blob: 8fa213cdb499b0c7e36460c6aa0af09cb1614254 [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>
5 * 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
Kumar Galafabbfb92006-01-14 13:20:50 -080020#include <linux/fs.h>
21#include <linux/init.h>
22#include <linux/kernel.h>
Anton Vorontsov500c9192008-07-03 23:51:34 -070023#include <linux/timer.h>
Kumar Galafabbfb92006-01-14 13:20:50 -080024#include <linux/miscdevice.h>
Anton Vorontsovef8ab122008-07-03 23:51:32 -070025#include <linux/of_platform.h>
Kumar Galafabbfb92006-01-14 13:20:50 -080026#include <linux/module.h>
27#include <linux/watchdog.h>
Alan Coxf26ef3d2008-05-19 14:07:09 +010028#include <linux/io.h>
29#include <linux/uaccess.h>
Anton Vorontsovef8ab122008-07-03 23:51:32 -070030#include <sysdev/fsl_soc.h>
Kumar Galafabbfb92006-01-14 13:20:50 -080031
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070032struct mpc8xxx_wdt {
Kumar Galafabbfb92006-01-14 13:20:50 -080033 __be32 res0;
34 __be32 swcrr; /* System watchdog control register */
35#define SWCRR_SWTC 0xFFFF0000 /* Software Watchdog Time Count. */
36#define SWCRR_SWEN 0x00000004 /* Watchdog Enable bit. */
37#define SWCRR_SWRI 0x00000002 /* Software Watchdog Reset/Interrupt Select bit.*/
38#define SWCRR_SWPR 0x00000001 /* Software Watchdog Counter Prescale bit. */
39 __be32 swcnr; /* System watchdog count register */
40 u8 res1[2];
41 __be16 swsrr; /* System watchdog service register */
42 u8 res2[0xF0];
43};
44
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070045struct mpc8xxx_wdt_type {
Anton Vorontsov500c9192008-07-03 23:51:34 -070046 int prescaler;
47 bool hw_enabled;
48};
49
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070050static struct mpc8xxx_wdt __iomem *wd_base;
Anton Vorontsov593fc172008-08-20 16:38:36 -070051static int mpc8xxx_wdt_init_late(void);
Kumar Galafabbfb92006-01-14 13:20:50 -080052
53static u16 timeout = 0xffff;
54module_param(timeout, ushort, 0);
Alan Coxf26ef3d2008-05-19 14:07:09 +010055MODULE_PARM_DESC(timeout,
Randy Dunlap76550d32010-05-01 09:46:15 -070056 "Watchdog timeout in ticks. (0<timeout<65536, default=65535)");
Kumar Galafabbfb92006-01-14 13:20:50 -080057
58static int reset = 1;
59module_param(reset, bool, 0);
Alan Coxf26ef3d2008-05-19 14:07:09 +010060MODULE_PARM_DESC(reset,
61 "Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset");
Kumar Galafabbfb92006-01-14 13:20:50 -080062
Anton Vorontsov500c9192008-07-03 23:51:34 -070063static int nowayout = WATCHDOG_NOWAYOUT;
64module_param(nowayout, int, 0);
65MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
66 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
67
Kumar Galafabbfb92006-01-14 13:20:50 -080068/*
69 * We always prescale, but if someone really doesn't want to they can set this
70 * to 0
71 */
72static int prescale = 1;
73static unsigned int timeout_sec;
74
75static unsigned long wdt_is_open;
Alexey Dobriyanc7dfd0c2007-11-01 16:27:08 -070076static DEFINE_SPINLOCK(wdt_spinlock);
Kumar Galafabbfb92006-01-14 13:20:50 -080077
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070078static void mpc8xxx_wdt_keepalive(void)
Kumar Galafabbfb92006-01-14 13:20:50 -080079{
80 /* Ping the WDT */
81 spin_lock(&wdt_spinlock);
82 out_be16(&wd_base->swsrr, 0x556c);
83 out_be16(&wd_base->swsrr, 0xaa39);
84 spin_unlock(&wdt_spinlock);
85}
86
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070087static void mpc8xxx_wdt_timer_ping(unsigned long arg);
88static DEFINE_TIMER(wdt_timer, mpc8xxx_wdt_timer_ping, 0, 0);
Anton Vorontsov500c9192008-07-03 23:51:34 -070089
