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