[WATCHDOG] Add support for the built-int RDC R-321x SoC watchdog

This patch adds support for the built-in RDC R-321x SoC watchdog.

Signed-off-by: Florian Fainelli <florian.fainelli@telecomint.eu>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/Kconfig

@@ -465,6 +465,16 @@ config PC87413_WDT
 
 	  Most people will say N.
 
+config RDC321X_WDT
+	tristate "RDC R-321x SoC watchdog"
+	depends on X86_RDC321X
+	help
+	  This is the driver for the built in hardware watchdog
+	  in the RDC R-321x SoC.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called rdc321x_wdt.
+
 config 60XX_WDT
 	tristate "SBC-60XX Watchdog Timer"
 	depends on X86

drivers/watchdog/Makefile

@@ -75,6 +75,7 @@ obj-$(CONFIG_HP_WATCHDOG) += hpwdt.o
 obj-$(CONFIG_SC1200_WDT) += sc1200wdt.o
 obj-$(CONFIG_SCx200_WDT) += scx200_wdt.o
 obj-$(CONFIG_PC87413_WDT) += pc87413_wdt.o
+obj-$(CONFIG_RDC321X_WDT) += rdc321x_wdt.o
 obj-$(CONFIG_60XX_WDT) += sbc60xxwdt.o
 obj-$(CONFIG_SBC8360_WDT) += sbc8360.o
 obj-$(CONFIG_SBC7240_WDT) += sbc7240_wdt.o

