2 * IDT Interprise 79RC32434 watchdog driver
4 * Copyright (C) 2006, Ondrej Zajicek <santiago@crfreenet.org>
5 * Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
8 * SoftDog 0.05: A Software Watchdog Device
10 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
11 * All Rights Reserved.
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
20 #include <linux/module.h>
21 #include <linux/types.h>
22 #include <linux/kernel.h>
25 #include <linux/miscdevice.h>
26 #include <linux/watchdog.h>
27 #include <linux/reboot.h>
28 #include <linux/smp_lock.h>
29 #include <linux/init.h>
30 #include <linux/platform_device.h>
31 #include <linux/uaccess.h>
33 #include <asm/bootinfo.h>
35 #include <asm/mach-rc32434/integ.h>
37 #define MAX_TIMEOUT 20
38 #define RC32434_WDT_INTERVAL (15 * HZ)
43 struct completion stop
;
45 struct timer_list timer
;
51 static struct integ __iomem
*wdt_reg
;
52 static int ticks
= 100 * HZ
;
54 static int expect_close
;
57 static int nowayout
= WATCHDOG_NOWAYOUT
;
58 module_param(nowayout
, int, 0);
59 MODULE_PARM_DESC(nowayout
, "Watchdog cannot be stopped once started (default="
60 __MODULE_STRING(WATCHDOG_NOWAYOUT
) ")");
63 static void rc32434_wdt_start(void)
67 if (!rc32434_wdt_device
.inuse
) {
68 writel(0, &wdt_reg
->wtcount
);
70 val
= RC32434_ERR_WRE
;
71 writel(readl(&wdt_reg
->errcs
) | val
, &wdt_reg
->errcs
);
74 writel(readl(&wdt_reg
->wtc
) | val
, &wdt_reg
->wtc
);
76 rc32434_wdt_device
.running
++;
79 static void rc32434_wdt_stop(void)
83 if (rc32434_wdt_device
.running
) {
85 val
= ~RC32434_WTC_EN
;
86 writel(readl(&wdt_reg
->wtc
) & val
, &wdt_reg
->wtc
);
88 val
= ~RC32434_ERR_WRE
;
89 writel(readl(&wdt_reg
->errcs
) & val
, &wdt_reg
->errcs
);
91 rc32434_wdt_device
.running
= 0;
95 static void rc32434_wdt_set(int new_timeout
)
97 u32 cmp
= new_timeout
* HZ
;
100 timeout
= new_timeout
;
102 * store and disable WTC
104 state
= (u32
)(readl(&wdt_reg
->wtc
) & RC32434_WTC_EN
);
105 val
= ~RC32434_WTC_EN
;
106 writel(readl(&wdt_reg
->wtc
) & val
, &wdt_reg
->wtc
);
108 writel(0, &wdt_reg
->wtcount
);
109 writel(cmp
, &wdt_reg
->wtcompare
);
115 writel(readl(&wdt_reg
->wtc
) | state
, &wdt_reg
);
118 static void rc32434_wdt_reset(void)
120 ticks
= rc32434_wdt_device
.default_ticks
;
123 static void rc32434_wdt_update(unsigned long unused
)
125 if (rc32434_wdt_device
.running
)
128 writel(0, &wdt_reg
->wtcount
);
130 if (rc32434_wdt_device
.queue
&& ticks
)
131 mod_timer(&rc32434_wdt_device
.timer
,
132 jiffies
+ RC32434_WDT_INTERVAL
);
134 complete(&rc32434_wdt_device
.stop
);
137 static int rc32434_wdt_open(struct inode
*inode
, struct file
*file
)
139 if (test_and_set_bit(0, &rc32434_wdt_device
.inuse
))
143 __module_get(THIS_MODULE
);
145 return nonseekable_open(inode
, file
);
148 static int rc32434_wdt_release(struct inode
*inode
, struct file
*file
)
150 if (expect_close
&& nowayout
== 0) {
152 printk(KERN_INFO KBUILD_MODNAME
": disabling watchdog timer\n");
153 module_put(THIS_MODULE
);
155 printk(KERN_CRIT KBUILD_MODNAME
156 ": device closed unexpectedly. WDT will not stop !\n");
158 clear_bit(0, &rc32434_wdt_device
.inuse
);
162 static ssize_t
rc32434_wdt_write(struct file
*file
, const char *data
