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/drivers/watchdog/w83697ug_wdt.c

https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t
C | 403 lines | 284 code | 69 blank | 50 comment | 40 complexity | a9758e7b483f0dc83553d24cde892c99 MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
  1/*
  2 *	w83697ug/uf WDT driver
  3 *
  4 *	(c) Copyright 2008 Flemming Fransen <ff@nrvissing.net>
  5 *		reused original code to support w83697ug/uf.
  6 *
  7 *	Based on w83627hf_wdt.c which is based on advantechwdt.c
  8 *	which is based on wdt.c.
  9 *	Original copyright messages:
 10 *
 11 *	(c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
 12 *		added support for W83627THF.
 13 *
 14 *	(c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
 15 *
 16 *	(c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
 17 *
 18 *	(c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
 19 *				http://www.redhat.com
 20 *
 21 *	This program is free software; you can redistribute it and/or
 22 *	modify it under the terms of the GNU General Public License
 23 *	as published by the Free Software Foundation; either version
 24 *	2 of the License, or (at your option) any later version.
 25 *
 26 *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
 27 *	warranty for any of this software. This material is provided
 28 *	"AS-IS" and at no charge.
 29 *
 30 *	(c) Copyright 1995    Alan Cox <alan@redhat.com>
 31 */
 32
 33#include <linux/module.h>
 34#include <linux/moduleparam.h>
 35#include <linux/types.h>
 36#include <linux/miscdevice.h>
 37#include <linux/watchdog.h>
 38#include <linux/fs.h>
 39#include <linux/ioport.h>
 40#include <linux/notifier.h>
 41#include <linux/reboot.h>
 42#include <linux/init.h>
 43#include <linux/spinlock.h>
 44#include <linux/io.h>
 45#include <linux/uaccess.h>
 46
 47#include <asm/system.h>
 48
 49#define WATCHDOG_NAME "w83697ug/uf WDT"
 50#define PFX WATCHDOG_NAME ": "
 51#define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */
 52
 53static unsigned long wdt_is_open;
 54static char expect_close;
 55static DEFINE_SPINLOCK(io_lock);
 56
 57static int wdt_io = 0x2e;
 58module_param(wdt_io, int, 0);
 59MODULE_PARM_DESC(wdt_io, "w83697ug/uf WDT io port (default 0x2e)");
 60
 61static int timeout = WATCHDOG_TIMEOUT;	/* in seconds */
 62module_param(timeout, int, 0);
 63MODULE_PARM_DESC(timeout,
 64	"Watchdog timeout in seconds. 1<= timeout <=255 (default="
 65				__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
 66
 67static int nowayout = WATCHDOG_NOWAYOUT;
 68module_param(nowayout, int, 0);
 69MODULE_PARM_DESC(nowayout,
 70	"Watchdog cannot be stopped once started (default="
 71				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 72
 73/*
 74 *	Kernel methods.
 75 */
 76
 77#define WDT_EFER (wdt_io+0)   /* Extended Function Enable Registers */
 78#define WDT_EFIR (wdt_io+0)   /* Extended Function Index Register
 79							(same as EFER) */
 80#define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
 81
 82static int w83697ug_select_wd_register(void)
 83{
 84	unsigned char c;
 85	unsigned char version;
 86
 87	outb_p(0x87, WDT_EFER); /* Enter extended function mode */
 88	outb_p(0x87, WDT_EFER); /* Again according to manual */
 89
 90	outb(0x20, WDT_EFER);	/* check chip version	*/
 91	version = inb(WDT_EFDR);
 92
 93	if (version == 0x68) {	/* W83697UG		*/
 94		printk(KERN_INFO PFX "Watchdog chip version 0x%02x = "
 95			"W83697UG/UF found at 0x%04x\n", version, wdt_io);
 96
 97		outb_p(0x2b, WDT_EFER);
 98		c = inb_p(WDT_EFDR);    /* select WDT0 */
 99		c &= ~0x04;
100		outb_p(0x2b, WDT_EFER);
101		outb_p(c, WDT_EFDR);	/* set pin118 to WDT0 */
102
103	} else {
104		printk(KERN_ERR PFX "No W83697UG/UF could be found\n");
105		return -ENODEV;
106	}
107
108	outb_p(0x07, WDT_EFER); /* point to logical device number reg */
109	outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
110	outb_p(0x30, WDT_EFER); /* select CR30 */
111	c = inb_p(WDT_EFDR);
112	outb_p(c | 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
113
114	return 0;
115}
116
117static void w83697ug_unselect_wd_register(void)
118{
119	outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
120}
121
122static int w83697ug_init(void)
123{
124	int ret;
125	unsigned char t;
126
127	ret = w83697ug_select_wd_register();
128	if (ret != 0)
129		return ret;
130
131	outb_p(0xF6, WDT_EFER); /* Select CRF6 */
132	t = inb_p(WDT_EFDR);    /* read CRF6 */
133	if (t != 0) {
134		printk(KERN_INFO PFX "Watchdog already running."
