blob: 7ef99a169e3bbaf6e433abe4a7591b576a35ad75 [file] [log] [blame]
Andrew Victor853807f2006-03-14 11:11:04 +02001/*
2 * Watchdog driver for Atmel AT91RM9200 (Thunder)
3 *
4 * Copyright (C) 2003 SAN People (Pty) Ltd
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
Joe Perches27c766a2012-02-15 15:06:19 -080012#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
Jiri Slaby1977f032007-10-18 23:40:25 -070014#include <linux/bitops.h>
Andrew Victor853807f2006-03-14 11:11:04 +020015#include <linux/errno.h>
16#include <linux/fs.h>
17#include <linux/init.h>
Jean-Christop PLAGNIOL-VILLARD02e07462009-01-23 10:06:07 +010018#include <linux/io.h>
Andrew Victor853807f2006-03-14 11:11:04 +020019#include <linux/kernel.h>
20#include <linux/miscdevice.h>
21#include <linux/module.h>
22#include <linux/moduleparam.h>
Andrew Victordfc7bd92006-05-21 15:32:59 +020023#include <linux/platform_device.h>
Andrew Victor853807f2006-03-14 11:11:04 +020024#include <linux/types.h>
25#include <linux/watchdog.h>
Alan Cox27606002008-05-19 14:05:19 +010026#include <linux/uaccess.h>
Russell Kinga09e64f2008-08-05 16:14:15 +010027#include <mach/at91_st.h>
Andrew Victor853807f2006-03-14 11:11:04 +020028
Andrew Victordfc7bd92006-05-21 15:32:59 +020029#define WDT_DEFAULT_TIME 5 /* seconds */
30#define WDT_MAX_TIME 256 /* seconds */
Andrew Victor853807f2006-03-14 11:11:04 +020031
32static int wdt_time = WDT_DEFAULT_TIME;
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010033static bool nowayout = WATCHDOG_NOWAYOUT;
Andrew Victor853807f2006-03-14 11:11:04 +020034
35module_param(wdt_time, int, 0);
Alan Cox27606002008-05-19 14:05:19 +010036MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
37 __MODULE_STRING(WDT_DEFAULT_TIME) ")");
Andrew Victor853807f2006-03-14 11:11:04 +020038
Andrew Victordfc7bd92006-05-21 15:32:59 +020039#ifdef CONFIG_WATCHDOG_NOWAYOUT
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010040module_param(nowayout, bool, 0);
Alan Cox27606002008-05-19 14:05:19 +010041MODULE_PARM_DESC(nowayout,
42 "Watchdog cannot be stopped once started (default="
43 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Andrew Victordfc7bd92006-05-21 15:32:59 +020044#endif
Andrew Victor853807f2006-03-14 11:11:04 +020045
46
47static unsigned long at91wdt_busy;
48
49/* ......................................................................... */
50
51/*
52 * Disable the watchdog.
53 */
Alan Cox27606002008-05-19 14:05:19 +010054static inline void at91_wdt_stop(void)
Andrew Victor853807f2006-03-14 11:11:04 +020055{
Jean-Christophe PLAGNIOL-VILLARD5e9cf5e2012-02-20 11:07:39 +010056 at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN);
Andrew Victor853807f2006-03-14 11:11:04 +020057}
58
59/*
60 * Enable and reset the watchdog.
61 */
Alan Cox27606002008-05-19 14:05:19 +010062static inline void at91_wdt_start(void)
Andrew Victor853807f2006-03-14 11:11:04 +020063{
Jean-Christophe PLAGNIOL-VILLARD5e9cf5e2012-02-20 11:07:39 +010064 at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
Alan Cox27606002008-05-19 14:05:19 +010065 (((65536 * wdt_time) >> 8) & AT91_ST_WDV));
Jean-Christophe PLAGNIOL-VILLARD5e9cf5e2012-02-20 11:07:39 +010066 at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
Andrew Victor853807f2006-03-14 11:11:04 +020067}
68
69/*
70 * Reload the watchdog timer. (ie, pat the watchdog)
71 */
Alan Cox27606002008-05-19 14:05:19 +010072static inline void at91_wdt_reload(void)
Andrew Victor853807f2006-03-14 11:11:04 +020073{
Jean-Christophe PLAGNIOL-VILLARD5e9cf5e2012-02-20 11:07:39 +010074 at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
Andrew Victor853807f2006-03-14 11:11:04 +020075}
76
77/* ......................................................................... */
78
79/*
80 * Watchdog device is opened, and watchdog starts running.
81 */
82static int at91_wdt_open(struct inode *inode, struct file *file)
83{
84 if (test_and_set_bit(0, &at91wdt_busy))
85 return -EBUSY;
86
87 at91_wdt_start();
88 return nonseekable_open(inode, file);
89}
90
91/*
92 * Close the watchdog device.
