blob: 7831955cd9e19f1ff3d3adca74512d48880c8be2 [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>
Rob Herring5af50732013-09-17 14:28:33 -050027#include <linux/of_address.h>
Anton Vorontsovef8ab122008-07-03 23:51:32 -070028#include <linux/of_platform.h>
Kumar Galafabbfb92006-01-14 13:20:50 -080029#include <linux/module.h>
30#include <linux/watchdog.h>
Alan Coxf26ef3d2008-05-19 14:07:09 +010031#include <linux/io.h>
32#include <linux/uaccess.h>
Anton Vorontsovef8ab122008-07-03 23:51:32 -070033#include <sysdev/fsl_soc.h>
Kumar Galafabbfb92006-01-14 13:20:50 -080034
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070035struct mpc8xxx_wdt {
Kumar Galafabbfb92006-01-14 13:20:50 -080036 __be32 res0;
37 __be32 swcrr; /* System watchdog control register */
38#define SWCRR_SWTC 0xFFFF0000 /* Software Watchdog Time Count. */
39#define SWCRR_SWEN 0x00000004 /* Watchdog Enable bit. */
40#define SWCRR_SWRI 0x00000002 /* Software Watchdog Reset/Interrupt Select bit.*/
41#define SWCRR_SWPR 0x00000001 /* Software Watchdog Counter Prescale bit. */
42 __be32 swcnr; /* System watchdog count register */
43 u8 res1[2];
44 __be16 swsrr; /* System watchdog service register */
45 u8 res2[0xF0];
46};
47
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070048struct mpc8xxx_wdt_type {
Anton Vorontsov500c9192008-07-03 23:51:34 -070049 int prescaler;
50 bool hw_enabled;
51};
52
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070053static struct mpc8xxx_wdt __iomem *wd_base;
Anton Vorontsov593fc172008-08-20 16:38:36 -070054static int mpc8xxx_wdt_init_late(void);
Kumar Galafabbfb92006-01-14 13:20:50 -080055
56static u16 timeout = 0xffff;
57module_param(timeout, ushort, 0);
Alan Coxf26ef3d2008-05-19 14:07:09 +010058MODULE_PARM_DESC(timeout,
Randy Dunlap76550d32010-05-01 09:46:15 -070059 "Watchdog timeout in ticks. (0<timeout<65536, default=65535)");
Kumar Galafabbfb92006-01-14 13:20:50 -080060
Rusty Russell90ab5ee2012-01-13 09:32:20 +103061static bool reset = 1;
Kumar Galafabbfb92006-01-14 13:20:50 -080062module_param(reset, bool, 0);
Alan Coxf26ef3d2008-05-19 14:07:09 +010063MODULE_PARM_DESC(reset,
64 "Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset");
Kumar Galafabbfb92006-01-14 13:20:50 -080065
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010066static bool nowayout = WATCHDOG_NOWAYOUT;
67module_param(nowayout, bool, 0);
Anton Vorontsov500c9192008-07-03 23:51:34 -070068MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
69 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
70
Kumar Galafabbfb92006-01-14 13:20:50 -080071/*
72 * We always prescale, but if someone really doesn't want to they can set this
73 * to 0
74 */
75static int prescale = 1;
Kumar Galafabbfb92006-01-14 13:20:50 -080076
Alexey Dobriyanc7dfd0c2007-11-01 16:27:08 -070077static DEFINE_SPINLOCK(wdt_spinlock);
Kumar Galafabbfb92006-01-14 13:20:50 -080078
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070079static void mpc8xxx_wdt_keepalive(void)
Kumar Galafabbfb92006-01-14 13:20:50 -080080{
81 /* Ping the WDT */
82 spin_lock(&wdt_spinlock);
83 out_be16(&wd_base->swsrr, 0x556c);
84 out_be16(&wd_base->swsrr, 0xaa39);
85 spin_unlock(&wdt_spinlock);
86}
87
Christophe Leroyd5cfaf02013-12-04 07:32:14 +010088static struct watchdog_device mpc8xxx_wdt_dev;
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070089static void mpc8xxx_wdt_timer_ping(unsigned long arg);
Christophe Leroyd5cfaf02013-12-04 07:32:14 +010090static DEFINE_TIMER(wdt_timer, mpc8xxx_wdt_timer_ping, 0,
