1 files changed, 423 insertions, 0 deletions

diff --git a/drivers/watchdog/alim7101_wdt.c b/drivers/watchdog/alim7101_wdt.c
new file mode 100644
index 000000000000..67aed9f8c362
--- /dev/null
+++ b/drivers/watchdog/alim7101_wdt.c
@@ -0,0 +1,423 @@
+/*
+ *      ALi M7101 PMU Computer Watchdog Timer driver
+ *
+ *      Based on w83877f_wdt.c by Scott Jennings <linuxdrivers@oro.net>
+ *      and the Cobalt kernel WDT timer driver by Tim Hockin
+ *                                            <thockin@cobaltnet.com>
+ *
+ *      (c)2002 Steve Hill <steve@navaho.co.uk>
+ *
+ *  This WDT driver is different from most other Linux WDT
+ *  drivers in that the driver will ping the watchdog by itself,
+ *  because this particular WDT has a very short timeout (1.6
+ *  seconds) and it would be insane to count on any userspace
+ *  daemon always getting scheduled within that time frame.
+ *
+ *  Additions:
+ *   Aug 23, 2004 - Added use_gpio module parameter for use on revision a1d PMUs
+ *                  found on very old cobalt hardware.
+ *                  -- Mike Waychison <michael.waychison@sun.com>
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/ioport.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/pci.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#define OUR_NAME "alim7101_wdt"
+#define PFX OUR_NAME ": "
+
+#define WDT_ENABLE 0x9C
+#define WDT_DISABLE 0x8C
+
+#define ALI_7101_WDT    0x92
+#define ALI_7101_GPIO   0x7D
+#define ALI_7101_GPIO_O 0x7E
+#define ALI_WDT_ARM     0x01
+
+/*
+ * We're going to use a 1 second timeout.
+ * If we reset the watchdog every ~250ms we should be safe.  */
+
+#define WDT_INTERVAL (HZ/4+1)
+
+/*
+ * We must not require too good response from the userspace daemon.
+ * Here we require the userspace daemon to send us a heartbeat
+ * char to /dev/watchdog every 30 seconds.
+ */
+
+#define WATCHDOG_TIMEOUT 30            /* 30 sec default timeout */
+static int timeout = WATCHDOG_TIMEOUT; /* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
+
+static int use_gpio = 0; /* Use the pic (for a1d revision alim7101) */
+module_param(use_gpio, int, 0);
+MODULE_PARM_DESC(use_gpio, "Use the gpio watchdog.  (required by old cobalt boards)");
+
+static void wdt_timer_ping(unsigned long);
+static DEFINE_TIMER(timer, wdt_timer_ping, 0, 1);
+static unsigned long next_heartbeat;
+static unsigned long wdt_is_open;
+static char wdt_expect_close;
+static struct pci_dev *alim7101_pmu;
+
+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) ")");
+
+/*
+ *      Whack the dog
+ */
+
+static void wdt_timer_ping(unsigned long data)
+{
+        /* If we got a heartbeat pulse within the WDT_US_INTERVAL
+         * we agree to ping the WDT
+         */
+        char    tmp;
+
+        if(time_before(jiffies, next_heartbeat))
+        {
+                /* Ping the WDT (this is actually a disarm/arm sequence) */
+                pci_read_config_byte(alim7101_pmu, 0x92, &tmp);
+                pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
+                pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp | ALI_WDT_ARM));
+                if (use_gpio) {
+                        pci_read_config_byte(alim7101_pmu, ALI_7101_GPIO_O, &tmp);
+                        pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp
+                                        | 0x20);
+                        pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp
+                                        & ~0x20);
+                }
+        } else {
+                printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
+        }
+        /* Re-set the timer interval */
+        mod_timer(&timer, jiffies + WDT_INTERVAL);
+}
+
+/*
+ * Utility routines
+ */
+
+static void wdt_change(int writeval)
+{
+        char    tmp;
+
+        pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp);
+        if (writeval == WDT_ENABLE) {
+                pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp | ALI_WDT_ARM));
+                if (use_gpio) {
+                        pci_read_config_byte(alim7101_pmu, ALI_7101_GPIO_O, &tmp);
+                        pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp & ~0x20);
+                }
+
+        } else {
+                pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
+                if (use_gpio) {
+                        pci_read_config_byte(alim7101_pmu, ALI_7101_GPIO_O, &tmp);
+                        pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp | 0x20);
+                }
+        }
+}
+
+static void wdt_startup(void)
+{
+        next_heartbeat = jiffies + (timeout * HZ);
+
+        /* We must enable before we kick off the timer in case the timer
+           occurs as we ping it */
+
+        wdt_change(WDT_ENABLE);
+
+        /* Start the timer */
+        mod_timer(&timer, jiffies + WDT_INTERVAL);
+
+        printk(KERN_INFO PFX "Watchdog timer is now enabled.\n");
+}
+
+static void wdt_turnoff(void)
+{
+        /* Stop the timer */
+        del_timer_sync(&timer);