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070090static void mpc8xxx_wdt_timer_ping(unsigned long arg)
Anton Vorontsov500c9192008-07-03 23:51:34 -070091{
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070092 mpc8xxx_wdt_keepalive();
Anton Vorontsov500c9192008-07-03 23:51:34 -070093 /* We're pinging it twice faster than needed, just to be sure. */
94 mod_timer(&wdt_timer, jiffies + HZ * timeout_sec / 2);
95}
96
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070097static void mpc8xxx_wdt_pr_warn(const char *msg)
Anton Vorontsov500c9192008-07-03 23:51:34 -070098{
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070099 pr_crit("mpc8xxx_wdt: %s, expect the %s soon!\n", msg,
Anton Vorontsov500c9192008-07-03 23:51:34 -0700100 reset ? "reset" : "machine check exception");
101}
102
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700103static ssize_t mpc8xxx_wdt_write(struct file *file, const char __user *buf,
Kumar Galafabbfb92006-01-14 13:20:50 -0800104 size_t count, loff_t *ppos)
105{
106 if (count)
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700107 mpc8xxx_wdt_keepalive();
Kumar Galafabbfb92006-01-14 13:20:50 -0800108 return count;
109}
110
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700111static int mpc8xxx_wdt_open(struct inode *inode, struct file *file)
Kumar Galafabbfb92006-01-14 13:20:50 -0800112{
113 u32 tmp = SWCRR_SWEN;
114 if (test_and_set_bit(0, &wdt_is_open))
115 return -EBUSY;
116
117 /* Once we start the watchdog we can't stop it */
Anton Vorontsov500c9192008-07-03 23:51:34 -0700118 if (nowayout)
119 __module_get(THIS_MODULE);
Kumar Galafabbfb92006-01-14 13:20:50 -0800120
121 /* Good, fire up the show */
122 if (prescale)
123 tmp |= SWCRR_SWPR;
124 if (reset)
125 tmp |= SWCRR_SWRI;
126
127 tmp |= timeout << 16;
128
129 out_be32(&wd_base->swcrr, tmp);
130
Anton Vorontsov500c9192008-07-03 23:51:34 -0700131 del_timer_sync(&wdt_timer);
132
Kumar Galafabbfb92006-01-14 13:20:50 -0800133 return nonseekable_open(inode, file);
134}
135
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700136static int mpc8xxx_wdt_release(struct inode *inode, struct file *file)
Kumar Galafabbfb92006-01-14 13:20:50 -0800137{
Anton Vorontsov500c9192008-07-03 23:51:34 -0700138 if (!nowayout)
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700139 mpc8xxx_wdt_timer_ping(0);
Anton Vorontsov500c9192008-07-03 23:51:34 -0700140 else
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700141 mpc8xxx_wdt_pr_warn("watchdog closed");
Kumar Galafabbfb92006-01-14 13:20:50 -0800142 clear_bit(0, &wdt_is_open);
143 return 0;
144}
145
Anton Vorontsovcb55d282008-07-03 23:51:36 -0700146static long mpc8xxx_wdt_ioctl(struct file *file, unsigned int cmd,
Alan Coxf26ef3d2008-05-19 14:07:09 +0100147 unsigned long arg)
Kumar Galafabbfb92006-01-14 13:20:50 -0800148{
149 void __user *argp = (void __user *)arg;
150 int __user *p = argp;
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000151 static const struct watchdog_info ident = {
Kumar Galafabbfb92006-01-14 13:20:50 -0800152 .options = WDIOF_KEEPALIVEPING,
153 .firmware_version = 1,
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700154 .identity = "MPC8xxx",
Kumar Galafabbfb92006-01-14 13:20:50 -0800155 };
156
157 switch (cmd) {
158 case WDIOC_GETSUPPORT:
159 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
Wim Van Sebroeck5c4eb612007-07-21 13:42:18 +0000160 case WDIOC_GETSTATUS:
161 case WDIOC_GETBOOTSTATUS:
162 return put_user(0, p);
Kumar Galafabbfb92006-01-14 13:20:50 -0800163 case WDIOC_KEEPALIVE:
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700164 mpc8xxx_wdt_keepalive();
