[WATCHDOG] alim1535_wdt.c

Add "ALi M1535 PMU Watchdog Timer" driver

drivers/char/watchdog/Kconfig

@@ -346,6 +346,18 @@ config ALIM7101_WDT
 	  module, say M here and read <file:Documentation/modules.txt>.  Most
 	  people will say N.
 
+config ALIM1535_WDT
+	tristate "ALi M1535 PMU Watchdog Timer"
+	depends on WATCHDOG
+	---help---
+	  This is the driver for the hardware watchdog on the ALi M1535 PMU.
+
+	  This driver is also available as a module ( = code which can be
+	  inserted in and removed from the running kernel whenever you want).
+	  The module is called alim1535_wdt.  If you want to compile it as a
+	  module, say M here and read <file:Documentation/modules.txt>.  Most
+	  people will say N.
+
 config SC1200_WDT
 	tristate "National Semiconductor PC87307/PC97307 (ala SC1200) Watchdog"
 	depends on WATCHDOG

drivers/char/watchdog/Makefile

@@ -27,6 +27,7 @@ obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
 obj-$(CONFIG_W83877F_WDT) += w83877f_wdt.o
 obj-$(CONFIG_SC520_WDT) += sc520_wdt.o
 obj-$(CONFIG_ALIM7101_WDT) += alim7101_wdt.o
+obj-$(CONFIG_ALIM1535_WDT) += alim1535_wdt.o
 obj-$(CONFIG_SC1200_WDT) += sc1200wdt.o
 obj-$(CONFIG_WAFER_WDT) += wafer5823wdt.o
 obj-$(CONFIG_CPU5_WDT) += cpu5wdt.o

