summaryrefslogtreecommitdiff
path: root/target/linux/brcm2708/patches-3.10/0003-bcm2708-watchdog-driver.patch
blob: be05d8396da3fde0900fea7d23c1faa4df4dec22 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
From dd611b3364087514ef5fc59c6106d8924d2a2a30 Mon Sep 17 00:00:00 2001
From: popcornmix <popcornmix@gmail.com>
Date: Wed, 1 May 2013 19:54:32 +0100
Subject: [PATCH 003/174] bcm2708 watchdog driver

Signed-off-by: popcornmix <popcornmix@gmail.com>
---
 drivers/watchdog/Kconfig        |   6 +
 drivers/watchdog/Makefile       |   1 +
 drivers/watchdog/bcm2708_wdog.c | 385 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 392 insertions(+)
 create mode 100644 drivers/watchdog/bcm2708_wdog.c

--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -391,6 +391,12 @@ config RETU_WATCHDOG
 	  To compile this driver as a module, choose M here: the
 	  module will be called retu_wdt.
 
+config BCM2708_WDT
+	tristate "BCM2708 Watchdog"
+	depends on ARCH_BCM2708
+	help
+	  Enables BCM2708 watchdog support.
+
 # AVR32 Architecture
 
 config AT32AP700X_WDT
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -54,6 +54,7 @@ obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_
 obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
 obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
 obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
+obj-$(CONFIG_BCM2708_WDT) += bcm2708_wdog.o
 
