| /* |
| * W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip |
| * |
| * (c) Copyright 2005 Jose Goncalves <jose.goncalves@inov.pt> |
| * |
| * Based on w83877f_wdt.c by Scott Jennings, |
| * and wdt977.c by Woody Suwalski |
| * |
| * ----------------------- |
| * |
| * 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/kernel.h> |
| #include <linux/fs.h> |
| #include <linux/miscdevice.h> |
| #include <linux/init.h> |
| #include <linux/ioport.h> |
| #include <linux/watchdog.h> |
| #include <linux/notifier.h> |
| #include <linux/reboot.h> |
| #include <linux/uaccess.h> |
| #include <linux/io.h> |
| |
| #include <asm/system.h> |
| |
| #define WATCHDOG_VERSION "1.00" |
| #define WATCHDOG_NAME "W83977F WDT" |
| |
| #define IO_INDEX_PORT 0x3F0 |
| #define IO_DATA_PORT (IO_INDEX_PORT+1) |
| |
| #define UNLOCK_DATA 0x87 |
| #define LOCK_DATA 0xAA |
| #define DEVICE_REGISTER 0x07 |
| |
| #define DEFAULT_TIMEOUT 45 /* default timeout in seconds */ |
| |
| static int timeout = DEFAULT_TIMEOUT; |
| static int timeoutW; /* timeout in watchdog counter units */ |
| static unsigned long timer_alive; |
| static int testmode; |
| static char expect_close; |
| static DEFINE_SPINLOCK(spinlock); |
| |
| module_param(timeout, int, 0); |
| MODULE_PARM_DESC(timeout, |
| "Watchdog timeout in seconds (15..7635), default=" |
| __MODULE_STRING(DEFAULT_TIMEOUT) ")"); |
| module_param(testmode, int, 0); |
| MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0"); |
| |
| 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) ")"); |
| |
| /* |
| * Start the watchdog |
| */ |
| |
| static int wdt_start(void) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&spinlock, flags); |
| |
| /* Unlock the SuperIO chip */ |
| outb_p(UNLOCK_DATA, IO_INDEX_PORT); |
| outb_p(UNLOCK_DATA, IO_INDEX_PORT); |
| |
| /* |
| * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4. |
| * F2 has the timeout in watchdog counter units. |
| * F3 is set to enable watchdog LED blink at timeout. |
| * F4 is used to just clear the TIMEOUT'ed state (bit 0). |
| */ |
| outb_p(DEVICE_REGISTER, IO_INDEX_PORT); |
| outb_p(0x08, IO_DATA_PORT); |
| outb_p(0xF2, IO_INDEX_PORT); |
| outb_p(timeoutW, IO_DATA_PORT); |
| outb_p(0xF3, IO_INDEX_PORT); |
| outb_p(0x08, IO_DATA_PORT); |
| outb_p(0xF4, IO_INDEX_PORT); |
| outb_p(0x00, IO_DATA_PORT); |
| |
| /* Set device Aux2 active */ |
| outb_p(0x30, IO_INDEX_PORT); |
| outb_p(0x01, IO_DATA_PORT); |
| |
| /* |
| * Select device Aux1 (dev=7) to set GP16 as the watchdog output |
| * (in reg E6) and GP13 as the watchdog LED output (in reg E3). |
| * Map GP16 at pin 119. |
| * In test mode watch the bit 0 on F4 to indicate "triggered" or |
| * check watchdog LED on SBC. |
| */ |
| outb_p(DEVICE_REGISTER, IO_INDEX_PORT); |
| outb_p(0x07, IO_DATA_PORT); |
| if (!testmode) { |
| unsigned pin_map; |
| |
| outb_p(0xE6, IO_INDEX_PORT); |
| outb_p(0x0A, IO_DATA_PORT); |
| outb_p(0x2C, IO_INDEX_PORT); |
| pin_map = inb_p(IO_DATA_PORT); |
| pin_map |= 0x10; |
| pin_map &= ~(0x20); |
| outb_p(0x2C, IO_INDEX_PORT); |
| outb_p(pin_map, IO_DATA_PORT); |
| } |
| outb_p(0xE3, IO_INDEX_PORT); |
| outb_p(0x08, IO_DATA_PORT); |
| |
| /* Set device Aux1 active */ |
