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Release 4.14 drivers/watchdog/alim1535_wdt.c

Directory: drivers/watchdog
/*
 *      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); }

Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck58100.00%1100.00%
Total58100.00%1100.00%

/* * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck58100.00%1100.00%
Total58100.00%1100.00%

/* * 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(); }

Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck11100.00%1100.00%
Total11100.00%1100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck96100.00%1100.00%
Total96100.00%1100.00%

/* * /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; }

Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck9496.91%133.33%
Alan Cox22.06%133.33%
Al Viro11.03%133.33%
Total97100.00%3100.00%

/* * 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; } }

Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck20188.55%350.00%
Al Viro2410.57%116.67%
Samuel Tardieu10.44%116.67%
Alan Cox10.44%116.67%
Total227100.00%6100.00%

/* * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck3786.05%150.00%
Linus Torvalds613.95%150.00%
Total43100.00%2100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck5096.15%150.00%
Joe Perches23.85%150.00%
Total52100.00%2100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck3597.22%150.00%
Alan Cox12.78%150.00%
Total36100.00%2100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck17183.01%125.00%
Andrey Borzenkov188.74%125.00%
Jiri Slaby146.80%125.00%
Alan Cox31.46%125.00%
Total206100.00%4100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck11787.97%360.00%
Joe Perches1410.53%120.00%
Alan Cox21.50%120.00%
Total133100.00%5100.00%

/* * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck2683.87%266.67%
Jiri Slaby516.13%133.33%
Total31100.00%3100.00%

module_init(watchdog_init); module_exit(watchdog_exit); MODULE_AUTHOR("Alan Cox"); MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
Wim Van Sebroeck121090.23%940.91%
Andrey Borzenkov282.09%14.55%
Al Viro251.86%14.55%
Joe Perches231.72%14.55%
Jiri Slaby191.42%14.55%
Alan Cox141.04%14.55%
Jingoo Han70.52%14.55%
Linus Torvalds60.45%14.55%
Alexey Dobriyan40.30%14.55%
Arjan van de Ven10.07%14.55%
Namhyung Kim10.07%14.55%
Rolf Eike Beer10.07%14.55%
Andrey Panin10.07%14.55%
Samuel Tardieu10.07%14.55%
Total1341100.00%22100.00%
Directory: drivers/watchdog
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