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path: root/drivers/char/watchdog/w83977f_wdt.c
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Diffstat (limited to 'drivers/char/watchdog/w83977f_wdt.c')
-rw-r--r--drivers/char/watchdog/w83977f_wdt.c548
1 files changed, 548 insertions, 0 deletions
diff --git a/drivers/char/watchdog/w83977f_wdt.c b/drivers/char/watchdog/w83977f_wdt.c
new file mode 100644
index 0000000..366d47b
--- /dev/null
+++ b/drivers/char/watchdog/w83977f_wdt.c
@@ -0,0 +1,548 @@
+/*
+ * W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip
+ *
+ * (c) Copyright 2005 Jose Goncalves <jose.goncalves@inov.pt>
+ *
+ * Based on w83877f_wdt.c by Scott Jennings,
+ * and wdt977.c by Woody Suwalski
+ *
+ * -----------------------
+ *
+ * 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/moduleparam.h>
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/watchdog.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+#define WATCHDOG_VERSION "1.00"
+#define WATCHDOG_NAME "W83977F WDT"
+#define PFX WATCHDOG_NAME ": "
+#define DRIVER_VERSION WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
+
+#define IO_INDEX_PORT 0x3F0
+#define IO_DATA_PORT (IO_INDEX_PORT+1)
+
+#define UNLOCK_DATA 0x87
+#define LOCK_DATA 0xAA
+#define DEVICE_REGISTER 0x07
+
+#define DEFAULT_TIMEOUT 45 /* default timeout in seconds */
+
+static int timeout = DEFAULT_TIMEOUT;
+static int timeoutW; /* timeout in watchdog counter units */
+static unsigned long timer_alive;
+static int testmode;
+static char expect_close;
+static spinlock_t spinlock;
+
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (15..7635), default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")");
+module_param(testmode, int, 0);
+MODULE_PARM_DESC(testmode,"Watchdog testmode (1 = no reboot), default=0");
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+/*
+ * Start the watchdog
+ */
+
+static int wdt_start(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&spinlock, flags);
+
+ /* Unlock the SuperIO chip */
+ outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+ outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+
+ /*
+ * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
+ * F2 has the timeout in watchdog counter units.
+ * F3 is set to enable watchdog LED blink at timeout.
+ * F4 is used to just clear the TIMEOUT'ed state (bit 0).
+ */
+ outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
+ outb_p(0x08,IO_DATA_PORT);
+ outb_p(0xF2,IO_INDEX_PORT);
+ outb_p(timeoutW,IO_DATA_PORT);
+ outb_p(0xF3,IO_INDEX_PORT);
+ outb_p(0x08,IO_DATA_PORT);
+ outb_p(0xF4,IO_INDEX_PORT);
+ outb_p(0x00,IO_DATA_PORT);
+
+ /* Set device Aux2 active */
+ outb_p(0x30,IO_INDEX_PORT);
+ outb_p(0x01,IO_DATA_PORT);
+
+ /*
+ * Select device Aux1 (dev=7) to set GP16 as the watchdog output
+ * (in reg E6) and GP13 as the watchdog LED output (in reg E3).
+ * Map GP16 at pin 119.
+ * In test mode watch the bit 0 on F4 to indicate "triggered" or
+ * check watchdog LED on SBC.
+ */
+ outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
+ outb_p(0x07,IO_DATA_PORT);
+ if (!testmode)
+ {
+ unsigned pin_map;
+
+ outb_p(0xE6,IO_INDEX_PORT);
+ outb_p(0x0A,IO_DATA_PORT);
+ outb_p(0x2C,IO_INDEX_PORT);
+ pin_map = inb_p(IO_DATA_PORT);
+ pin_map |= 0x10;
+ pin_map &= ~(0x20);
+ outb_p(0x2C,IO_INDEX_PORT);
+ outb_p(pin_map,IO_DATA_PORT);
+ }
+ outb_p(0xE3,IO_INDEX_PORT);
+ outb_p(0x08,IO_DATA_PORT);
+
+ /* Set device Aux1 active */
+ outb_p(0x30,IO_INDEX_PORT);
+ outb_p(0x01,IO_DATA_PORT);
+
+ /* Lock the SuperIO chip */
+ outb_p(LOCK_DATA,IO_INDEX_PORT);
+
+ spin_unlock_irqrestore(&spinlock, flags);
+
+ printk(KERN_INFO PFX "activated.\n");
+
+ return 0;
+}
+
+/*
+ * Stop the watchdog
+ */
+
+static int wdt_stop(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&spinlock, flags);
+
+ /* Unlock the SuperIO chip */
+ outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+ outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+
+ /*
+ * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
+ * F2 is reset to its default value (watchdog timer disabled).
+ * F3 is reset to its default state.