93 * If CONFIG_WATCHDOG_NOWAYOUT is NOT defined then the watchdog is also
94 * disabled.
95 */
96static int at91_wdt_close(struct inode *inode, struct file *file)
97{
Alan Cox27606002008-05-19 14:05:19 +010098 /* Disable the watchdog when file is closed */
Andrew Victor853807f2006-03-14 11:11:04 +020099 if (!nowayout)
Alan Cox27606002008-05-19 14:05:19 +0100100 at91_wdt_stop();
Andrew Victor853807f2006-03-14 11:11:04 +0200101
102 clear_bit(0, &at91wdt_busy);
103 return 0;
104}
105
106/*
107 * Change the watchdog time interval.
108 */
109static int at91_wdt_settimeout(int new_time)
110{
111 /*
Andrew Victor2af29b72009-02-11 21:23:10 +0100112 * All counting occurs at SLOW_CLOCK / 128 = 256 Hz
Andrew Victor853807f2006-03-14 11:11:04 +0200113 *
114 * Since WDV is a 16-bit counter, the maximum period is
Andrew Victor2af29b72009-02-11 21:23:10 +0100115 * 65536 / 256 = 256 seconds.
Andrew Victor853807f2006-03-14 11:11:04 +0200116 */
117 if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
118 return -EINVAL;
119
Alan Cox27606002008-05-19 14:05:19 +0100120 /* Set new watchdog time. It will be used when
121 at91_wdt_start() is called. */
Andrew Victor853807f2006-03-14 11:11:04 +0200122 wdt_time = new_time;
123 return 0;
124}
125
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000126static const struct watchdog_info at91_wdt_info = {
Andrew Victor853807f2006-03-14 11:11:04 +0200127 .identity = "at91 watchdog",
128 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
129};
130
131/*
132 * Handle commands from user-space.
133 */
Adrian Bunk3c4fafd2008-08-08 18:57:45 +0300134static long at91_wdt_ioctl(struct file *file,
Alan Cox27606002008-05-19 14:05:19 +0100135 unsigned int cmd, unsigned long arg)
Andrew Victor853807f2006-03-14 11:11:04 +0200136{
137 void __user *argp = (void __user *)arg;
138 int __user *p = argp;
139 int new_value;
140
Alan Cox27606002008-05-19 14:05:19 +0100141 switch (cmd) {
Alan Cox27606002008-05-19 14:05:19 +0100142 case WDIOC_GETSUPPORT:
143 return copy_to_user(argp, &at91_wdt_info,
144 sizeof(at91_wdt_info)) ? -EFAULT : 0;
Alan Cox27606002008-05-19 14:05:19 +0100145 case WDIOC_GETSTATUS:
146 case WDIOC_GETBOOTSTATUS:
147 return put_user(0, p);
148 case WDIOC_SETOPTIONS:
149 if (get_user(new_value, p))
150 return -EFAULT;
151 if (new_value & WDIOS_DISABLECARD)
152 at91_wdt_stop();
153 if (new_value & WDIOS_ENABLECARD)
Andrew Victor853807f2006-03-14 11:11:04 +0200154 at91_wdt_start();
Alan Cox27606002008-05-19 14:05:19 +0100155 return 0;
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000156 case WDIOC_KEEPALIVE:
157 at91_wdt_reload(); /* pat the watchdog */
158 return 0;
159 case WDIOC_SETTIMEOUT:
160 if (get_user(new_value, p))
161 return -EFAULT;
162 if (at91_wdt_settimeout(new_value))
163 return -EINVAL;
164 /* Enable new time value */
165 at91_wdt_start();
166 /* Return current value */
167 return put_user(wdt_time, p);
168 case WDIOC_GETTIMEOUT:
169 return put_user(wdt_time, p);
Alan Cox27606002008-05-19 14:05:19 +0100170 default:
171 return -ENOTTY;
Andrew Victor853807f2006-03-14 11:11:04 +0200172 }
173}
174
175/*
176 * Pat the watchdog whenever device is written to.
