--- /dev/null
+/*
+ * Watchdog driver for the BCM963xx devices
+ *
+ * Copyright (C) 2007 OpenWrt.org
+ * Florian Fainelli <florian@openwrt.org>
+ *
+ * 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/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/notifier.h>
+#include <linux/watchdog.h>
+#include <linux/timer.h>
+#include <linux/jiffies.h>
+#include <linux/completion.h>
+#include <linux/ioport.h>
+
+typedef struct bcm963xx_timer {
+ unsigned short unused0;
+ unsigned char timer_mask;
+#define TIMER0EN 0x01
+#define TIMER1EN 0x02
+#define TIMER2EN 0x04
+ unsigned char timer_ints;
+#define TIMER0 0x01
+#define TIMER1 0x02
+#define TIMER2 0x04
+#define WATCHDOG 0x08
+ unsigned long timer_ctl0;
+ unsigned long timer_ctl1;
+ unsigned long timer_ctl2;
+#define TIMERENABLE 0x80000000
+#define RSTCNTCLR 0x40000000
+ unsigned long timer_cnt0;
+ unsigned long timer_cnt1;
+ unsigned long timer_cnt2;
+ unsigned long wdt_def_count;
+
+ /* Write 0xff00 0x00ff to Start timer
+ * Write 0xee00 0x00ee to Stop and re-load default count
+ * Read from this register returns current watch dog count
+ */
+ unsigned long wdt_ctl;
+
+ /* Number of 40-MHz ticks for WD Reset pulse to last */
+ unsigned long wdt_rst_count;
+} bcm963xx_timer;
+
+static struct bcm963xx_wdt_device {
+ struct completion stop;
+ volatile int running;
+ struct timer_list timer;
+ volatile int queue;
+ int default_ticks;
+ unsigned long inuse;
+} bcm963xx_wdt_device;
+
+static int ticks = 1000;
+
+#define WDT_BASE 0xfffe0200
+#define WDT ((volatile bcm963xx_timer * const) WDT_BASE)
+
+#define BCM963XX_INTERVAL (HZ/10+1)
+
+static void bcm963xx_wdt_trigger(unsigned long unused)
+{
+ if (bcm963xx_wdt_device.running)
+ ticks--;
+
+ /* Load the default ticking value into the reset counter register */
+ WDT->wdt_rst_count = bcm963xx_wdt_device.default_ticks;
+
+ if (bcm963xx_wdt_device.queue && ticks) {
+ bcm963xx_wdt_device.timer.expires = jiffies + BCM963XX_INTERVAL;
+ add_timer(&bcm963xx_wdt_device.timer);
+ }
+ else {
+ complete(&bcm963xx_wdt_device.stop);
+ }
+}
+
+static void bcm963xx_wdt_reset(void)
+{
+ ticks = bcm963xx_wdt_device.default_ticks;
+ /* Also reload default count */
+ WDT->wdt_def_count = ticks;
+ WDT->wdt_ctl = 0xee00;
+ WDT->wdt_ctl = 0x00ee;
+}
+
+static void bcm963xx_wdt_start(void)
+{
+ if (!bcm963xx_wdt_device.queue) {
+ bcm963xx_wdt_device.queue;
+ /* Enable the watchdog by writing 0xff00 ,then 0x00ff to the control register */
+ WDT->wdt_ctl = 0xff00;
+ WDT->wdt_ctl = 0x00ff;
+ bcm963xx_wdt_device.timer.expires = jiffies + BCM963XX_INTERVAL;
+ add_timer(&bcm963xx_wdt_device.timer);
+ }
+ bcm963xx_wdt_device.running++;
+}
+
+static int bcm963xx_wdt_stop(void)
+{
+ if (bcm963xx_wdt_device.running)
+ bcm963xx_wdt_device.running = 0;
+
+ ticks = bcm963xx_wdt_device.default_ticks;
+
+ /* Stop the watchdog by writing 0xee00 then 0x00ee to the control register */
+ WDT->wdt_ctl = 0xee00;
+ WDT->wdt_ctl = 0x00ee;
+
+ return -EIO;
+}
+
+static int bcm963xx_wdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &bcm963xx_wdt_device.inuse))
+ return -EBUSY;
+ return nonseekable_open(inode, file);
+}
+
+static int bcm963xx_wdt_release(struct inode *inode, struct file *file)
+{
+ clear_bit(0, &bcm963xx_wdt_device.inuse);
+ return 0;
+}
+
+static int bcm963xx_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 = "BCM963xx WDT",
+ };
+
+ switch (cmd) {
+ case WDIOC_KEEPALIVE:
+ bcm963xx_wdt_reset();
+ break;
+ case WDIOC_GETSTATUS:
+ /* Reading from the control register will return the current value */
+ value = WDT->wdt_ctl;
+ 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:
+ bcm963xx_wdt_start();
+ break;
+ case WDIOS_DISABLECARD:
+ bcm963xx_wdt_stop();
+ break;
+ default:
+ return -EINVAL;
+ }
+ break;
+ default:
+ return -ENOTTY;
+ }
+ return 0;
+}
+
+static int bcm963xx_wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+ if (!count)
+ return -EIO;
+ bcm963xx_wdt_reset();
+ return count;
+}
+
+static const struct file_operations bcm963xx_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = bcm963xx_wdt_write,
+ .ioctl = bcm963xx_wdt_ioctl,
+ .open = bcm963xx_wdt_open,
+ .release = bcm963xx_wdt_release,
+};
+
+static struct miscdevice bcm963xx_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &bcm963xx_wdt_fops,
+};
+
+static void __exit bcm963xx_wdt_exit(void)
+{
+ if (bcm963xx_wdt_device.queue ){
+ bcm963xx_wdt_device.queue = 0;
+ wait_for_completion(&bcm963xx_wdt_device.stop);
+ }
+ misc_deregister(&bcm963xx_wdt_miscdev);
+}
+
+static int __init bcm963xx_wdt_init(void)
+{
+ int ret = 0;
+
+ printk("Broadcom BCM963xx Watchdog timer\n");
+
+ ret = misc_register(&bcm963xx_wdt_miscdev);
+ if (ret) {
+ printk(KERN_CRIT "Cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret);
+ return ret;
+ }
+ init_completion(&bcm963xx_wdt_device.stop);
+ bcm963xx_wdt_device.queue = 0;
+
+ clear_bit(0, &bcm963xx_wdt_device.inuse);
+
+ init_timer(&bcm963xx_wdt_device.timer);
+ bcm963xx_wdt_device.timer.function = bcm963xx_wdt_trigger;
+ bcm963xx_wdt_device.timer.data = 0;
+
+ bcm963xx_wdt_device.default_ticks = ticks;
+ return ret;
+}
+
+
+module_init(bcm963xx_wdt_init);
+module_exit(bcm963xx_wdt_exit);
+
+MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
+MODULE_DESCRIPTION("Broadcom BCM963xx Watchdog driver");
+MODULE_LICENSE("GPL");
projects / openwrt.git / blobdiff