--- /dev/null
+/*
+ * ADM5120_WDT 0.01: Infineon ADM5120 SoC watchdog driver
+ * Copyright (c) Ondrej Zajicek <santiago@crfreenet.org>, 2007
+ *
+ * based on
+ *
+ * RC32434_WDT 0.01: IDT Interprise 79RC32434 watchdog 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.
+ *
+ */
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/irq.h>
+
+#include <asm/bootinfo.h>
+
+#include <asm/mach-adm5120/adm5120_info.h>
+#include <asm/mach-adm5120/adm5120_defs.h>
+#include <asm/mach-adm5120/adm5120_switch.h>
+
+#define DEFAULT_TIMEOUT 15 /* (secs) Default is 15 seconds */
+#define MAX_TIMEOUT 327
+/* Max is 327 seconds, counter is 15-bit integer, step is 10 ms */
+
+#define NAME "adm5120_wdt"
+#define VERSION "0.1"
+
+static int expect_close;
+static int access;
+static unsigned int timeout = DEFAULT_TIMEOUT;
+
+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 wdt_set_timeout(void)
+{
+ u32 val = (1 << 31) | (((timeout * 100) & 0x7FFF) << 16);
+ SW_WRITE_REG(SWITCH_REG_WDOG0, val);
+}
+
+/*
+ It looks like WDOG0-register-write don't modify counter,
+ but WDOG0-register-read resets counter.
+*/
+
+static inline void wdt_reset_counter(void)
+{
+ SW_READ_REG(SWITCH_REG_WDOG0);
+}
+
+static inline void wdt_disable(void)
+{
+ SW_WRITE_REG(SWITCH_REG_WDOG0, 0x7FFF0000);
+}
+
+
+
+static int wdt_open(struct inode *inode, struct file *file)
+{
+ /* Allow only one person to hold it open */
+ if (access)
+ return -EBUSY;
+
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ /* Activate timer */
+ wdt_reset_counter();
+ wdt_set_timeout();
+ 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)) {
+ wdt_disable();
+ 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;
+ }
+ }
+ wdt_reset_counter();
+ return len;
+ }
+ return 0;
+}
+
+static long wdt_ioctl(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 = "ADM5120_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:
+ wdt_reset_counter();
+ 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;
+ timeout = new_timeout;
+ wdt_set_timeout();
+ /* Fall */
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, (int *)arg);
+ }
+}
+
+static const struct file_operations wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = wdt_write,
+ .unlocked_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 "\n";
+
+static int __init watchdog_init(void)
+{
+ int ret;
+
+ ret = misc_register(&wdt_miscdev);
+
+ if (ret)
+ return ret;
+
+ wdt_disable();
+ printk(banner);
+
+ return 0;
+}
+
+static void __exit watchdog_exit(void)
+{
+ misc_deregister(&wdt_miscdev);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_exit);
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