patch-2.4.20 linux-2.4.20/drivers/char/alim1535d_wdt.c

• Lines: 357
• Date: Thu Nov 28 15:53:12 2002
• Orig file: linux-2.4.19/drivers/char/alim1535d_wdt.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/drivers/char/alim1535d_wdt.c linux-2.4.20/drivers/char/alim1535d_wdt.c
@@ -0,0 +1,356 @@
+/*
+ *	Watchdog for the 7101 PMU version found in the ALi1535 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/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/ioport.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+static spinlock_t ali_lock;	/* Guards the hardware */
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+
+MODULE_PARM(nowayout,"i");
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+static unsigned long timer_alive;
+static char ali_expect_close;
+static u32 ali_timeout = 60;			/* 60 seconds */
+static u32 ali_timeout_bits = 1 | (1<<7);	/* 1 count in minutes */
+
+static struct pci_dev *ali_pci;
+
+/**
+ *	ali_timer_start		-	start watchdog countdown
+ *	@dev: PCI device of the PMU
+ *
+ *	Starts the timer running providing the timer has a counter
+ *	configuration set.
+ */
+ 
+static void ali_timer_start(struct pci_dev *pdev)
+{
+	u32 val;
+
+	spin_lock(&ali_lock);
+	
+	pci_read_config_dword(pdev, 0xCC, &val);
+	val &= ~0x3F;	/* Mask count */
+	val |= (1<<25) | ali_timeout_bits;
+	pci_write_config_dword(pdev, 0xCC, val);
+	spin_unlock(&ali_lock);
+}
+
+/**
+ *	ali_timer_stop	-	stop the timer countdown
+ *	@pdev: PCI device of the PMU
+ *
+ *	Stop the ALi watchdog countdown
+ */
+ 
+static void ali_timer_stop (struct pci_dev *pdev)
+{
+	u32 val;
+
+	spin_lock(&ali_lock);
+	pci_read_config_dword(pdev, 0xCC, &val);
+	val &= ~0x3F;	/* Mask count to zero (disabled) */
+	val &= ~(1<<25);/* and for safety mask the reset enable */
+	pci_write_config_dword(pdev, 0xCC, val);
+	spin_unlock(&ali_lock);
+}
+
+/**
+ *	ali_timer_settimer	-	compute the timer reload value
+ *	@pdev: PCI device of the PMU
+ *	@t: time in seconds
+ *
+ *	Computes the timeout values needed and then restarts the timer
+ *	running with the new timeout values
+ */
+
+static int ali_timer_settimer(struct pci_dev *pdev, unsigned long t)
+{
+	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;
+	
+	ali_timeout = t;
+	ali_timer_start(pdev);
+	return 0;
+}
+
+/**
+ *	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)
+{
+	if (test_and_set_bit(0, &timer_alive))
+		return -EBUSY;
+	ali_timer_start (ali_pci);
+	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 or nowayout is 
+ *	disabled
+ */
+ 
+static int ali_release (struct inode *inode, struct file *file)
+{
+	/*
+	 *      Shut off the timer.
+	 */
+	if (ali_expect_close == 42 && !nowayout) {
+		ali_timer_stop(ali_pci);
+	} else {
+		ali_timer_start(ali_pci);
+		printk(KERN_CRIT  "ali1535_wdt: Unexpected close, not stopping watchdog!\n");
+	}
+	clear_bit(0, &timer_alive);
+	ali_expect_close = 0;
+	return 0;
+}
+
+/**
+ *	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) {
+		size_t i;
+
+		ali_expect_close = 0;
+
+		/* scan to see wether or not we got the magic character */
+		for (i = 0; i != len; i++) {
+			u8 c;
+			if(get_user(c, data+i))
+				return -EFAULT;
+			if (c == 'V')
+				ali_expect_close = 42;
+		}
+
+		/* someone wrote to us, we should reload the timer */
+		ali_timer_start(ali_pci);
+		return 1;
+	}
+	return 0;
+}
+
+/**
+ *	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)
+{
+	int options, retval = -EINVAL;
+	u32 t;
+	static struct watchdog_info ident = {
+		options:		WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+		firmware_version:	0,
+		identity:		"ALi 1535D+ TCO timer",
+	};
+	switch (cmd) {
+		default:
+			return -ENOTTY;
+		case WDIOC_GETSUPPORT:
+			if (copy_to_user((struct watchdog_info *) arg, &ident, sizeof (ident)))
+				return -EFAULT;
+			return 0;
+		case WDIOC_GETSTATUS:
+		case WDIOC_GETBOOTSTATUS:
+			return put_user(0, (int *) arg);
+		case WDIOC_SETOPTIONS:
+			if (get_user (options, (int *) arg))
+				return -EFAULT;
+			if (options & WDIOS_DISABLECARD) {
+				ali_timer_stop(ali_pci);
+				retval = 0;
+			}
+			if (options & WDIOS_ENABLECARD) {
+				ali_timer_start(ali_pci);
+				retval = 0;
+			}
+			return retval;
+		case WDIOC_KEEPALIVE:
+			ali_timer_start(ali_pci);
+			return 0;
+		case WDIOC_SETTIMEOUT:
+			if (get_user(t, (int *) arg))
+				return -EFAULT;
+			if (ali_timer_settimer(ali_pci, t))
+			    return -EINVAL;
+			ali_timer_start(ali_pci);
+			/* Fall */
+		case WDIOC_GETTIMEOUT:
+			return put_user(ali_timeout, (int *)arg);
+	}
+}
+
+/*
+ * 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;
+}
+
+static struct file_operations ali_fops = {
+	owner:		THIS_MODULE,
+	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,
+};
+
+/**
+ *	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)
+{
+	spin_lock_init(&ali_lock);
+	if (!ali_find_watchdog())
+		return -ENODEV;
+	if (misc_register (&ali_miscdev) != 0) {
+		printk (KERN_ERR "alim1535d: cannot register watchdog device node.\n");
+		return -EIO;
+	}
+	return 0;
+}
+
+/**
+ *	watchdog_cleanup	-	unload watchdog
+ *
+ *	Called on the unload of a successfully installed watchdog module.
+ */
+ 
+static void __exit watchdog_cleanup (void)
+{
+	ali_timer_stop(ali_pci);
+	misc_deregister (&ali_miscdev);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_cleanup);
+
+MODULE_AUTHOR("Alan Cox");
+MODULE_DESCRIPTION("Watchdog driver for the ALi 1535+ PMU");
+MODULE_LICENSE("GPL");
+EXPORT_NO_SYMBOLS;