drivers/char/watchdog/alim1535_wdt.c

+/*
+ *	Watchdog for the 7101 PMU version found in the ALi M1535 chipsets
+ *
+ *	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/types.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/pci.h>
+
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+#define WATCHDOG_NAME "ALi_M1535"
+#define PFX WATCHDOG_NAME ": "
+#define WATCHDOG_TIMEOUT 60	/* 60 sec default timeout */
+
+/* internal variables */
+static unsigned long ali_is_open;
+static char ali_expect_release;
+static struct pci_dev *ali_pci;
+static u32 ali_timeout_bits;	/* stores the computed timeout */
+static spinlock_t ali_lock;	/* Guards the hardware */
+
+/* module parameters */
+static int timeout = WATCHDOG_TIMEOUT;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (0<timeout<18000, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
+
+#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)");
+
+/*
+ *	ali_start	-	start watchdog countdown
+ *
+ *	Starts the timer running providing the timer has a counter
+ *	configuration set.
+ */
+
+static void ali_start(void)
+{
+	u32 val;
+
+	spin_lock(&ali_lock);
+
+	pci_read_config_dword(ali_pci, 0xCC, &val);
+	val &= ~0x3F;	/* Mask count */
+	val |= (1<<25) | ali_timeout_bits;
+	pci_write_config_dword(ali_pci, 0xCC, val);
+
+	spin_unlock(&ali_lock);
+}
+
+/*
+ *	ali_stop	-	stop the timer countdown
+ *
+ *	Stop the ALi watchdog countdown
+ */
+
+static void ali_stop(void)
+{
+	u32 val;
+
+	spin_lock(&ali_lock);
+
+	pci_read_config_dword(ali_pci, 0xCC, &val);
+	val &= ~0x3F;	/* Mask count to zero (disabled) */
+	val &= ~(1<<25);/* and for safety mask the reset enable */
+	pci_write_config_dword(ali_pci, 0xCC, val);
+
+	spin_unlock(&ali_lock);
+}
+
+/*
+ *	ali_keepalive	-	send a keepalive to the watchdog
+ *
+ *      Send a keepalive to the timer (actually we restart the timer).
+ */
+
+static void ali_keepalive(void)
+{
+	ali_start();
+}
+
+/*
+ *	ali_settimer	-	compute the timer reload value
+ *	@t: time in seconds
+ *
+ *	Computes the timeout values needed
+ */
+
+static int ali_settimer(int t)
+{
+	if(t < 0)
+		return -EINVAL;
+	else if(t < 60)
+		ali_timeout_bits = t|(1<<6);
+	else if(t < 3600)
+		ali_timeout_bits = (t/60)|(1<<7);
+	else if(t < 18000)
+		ali_timeout_bits = (t/300)|(1<<6)|(1<<7);
+	else return -EINVAL;
+
+	timeout = t;
+	return 0;
+}
+
+/*
+ *	/dev/watchdog handling
+ */
+
+/*
+ *	ali_write	-	writes to ALi watchdog
+ *	@file: file from VFS
+ *	@data: user address of data
+ *	@len: length of data
+ *	@ppos: pointer to the file offset
+ *
+ *	Handle a write to the ALi watchdog. Writing to the file pings
+ *	the watchdog and resets it. Writing the magic 'V' sequence allows
+ *	the next close to turn off the watchdog.
+ */
+
+static ssize_t ali_write(struct file *file, const char *data,
+			      size_t len, loff_t * ppos)
+{
+	/*  Can't seek (pwrite) on this device  */
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	/* See if we got the magic character 'V' and reload the timer */
+	if (len) {
+		if (!nowayout) {
+			size_t i;
+
+			/* note: just in case someone wrote the magic character
+			 * five months ago... */
+			ali_expect_release = 0;
+
+			/* scan to see wether or not we got the magic character */
+			for (i = 0; i != len; i++) {
+				char c;
+				if(get_user(c, data+i))
+					return -EFAULT;
+				if (c == 'V')
+					ali_expect_release = 42;
+			}
+		}
+
+		/* someone wrote to us, we should reload the timer */
+		ali_start();
+	}
+	return len;
+}
+
+/*
+ *	ali_ioctl	-	handle watchdog ioctls
+ *	@inode: VFS inode
+ *	@file: VFS file pointer
+ *	@cmd: ioctl number
+ *	@arg: arguments to the ioctl
+ *
+ *	Handle the watchdog ioctls supported by the ALi driver. Really
+ *	we want an extension to enable irq ack monitoring and the like
+ */
+
+static int ali_ioctl(struct inode *inode, struct file *file,
+			  unsigned int cmd, unsigned long arg)
+{
+	static struct watchdog_info ident = {
+		.options =		WDIOF_KEEPALIVEPING |
+					WDIOF_SETTIMEOUT |
+					WDIOF_MAGICCLOSE,
+		.firmware_version =	0,
+		.identity =		"ALi M1535 WatchDog Timer",
+	};
+
+	switch (cmd) {
+		case WDIOC_GETSUPPORT:
+			return copy_to_user((struct watchdog_info *) arg, &ident,
+				sizeof (ident)) ? -EFAULT : 0;
+
+		case WDIOC_GETSTATUS:
+		case WDIOC_GETBOOTSTATUS:
+			return put_user(0, (int *) arg);
+
+		case WDIOC_KEEPALIVE:
+			ali_keepalive();
+			return 0;
+
+		case WDIOC_SETOPTIONS:
+		{
+			int new_options, retval = -EINVAL;
+
+			if (get_user (new_options, (int *) arg))
+				return -EFAULT;
+
+			if (new_options & WDIOS_DISABLECARD) {
+				ali_stop();
+				retval = 0;
+			}
+
+			if (new_options & WDIOS_ENABLECARD) {
+				ali_start();
+				retval = 0;
+			}
+
+			return retval;
+		}
+
+		case WDIOC_SETTIMEOUT:
+		{
+			int new_timeout;
+
+			if (get_user(new_timeout, (int *) arg))
+				return -EFAULT;
+
+			if (ali_settimer(new_timeout))
+			    return -EINVAL;
+
+			ali_keepalive();
+			/* Fall */
+		}
+