+ * F4 clears the TIMEOUT'ed state (bit 0) - back to default.
+ */
+ outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
+ outb_p(0x08,IO_DATA_PORT);
+ outb_p(0xF2,IO_INDEX_PORT);
+ outb_p(0xFF,IO_DATA_PORT);
+ outb_p(0xF3,IO_INDEX_PORT);
+ outb_p(0x00,IO_DATA_PORT);
+ outb_p(0xF4,IO_INDEX_PORT);
+ outb_p(0x00,IO_DATA_PORT);
+ outb_p(0xF2,IO_INDEX_PORT);
+ outb_p(0x00,IO_DATA_PORT);
+
+ /*
+ * Select device Aux1 (dev=7) to set GP16 (in reg E6) and
+ * Gp13 (in reg E3) as inputs.
+ */
+ outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
+ outb_p(0x07,IO_DATA_PORT);
+ if (!testmode)
+ {
+ outb_p(0xE6,IO_INDEX_PORT);
+ outb_p(0x01,IO_DATA_PORT);
+ }
+ outb_p(0xE3,IO_INDEX_PORT);
+ outb_p(0x01,IO_DATA_PORT);
+
+ /* Lock the SuperIO chip */
+ outb_p(LOCK_DATA,IO_INDEX_PORT);
+
+ spin_unlock_irqrestore(&spinlock, flags);
+
+ printk(KERN_INFO PFX "shutdown.\n");
+
+ return 0;
+}
+
+/*
+ * Send a keepalive ping to the watchdog
+ * This is done by simply re-writing the timeout to reg. 0xF2
+ */
+
+static int wdt_keepalive(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&spinlock, flags);
+
+ /* Unlock the SuperIO chip */
+ outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+ outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+
+ /* Select device Aux2 (device=8) to kick watchdog reg F2 */
+ outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
+ outb_p(0x08,IO_DATA_PORT);
+ outb_p(0xF2,IO_INDEX_PORT);
+ outb_p(timeoutW,IO_DATA_PORT);
+
+ /* Lock the SuperIO chip */
+ outb_p(LOCK_DATA,IO_INDEX_PORT);
+
+ spin_unlock_irqrestore(&spinlock, flags);
+
+ return 0;
+}
+
+/*
+ * Set the watchdog timeout value
+ */
+
+static int wdt_set_timeout(int t)
+{
+ int tmrval;
+
+ /*
+ * Convert seconds to watchdog counter time units, rounding up.
+ * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup
+ * value. This information is supplied in the PCM-5335 manual and was
+ * checked by me on a real board. This is a bit strange because W83977f
+ * datasheet says counter unit is in minutes!
+ */
+ if (t < 15)
+ return -EINVAL;
+
+ tmrval = ((t + 15) + 29) / 30;
+
+ if (tmrval > 255)
+ return -EINVAL;
+
+ /*
+ * timeout is the timeout in seconds,
+ * timeoutW is the timeout in watchdog counter units.
+ */
+ timeoutW = tmrval;
+ timeout = (timeoutW * 30) - 15;
+ return 0;
+}
+
+/*
+ * Get the watchdog status
+ */
+
+static int wdt_get_status(int *status)
+{
+ int new_status;
+ unsigned long flags;
+
+ spin_lock_irqsave(&spinlock, flags);
+
+ /* Unlock the SuperIO chip */
+ outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+ outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+
+ /* Select device Aux2 (device=8) to read watchdog reg F4 */
+ outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
+ outb_p(0x08,IO_DATA_PORT);
+ outb_p(0xF4,IO_INDEX_PORT);
+ new_status = inb_p(IO_DATA_PORT);
+
+ /* Lock the SuperIO chip */
+ outb_p(LOCK_DATA,IO_INDEX_PORT);
+
+ spin_unlock_irqrestore(&spinlock, flags);
+
+ *status = 0;
+ if (new_status & 1)
+ *status |= WDIOF_CARDRESET;
+
+ return 0;
+}
+
+
+/*
+ * /dev/watchdog handling
+ */
+
+static int wdt_open(struct inode *inode, struct file *file)
+{
+ /* If the watchdog is alive we don't need to start it again */
+ if( test_and_set_bit(0, &timer_alive) )
+ return -EBUSY;
+
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ wdt_start();
+ return nonseekable_open(inode, file);
+}
+
+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 == 42)
+ {
+ wdt_stop();
+ clear_bit(0, &timer_alive);
+ } else {
+ wdt_keepalive();
+ printk(KERN_CRIT PFX "unexpected close, not stopping watchdog!\n");
+ }
+ expect_close = 0;
+ return 0;
+}
+
+/*
+ * wdt_write:
+ * @file: file handle to the watchdog
+ * @buf: buffer to write (unused as data does not matter here
+ * @count: count of bytes
+ * @ppos: pointer to the position to write. No seeks allowed
+ *
+ * A write to a watchdog device is defined as a keepalive signal. Any
+ * write of data will do, as we we don't define content meaning.