91 (unsigned long)&mpc8xxx_wdt_dev);
Anton Vorontsov500c9192008-07-03 23:51:34 -070092
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070093static void mpc8xxx_wdt_timer_ping(unsigned long arg)
Anton Vorontsov500c9192008-07-03 23:51:34 -070094{
Christophe Leroyd5cfaf02013-12-04 07:32:14 +010095 struct watchdog_device *w = (struct watchdog_device *)arg;
96
Anton Vorontsov59ca1b02008-07-03 23:51:35 -070097 mpc8xxx_wdt_keepalive();
Anton Vorontsov500c9192008-07-03 23:51:34 -070098 /* We're pinging it twice faster than needed, just to be sure. */
Christophe Leroyd5cfaf02013-12-04 07:32:14 +010099 mod_timer(&wdt_timer, jiffies + HZ * w->timeout / 2);
Anton Vorontsov500c9192008-07-03 23:51:34 -0700100}
101
Christophe Leroyd5cfaf02013-12-04 07:32:14 +0100102static int mpc8xxx_wdt_start(struct watchdog_device *w)
Kumar Galafabbfb92006-01-14 13:20:50 -0800103{
104 u32 tmp = SWCRR_SWEN;
Kumar Galafabbfb92006-01-14 13:20:50 -0800105
106 /* Good, fire up the show */
107 if (prescale)
108 tmp |= SWCRR_SWPR;
109 if (reset)
110 tmp |= SWCRR_SWRI;
111
112 tmp |= timeout << 16;
113
114 out_be32(&wd_base->swcrr, tmp);
115
Anton Vorontsov500c9192008-07-03 23:51:34 -0700116 del_timer_sync(&wdt_timer);
117
Kumar Galafabbfb92006-01-14 13:20:50 -0800118 return 0;
119}
120
Christophe Leroyd5cfaf02013-12-04 07:32:14 +0100121static int mpc8xxx_wdt_ping(struct watchdog_device *w)
Kumar Galafabbfb92006-01-14 13:20:50 -0800122{
Christophe Leroyd5cfaf02013-12-04 07:32:14 +0100123 mpc8xxx_wdt_keepalive();
124 return 0;
Kumar Galafabbfb92006-01-14 13:20:50 -0800125}
126
Christophe Leroyd5cfaf02013-12-04 07:32:14 +0100127static int mpc8xxx_wdt_stop(struct watchdog_device *w)
128{
129 mod_timer(&wdt_timer, jiffies);
130 return 0;
131}
132
133static struct watchdog_info mpc8xxx_wdt_info = {
134 .options = WDIOF_KEEPALIVEPING,
135 .firmware_version = 1,
136 .identity = "MPC8xxx",
Kumar Galafabbfb92006-01-14 13:20:50 -0800137};
138
Christophe Leroyd5cfaf02013-12-04 07:32:14 +0100139static struct watchdog_ops mpc8xxx_wdt_ops = {
140 .owner = THIS_MODULE,
141 .start = mpc8xxx_wdt_start,
142 .ping = mpc8xxx_wdt_ping,
143 .stop = mpc8xxx_wdt_stop,
144};
145
146static struct watchdog_device mpc8xxx_wdt_dev = {
147 .info = &mpc8xxx_wdt_info,
148 .ops = &mpc8xxx_wdt_ops,
Kumar Galafabbfb92006-01-14 13:20:50 -0800149};
150
Grant Likelyb1608d62011-05-18 11:19:24 -0600151static const struct of_device_id mpc8xxx_wdt_match[];
Bill Pemberton2d991a12012-11-19 13:21:41 -0500152static int mpc8xxx_wdt_probe(struct platform_device *ofdev)
Kumar Galafabbfb92006-01-14 13:20:50 -0800153{
Kumar Galafabbfb92006-01-14 13:20:50 -0800154 int ret;
Grant Likelyb1608d62011-05-18 11:19:24 -0600155 const struct of_device_id *match;
Michael Guntschede2b6062010-06-02 02:25:52 -0600156 struct device_node *np = ofdev->dev.of_node;
Arnd Bergmann639397e2012-05-21 21:57:39 +0200157 const struct mpc8xxx_wdt_type *wdt_type;
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700158 u32 freq = fsl_get_sys_freq();
Anton Vorontsov500c9192008-07-03 23:51:34 -0700159 bool enabled;
Christophe Leroyd5cfaf02013-12-04 07:32:14 +0100160 unsigned int timeout_sec;
Kumar Galafabbfb92006-01-14 13:20:50 -0800161
Grant Likelyb1608d62011-05-18 11:19:24 -0600162 match = of_match_device(mpc8xxx_wdt_match, &ofdev->dev);
163 if (!match)
Grant Likely1c48a5c2011-02-17 02:43:24 -0700164 return -EINVAL;
Grant Likelyb1608d62011-05-18 11:19:24 -0600165 wdt_type = match->data;