+		case WDIOC_GETTIMEOUT:
+			return put_user(timeout, (int *)arg);
+
+		default:
+			return -ENOIOCTLCMD;
+	}
+}
+
+/*
+ *	ali_open	-	handle open of ali watchdog
+ *	@inode: inode from VFS
+ *	@file: file from VFS
+ *
+ *	Open the ALi watchdog device. Ensure only one person opens it
+ *	at a time. Also start the watchdog running.
+ */
+
+static int ali_open(struct inode *inode, struct file *file)
+{
+	/* /dev/watchdog can only be opened once */
+	if (test_and_set_bit(0, &ali_is_open))
+		return -EBUSY;
+
+	/* Activate */
+	ali_start();
+	return 0;
+}
+
+/*
+ *	ali_release	-	close an ALi watchdog
+ *	@inode: inode from VFS
+ *	@file: file from VFS
+ *
+ *	Close the ALi watchdog device. Actual shutdown of the timer
+ *	only occurs if the magic sequence has been set.
+ */
+
+static int ali_release(struct inode *inode, struct file *file)
+{
+	/*
+	 *      Shut off the timer.
+	 */
+	if (ali_expect_release == 42) {
+		ali_stop();
+	} else {
+		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
+		ali_keepalive();
+	}
+	clear_bit(0, &ali_is_open);
+	ali_expect_release = 0;
+	return 0;
+}
+
+/*
+ *	ali_notify_sys	-	System down notifier
+ *
+ *	Notifier for system down
+ */
+
+
+static int ali_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
+{
+	if (code==SYS_DOWN || code==SYS_HALT) {
+		/* Turn the WDT off */
+		ali_stop();
+	}
+
+	return NOTIFY_DONE;
+}
+
+/*
+ *	Data for PCI driver interface
+ *
+ *	This data only exists for exporting the supported
+ *	PCI ids via MODULE_DEVICE_TABLE.  We do not actually
+ *	register a pci_driver, because someone else might one day
+ *	want to register another driver on the same PCI id.
+ */
+
+static struct pci_device_id ali_pci_tbl[] __initdata = {
+	{ PCI_VENDOR_ID_AL, 1535, PCI_ANY_ID, PCI_ANY_ID,},
+	{ 0, },
+};
+MODULE_DEVICE_TABLE(pci, ali_pci_tbl);
+
+/*
+ *	ali_find_watchdog	-	find a 1535 and 7101
+ *
+ *	Scans the PCI hardware for a 1535 series bridge and matching 7101
+ *	watchdog device. This may be overtight but it is better to be safe
+ */
+
+static int __init ali_find_watchdog(void)
+{
+	struct pci_dev *pdev;
+	u32 wdog;
+
+	/* Check for a 1535 series bridge */
+	pdev = pci_find_device(PCI_VENDOR_ID_AL, 0x1535, NULL);
+	if(pdev == NULL)
+		return -ENODEV;
+
+	/* Check for the a 7101 PMU */
+	pdev = pci_find_device(PCI_VENDOR_ID_AL, 0x7101, NULL);
+	if(pdev == NULL)
+		return -ENODEV;
+
+	if(pci_enable_device(pdev))
+		return -EIO;
+
+	ali_pci = pdev;
+
+	/*
+	 *	Initialize the timer bits
+	 */
+	pci_read_config_dword(pdev, 0xCC, &wdog);
+
+	wdog &= ~0x3F;		/* Timer bits */
+	wdog &= ~((1<<27)|(1<<26)|(1<<25)|(1<<24));	/* Issued events */
+	wdog &= ~((1<<16)|(1<<13)|(1<<12)|(1<<11)|(1<<10)|(1<<9));	/* No monitor bits */
+
+	pci_write_config_dword(pdev, 0xCC, wdog);
+
+	return 0;
+}
+
+/*
+ *	Kernel Interfaces
+ */
+
+static struct file_operations ali_fops = {
+	.owner =	THIS_MODULE,
+	.llseek =	no_llseek,
+	.write =	ali_write,
+	.ioctl =	ali_ioctl,
+	.open =		ali_open,
+	.release =	ali_release,
+};
+
+static struct miscdevice ali_miscdev = {
+	.minor =	WATCHDOG_MINOR,
+	.name =		"watchdog",
+	.fops =		&ali_fops,
+};
+
+static struct notifier_block ali_notifier = {
+	.notifier_call =	ali_notify_sys,
+	.next =			NULL,
+	.priority =		0,
+};
+
+/*
+ *	watchdog_init	-	module initialiser
+ *
+ *	Scan for a suitable watchdog and if so initialize it. Return an error
+ *	if we cannot, the error causes the module to unload
+ */
+
+static int __init watchdog_init(void)
+{
+	int ret;
+
+	spin_lock_init(&ali_lock);
+
+	/* Check wether or not the hardware watchdog is there */
+	if (ali_find_watchdog() != 0) {
+		return -ENODEV;
+	}
+
+	/* Check that the timeout value is within it's range ; if not reset to the default */
+	if (timeout < 1 || timeout >= 18000) {
+		timeout = WATCHDOG_TIMEOUT;
+		printk(KERN_INFO PFX "timeout value must be 0<timeout<18000, using %d\n",
+			timeout);
+	}
+
+	/* Calculate the watchdog's timeout */
+	ali_settimer(timeout);
+
+	ret = misc_register(&ali_miscdev);
+	if (ret != 0) {
+		printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+			WATCHDOG_MINOR, ret);
+		goto out;
+	}
+
+	ret = register_reboot_notifier(&ali_notifier);
+	if (ret != 0) {
+		printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+			ret);
+		goto unreg_miscdev;
+	}
+
+	printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
+		timeout, nowayout);
+
+out:
+	return ret;
+unreg_miscdev:
+	misc_deregister(&ali_miscdev);
+	goto out;
+}
+
+/*
+ *	watchdog_exit	-	module de-initialiser
+ *
+ *	Called while unloading a successfully installed watchdog module.
+ */
+
+static void __exit watchdog_exit(void)
+{
+	/* Stop the timer before we leave */
+	ali_stop();
+
+	/* Deregister */
+	unregister_reboot_notifier(&ali_notifier);
+	misc_deregister(&ali_miscdev);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_exit);
+
+MODULE_AUTHOR("Alan Cox");
+MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver");
+MODULE_LICENSE("GPL");