123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454 |
- /*
- * 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.
- */
- #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
- #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/fs.h>
- #include <linux/pci.h>
- #include <linux/uaccess.h>
- #include <linux/io.h>
- #define WATCHDOG_NAME "ALi_M1535"
- #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 DEFINE_SPINLOCK(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) ")");
- 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) ")");
- /*
- * 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 __user *data,
- size_t len, loff_t *ppos)
- {
- /* 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 whether 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
- * @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 long ali_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 = 0,
- .identity = "ALi M1535 WatchDog Timer",
- };
- 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) {
- ali_stop();
- retval = 0;
- }
- if (new_options & WDIOS_ENABLECARD) {
- ali_start();
- retval = 0;
- }
- return retval;
- }
- case WDIOC_KEEPALIVE:
- ali_keepalive();
- return 0;
- case WDIOC_SETTIMEOUT:
- {
- int new_timeout;
- if (get_user(new_timeout, p))
- return -EFAULT;
- if (ali_settimer(new_timeout))
- return -EINVAL;
- ali_keepalive();
- /* Fall */
- }
- case WDIOC_GETTIMEOUT:
- return put_user(timeout, p);
- default:
- return -ENOTTY;
- }
- }
- /*
- * 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 nonseekable_open(inode, file);
- }
- /*
- * 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 {
- pr_crit("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)
- ali_stop(); /* Turn the WDT off */
- 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 const struct pci_device_id ali_pci_tbl[] __used = {
- { PCI_VENDOR_ID_AL, 0x1533, PCI_ANY_ID, PCI_ANY_ID,},
- { PCI_VENDOR_ID_AL, 0x1535, 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 1533/1535 series bridge */
- pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1535, NULL);
- if (pdev == NULL)
- pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1533, NULL);
- if (pdev == NULL)
- return -ENODEV;
- pci_dev_put(pdev);
- /* Check for the a 7101 PMU */
- pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x7101, NULL);
- if (pdev == NULL)
- return -ENODEV;
- if (pci_enable_device(pdev)) {
- pci_dev_put(pdev);
- return -EIO;
- }
- ali_pci = pdev;
- /*
- * Initialize the timer bits
- */
- pci_read_config_dword(pdev, 0xCC, &wdog);
- /* Timer bits */
- wdog &= ~0x3F;
- /* Issued events */
- wdog &= ~((1 << 27)|(1 << 26)|(1 << 25)|(1 << 24));
- /* No monitor bits */
- wdog &= ~((1 << 16)|(1 << 13)|(1 << 12)|(1 << 11)|(1 << 10)|(1 << 9));
- pci_write_config_dword(pdev, 0xCC, wdog);
- return 0;
- }
- /*
- * Kernel Interfaces
- */
- static const struct file_operations ali_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .write = ali_write,
- .unlocked_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,
- };
- /*
- * 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;
- /* Check whether 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;
- pr_info("timeout value must be 0 < timeout < 18000, using %d\n",
- timeout);
- }
- /* Calculate the watchdog's timeout */
- ali_settimer(timeout);
- ret = register_reboot_notifier(&ali_notifier);
- if (ret != 0) {
- pr_err("cannot register reboot notifier (err=%d)\n", ret);
- goto out;
- }
- ret = misc_register(&ali_miscdev);
- if (ret != 0) {
- pr_err("cannot register miscdev on minor=%d (err=%d)\n",
- WATCHDOG_MINOR, ret);
- goto unreg_reboot;
- }
- pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
- timeout, nowayout);
- out:
- return ret;
- unreg_reboot:
- unregister_reboot_notifier(&ali_notifier);
- 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 */
- misc_deregister(&ali_miscdev);
- unregister_reboot_notifier(&ali_notifier);
- pci_dev_put(ali_pci);
- }
- module_init(watchdog_init);
- module_exit(watchdog_exit);
- MODULE_AUTHOR("Alan Cox");
- MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver");
- MODULE_LICENSE("GPL");
|