Kumar Galafabbfb92006-01-14 13:20:50 -0800165 return 0;
166 case WDIOC_GETTIMEOUT:
167 return put_user(timeout_sec, p);
168 default:
Samuel Tardieu795b89d2006-09-09 17:34:31 +0200169 return -ENOTTY;
Kumar Galafabbfb92006-01-14 13:20:50 -0800170 }
171}
172
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700173static const struct file_operations mpc8xxx_wdt_fops = {
Kumar Galafabbfb92006-01-14 13:20:50 -0800174 .owner = THIS_MODULE,
175 .llseek = no_llseek,
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700176 .write = mpc8xxx_wdt_write,
177 .unlocked_ioctl = mpc8xxx_wdt_ioctl,
178 .open = mpc8xxx_wdt_open,
179 .release = mpc8xxx_wdt_release,
Kumar Galafabbfb92006-01-14 13:20:50 -0800180};
181
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700182static struct miscdevice mpc8xxx_wdt_miscdev = {
Kumar Galafabbfb92006-01-14 13:20:50 -0800183 .minor = WATCHDOG_MINOR,
184 .name = "watchdog",
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700185 .fops = &mpc8xxx_wdt_fops,
Kumar Galafabbfb92006-01-14 13:20:50 -0800186};
187
Grant Likely2dc11582010-08-06 09:25:50 -0600188static int __devinit mpc8xxx_wdt_probe(struct platform_device *ofdev,
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700189 const struct of_device_id *match)
Kumar Galafabbfb92006-01-14 13:20:50 -0800190{
Kumar Galafabbfb92006-01-14 13:20:50 -0800191 int ret;
Michael Guntschede2b6062010-06-02 02:25:52 -0600192 struct device_node *np = ofdev->dev.of_node;
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700193 struct mpc8xxx_wdt_type *wdt_type = match->data;
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700194 u32 freq = fsl_get_sys_freq();
Anton Vorontsov500c9192008-07-03 23:51:34 -0700195 bool enabled;
Kumar Galafabbfb92006-01-14 13:20:50 -0800196
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700197 if (!freq || freq == -1)
198 return -EINVAL;
Kumar Galafabbfb92006-01-14 13:20:50 -0800199
Anton Vorontsov500c9192008-07-03 23:51:34 -0700200 wd_base = of_iomap(np, 0);
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700201 if (!wd_base)
202 return -ENOMEM;
Kumar Galafabbfb92006-01-14 13:20:50 -0800203
Anton Vorontsov500c9192008-07-03 23:51:34 -0700204 enabled = in_be32(&wd_base->swcrr) & SWCRR_SWEN;
205 if (!enabled && wdt_type->hw_enabled) {
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700206 pr_info("mpc8xxx_wdt: could not be enabled in software\n");
Anton Vorontsov500c9192008-07-03 23:51:34 -0700207 ret = -ENOSYS;
208 goto err_unmap;
209 }
210
Kumar Galafabbfb92006-01-14 13:20:50 -0800211 /* Calculate the timeout in seconds */
212 if (prescale)
Anton Vorontsov500c9192008-07-03 23:51:34 -0700213 timeout_sec = (timeout * wdt_type->prescaler) / freq;
Kumar Galafabbfb92006-01-14 13:20:50 -0800214 else
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700215 timeout_sec = timeout / freq;
Kumar Galafabbfb92006-01-14 13:20:50 -0800216
Anton Vorontsov593fc172008-08-20 16:38:36 -0700217#ifdef MODULE
218 ret = mpc8xxx_wdt_init_late();
219 if (ret)
220 goto err_unmap;
221#endif
222
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700223 pr_info("WDT driver for MPC8xxx initialized. mode:%s timeout=%d "
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700224 "(%d seconds)\n", reset ? "reset" : "interrupt", timeout,
225 timeout_sec);
Anton Vorontsov500c9192008-07-03 23:51:34 -0700226
227 /*
228 * If the watchdog was previously enabled or we're running on
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700229 * MPC8xxx, we should ping the wdt from the kernel until the
Anton Vorontsov500c9192008-07-03 23:51:34 -0700230 * userspace handles it.
