watchdog driver for RB 532

Here is the driver for the hardware watchdog timer
integrated in RB 532 (as part of the SoC IDT 79RC32434).

File include/asm-mips/rc32434/integ.h is taken from
Mikrotik RB 532 kernel patch.

Signed-off-by: Ondrej Zajicek <santiago@crfreenet.org>


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@9896 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 240 insertions, 0 deletions

diff --git a/target/linux/rb532/files/drivers/char/watchdog/rc32434_wdt.c b/target/linux/rb532/files/drivers/char/watchdog/rc32434_wdt.c
new file mode 100644
index 000000000..2266329de
--- /dev/null
+++ b/target/linux/rb532/files/drivers/char/watchdog/rc32434_wdt.c
@@ -0,0 +1,240 @@
+/*
+ *	RC32434_WDT 0.01: IDT Interprise 79RC32434 watchdog driver 
+ *	Copyright (c) Ondrej Zajicek <santiago@crfreenet.org>, 2006
+ *
+ *	based on
+ *
+ *	SoftDog	0.05:	A Software Watchdog Device
+ *
+ *	(c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
+ *
+ *	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.
+ *	
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/reboot.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <asm/bootinfo.h>
+#include <asm/time.h>
+#include <asm/uaccess.h>
+#include <asm/rc32434/integ.h>
+
+#define DEFAULT_TIMEOUT	15		/* (secs) Default is 15 seconds */
+#define MAX_TIMEOUT	20		
+/*
+ * (secs) Max is 20 seconds 
+ * (max frequency of counter is ~200 MHz, counter is 32-bit unsigned int) 
+ */
+
+#define NAME "rc32434_wdt"
+#define VERSION "0.1"
+
+static INTEG_t rc_wdt = (INTEG_t) INTEG_VirtualAddress;                                                                     
+
+static int expect_close = 0;
+static int access = 0;
+static int timeout = 0;
+
+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) ")");
+MODULE_LICENSE("GPL");
+
+
+static inline void start_wdt(void)
+{
+	rc_wdt -> wtcount = 0;
+	rc_wdt -> errcs |= ERRCS_wre_m;
+	rc_wdt -> wtc   |= WTC_en_m;
+}
+
+static inline void stop_wdt(void)
+{
+	rc_wdt -> wtc   &= ~WTC_en_m;
+	rc_wdt -> errcs &= ~ERRCS_wre_m;
+}
+
+static inline void set_wdt(int new_timeout)
+{
+	u32 cmp = new_timeout * mips_hpt_frequency;
+	u32 state;
+	
+	timeout = new_timeout;
+	/*
+	 * store and disable WTC
+	 */
+	state = rc_wdt -> wtc & WTC_en_m;
+	rc_wdt -> wtc   &= ~WTC_en_m;
+
+	rc_wdt -> wtcount = 0;
+	rc_wdt -> wtcompare = cmp;
+
+	/*
+	 * restore WTC
+	 */	
+	rc_wdt -> wtc |= state;
+}
+
+static inline void update_wdt(void)
+{
+	rc_wdt -> wtcount = 0;
+}
+
+/*
+ *	Allow only one person to hold it open
+ */
+ 
+static int wdt_open(struct inode *inode, struct file *file)
+{
+	if (access)
+		return -EBUSY;
+	if (nowayout) {
+		__module_get(THIS_MODULE);
+	}
+	/*
+	 *	Activate timer
+	 */
+	start_wdt();
+	printk(KERN_INFO NAME ": enabling watchdog timer\n");
+	access = 1;
+	return 0;
+}
+
+static int wdt_release(struct inode *inode, struct file *file)
+{
+	/*
+	 *	Shut off the timer.
+	 * 	Lock it in if it's a module and we set nowayout
+	 */
+	if (expect_close && nowayout == 0) {
+		stop_wdt ();
+		printk(KERN_INFO NAME ": disabling watchdog timer\n");
+		module_put(THIS_MODULE);
+	} else {
+		printk (KERN_CRIT NAME ": device closed unexpectedly.  WDT will not stop!\n");
+	}
+	access = 0;
+	return 0;
+}
+
+static ssize_t wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+{
+	/*
+	 *	Refresh the timer.
+	 */
+	if (len) {
+		if (!nowayout) {
+			size_t i;
+
+			/* In case it was set long ago */
+			expect_close = 0;
+
+			for (i = 0; i != len; i++) {
+				char c;
+				if (get_user(c, data + i))
+					return -EFAULT;
+				if (c == 'V')
+					expect_close = 1;
+			}
+		}
+		update_wdt ();
+		return len;
+	}
+	return 0;
+}
+
+static int wdt_ioctl(struct inode *inode, struct file *file,
+	unsigned int cmd, unsigned long arg)
+{
+	int new_timeout;
+	static struct watchdog_info ident = {
+		.options =		WDIOF_SETTIMEOUT |
+					WDIOF_KEEPALIVEPING |
+					WDIOF_MAGICCLOSE,
+		.firmware_version =	0,
+		.identity =		"RC32434_WDT Watchdog",
+	};
+	switch (cmd) {
+		default:
+			return -ENOTTY;
+		case WDIOC_GETSUPPORT:
+			if(copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)))
+				return -EFAULT;
+			return 0;
+		case WDIOC_GETSTATUS:
+		case WDIOC_GETBOOTSTATUS:
+			return put_user(0,(int *)arg);
+		case WDIOC_KEEPALIVE:
+			update_wdt();
+			return 0;
+		case WDIOC_SETTIMEOUT:
+			if (get_user(new_timeout, (int *)arg))
+				return -EFAULT;
+			if (new_timeout < 1)
+				return -EINVAL;
+			if (new_timeout > MAX_TIMEOUT)
+				return -EINVAL;
+			set_wdt(new_timeout);
+			/* Fall */
+		case WDIOC_GETTIMEOUT:
+			return put_user(timeout, (int *)arg);
+	}
+}
+
+static struct file_operations wdt_fops = {
+	owner:		THIS_MODULE,
+	llseek:		no_llseek,
+	write:		wdt_write,
+	ioctl:		wdt_ioctl,
+	open:		wdt_open,
+	release:	wdt_release,
+};
+
+static struct miscdevice wdt_miscdev = {
+	minor:		WATCHDOG_MINOR,
+	name:		"watchdog",
+	fops:		&wdt_fops,
+};
+
+static char banner[] __initdata = KERN_INFO NAME ": Watchdog Timer version " VERSION ", timer margin: %d sec\n";
+
+static int __init watchdog_init(void)
+{
+	int ret;
+
+	/*
+  	 * There should be check for RC32434 SoC
+	 */
+	if (mips_machgroup != MACH_GROUP_MIKROTIK) return -1;
+
+	ret = misc_register(&wdt_miscdev);
+
+	if (ret)
+		return ret;
+
+	stop_wdt();
+	set_wdt(DEFAULT_TIMEOUT);
+
+	printk(banner, timeout);
+
+	return 0;
+}
+
+static void __exit watchdog_exit(void)
+{
+	misc_deregister(&wdt_miscdev);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_exit);