 # AVR32 Architecture
 obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
--- /dev/null
+++ b/drivers/watchdog/bcm2708_wdog.c
@@ -0,0 +1,385 @@
+/*
+ *	Broadcom BCM2708 watchdog driver.
+ *
+ *	(c) Copyright 2010 Broadcom Europe Ltd
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ *      BCM2708 watchdog driver. Loosely based on wdt driver.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/fs.h>
+#include <linux/ioport.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <mach/platform.h>
+
+#include <asm/system.h>
+
+#define SECS_TO_WDOG_TICKS(x) ((x) << 16)
+#define WDOG_TICKS_TO_SECS(x) ((x) >> 16)
+
+static unsigned long wdog_is_open;
+static uint32_t wdog_ticks;	       /* Ticks to load into wdog timer */
+static char expect_close;
+
+/*
+ *	Module parameters
+ */
+
+#define WD_TIMO 10		       /* Default heartbeat = 60 seconds */
+static int heartbeat = WD_TIMO;	       /* Heartbeat in seconds */
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat,
+	"Watchdog heartbeat in seconds. (0 < heartbeat < 65536, default="
+				__MODULE_STRING(WD_TIMO) ")");
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout,
+	"Watchdog cannot be stopped once started (default="
+				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static DEFINE_SPINLOCK(wdog_lock);
+
+/**
+ *	Start the watchdog driver.
+ */
+
+static int wdog_start(unsigned long timeout)
+{
+	uint32_t cur;
+	unsigned long flags;
+	spin_lock_irqsave(&wdog_lock, flags);
+
+	/* enable the watchdog */
+	iowrite32(PM_PASSWORD | (timeout & PM_WDOG_TIME_SET), 
+		  __io_address(PM_WDOG));
+	cur = ioread32(__io_address(PM_RSTC));
+	iowrite32(PM_PASSWORD | (cur & PM_RSTC_WRCFG_CLR) |
+		  PM_RSTC_WRCFG_FULL_RESET, __io_address(PM_RSTC));
+
+	spin_unlock_irqrestore(&wdog_lock, flags);
+	return 0;
+}
+
+/**
+ *	Stop the watchdog driver.
+ */
+
+static int wdog_stop(void)
+{
+	iowrite32(PM_PASSWORD | PM_RSTC_RESET, __io_address(PM_RSTC));
+	printk(KERN_INFO "watchdog stopped\n");
+	return 0;
+}
+
+/**
+ *	Reload counter one with the watchdog heartbeat. We don't bother
+ *	reloading the cascade counter.
+ */
+
+static void wdog_ping(void)
+{
+	wdog_start(wdog_ticks);
+}
+
+/**
+ *	@t:		the new heartbeat value that needs to be set.
+ *
+ *	Set a new heartbeat value for the watchdog device. If the heartbeat
+ *	value is incorrect we keep the old value and return -EINVAL. If
+ *	successful we return 0.
+ */
+
+static int wdog_set_heartbeat(int t)
+{
+	if (t < 1 || t > WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET))
+		return -EINVAL;
+
+	heartbeat = t;
+	wdog_ticks = SECS_TO_WDOG_TICKS(t);
+	return 0;
+}
+
+/**
+ *	@file: file handle to the watchdog
+ *	@buf: buffer to write (unused as data does not matter here
+ *	@count: count of bytes
+ *	@ppos: pointer to the position to write. No seeks allowed
+ *
+ *	A write to a watchdog device is defined as a keepalive signal.
+ *	
+ *      if 'nowayout' is set then normally a close() is ignored. But
+ *      if you write 'V' first then the close() will stop the timer.
+ */
+
+static ssize_t wdog_write(struct file *file, const char __user *buf,
+						size_t count, loff_t *ppos)
+{
+	if (count) {
+		if (!nowayout) {
+			size_t i;
+
+			/* In case it was set long ago */
+			expect_close = 0;
+
+			for (i = 0; i != count; i++) {
+				char c;
+				if (get_user(c, buf + i))
+					return -EFAULT;
+				if (c == 'V')
+					expect_close = 42;
+			}
+		}
+		wdog_ping();
+	}
+	return count;
+}
+
+static int wdog_get_status(void)
+{
+	unsigned long flags;
+	int status = 0;
+	spin_lock_irqsave(&wdog_lock, flags);
+	/* FIXME: readback reset reason */
+	spin_unlock_irqrestore(&wdog_lock, flags);
+	return status;
+}
+
+static uint32_t wdog_get_remaining(void)
+{
+	uint32_t ret = ioread32(__io_address(PM_WDOG));
+	return ret & PM_WDOG_TIME_SET;
+}
+
+/**
+ *	@file: file handle to the device
+ *	@cmd: watchdog command
+ *	@arg: argument pointer
+ *
+ *	The watchdog API defines a common set of functions for all watchdogs
+ *	according to their available features. We only actually usefully support
+ *	querying capabilities and current status.
+ */
+
+static long wdog_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+	int __user *p = argp;
+	int new_heartbeat;
+	int status;
+	int options;
+	uint32_t remaining;
+
+	struct watchdog_info ident = {
+		.options =		WDIOF_SETTIMEOUT|
+					WDIOF_MAGICCLOSE|
+					WDIOF_KEEPALIVEPING,
+		.firmware_version =	1,
+		.identity =		"BCM2708",
+	};
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