231 */
232 if (enabled)
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700233 mpc8xxx_wdt_timer_ping(0);
Kumar Galafabbfb92006-01-14 13:20:50 -0800234 return 0;
Kumar Galafabbfb92006-01-14 13:20:50 -0800235err_unmap:
236 iounmap(wd_base);
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700237 wd_base = NULL;
Kumar Galafabbfb92006-01-14 13:20:50 -0800238 return ret;
239}
240
Grant Likely2dc11582010-08-06 09:25:50 -0600241static int __devexit mpc8xxx_wdt_remove(struct platform_device *ofdev)
Kumar Galafabbfb92006-01-14 13:20:50 -0800242{
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700243 mpc8xxx_wdt_pr_warn("watchdog removed");
Anton Vorontsov500c9192008-07-03 23:51:34 -0700244 del_timer_sync(&wdt_timer);
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700245 misc_deregister(&mpc8xxx_wdt_miscdev);
Kumar Galafabbfb92006-01-14 13:20:50 -0800246 iounmap(wd_base);
247
248 return 0;
249}
250
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700251static const struct of_device_id mpc8xxx_wdt_match[] = {
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700252 {
253 .compatible = "mpc83xx_wdt",
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700254 .data = &(struct mpc8xxx_wdt_type) {
Anton Vorontsov500c9192008-07-03 23:51:34 -0700255 .prescaler = 0x10000,
256 },
257 },
258 {
259 .compatible = "fsl,mpc8610-wdt",
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700260 .data = &(struct mpc8xxx_wdt_type) {
Anton Vorontsov500c9192008-07-03 23:51:34 -0700261 .prescaler = 0x10000,
262 .hw_enabled = true,
263 },
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700264 },
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700265 {
266 .compatible = "fsl,mpc823-wdt",
267 .data = &(struct mpc8xxx_wdt_type) {
268 .prescaler = 0x800,
269 },
270 },
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700271 {},
272};
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700273MODULE_DEVICE_TABLE(of, mpc8xxx_wdt_match);
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700274
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700275static struct of_platform_driver mpc8xxx_wdt_driver = {
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700276 .probe = mpc8xxx_wdt_probe,
277 .remove = __devexit_p(mpc8xxx_wdt_remove),
Grant Likely40182942010-04-13 16:13:02 -0700278 .driver = {
279 .name = "mpc8xxx_wdt",
280 .owner = THIS_MODULE,
281 .of_match_table = mpc8xxx_wdt_match,
Kumar Galafabbfb92006-01-14 13:20:50 -0800282 },
283};
284
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700285/*
286 * We do wdt initialization in two steps: arch_initcall probes the wdt
287 * very early to start pinging the watchdog (misc devices are not yet
288 * available), and later module_init() just registers the misc device.
289 */
Anton Vorontsov593fc172008-08-20 16:38:36 -0700290static int mpc8xxx_wdt_init_late(void)
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700291{
292 int ret;
293
294 if (!wd_base)
295 return -ENODEV;
296
297 ret = misc_register(&mpc8xxx_wdt_miscdev);
298 if (ret) {
299 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
300 WATCHDOG_MINOR, ret);
301 return ret;
302 }
303 return 0;
304}
Anton Vorontsov593fc172008-08-20 16:38:36 -0700305#ifndef MODULE
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700306module_init(mpc8xxx_wdt_init_late);
Anton Vorontsov593fc172008-08-20 16:38:36 -0700307#endif
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700308
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700309static int __init mpc8xxx_wdt_init(void)
Kumar Galafabbfb92006-01-14 13:20:50 -0800310{
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700311 return of_register_platform_driver(&mpc8xxx_wdt_driver);
Kumar Galafabbfb92006-01-14 13:20:50 -0800312}
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700313arch_initcall(mpc8xxx_wdt_init);
Kumar Galafabbfb92006-01-14 13:20:50 -0800314
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700315static void __exit mpc8xxx_wdt_exit(void)
Kumar Galafabbfb92006-01-14 13:20:50 -0800316{
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700317 of_unregister_platform_driver(&mpc8xxx_wdt_driver);
Kumar Galafabbfb92006-01-14 13:20:50 -0800318}
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700319module_exit(mpc8xxx_wdt_exit);
Kumar Galafabbfb92006-01-14 13:20:50 -0800320
321MODULE_AUTHOR("Dave Updegraff, Kumar Gala");
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700322MODULE_DESCRIPTION("Driver for watchdog timer in MPC8xx/MPC83xx/MPC86xx "
323 "uProcessors");
Kumar Galafabbfb92006-01-14 13:20:50 -0800324MODULE_LICENSE("GPL");
325MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);