+        wdt_change(WDT_DISABLE);
+        printk(KERN_INFO PFX "Watchdog timer is now disabled...\n");
+}
+
+static void wdt_keepalive(void)
+{
+        /* user land ping */
+        next_heartbeat = jiffies + (timeout * HZ);
+}
+
+/*
+ * /dev/watchdog handling
+ */
+
+static ssize_t fop_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
+                         * five months ago... */
+                        wdt_expect_close = 0;
+
+                        /* now scan */
+                        for (ofs = 0; ofs != count; ofs++) {
+                                char c;
+                                if (get_user(c, buf+ofs))
+                                        return -EFAULT;
+                                if (c == 'V')
+                                        wdt_expect_close = 42;
+                        }
+                }
+                /* someone wrote to us, we should restart timer */
+                wdt_keepalive();
+        }
+        return count;
+}
+
+static int fop_open(struct inode * inode, struct file * file)
+{
+        /* Just in case we're already talking to someone... */
+        if(test_and_set_bit(0, &wdt_is_open))
+                return -EBUSY;
+        /* Good, fire up the show */
+        wdt_startup();
+        return nonseekable_open(inode, file);
+}
+
+static int fop_close(struct inode * inode, struct file * file)
+{
+        if(wdt_expect_close == 42)
+                wdt_turnoff();
+        else {
+                /* wim: shouldn't there be a: del_timer(&timer); */
+                printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n");
+        }
+        clear_bit(0, &wdt_is_open);
+        wdt_expect_close = 0;
+        return 0;
+}
+
+static int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
+{
+        void __user *argp = (void __user *)arg;
+        int __user *p = argp;
+        static struct watchdog_info ident =
+        {
+                .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+                .firmware_version = 1,
+                .identity = "ALiM7101",
+        };
+
+        switch(cmd)
+        {
+                case WDIOC_GETSUPPORT:
+                        return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0;
+                case WDIOC_GETSTATUS:
+                case WDIOC_GETBOOTSTATUS:
+                        return put_user(0, p);
+                case WDIOC_KEEPALIVE:
+                        wdt_keepalive();
+                        return 0;
+                case WDIOC_SETOPTIONS:
+                {
+                        int new_options, retval = -EINVAL;
+
+                        if(get_user(new_options, p))
+                                return -EFAULT;
+
+                        if(new_options & WDIOS_DISABLECARD) {
+                                wdt_turnoff();
+                                retval = 0;
+                        }
+
+                        if(new_options & WDIOS_ENABLECARD) {
+                                wdt_startup();
+                                retval = 0;
+                        }
+
+                        return retval;
+                }
+                case WDIOC_SETTIMEOUT:
+                {
+                        int new_timeout;
+
+                        if(get_user(new_timeout, p))
+                                return -EFAULT;
+
+                        if(new_timeout < 1 || new_timeout > 3600) /* arbitrary upper limit */
+                                return -EINVAL;
+
+                        timeout = new_timeout;
+                        wdt_keepalive();
+                        /* Fall through */
+                }
+                case WDIOC_GETTIMEOUT:
+                        return put_user(timeout, p);
+                default:
+                        return -ENOTTY;
+        }
+}
+
+static const struct file_operations wdt_fops = {
+        .owner=         THIS_MODULE,
+        .llseek=        no_llseek,
+        .write=         fop_write,
+        .open=          fop_open,
+        .release=       fop_close,
+        .ioctl=         fop_ioctl,
+};
+
+static struct miscdevice wdt_miscdev = {
+        .minor=WATCHDOG_MINOR,
+        .name="watchdog",
+        .fops=&wdt_fops,
+};
+
+/*
+ *      Notifier for system down
+ */
+
+static int wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
+{
+        if (code==SYS_DOWN || code==SYS_HALT)
+                wdt_turnoff();
+
+        if (code==SYS_RESTART) {
+                /*
+                 * Cobalt devices have no way of rebooting themselves other than
+                 * getting the watchdog to pull reset, so we restart the watchdog on
+                 * reboot with no heartbeat
+                 */
+                wdt_change(WDT_ENABLE);
+                printk(KERN_INFO PFX "Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second.\n");
+        }
+        return NOTIFY_DONE;
+}
+
+/*
+ *      The WDT needs to learn about soft shutdowns in order to
+ *      turn the timebomb registers off.
