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![Arnd Bergmann](/assets/img/avatar_default.png)
All watchdog drivers implement the same set of ioctl commands, and fortunately all of them are compatible between 32-bit and 64-bit architectures. Modern drivers always go through drivers/watchdog/wdt.c as an abstraction layer, but older ones implement their own file_operations on a character device for this. Move the handling from fs/compat_ioctl.c into the individual drivers. Note that most of the legacy drivers will never be used on 64-bit hardware, because they are for an old 32-bit SoC implementation, but doing them all at once is safer than trying to guess which ones do or do not need the compat_ioctl handling. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
219 lines
4.8 KiB
C
219 lines
4.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* SBC EPX C3 0.1 A Hardware Watchdog Device for the Winsystems EPX-C3
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* single board computer
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*
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* (c) Copyright 2006 Calin A. Culianu <calin@ajvar.org>, All Rights
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* Reserved.
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*
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* based on softdog.c by Alan Cox <alan@lxorguk.ukuu.org.uk>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/notifier.h>
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#include <linux/reboot.h>
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#include <linux/init.h>
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#include <linux/ioport.h>
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#include <linux/uaccess.h>
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#include <linux/io.h>
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static int epx_c3_alive;
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#define WATCHDOG_TIMEOUT 1 /* 1 sec default timeout */
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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#define EPXC3_WATCHDOG_CTL_REG 0x1ee /* write 1 to enable, 0 to disable */
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#define EPXC3_WATCHDOG_PET_REG 0x1ef /* write anything to pet once enabled */
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static void epx_c3_start(void)
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{
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outb(1, EPXC3_WATCHDOG_CTL_REG);
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}
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static void epx_c3_stop(void)
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{
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outb(0, EPXC3_WATCHDOG_CTL_REG);
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pr_info("Stopped watchdog timer\n");
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}
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static void epx_c3_pet(void)
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{
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outb(1, EPXC3_WATCHDOG_PET_REG);
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}
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/*
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* Allow only one person to hold it open
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*/
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static int epx_c3_open(struct inode *inode, struct file *file)
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{
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if (epx_c3_alive)
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return -EBUSY;
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if (nowayout)
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__module_get(THIS_MODULE);
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/* Activate timer */
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epx_c3_start();
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epx_c3_pet();
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epx_c3_alive = 1;
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pr_info("Started watchdog timer\n");
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return stream_open(inode, file);
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}
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static int epx_c3_release(struct inode *inode, struct file *file)
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{
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/* Shut off the timer.
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* Lock it in if it's a module and we defined ...NOWAYOUT */
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if (!nowayout)
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epx_c3_stop(); /* Turn the WDT off */
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epx_c3_alive = 0;
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return 0;
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}
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static ssize_t epx_c3_write(struct file *file, const char __user *data,
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size_t len, loff_t *ppos)
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{
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/* Refresh the timer. */
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if (len)
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epx_c3_pet();
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return len;
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}
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static long epx_c3_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int options, retval = -EINVAL;
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int __user *argp = (void __user *)arg;
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static const struct watchdog_info ident = {
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.options = WDIOF_KEEPALIVEPING,
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.firmware_version = 0,
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.identity = "Winsystems EPX-C3 H/W Watchdog",
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};
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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if (copy_to_user(argp, &ident, sizeof(ident)))
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return -EFAULT;
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return 0;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, argp);
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case WDIOC_SETOPTIONS:
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if (get_user(options, argp))
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return -EFAULT;
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if (options & WDIOS_DISABLECARD) {
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epx_c3_stop();
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retval = 0;
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}
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if (options & WDIOS_ENABLECARD) {
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epx_c3_start();
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retval = 0;
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}
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return retval;
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case WDIOC_KEEPALIVE:
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epx_c3_pet();
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return 0;
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case WDIOC_GETTIMEOUT:
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return put_user(WATCHDOG_TIMEOUT, argp);
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default:
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return -ENOTTY;
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}
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}
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static int epx_c3_notify_sys(struct notifier_block *this, unsigned long code,
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void *unused)
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{
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if (code == SYS_DOWN || code == SYS_HALT)
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epx_c3_stop(); /* Turn the WDT off */
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return NOTIFY_DONE;
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}
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static const struct file_operations epx_c3_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = epx_c3_write,
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.unlocked_ioctl = epx_c3_ioctl,
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.compat_ioctl = compat_ptr_ioctl,
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.open = epx_c3_open,
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.release = epx_c3_release,
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};
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static struct miscdevice epx_c3_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &epx_c3_fops,
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};
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static struct notifier_block epx_c3_notifier = {
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.notifier_call = epx_c3_notify_sys,
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};
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static int __init watchdog_init(void)
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{
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int ret;
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if (!request_region(EPXC3_WATCHDOG_CTL_REG, 2, "epxc3_watchdog"))
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return -EBUSY;
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ret = register_reboot_notifier(&epx_c3_notifier);
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if (ret) {
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pr_err("cannot register reboot notifier (err=%d)\n", ret);
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goto out;
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}
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ret = misc_register(&epx_c3_miscdev);
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if (ret) {
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pr_err("cannot register miscdev on minor=%d (err=%d)\n",
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WATCHDOG_MINOR, ret);
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unregister_reboot_notifier(&epx_c3_notifier);
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goto out;
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}
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pr_info("Hardware Watchdog Timer for Winsystems EPX-C3 SBC: 0.1\n");
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return 0;
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out:
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release_region(EPXC3_WATCHDOG_CTL_REG, 2);
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return ret;
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}
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static void __exit watchdog_exit(void)
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{
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misc_deregister(&epx_c3_miscdev);
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unregister_reboot_notifier(&epx_c3_notifier);
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release_region(EPXC3_WATCHDOG_CTL_REG, 2);
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}
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module_init(watchdog_init);
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module_exit(watchdog_exit);
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MODULE_AUTHOR("Calin A. Culianu <calin@ajvar.org>");
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MODULE_DESCRIPTION("Hardware Watchdog Device for Winsystems EPX-C3 SBC. "
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"Note that there is no way to probe for this device -- "
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"so only use it if you are *sure* you are running on this specific "
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"SBC system from Winsystems! It writes to IO ports 0x1ee and 0x1ef!");
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MODULE_LICENSE("GPL");
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