| outb_p(0x30, IO_INDEX_PORT); |
| outb_p(0x01, IO_DATA_PORT); |
| |
| /* Lock the SuperIO chip */ |
| outb_p(LOCK_DATA, IO_INDEX_PORT); |
| |
| spin_unlock_irqrestore(&spinlock, flags); |
| |
| pr_info("activated\n"); |
| |
| return 0; |
| } |
| |
| /* |
| * Stop the watchdog |
| */ |
| |
| static int wdt_stop(void) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&spinlock, flags); |
| |
| /* Unlock the SuperIO chip */ |
| outb_p(UNLOCK_DATA, IO_INDEX_PORT); |
| outb_p(UNLOCK_DATA, IO_INDEX_PORT); |
| |
| /* |
| * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4. |
| * F2 is reset to its default value (watchdog timer disabled). |
| * F3 is reset to its default state. |
| * F4 clears the TIMEOUT'ed state (bit 0) - back to default. |
| */ |
| outb_p(DEVICE_REGISTER, IO_INDEX_PORT); |
| outb_p(0x08, IO_DATA_PORT); |
| outb_p(0xF2, IO_INDEX_PORT); |
| outb_p(0xFF, IO_DATA_PORT); |
| outb_p(0xF3, IO_INDEX_PORT); |
| outb_p(0x00, IO_DATA_PORT); |
| outb_p(0xF4, IO_INDEX_PORT); |
| outb_p(0x00, IO_DATA_PORT); |
| outb_p(0xF2, IO_INDEX_PORT); |
| outb_p(0x00, IO_DATA_PORT); |
| |
| /* |
| * Select device Aux1 (dev=7) to set GP16 (in reg E6) and |
| * Gp13 (in reg E3) as inputs. |
| */ |
| outb_p(DEVICE_REGISTER, IO_INDEX_PORT); |
| outb_p(0x07, IO_DATA_PORT); |
| if (!testmode) { |
| outb_p(0xE6, IO_INDEX_PORT); |
| outb_p(0x01, IO_DATA_PORT); |
| } |
| outb_p(0xE3, IO_INDEX_PORT); |
| outb_p(0x01, IO_DATA_PORT); |
| |
| /* Lock the SuperIO chip */ |
| outb_p(LOCK_DATA, IO_INDEX_PORT); |
| |
| spin_unlock_irqrestore(&spinlock, flags); |
| |
| pr_info("shutdown\n"); |
| |
| return 0; |
| } |
| |
| /* |
| * Send a keepalive ping to the watchdog |
| * This is done by simply re-writing the timeout to reg. 0xF2 |
| */ |
| |
| static int wdt_keepalive(void) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&spinlock, flags); |
| |
| /* Unlock the SuperIO chip */ |
| outb_p(UNLOCK_DATA, IO_INDEX_PORT); |
| outb_p(UNLOCK_DATA, IO_INDEX_PORT); |
| |
| /* Select device Aux2 (device=8) to kick watchdog reg F2 */ |
| outb_p(DEVICE_REGISTER, IO_INDEX_PORT); |
| outb_p(0x08, IO_DATA_PORT); |
| outb_p(0xF2, IO_INDEX_PORT); |
| outb_p(timeoutW, IO_DATA_PORT); |
| |
| /* Lock the SuperIO chip */ |
| outb_p(LOCK_DATA, IO_INDEX_PORT); |
| |
| spin_unlock_irqrestore(&spinlock, flags); |
| |
| return 0; |
| } |
| |
| /* |
| * Set the watchdog timeout value |
| */ |
| |
| static int wdt_set_timeout(int t) |
| { |
| int tmrval; |
| |
| /* |
| * Convert seconds to watchdog counter time units, rounding up. |
| * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup |
| * value. This information is supplied in the PCM-5335 manual and was |
| * checked by me on a real board. This is a bit strange because W83977f |
| * datasheet says counter unit is in minutes! |
| */ |
| if (t < 15) |
| return -EINVAL; |
| |
| tmrval = ((t + 15) + 29) / 30; |
| |
| if (tmrval > 255) |
| return -EINVAL; |
| |
| /* |
| * timeout is the timeout in seconds, |
| * timeoutW is the timeout in watchdog counter units. |
| */ |
| timeoutW = tmrval; |
| timeout = (timeoutW * 30) - 15; |
| return 0; |
| } |
| |
| /* |
| * Get the watchdog status |
| */ |
| |
| static int wdt_get_status(int *status) |
| { |