Grant Likely1c48a5c2011-02-17 02:43:24 -0700166
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700167 if (!freq || freq == -1)
168 return -EINVAL;
Kumar Galafabbfb92006-01-14 13:20:50 -0800169
Anton Vorontsov500c9192008-07-03 23:51:34 -0700170 wd_base = of_iomap(np, 0);
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700171 if (!wd_base)
172 return -ENOMEM;
Kumar Galafabbfb92006-01-14 13:20:50 -0800173
Anton Vorontsov500c9192008-07-03 23:51:34 -0700174 enabled = in_be32(&wd_base->swcrr) & SWCRR_SWEN;
175 if (!enabled && wdt_type->hw_enabled) {
Joe Perches27c766a2012-02-15 15:06:19 -0800176 pr_info("could not be enabled in software\n");
Anton Vorontsov500c9192008-07-03 23:51:34 -0700177 ret = -ENOSYS;
178 goto err_unmap;
179 }
180
Kumar Galafabbfb92006-01-14 13:20:50 -0800181 /* Calculate the timeout in seconds */
182 if (prescale)
Anton Vorontsov500c9192008-07-03 23:51:34 -0700183 timeout_sec = (timeout * wdt_type->prescaler) / freq;
Kumar Galafabbfb92006-01-14 13:20:50 -0800184 else
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700185 timeout_sec = timeout / freq;
Kumar Galafabbfb92006-01-14 13:20:50 -0800186
Christophe Leroyd5cfaf02013-12-04 07:32:14 +0100187 mpc8xxx_wdt_dev.timeout = timeout_sec;
Anton Vorontsov593fc172008-08-20 16:38:36 -0700188#ifdef MODULE
189 ret = mpc8xxx_wdt_init_late();
190 if (ret)
191 goto err_unmap;
192#endif
193
Joe Perches27c766a2012-02-15 15:06:19 -0800194 pr_info("WDT driver for MPC8xxx initialized. mode:%s timeout=%d (%d seconds)\n",
195 reset ? "reset" : "interrupt", timeout, timeout_sec);
Anton Vorontsov500c9192008-07-03 23:51:34 -0700196
197 /*
198 * If the watchdog was previously enabled or we're running on
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700199 * MPC8xxx, we should ping the wdt from the kernel until the
Anton Vorontsov500c9192008-07-03 23:51:34 -0700200 * userspace handles it.
201 */
202 if (enabled)
Christophe Leroyd5cfaf02013-12-04 07:32:14 +0100203 mod_timer(&wdt_timer, jiffies);
Kumar Galafabbfb92006-01-14 13:20:50 -0800204 return 0;
Kumar Galafabbfb92006-01-14 13:20:50 -0800205err_unmap:
206 iounmap(wd_base);
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700207 wd_base = NULL;
Kumar Galafabbfb92006-01-14 13:20:50 -0800208 return ret;
209}
210
Bill Pemberton4b12b892012-11-19 13:26:24 -0500211static int mpc8xxx_wdt_remove(struct platform_device *ofdev)
Kumar Galafabbfb92006-01-14 13:20:50 -0800212{
Christophe Leroyd5cfaf02013-12-04 07:32:14 +0100213 pr_crit("Watchdog removed, expect the %s soon!\n",
214 reset ? "reset" : "machine check exception");
Anton Vorontsov500c9192008-07-03 23:51:34 -0700215 del_timer_sync(&wdt_timer);
Christophe Leroyd5cfaf02013-12-04 07:32:14 +0100216 watchdog_unregister_device(&mpc8xxx_wdt_dev);
Kumar Galafabbfb92006-01-14 13:20:50 -0800217 iounmap(wd_base);
218
219 return 0;
220}
221
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700222static const struct of_device_id mpc8xxx_wdt_match[] = {
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700223 {
224 .compatible = "mpc83xx_wdt",
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700225 .data = &(struct mpc8xxx_wdt_type) {
Anton Vorontsov500c9192008-07-03 23:51:34 -0700226 .prescaler = 0x10000,
227 },
228 },
229 {
230 .compatible = "fsl,mpc8610-wdt",
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700231 .data = &(struct mpc8xxx_wdt_type) {
Anton Vorontsov500c9192008-07-03 23:51:34 -0700232 .prescaler = 0x10000,