+	case WDIOC_GETSTATUS:
+		status = wdog_get_status();
+		return put_user(status, p);
+	case WDIOC_GETBOOTSTATUS:
+		return put_user(0, p);
+	case WDIOC_KEEPALIVE:
+		wdog_ping();
+		return 0;
+	case WDIOC_SETTIMEOUT:
+		if (get_user(new_heartbeat, p))
+			return -EFAULT;
+		if (wdog_set_heartbeat(new_heartbeat))
+			return -EINVAL;
+		wdog_ping();
+		/* Fall */
+	case WDIOC_GETTIMEOUT:
+		return put_user(heartbeat, p);
+	case WDIOC_GETTIMELEFT:
+		remaining = WDOG_TICKS_TO_SECS(wdog_get_remaining());
+		return put_user(remaining, p);
+	case WDIOC_SETOPTIONS:
+		if (get_user(options, p))
+			return -EFAULT;
+		if (options & WDIOS_DISABLECARD)
+			wdog_stop();
+		if (options & WDIOS_ENABLECARD)
+			wdog_start(wdog_ticks);
+		return 0;
+	default:
+		return -ENOTTY;
+	}
+}
+
+/**
+ *	@inode: inode of device
+ *	@file: file handle to device
+ *
+ *	The watchdog device has been opened. The watchdog device is single
+ *	open and on opening we load the counters.
+ */
+
+static int wdog_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(0, &wdog_is_open))
+		return -EBUSY;
+	/*
+	 *	Activate
+	 */
+	wdog_start(wdog_ticks);
+	return nonseekable_open(inode, file);
+}
+
+/**
+ *	@inode: inode to board
+ *	@file: file handle to board
+ *
+ *	The watchdog has a configurable API. There is a religious dispute
+ *	between people who want their watchdog to be able to shut down and
+ *	those who want to be sure if the watchdog manager dies the machine
+ *	reboots. In the former case we disable the counters, in the latter
+ *	case you have to open it again very soon.
+ */
+
+static int wdog_release(struct inode *inode, struct file *file)
+{
+	if (expect_close == 42) {
+		wdog_stop();
+	} else {
+		printk(KERN_CRIT
+		 "wdt: WDT device closed unexpectedly.  WDT will not stop!\n");
+		wdog_ping();
+	}
+	clear_bit(0, &wdog_is_open);
+	expect_close = 0;
+	return 0;
+}
+
+/**
+ *	@this: our notifier block
+ *	@code: the event being reported
+ *	@unused: unused
+ *
+ *	Our notifier is called on system shutdowns. Turn the watchdog
+ *	off so that it does not fire during the next reboot.
+ */
+
+static int wdog_notify_sys(struct notifier_block *this, unsigned long code,
+	void *unused)
+{
+	if (code == SYS_DOWN || code == SYS_HALT)
+		wdog_stop();
+	return NOTIFY_DONE;
+}
+
+/*
+ *	Kernel Interfaces
+ */
+
+
+static const struct file_operations wdog_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= wdog_write,
+	.unlocked_ioctl	= wdog_ioctl,
+	.open		= wdog_open,
+	.release	= wdog_release,
+};
+
+static struct miscdevice wdog_miscdev = {
+	.minor	= WATCHDOG_MINOR,
+	.name	= "watchdog",
+	.fops	= &wdog_fops,
+};
+
+/*
+ *	The WDT card needs to learn about soft shutdowns in order to
+ *	turn the timebomb registers off.
+ */
+
+static struct notifier_block wdog_notifier = {
+	.notifier_call = wdog_notify_sys,
+};
+
+/**
+ *	cleanup_module:
+ *
+ *	Unload the watchdog. You cannot do this with any file handles open.
+ *	If your watchdog is set to continue ticking on close and you unload
+ *	it, well it keeps ticking. We won't get the interrupt but the board
+ *	will not touch PC memory so all is fine. You just have to load a new
+ *	module in 60 seconds or reboot.
+ */
+
+static void __exit wdog_exit(void)
+{
+	misc_deregister(&wdog_miscdev);
+	unregister_reboot_notifier(&wdog_notifier);
+}
+
+static int __init wdog_init(void)
+{
+	int ret;
+
+	/* Check that the heartbeat value is within it's range;
+	   if not reset to the default */
+	if (wdog_set_heartbeat(heartbeat)) {
+		wdog_set_heartbeat(WD_TIMO);
+		printk(KERN_INFO "bcm2708_wdog: heartbeat value must be "
+			"0 < heartbeat < %d, using %d\n", 
+				WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
+				WD_TIMO);
+	}
+
+	ret = register_reboot_notifier(&wdog_notifier);
+	if (ret) {
+		printk(KERN_ERR
+		      "wdt: cannot register reboot notifier (err=%d)\n", ret);
+		goto out_reboot;
+	}
+
+	ret = misc_register(&wdog_miscdev);
+	if (ret) {
+		printk(KERN_ERR
+			"wdt: cannot register miscdev on minor=%d (err=%d)\n",
+							WATCHDOG_MINOR, ret);
+		goto out_misc;
+	}
+
+	printk(KERN_INFO "bcm2708 watchdog, heartbeat=%d sec (nowayout=%d)\n",
+		heartbeat, nowayout);
+	return 0;
+
+out_misc:
+	unregister_reboot_notifier(&wdog_notifier);
+out_reboot:
+	return ret;
+}
+
+module_init(wdog_init);
+module_exit(wdog_exit);
+
+MODULE_AUTHOR("Luke Diamand");
+MODULE_DESCRIPTION("Driver for BCM2708 watchdog");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+MODULE_ALIAS_MISCDEV(TEMP_MINOR);
+MODULE_LICENSE("GPL");
+