Initial import

1 files changed, 449 insertions, 0 deletions

diff --git a/drivers/watchdog/alim7101_wdt.c b/drivers/watchdog/alim7101_wdt.c
new file mode 100644
index 000000000..665e0e7df
--- /dev/null
+++ b/drivers/watchdog/alim7101_wdt.c
@@ -0,0 +1,449 @@
+/*
+ *	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>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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 <linux/io.h>
+#include <linux/uaccess.h>
+
+
+#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 */
+/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
+static int timeout = WATCHDOG_TIMEOUT;
+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; /* 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 bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 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 {
+		pr_warn("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);
+
+	pr_info("Watchdog timer is now enabled\n");
+}
+
+static void wdt_turnoff(void)
+{
+	/* Stop the timer */
+	del_timer_sync(&timer);
+	wdt_change(WDT_DISABLE);
+	pr_info("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); */
+		pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
+	}
+	clear_bit(0, &wdt_is_open);
+	wdt_expect_close = 0;
+	return 0;
+}
+
+static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+	int __user *p = argp;
+	static const 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_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_KEEPALIVE:
+		wdt_keepalive();
+		return 0;
+	case WDIOC_SETTIMEOUT:
+	{
+		int new_timeout;
+
+		if (get_user(new_timeout, p))
+			return -EFAULT;
+		/* arbitrary upper limit */
+		if (new_timeout < 1 || new_timeout > 3600)
+			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,
+	.unlocked_ioctl	=	fop_ioctl,
+};
+
+static struct miscdevice wdt_miscdev = {
+	.minor	=	WATCHDOG_MINOR,
+	.name	=	"watchdog",
+	.fops	=	&wdt_fops,
+};
+
+static int wdt_restart_handle(struct notifier_block *this, unsigned long mode,
+			      void *cmd)
+{
+	/*
+	 * 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);
+
+	/* loop until the watchdog fires */
+	while (true)
+		;
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block wdt_restart_handler = {
+	.notifier_call = wdt_restart_handle,
+	.priority = 128,
+};
+
+/*
+ *	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();
+
+	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);
+	unregister_restart_handler(&wdt_restart_handler);
+	pci_dev_put(alim7101_pmu);
+}
+
+static int __init alim7101_wdt_init(void)
+{
+	int rc = -EBUSY;
+	struct pci_dev *ali1543_south;
+	char tmp;
+
+	pr_info("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) {
+		pr_info("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) {
+		pr_info("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) {
+			pr_info("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) {
+		pr_info("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;
+		pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
+			timeout);
+	}
+
+	rc = register_reboot_notifier(&wdt_notifier);
+	if (rc) {
+		pr_err("cannot register reboot notifier (err=%d)\n", rc);
+		goto err_out;
+	}
+
+	rc = register_restart_handler(&wdt_restart_handler);
+	if (rc) {
+		pr_err("cannot register restart handler (err=%d)\n", rc);
+		goto err_out_reboot;
+	}
+
+	rc = misc_register(&wdt_miscdev);
+	if (rc) {
+		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+		       wdt_miscdev.minor, rc);
+		goto err_out_restart;
+	}
+
+	if (nowayout)
+		__module_get(THIS_MODULE);
+
+	pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
+		timeout, nowayout);
+	return 0;
+
+err_out_restart:
+	unregister_restart_handler(&wdt_restart_handler);
+err_out_reboot:
+	unregister_reboot_notifier(&wdt_notifier);
+err_out:
+	pci_dev_put(alim7101_pmu);
+	return rc;
+}
+
+module_init(alim7101_wdt_init);
+module_exit(alim7101_wdt_unload);
+
+static const struct pci_device_id alim7101_pci_tbl[] __used = {
+	{ 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");