drivers/watchdog/rdc321x_wdt.c

@@ -0,0 +1,285 @@
+/*
+ * RDC321x watchdog driver
+ *
+ * Copyright (C) 2007 Florian Fainelli <florian@openwrt.org>
+ *
+ * This driver is highly inspired from the cpu5_wdt driver
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/timer.h>
+#include <linux/completion.h>
+#include <linux/jiffies.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#include <asm/mach-rdc321x/rdc321x_defs.h>
+
+#define RDC_WDT_MASK	0x80000000 /* Mask */
+#define RDC_WDT_EN	0x00800000 /* Enable bit */
+#define RDC_WDT_WTI	0x00200000 /* Generate CPU reset/NMI/WDT on timeout */
+#define RDC_WDT_RST	0x00100000 /* Reset bit */
+#define RDC_WDT_WIF	0x00040000 /* WDT IRQ Flag */
+#define RDC_WDT_IRT	0x00000100 /* IRQ Routing table */
+#define RDC_WDT_CNT	0x00000001 /* WDT count */
+
+#define RDC_CLS_TMR	0x80003844 /* Clear timer */
+
+#define RDC_WDT_INTERVAL	(HZ/10+1)
+
+static int ticks = 1000;
+
+/* some device data */
+
+static struct {
+	struct completion stop;
+	int running;
+	struct timer_list timer;
+	int queue;
+	int default_ticks;
+	unsigned long inuse;
+	spinlock_t lock;
+} rdc321x_wdt_device;
+
+/* generic helper functions */
+
+static void rdc321x_wdt_trigger(unsigned long unused)
+{
+	unsigned long flags;
+
+	if (rdc321x_wdt_device.running)
+		ticks--;
+
+	/* keep watchdog alive */
+	spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
+	outl(RDC_WDT_EN | inl(RDC3210_CFGREG_DATA),
+		RDC3210_CFGREG_DATA);
+	spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
+
+	/* requeue?? */
+	if (rdc321x_wdt_device.queue && ticks)
+		mod_timer(&rdc321x_wdt_device.timer,
+				jiffies + RDC_WDT_INTERVAL);
+	else {
+		/* ticks doesn't matter anyway */
+		complete(&rdc321x_wdt_device.stop);
+	}
+
+}
+
+static void rdc321x_wdt_reset(void)
+{
+	ticks = rdc321x_wdt_device.default_ticks;
+}
+
+static void rdc321x_wdt_start(void)
+{
+	unsigned long flags;
+
+	if (!rdc321x_wdt_device.queue) {
+		rdc321x_wdt_device.queue = 1;
+
+		/* Clear the timer */
+		spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
+		outl(RDC_CLS_TMR, RDC3210_CFGREG_ADDR);
+
+		/* Enable watchdog and set the timeout to 81.92 us */
+		outl(RDC_WDT_EN | RDC_WDT_CNT, RDC3210_CFGREG_DATA);
+		spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
+
+		mod_timer(&rdc321x_wdt_device.timer,
+				jiffies + RDC_WDT_INTERVAL);
+	}
+
+	/* if process dies, counter is not decremented */
+	rdc321x_wdt_device.running++;
+}
+
+static int rdc321x_wdt_stop(void)
+{
+	if (rdc321x_wdt_device.running)
+		rdc321x_wdt_device.running = 0;
+
+	ticks = rdc321x_wdt_device.default_ticks;
+
+	return -EIO;
+}
+
+/* filesystem operations */
+static int rdc321x_wdt_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(0, &rdc321x_wdt_device.inuse))
+		return -EBUSY;
+
+	return nonseekable_open(inode, file);
+}
+
+static int rdc321x_wdt_release(struct inode *inode, struct file *file)
+{
+	clear_bit(0, &rdc321x_wdt_device.inuse);
+	return 0;
+}
+
+static int rdc321x_wdt_ioctl(struct inode *inode, struct file *file,
+				unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+	unsigned int value;
+	static struct watchdog_info ident = {
+		.options = WDIOF_CARDRESET,
+		.identity = "RDC321x WDT",
+	};
+	unsigned long flags;
+
+	switch (cmd) {
+	case WDIOC_KEEPALIVE:
+		rdc321x_wdt_reset();
+		break;
+	case WDIOC_GETSTATUS:
+		/* Read the value from the DATA register */
+		spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
+		value = inl(RDC3210_CFGREG_DATA);
+		spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
+		if (copy_to_user(argp, &value, sizeof(int)))
+			return -EFAULT;
+		break;
+	case WDIOC_GETSUPPORT:
+		if (copy_to_user(argp, &ident, sizeof(ident)))
+			return -EFAULT;
+		break;
+	case WDIOC_SETOPTIONS:
+		if (copy_from_user(&value, argp, sizeof(int)))
+			return -EFAULT;
+		switch (value) {
+		case WDIOS_ENABLECARD:
+			rdc321x_wdt_start();
+			break;
+		case WDIOS_DISABLECARD:
+			return rdc321x_wdt_stop();
+		default:
+			return -EINVAL;
+		}
+		break;
+	default:
+		return -ENOTTY;
+	}
+	return 0;
+}
+
+static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf,
+				size_t count, loff_t *ppos)
+{
+	if (!count)
+		return -EIO;
+
+	rdc321x_wdt_reset();
+
+	return count;
+}
+
+static const struct file_operations rdc321x_wdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.ioctl		= rdc321x_wdt_ioctl,
+	.open		= rdc321x_wdt_open,
+	.write		= rdc321x_wdt_write,
+	.release	= rdc321x_wdt_release,
+};
+
+static struct miscdevice rdc321x_wdt_misc = {
+	.minor	= WATCHDOG_MINOR,
+	.name	= "watchdog",
+	.fops	= &rdc321x_wdt_fops,
+};
+
+static int __devinit rdc321x_wdt_probe(struct platform_device *pdev)
+{
+	int err;
+
+	err = misc_register(&rdc321x_wdt_misc);
+	if (err < 0) {
+		printk(KERN_ERR PFX "watchdog misc_register failed\n");
+		return err;
+	}
+
+	spin_lock_init(&rdc321x_wdt_device.lock);
+
+	/* Reset the watchdog */
+	outl(RDC_WDT_RST, RDC3210_CFGREG_DATA);
+
+	init_completion(&rdc321x_wdt_device.stop);
+	rdc321x_wdt_device.queue = 0;
+
+	clear_bit(0, &rdc321x_wdt_device.inuse);
+
+	setup_timer(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);
+
+	rdc321x_wdt_device.default_ticks = ticks;
+
+	printk(KERN_INFO PFX "watchdog init success\n");
+
+	return 0;
+}
+
+static int rdc321x_wdt_remove(struct platform_device *pdev)
+{
+	if (rdc321x_wdt_device.queue) {
+		rdc321x_wdt_device.queue = 0;
+		wait_for_completion(&rdc321x_wdt_device.stop);
+	}
+
+	misc_deregister(&rdc321x_wdt_misc);
+
+	return 0;
+}
+
+static struct platform_driver rdc321x_wdt_driver = {
+	.probe = rdc321x_wdt_probe,
+	.remove = rdc321x_wdt_remove,
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "rdc321x-wdt",
+	},
+};
+
+static int __init rdc321x_wdt_init(void)
+{
+	return platform_driver_register(&rdc321x_wdt_driver);
+}
+
+static void __exit rdc321x_wdt_exit(void)
+{
+	platform_driver_unregister(&rdc321x_wdt_driver);
+}
+
+module_init(rdc321x_wdt_init);
+module_exit(rdc321x_wdt_exit);
+
+MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
+MODULE_DESCRIPTION("RDC321x watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);