135			" Resetting timeout to %d sec\n", timeout);
136		outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
137	}
138	outb_p(0xF5, WDT_EFER); /* Select CRF5 */
139	t = inb_p(WDT_EFDR);    /* read CRF5 */
140	t &= ~0x0C;             /* set second mode &
141					disable keyboard turning off watchdog */
142	outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
143
144	w83697ug_unselect_wd_register();
145	return 0;
146}
147
148static void wdt_ctrl(int timeout)
149{
150	spin_lock(&io_lock);
151
152	if (w83697ug_select_wd_register() < 0) {
153		spin_unlock(&io_lock);
154		return;
155	}
156
157	outb_p(0xF4, WDT_EFER);    /* Select CRF4 */
158	outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */
159
160	w83697ug_unselect_wd_register();
161
162	spin_unlock(&io_lock);
163}
164
165static int wdt_ping(void)
166{
167	wdt_ctrl(timeout);
168	return 0;
169}
170
171static int wdt_disable(void)
172{
173	wdt_ctrl(0);
174	return 0;
175}
176
177static int wdt_set_heartbeat(int t)
178{
179	if (t < 1 || t > 255)
180		return -EINVAL;
181
182	timeout = t;
183	return 0;
184}
185
186static ssize_t wdt_write(struct file *file, const char __user *buf,
187						size_t count, loff_t *ppos)
188{
189	if (count) {
190		if (!nowayout) {
191			size_t i;
192
193			expect_close = 0;
194
195			for (i = 0; i != count; i++) {
196				char c;
197				if (get_user(c, buf + i))
198					return -EFAULT;
199				if (c == 'V')
200					expect_close = 42;
201			}
202		}
203		wdt_ping();
204	}
205	return count;
206}
207
208static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
209{
210	void __user *argp = (void __user *)arg;
211	int __user *p = argp;
212	int new_timeout;
213	static const struct watchdog_info ident = {
214		.options =		WDIOF_KEEPALIVEPING |
215					WDIOF_SETTIMEOUT |
216					WDIOF_MAGICCLOSE,
217		.firmware_version =	1,
218		.identity =		"W83697UG WDT",
219	};
220
221	switch (cmd) {
222	case WDIOC_GETSUPPORT:
223		if (copy_to_user(argp, &ident, sizeof(ident)))
224			return -EFAULT;
225		break;
226
227	case WDIOC_GETSTATUS:
228	case WDIOC_GETBOOTSTATUS:
229		return put_user(0, p);
230
231	case WDIOC_SETOPTIONS:
232	{
233		int options, retval = -EINVAL;
234
235		if (get_user(options, p))
236			return -EFAULT;
237
238		if (options & WDIOS_DISABLECARD) {
239			wdt_disable();
240			retval = 0;
241		}
242
243		if (options & WDIOS_ENABLECARD) {
244			wdt_ping();
245			retval = 0;
246		}
247
248		return retval;
249	}
250
251	case WDIOC_KEEPALIVE:
252		wdt_ping();
253		break;
254
255	case WDIOC_SETTIMEOUT:
256		if (get_user(new_timeout, p))
257			return -EFAULT;
258		if (wdt_set_heartbeat(new_timeout))
259			return -EINVAL;
260		wdt_ping();
261		/* Fall */
262
263	case WDIOC_GETTIMEOUT:
264		return put_user(timeout, p);
265
266	default:
267		return -ENOTTY;
268	}
269	return 0;
270}
271
272static int wdt_open(struct inode *inode, struct file *file)
273{
274	if (test_and_set_bit(0, &wdt_is_open))
275		return -EBUSY;
276	/*