233 .hw_enabled = true,
234 },
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700235 },
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700236 {
237 .compatible = "fsl,mpc823-wdt",
238 .data = &(struct mpc8xxx_wdt_type) {
239 .prescaler = 0x800,
Christophe Leroy4af897f2013-11-30 16:45:40 +0100240 .hw_enabled = true,
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700241 },
242 },
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700243 {},
244};
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700245MODULE_DEVICE_TABLE(of, mpc8xxx_wdt_match);
Anton Vorontsovef8ab122008-07-03 23:51:32 -0700246
Grant Likely1c48a5c2011-02-17 02:43:24 -0700247static struct platform_driver mpc8xxx_wdt_driver = {
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700248 .probe = mpc8xxx_wdt_probe,
Bill Pemberton82268712012-11-19 13:21:12 -0500249 .remove = mpc8xxx_wdt_remove,
Grant Likely40182942010-04-13 16:13:02 -0700250 .driver = {
251 .name = "mpc8xxx_wdt",
252 .owner = THIS_MODULE,
253 .of_match_table = mpc8xxx_wdt_match,
Kumar Galafabbfb92006-01-14 13:20:50 -0800254 },
255};
256
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700257/*
258 * We do wdt initialization in two steps: arch_initcall probes the wdt
259 * very early to start pinging the watchdog (misc devices are not yet
260 * available), and later module_init() just registers the misc device.
261 */
Anton Vorontsov593fc172008-08-20 16:38:36 -0700262static int mpc8xxx_wdt_init_late(void)
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700263{
264 int ret;
265
266 if (!wd_base)
267 return -ENODEV;
268
Christophe Leroyd5cfaf02013-12-04 07:32:14 +0100269 watchdog_set_nowayout(&mpc8xxx_wdt_dev, nowayout);
270
271 ret = watchdog_register_device(&mpc8xxx_wdt_dev);
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700272 if (ret) {
Christophe Leroyd5cfaf02013-12-04 07:32:14 +0100273 pr_err("cannot register watchdog device (err=%d)\n", ret);
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700274 return ret;
275 }
276 return 0;
277}
Anton Vorontsov593fc172008-08-20 16:38:36 -0700278#ifndef MODULE
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700279module_init(mpc8xxx_wdt_init_late);
Anton Vorontsov593fc172008-08-20 16:38:36 -0700280#endif
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700281
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700282static int __init mpc8xxx_wdt_init(void)
Kumar Galafabbfb92006-01-14 13:20:50 -0800283{
Grant Likely1c48a5c2011-02-17 02:43:24 -0700284 return platform_driver_register(&mpc8xxx_wdt_driver);
Kumar Galafabbfb92006-01-14 13:20:50 -0800285}
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700286arch_initcall(mpc8xxx_wdt_init);
Kumar Galafabbfb92006-01-14 13:20:50 -0800287
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700288static void __exit mpc8xxx_wdt_exit(void)
Kumar Galafabbfb92006-01-14 13:20:50 -0800289{
Grant Likely1c48a5c2011-02-17 02:43:24 -0700290 platform_driver_unregister(&mpc8xxx_wdt_driver);
Kumar Galafabbfb92006-01-14 13:20:50 -0800291}
Anton Vorontsov59ca1b02008-07-03 23:51:35 -0700292module_exit(mpc8xxx_wdt_exit);
Kumar Galafabbfb92006-01-14 13:20:50 -0800293
294MODULE_AUTHOR("Dave Updegraff, Kumar Gala");
Anton Vorontsov0d7b1012008-07-03 23:51:36 -0700295MODULE_DESCRIPTION("Driver for watchdog timer in MPC8xx/MPC83xx/MPC86xx "
296 "uProcessors");
Kumar Galafabbfb92006-01-14 13:20:50 -0800297MODULE_LICENSE("GPL");