177 */
Alan Cox27606002008-05-19 14:05:19 +0100178static ssize_t at91_wdt_write(struct file *file, const char *data,
179 size_t len, loff_t *ppos)
Andrew Victor853807f2006-03-14 11:11:04 +0200180{
181 at91_wdt_reload(); /* pat the watchdog */
182 return len;
183}
184
185/* ......................................................................... */
186
Arjan van de Ven62322d22006-07-03 00:24:21 -0700187static const struct file_operations at91wdt_fops = {
Andrew Victor853807f2006-03-14 11:11:04 +0200188 .owner = THIS_MODULE,
189 .llseek = no_llseek,
Alan Cox27606002008-05-19 14:05:19 +0100190 .unlocked_ioctl = at91_wdt_ioctl,
Andrew Victor853807f2006-03-14 11:11:04 +0200191 .open = at91_wdt_open,
192 .release = at91_wdt_close,
193 .write = at91_wdt_write,
194};
195
196static struct miscdevice at91wdt_miscdev = {
197 .minor = WATCHDOG_MINOR,
198 .name = "watchdog",
199 .fops = &at91wdt_fops,
200};
201
Uwe Kleine-König47dec7c2009-03-28 00:26:26 +0100202static int __devinit at91wdt_probe(struct platform_device *pdev)
Andrew Victor853807f2006-03-14 11:11:04 +0200203{
204 int res;
205
Andrew Victore0b79e02006-12-04 15:56:18 +0200206 if (at91wdt_miscdev.parent)
Andrew Victordfc7bd92006-05-21 15:32:59 +0200207 return -EBUSY;
Andrew Victore0b79e02006-12-04 15:56:18 +0200208 at91wdt_miscdev.parent = &pdev->dev;
Andrew Victor853807f2006-03-14 11:11:04 +0200209
210 res = misc_register(&at91wdt_miscdev);
211 if (res)
212 return res;
213
Joe Perches27c766a2012-02-15 15:06:19 -0800214 pr_info("AT91 Watchdog Timer enabled (%d seconds%s)\n",
215 wdt_time, nowayout ? ", nowayout" : "");
Andrew Victor853807f2006-03-14 11:11:04 +0200216 return 0;
217}
218
Uwe Kleine-König47dec7c2009-03-28 00:26:26 +0100219static int __devexit at91wdt_remove(struct platform_device *pdev)
Andrew Victordfc7bd92006-05-21 15:32:59 +0200220{
221 int res;
222
223 res = misc_deregister(&at91wdt_miscdev);
224 if (!res)
Andrew Victore0b79e02006-12-04 15:56:18 +0200225 at91wdt_miscdev.parent = NULL;
Andrew Victordfc7bd92006-05-21 15:32:59 +0200226
227 return res;
228}
229
230static void at91wdt_shutdown(struct platform_device *pdev)
231{
232 at91_wdt_stop();
233}
234
235#ifdef CONFIG_PM
236
237static int at91wdt_suspend(struct platform_device *pdev, pm_message_t message)
238{
239 at91_wdt_stop();
240 return 0;
241}
242
243static int at91wdt_resume(struct platform_device *pdev)
244{
245 if (at91wdt_busy)
246 at91_wdt_start();
Ilpo Jarvinen95f62bd2008-08-19 09:01:14 +0300247 return 0;
Andrew Victordfc7bd92006-05-21 15:32:59 +0200248}
249
250#else
251#define at91wdt_suspend NULL
252#define at91wdt_resume NULL
253#endif
254
255static struct platform_driver at91wdt_driver = {
256 .probe = at91wdt_probe,
Uwe Kleine-König47dec7c2009-03-28 00:26:26 +0100257 .remove = __devexit_p(at91wdt_remove),
Andrew Victordfc7bd92006-05-21 15:32:59 +0200258 .shutdown = at91wdt_shutdown,
259 .suspend = at91wdt_suspend,
260 .resume = at91wdt_resume,
261 .driver = {
262 .name = "at91_wdt",
263 .owner = THIS_MODULE,
264 },
265};
266
267static int __init at91_wdt_init(void)
268{
Alan Cox27606002008-05-19 14:05:19 +0100269 /* Check that the heartbeat value is within range;
270 if not reset to the default */
Andrew Victordfc7bd92006-05-21 15:32:59 +0200271 if (at91_wdt_settimeout(wdt_time)) {
272 at91_wdt_settimeout(WDT_DEFAULT_TIME);
Joe Perches27c766a2012-02-15 15:06:19 -0800273 pr_info("wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
274 wdt_time);
Andrew Victordfc7bd92006-05-21 15:32:59 +0200275 }
276
277 return platform_driver_register(&at91wdt_driver);
278}
279
Andrew Victor853807f2006-03-14 11:11:04 +0200280static void __exit at91_wdt_exit(void)
281{
Andrew Victordfc7bd92006-05-21 15:32:59 +0200282 platform_driver_unregister(&at91wdt_driver);
Andrew Victor853807f2006-03-14 11:11:04 +0200283}
284
285module_init(at91_wdt_init);
286module_exit(at91_wdt_exit);
287
288MODULE_AUTHOR("Andrew Victor");
289MODULE_DESCRIPTION("Watchdog driver for Atmel AT91RM9200");
290MODULE_LICENSE("GPL");
291MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Kay Sieversf37d1932008-04-10 21:29:23 -0700292MODULE_ALIAS("platform:at91_wdt");