| int new_status; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&spinlock, flags); |
| |
| /* Unlock the SuperIO chip */ |
| outb_p(UNLOCK_DATA, IO_INDEX_PORT); |
| outb_p(UNLOCK_DATA, IO_INDEX_PORT); |
| |
| /* Select device Aux2 (device=8) to read watchdog reg F4 */ |
| outb_p(DEVICE_REGISTER, IO_INDEX_PORT); |
| outb_p(0x08, IO_DATA_PORT); |
| outb_p(0xF4, IO_INDEX_PORT); |
| new_status = inb_p(IO_DATA_PORT); |
| |
| /* Lock the SuperIO chip */ |
| outb_p(LOCK_DATA, IO_INDEX_PORT); |
| |
| spin_unlock_irqrestore(&spinlock, flags); |
| |
| *status = 0; |
| if (new_status & 1) |
| *status |= WDIOF_CARDRESET; |
| |
| return 0; |
| } |
| |
| |
| /* |
| * /dev/watchdog handling |
| */ |
| |
| static int wdt_open(struct inode *inode, struct file *file) |
| { |
| /* If the watchdog is alive we don't need to start it again */ |
| if (test_and_set_bit(0, &timer_alive)) |
| return -EBUSY; |
| |
| if (nowayout) |
| __module_get(THIS_MODULE); |
| |
| wdt_start(); |
| return nonseekable_open(inode, file); |
| } |
| |
| static int wdt_release(struct inode *inode, struct file *file) |
| { |
| /* |
| * Shut off the timer. |
| * Lock it in if it's a module and we set nowayout |
| */ |
| if (expect_close == 42) { |
| wdt_stop(); |
| clear_bit(0, &timer_alive); |
| } else { |
| wdt_keepalive(); |
| pr_crit("unexpected close, not stopping watchdog!\n"); |
| } |
| expect_close = 0; |
| return 0; |
| } |
| |
| /* |
| * wdt_write: |
| * @file: file handle to the watchdog |
| * @buf: buffer to write (unused as data does not matter here |
| * @count: count of bytes |
| * @ppos: pointer to the position to write. No seeks allowed |
| * |
| * A write to a watchdog device is defined as a keepalive signal. Any |
| * write of data will do, as we we don't define content meaning. |
| */ |
| |
| static ssize_t wdt_write(struct file *file, const char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| /* See if we got the magic character 'V' and reload the timer */ |
| if (count) { |
| if (!nowayout) { |
| size_t ofs; |
| |
| /* note: just in case someone wrote the |
| magic character long ago */ |
| expect_close = 0; |
| |
| /* scan to see whether or not we got the |
| magic character */ |
| for (ofs = 0; ofs != count; ofs++) { |
| char c; |
| if (get_user(c, buf + ofs)) |
| return -EFAULT; |
| if (c == 'V') |
| expect_close = 42; |
| } |
| } |
| |
| /* someone wrote to us, we should restart timer */ |
| wdt_keepalive(); |
| } |
| return count; |
| } |
| |
| /* |
| * wdt_ioctl: |
| * @inode: inode of the device |
| * @file: file handle to the device |
| * @cmd: watchdog command |
| * @arg: argument pointer |
| * |
| * The watchdog API defines a common set of functions for all watchdogs |
| * according to their available features. |
| */ |
| |
| static const struct watchdog_info ident = { |
| .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, |
| .firmware_version = 1, |
| .identity = WATCHDOG_NAME, |
| }; |
| |
| static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| { |
| int status; |
| int new_options, retval = -EINVAL; |
| int new_timeout; |
| union { |
| struct watchdog_info __user *ident; |
| int __user *i; |
| } uarg; |
| |
| uarg.i = (int __user *)arg; |