,
163 size_t len
, loff_t
*ppos
)
169 /* In case it was set long ago */
172 for (i
= 0; i
!= len
; i
++) {
174 if (get_user(c
, data
+ i
))
180 rc32434_wdt_update(0);
186 static long rc32434_wdt_ioctl(struct file
*file
, unsigned int cmd
,
189 void __user
*argp
= (void __user
*)arg
;
192 static struct watchdog_info ident
= {
193 .options
= WDIOF_SETTIMEOUT
|
194 WDIOF_KEEPALIVEPING
|
196 .identity
= "RC32434_WDT Watchdog",
199 case WDIOC_KEEPALIVE
:
202 case WDIOC_GETSTATUS
:
203 case WDIOC_GETBOOTSTATUS
:
204 value
= readl(&wdt_reg
->wtcount
);
205 if (copy_to_user(argp
, &value
, sizeof(int)))
208 case WDIOC_GETSUPPORT
:
209 if (copy_to_user(argp
, &ident
, sizeof(ident
)))
212 case WDIOC_SETOPTIONS
:
213 if (copy_from_user(&value
, argp
, sizeof(int)))
216 case WDIOS_ENABLECARD
:
219 case WDIOS_DISABLECARD
:
225 case WDIOC_SETTIMEOUT
:
226 if (copy_from_user(&new_timeout
, argp
, sizeof(int)))
230 if (new_timeout
> MAX_TIMEOUT
)
232 rc32434_wdt_set(new_timeout
);
233 case WDIOC_GETTIMEOUT
:
234 return copy_to_user(argp
, &timeout
, sizeof(int));
242 static struct file_operations rc32434_wdt_fops
= {
243 .owner
= THIS_MODULE
,
245 .write
= rc32434_wdt_write
,
246 .unlocked_ioctl
= rc32434_wdt_ioctl
,
247 .open
= rc32434_wdt_open
,
248 .release
= rc32434_wdt_release
,
251 static struct miscdevice rc32434_wdt_miscdev
= {
252 .minor
= WATCHDOG_MINOR
,
254 .fops
= &rc32434_wdt_fops
,
257 static char banner
[] = KERN_INFO KBUILD_MODNAME
258 ": Watchdog Timer version " VERSION
", timer margin: %d sec\n";
260 static int rc32434_wdt_probe(struct platform_device
*pdev
)
265 r
= platform_get_resource_byname(pdev
, IORESOURCE_MEM
, "rb500_wdt_res");
267 printk(KERN_ERR KBUILD_MODNAME
268 "failed to retrieve resources\n");
272 wdt_reg
= ioremap_nocache(r
->start
, r
->end
- r
->start
);
274 printk(KERN_ERR KBUILD_MODNAME
275 "failed to remap I/O resources\n");
279 ret
= misc_register(&rc32434_wdt_miscdev
);
282 printk(KERN_ERR KBUILD_MODNAME
283 "failed to register watchdog device\n");
287 init_completion(&rc32434_wdt_device
.stop
);
288 rc32434_wdt_device
.queue
= 0;
290 clear_bit(0, &rc32434_wdt_device
.inuse
);
292 setup_timer(&rc32434_wdt_device
.timer
, rc32434_wdt_update
, 0L);
294 rc32434_wdt_device
.default_ticks
= ticks
;
298 printk(banner
, timeout
);
307 static int rc32434_wdt_remove(struct platform_device
*pdev
)
309 if (rc32434_wdt_device
.queue
) {
310 rc32434_wdt_device
.queue
= 0;
311 wait_for_completion(&rc32434_wdt_device
.stop
);
313 misc_deregister(&rc32434_wdt_miscdev
);
320 static struct platform_driver rc32434_wdt
= {
321 .probe
= rc32434_wdt_probe
,
322 .remove
= rc32434_wdt_remove
,
324 .name
= "rc32434_wdt",
328 static int __init
rc32434_wdt_init(void)
330 return platform_driver_register(&rc32434_wdt
);
333 static void __exit
rc32434_wdt_exit(void)
335 platform_driver_unregister(&rc32434_wdt
);
338 module_init(rc32434_wdt_init
);
339 module_exit(rc32434_wdt_exit
);
341 MODULE_AUTHOR("Ondrej Zajicek <santiago@crfreenet.org>,"
342 "Florian Fainelli <florian@openwrt.org>");
343 MODULE_DESCRIPTION("Driver for the IDT RC32434 SoC watchdog");
344 MODULE_LICENSE("GPL");
345 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR
);