aboutsummaryrefslogtreecommitdiff
path: root/drivers/watchdog/rdc321x_wdt.c
diff options
context:
space:
mode:
authorFlorian Fainelli <florian.fainelli@telecomint.eu>2008-02-25 12:59:26 +0100
committerWim Van Sebroeck <wim@iguana.be>2008-08-26 20:20:05 +0000
commitb3e8f2c13ae964a8889fe96a2f3f7fd7e0cfae76 (patch)
tree8b6a2156f20d5205e86c3d094d6af42820764f35 /drivers/watchdog/rdc321x_wdt.c
parenteaa95eb6ea43e6de8bea702c13556de9a1a1195a (diff)
downloadvexpress-lsk-b3e8f2c13ae964a8889fe96a2f3f7fd7e0cfae76.tar.gz
[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>
Diffstat (limited to 'drivers/watchdog/rdc321x_wdt.c')
-rw-r--r--drivers/watchdog/rdc321x_wdt.c285
1 files changed, 285 insertions, 0 deletions
diff --git a/drivers/watchdog/rdc321x_wdt.c b/drivers/watchdog/rdc321x_wdt.c
new file mode 100644
index 00000000000..9108efa73e7
--- /dev/null
+++ b/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);