diff options
Diffstat (limited to 'drivers/watchdog/w83977f_wdt.c')
| -rw-r--r-- | drivers/watchdog/w83977f_wdt.c | 525 |
1 files changed, 525 insertions, 0 deletions
diff --git a/drivers/watchdog/w83977f_wdt.c b/drivers/watchdog/w83977f_wdt.c new file mode 100644 index 000000000..fd64ae777 --- /dev/null +++ b/drivers/watchdog/w83977f_wdt.c @@ -0,0 +1,525 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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 + * + * ----------------------- + */ + +#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> + + +#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) +{ + unsigned 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 stream_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(); + fallthrough; + + 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, + .compat_ioctl = compat_ptr_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"); |