| |
| switch (cmd) { |
| case WDIOC_GETSUPPORT: |
| return copy_to_user(uarg.ident, &ident, |
| sizeof(ident)) ? -EFAULT : 0; |
| |
| case WDIOC_GETSTATUS: |
| wdt_get_status(&status); |
| return put_user(status, uarg.i); |
| |
| case WDIOC_GETBOOTSTATUS: |
| return put_user(0, uarg.i); |
| |
| case WDIOC_SETOPTIONS: |
| if (get_user(new_options, uarg.i)) |
| return -EFAULT; |
| |
| if (new_options & WDIOS_DISABLECARD) { |
| wdt_stop(); |
| retval = 0; |
| } |
| |
| if (new_options & WDIOS_ENABLECARD) { |
| wdt_start(); |
| retval = 0; |
| } |
| |
| return retval; |
| |
| case WDIOC_KEEPALIVE: |
| wdt_keepalive(); |
| return 0; |
| |
| case WDIOC_SETTIMEOUT: |
| if (get_user(new_timeout, uarg.i)) |
| return -EFAULT; |
| |
| if (wdt_set_timeout(new_timeout)) |
| return -EINVAL; |
| |
| wdt_keepalive(); |
| /* Fall */ |
| |
| case WDIOC_GETTIMEOUT: |
| return put_user(timeout, uarg.i); |
| |
| default: |
| return -ENOTTY; |
| |
| } |
| } |
| |
| static int wdt_notify_sys(struct notifier_block *this, unsigned long code, |
| void *unused) |
| { |
| if (code == SYS_DOWN || code == SYS_HALT) |
| wdt_stop(); |
| return NOTIFY_DONE; |
| } |
| |
| static const struct file_operations wdt_fops = { |
| .owner = THIS_MODULE, |
| .llseek = no_llseek, |
| .write = wdt_write, |
| .unlocked_ioctl = wdt_ioctl, |
| .open = wdt_open, |
| .release = wdt_release, |
| }; |
| |
| static struct miscdevice wdt_miscdev = { |
| .minor = WATCHDOG_MINOR, |
| .name = "watchdog", |
| .fops = &wdt_fops, |
| }; |
| |
| static struct notifier_block wdt_notifier = { |
| .notifier_call = wdt_notify_sys, |
| }; |
| |
| static int __init w83977f_wdt_init(void) |
| { |
| int rc; |
| |
| pr_info("driver v%s\n", WATCHDOG_VERSION); |
| |
| /* |
| * Check that the timeout value is within it's range; |
| * if not reset to the default |
| */ |
| if (wdt_set_timeout(timeout)) { |
| wdt_set_timeout(DEFAULT_TIMEOUT); |
| pr_info("timeout value must be 15 <= timeout <= 7635, using %d\n", |
| DEFAULT_TIMEOUT); |
| } |
| |
| if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) { |
| pr_err("I/O address 0x%04x already in use\n", IO_INDEX_PORT); |
| rc = -EIO; |
| goto err_out; |
| } |
| |
| rc = register_reboot_notifier(&wdt_notifier); |
| if (rc) { |
| pr_err("cannot register reboot notifier (err=%d)\n", rc); |
| goto err_out_region; |
| } |
| |
| rc = misc_register(&wdt_miscdev); |
| if (rc) { |
| pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
| wdt_miscdev.minor, rc); |
| goto err_out_reboot; |
| } |
| |
| pr_info("initialized. timeout=%d sec (nowayout=%d testmode=%d)\n", |
| timeout, nowayout, testmode); |
| |
| return 0; |
| |
| err_out_reboot: |
| unregister_reboot_notifier(&wdt_notifier); |
| err_out_region: |
| release_region(IO_INDEX_PORT, 2); |
| err_out: |
| return rc; |
| } |
| |
| static void __exit w83977f_wdt_exit(void) |
| { |
| wdt_stop(); |
| misc_deregister(&wdt_miscdev); |
| unregister_reboot_notifier(&wdt_notifier); |
| release_region(IO_INDEX_PORT, 2); |
| } |
| |
| module_init(w83977f_wdt_init); |
| module_exit(w83977f_wdt_exit); |
| |
| MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>"); |
| MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |