50 -0800253 iounmap(wd_base);
254
255 return 0;
256}
257
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700258static const struct of_device_id mpc8xxx_wdt_match[] = {
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700259 {
260 .compatible = "mpc83xx_wdt",
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700261 .data = &(struct mpc8xxx_wdt_type) {
Anton Vorontsov500c9192008-07-03 23:51:34 -0700262 .prescaler = 0x10000,
263 },
264 },
265 {
266 .compatible = "fsl,mpc8610-wdt",
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700267 .data = &(struct mpc8xxx_wdt_type) {
Anton Vorontsov500c9192008-07-03 23:51:34 -0700268 .prescaler = 0x10000,
269 .hw_enabled = true,
270 },
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700271 },
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700272 {
273 .compatible = "fsl,mpc823-wdt",
274 .data = &(struct mpc8xxx_wdt_type) {
275 .prescaler = 0x800,
276 },
277 },
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700278 {},
279};
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700280MODULE_DEVICE_TABLE(of, mpc8xxx_wdt_match);
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700281
Grant Likely1c48a5c2011-02-17 02:43:24 -0700282static struct platform_driver mpc8xxx_wdt_driver = {
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700283 .probe = mpc8xxx_wdt_probe,
284 .remove = __devexit_p(mpc8xxx_wdt_remove),
Grant Likely40182942010-04-13 16:13:02 -0700285 .driver = {
286 .name = "mpc8xxx_wdt",
287 .owner = THIS_MODULE,
288 .of_match_table = mpc8xxx_wdt_match,
Kumar Galafabbfb92006-01-14 13:20:50 -0800289 },
290};
291
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700292/*
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 */
Anton Vorontsov593fc172008-08-20 16:38:36 -0700297static int mpc8xxx_wdt_init_late(void)
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700298{
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",
Joe Perches27c766a2012-02-15 15:06:19 -0800307 WATCHDOG_MINOR, ret);
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700308 return ret;
309 }
310 return 0;
311}
Anton Vorontsov593fc172008-08-20 16:38:36 -0700312#ifndef MODULE
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700313module_init(mpc8xxx_wdt_init_late);
Anton Vorontsov593fc172008-08-20 16:38:36 -0700314#endif
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700315
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700316static int __init mpc8xxx_wdt_init(void)
Kumar Galafabbfb92006-01-14 13:20:50 -0800317{
Grant Likely1c48a5c2011-02-17 02:43:24 -0700318 return platform_driver_register(&mpc8xxx_wdt_driver);
Kumar Galafabbfb92006-01-14 13:20:50 -0800319}
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700320arch_initcall(mpc8xxx_wdt_init);
Kumar Galafabbfb92006-01-14 13:20:50 -0800321
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700322static void __exit mpc8xxx_wdt_exit(void)
Kumar Galafabbfb92006-01-14 13:20:50 -0800323{
Grant Likely1c48a5c2011-02-17 02:43:24 -0700324 platform_driver_unregister(&mpc8xxx_wdt_driver);
Kumar Galafabbfb92006-01-14 13:20:50 -0800325}
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700326module_exit(mpc8xxx_wdt_exit);
Kumar Galafabbfb92006-01-14 13:20:50 -0800327
328MODULE_AUTHOR("Dave Updegraff, Kumar Gala");
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700329MODULE_DESCRIPTION("Driver for watchdog timer in MPC8xx/MPC83xx/MPC86xx "
330 "uProcessors");
Kumar Galafabbfb92006-01-14 13:20:50 -0800331MODULE_LICENSE("GPL");
332MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);