[WATCHDOG] w83977f-watchdog-driver.patch

In a project for my company I've needed to use the watchdog device in a
PCM-5335 SBC from AAEON.  The watchdog timer is from a Winbond's SuperIO
chip, the W83977F.

I've made this driver based on two others already on the kernel tree,
the w83877f_wdt and the wdt977.

Signed-off-by: Jose Goncalves <jose.goncalves@inov.pt>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

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 000000000000..366d47bca16e
--- /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);