+ */
+
+static struct notifier_block wdt_notifier=
+{
+        .notifier_call = wdt_notify_sys,
+};
+
+static void __exit alim7101_wdt_unload(void)
+{
+        wdt_turnoff();
+        /* Deregister */
+        misc_deregister(&wdt_miscdev);
+        unregister_reboot_notifier(&wdt_notifier);
+        pci_dev_put(alim7101_pmu);
+}
+
+static int __init alim7101_wdt_init(void)
+{
+        int rc = -EBUSY;
+        struct pci_dev *ali1543_south;
+        char tmp;
+
+        printk(KERN_INFO PFX "Steve Hill <steve@navaho.co.uk>.\n");
+        alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
+                NULL);
+        if (!alim7101_pmu) {
+                printk(KERN_INFO PFX "ALi M7101 PMU not present - WDT not set\n");
+                return -EBUSY;
+        }
+
+        /* Set the WDT in the PMU to 1 second */
+        pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02);
+
+        ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
+                NULL);
+        if (!ali1543_south) {
+                printk(KERN_INFO PFX "ALi 1543 South-Bridge not present - WDT not set\n");
+                goto err_out;
+        }
+        pci_read_config_byte(ali1543_south, 0x5e, &tmp);
+        pci_dev_put(ali1543_south);
+        if ((tmp & 0x1e) == 0x00) {
+                if (!use_gpio) {
+                        printk(KERN_INFO PFX "Detected old alim7101 revision 'a1d'.  If this is a cobalt board, set the 'use_gpio' module parameter.\n");
+                        goto err_out;
+                } 
+                nowayout = 1;
+        } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
+                printk(KERN_INFO PFX "ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
+                goto err_out;
+        }
+
+        if(timeout < 1 || timeout > 3600) /* arbitrary upper limit */
+        {
+                timeout = WATCHDOG_TIMEOUT;
+                printk(KERN_INFO PFX "timeout value must be 1<=x<=3600, using %d\n",
+                        timeout);
+        }
+
+        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;
+        }
+
+        rc = register_reboot_notifier(&wdt_notifier);
+        if (rc) {
+                printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+                        rc);
+                goto err_out_miscdev;
+        }
+
+        if (nowayout) {
+                __module_get(THIS_MODULE);
+        }
+
+        printk(KERN_INFO PFX "WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
+                timeout, nowayout);
+        return 0;
+
+err_out_miscdev:
+        misc_deregister(&wdt_miscdev);
+err_out:
+        pci_dev_put(alim7101_pmu);
+        return rc;
+}
+
+module_init(alim7101_wdt_init);
+module_exit(alim7101_wdt_unload);
+
+static struct pci_device_id alim7101_pci_tbl[] __devinitdata = {
+        { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
+        { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
+        { }
+};
+
+MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);
+
+MODULE_AUTHOR("Steve Hill");
+MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);