+ */
+
+static ssize_t wdt_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ /* See if we got the magic character 'V' and reload the timer */
+ if(count)
+ {
+ if (!nowayout)
+ {
+ size_t ofs;
+
+ /* note: just in case someone wrote the magic character long ago */
+ expect_close = 0;
+
+ /* scan to see whether or not we got the magic character */
+ for(ofs = 0; ofs != count; ofs++)
+ {
+ char c;
+ if (get_user(c, buf + ofs))
+ return -EFAULT;
+ if (c == 'V') {
+ expect_close = 42;
+ }
+ }
+ }
+
+ /* someone wrote to us, we should restart timer */
+ wdt_keepalive();
+ }
+ return count;
+}
+
+/*
+ * wdt_ioctl:
+ * @inode: inode of the device
+ * @file: file handle to the device
+ * @cmd: watchdog command
+ * @arg: argument pointer
+ *
+ * The watchdog API defines a common set of functions for all watchdogs
+ * according to their available features.
+ */
+
+static struct watchdog_info ident = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
+ .firmware_version = 1,
+ .identity = WATCHDOG_NAME,
+};
+
+static int wdt_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int status;
+ int new_options, retval = -EINVAL;
+ int new_timeout;
+ union {
+ struct watchdog_info __user *ident;
+ int __user *i;
+ } uarg;
+
+ uarg.i = (int __user *)arg;
+
+ switch(cmd)
+ {
+ default:
+ return -ENOIOCTLCMD;
+
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(uarg.ident, &ident, sizeof(ident)) ? -EFAULT : 0;
+
+ case WDIOC_GETSTATUS:
+ wdt_get_status(&status);
+ return put_user(status, uarg.i);
+
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, uarg.i);
+
+ case WDIOC_KEEPALIVE:
+ wdt_keepalive();
+ return 0;
+
+ case WDIOC_SETOPTIONS:
+ if (get_user (new_options, uarg.i))
+ return -EFAULT;
+
+ if (new_options & WDIOS_DISABLECARD) {
+ wdt_stop();
+ retval = 0;
+ }
+
+ if (new_options & WDIOS_ENABLECARD) {
+ wdt_start();
+ retval = 0;
+ }
+
+ return retval;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_timeout, uarg.i))
+ return -EFAULT;
+
+ if (wdt_set_timeout(new_timeout))
+ return -EINVAL;
+
+ wdt_keepalive();
+ /* Fall */
+
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, uarg.i);
+
+ }
+}
+
+static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
+ void *unused)
+{
+ if (code==SYS_DOWN || code==SYS_HALT)
+ wdt_stop();
+ return NOTIFY_DONE;
+}
+
+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 struct notifier_block wdt_notifier = {
+ .notifier_call = wdt_notify_sys,
+};
+
+static int __init w83977f_wdt_init(void)
+{
+ int rc;
+
+ printk(KERN_INFO PFX DRIVER_VERSION);
+
+ spin_lock_init(&spinlock);
+
+ /*
+ * Check that the timeout value is within it's range ;
+ * if not reset to the default
+ */
+ if (wdt_set_timeout(timeout)) {
+ wdt_set_timeout(DEFAULT_TIMEOUT);
+ printk(KERN_INFO PFX "timeout value must be 15<=timeout<=7635, using %d\n",
+ DEFAULT_TIMEOUT);
+ }
+
+ if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME))
+ {
+ printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
+ IO_INDEX_PORT);
+ rc = -EIO;
+ goto err_out;
+ }
+
+ rc = misc_register(&wdt_miscdev);
+ if (rc)
+ {
+ printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+ wdt_miscdev.minor, rc);
+ goto err_out_region;
+ }
+
+ rc = register_reboot_notifier(&wdt_notifier);
+ if (rc)
+ {
+ printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+ rc);
+ goto err_out_miscdev;
+ }
+
+ printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
+ timeout, nowayout, testmode);
+
+ return 0;
+
+err_out_miscdev:
+ misc_deregister(&wdt_miscdev);
+err_out_region:
+ release_region(IO_INDEX_PORT,2);
+err_out:
+ return rc;
+}
+
+static void __exit w83977f_wdt_exit(void)
+{
+ wdt_stop();
+ misc_deregister(&wdt_miscdev);
+ unregister_reboot_notifier(&wdt_notifier);
+ release_region(IO_INDEX_PORT,2);
+}
+
+module_init(w83977f_wdt_init);
+module_exit(w83977f_wdt_exit);
+
+MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
+MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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