277	 *	Activate
278	 */
279
280	wdt_ping();
281	return nonseekable_open(inode, file);
282}
283
284static int wdt_close(struct inode *inode, struct file *file)
285{
286	if (expect_close == 42)
287		wdt_disable();
288	else {
289		printk(KERN_CRIT PFX
290			"Unexpected close, not stopping watchdog!\n");
291		wdt_ping();
292	}
293	expect_close = 0;
294	clear_bit(0, &wdt_is_open);
295	return 0;
296}
297
298/*
299 *	Notifier for system down
300 */
301
302static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
303	void *unused)
304{
305	if (code == SYS_DOWN || code == SYS_HALT)
306		wdt_disable();	/* Turn the WDT off */
307
308	return NOTIFY_DONE;
309}
310
311/*
312 *	Kernel Interfaces
313 */
314
315static const struct file_operations wdt_fops = {
316	.owner		= THIS_MODULE,
317	.llseek		= no_llseek,
318	.write		= wdt_write,
319	.unlocked_ioctl	= wdt_ioctl,
320	.open		= wdt_open,
321	.release	= wdt_close,
322};
323
324static struct miscdevice wdt_miscdev = {
325	.minor = WATCHDOG_MINOR,
326	.name = "watchdog",
327	.fops = &wdt_fops,
328};
329
330/*
331 *	The WDT needs to learn about soft shutdowns in order to
332 *	turn the timebomb registers off.
333 */
334
335static struct notifier_block wdt_notifier = {
336	.notifier_call = wdt_notify_sys,
337};
338
339static int __init wdt_init(void)
340{
341	int ret;
342
343	printk(KERN_INFO "WDT driver for the Winbond(TM) W83697UG/UF Super I/O chip initialising.\n");
344
345	if (wdt_set_heartbeat(timeout)) {
346		wdt_set_heartbeat(WATCHDOG_TIMEOUT);
347		printk(KERN_INFO PFX
348			"timeout value must be 1<=timeout<=255, using %d\n",
349			WATCHDOG_TIMEOUT);
350	}
351
352	if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
353		printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
354			wdt_io);
355		ret = -EIO;
356		goto out;
357	}
358
359	ret = w83697ug_init();
360	if (ret != 0)
361		goto unreg_regions;
362
363	ret = register_reboot_notifier(&wdt_notifier);
364	if (ret != 0) {
365		printk(KERN_ERR PFX
366			"cannot register reboot notifier (err=%d)\n", ret);
367		goto unreg_regions;
368	}
369
370	ret = misc_register(&wdt_miscdev);
371	if (ret != 0) {
372		printk(KERN_ERR PFX
373			"cannot register miscdev on minor=%d (err=%d)\n",
374			WATCHDOG_MINOR, ret);
375		goto unreg_reboot;
376	}
377
378	printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
379		timeout, nowayout);
380
381out:
382	return ret;
383unreg_reboot:
384	unregister_reboot_notifier(&wdt_notifier);
385unreg_regions:
386	release_region(wdt_io, 1);
387	goto out;
388}
389
390static void __exit wdt_exit(void)
391{
392	misc_deregister(&wdt_miscdev);
393	unregister_reboot_notifier(&wdt_notifier);
394	release_region(wdt_io, 1);
395}
396
397module_init(wdt_init);
398module_exit(wdt_exit);
399
400MODULE_LICENSE("GPL");
401MODULE_AUTHOR("Flemming Frandsen <ff@nrvissing.net>");
402MODULE_DESCRIPTION("w83697ug/uf WDT driver");
403MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);