+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * drivers/char/watchdog/iop_wdt.c
- *
- * WDT driver for Intel I/O Processors
- * Copyright (C) 2005, Intel Corporation.
- *
- * Based on ixp4xx driver, Copyright 2004 (c) MontaVista, Software, Inc.
- *
- * Curt E Bruns <curt.e.bruns@intel.com>
- * Peter Milne <peter.milne@d-tacq.com>
- * Dan Williams <dan.j.williams@intel.com>
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/init.h>
-#include <linux/device.h>
-#include <linux/miscdevice.h>
-#include <linux/watchdog.h>
-#include <linux/uaccess.h>
-#include <mach/hardware.h>
-
-static bool nowayout = WATCHDOG_NOWAYOUT;
-static unsigned long wdt_status;
-static unsigned long boot_status;
-static DEFINE_SPINLOCK(wdt_lock);
-
-#define WDT_IN_USE 0
-#define WDT_OK_TO_CLOSE 1
-#define WDT_ENABLED 2
-
-static unsigned long iop_watchdog_timeout(void)
-{
- return (0xffffffffUL / get_iop_tick_rate());
-}
-
-/**
- * wdt_supports_disable - determine if we are accessing a iop13xx watchdog
- * or iop3xx by whether it has a disable command
- */
-static int wdt_supports_disable(void)
-{
- int can_disable;
-
- if (IOP_WDTCR_EN_ARM != IOP_WDTCR_DIS_ARM)
- can_disable = 1;
- else
- can_disable = 0;
-
- return can_disable;
-}
-
-static void wdt_enable(void)
-{
- /* Arm and enable the Timer to starting counting down from 0xFFFF.FFFF
- * Takes approx. 10.7s to timeout
- */
- spin_lock(&wdt_lock);
- write_wdtcr(IOP_WDTCR_EN_ARM);
- write_wdtcr(IOP_WDTCR_EN);
- spin_unlock(&wdt_lock);
-}
-
-/* returns 0 if the timer was successfully disabled */
-static int wdt_disable(void)
-{
- /* Stop Counting */
- if (wdt_supports_disable()) {
- spin_lock(&wdt_lock);
- write_wdtcr(IOP_WDTCR_DIS_ARM);
- write_wdtcr(IOP_WDTCR_DIS);
- clear_bit(WDT_ENABLED, &wdt_status);
- spin_unlock(&wdt_lock);
- pr_info("Disabled\n");
- return 0;
- } else
- return 1;
-}
-
-static int iop_wdt_open(struct inode *inode, struct file *file)
-{
- if (test_and_set_bit(WDT_IN_USE, &wdt_status))
- return -EBUSY;
-
- clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
- wdt_enable();
- set_bit(WDT_ENABLED, &wdt_status);
- return stream_open(inode, file);
-}
-
-static ssize_t iop_wdt_write(struct file *file, const char *data, size_t len,
- loff_t *ppos)
-{
- if (len) {
- if (!nowayout) {
- size_t i;
-
- clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
-
- for (i = 0; i != len; i++) {
- char c;
-
- if (get_user(c, data + i))
- return -EFAULT;
- if (c == 'V')
- set_bit(WDT_OK_TO_CLOSE, &wdt_status);
- }
- }
- wdt_enable();
- }
- return len;
-}
-
-static const struct watchdog_info ident = {
- .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
- .identity = "iop watchdog",
-};
-
-static long iop_wdt_ioctl(struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- int options;
- int ret = -ENOTTY;
- int __user *argp = (int __user *)arg;
-
- switch (cmd) {
- case WDIOC_GETSUPPORT:
- if (copy_to_user(argp, &ident, sizeof(ident)))
- ret = -EFAULT;
- else
- ret = 0;
- break;
-
- case WDIOC_GETSTATUS:
- ret = put_user(0, argp);
- break;
-
- case WDIOC_GETBOOTSTATUS:
- ret = put_user(boot_status, argp);
- break;
-
- case WDIOC_SETOPTIONS:
- if (get_user(options, (int *)arg))
- return -EFAULT;
-
- if (options & WDIOS_DISABLECARD) {
- if (!nowayout) {
- if (wdt_disable() == 0) {
- set_bit(WDT_OK_TO_CLOSE, &wdt_status);
- ret = 0;
- } else
- ret = -ENXIO;
- } else
- ret = 0;
- }
- if (options & WDIOS_ENABLECARD) {
- wdt_enable();
- ret = 0;
- }
- break;
-
- case WDIOC_KEEPALIVE:
- wdt_enable();
- ret = 0;
- break;
-
- case WDIOC_GETTIMEOUT:
- ret = put_user(iop_watchdog_timeout(), argp);
- break;
- }
- return ret;
-}
-
-static int iop_wdt_release(struct inode *inode, struct file *file)
-{
- int state = 1;
- if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
- if (test_bit(WDT_ENABLED, &wdt_status))
- state = wdt_disable();
-
- /* if the timer is not disabled reload and notify that we are still
- * going down
- */
- if (state != 0) {
- wdt_enable();
- pr_crit("Device closed unexpectedly - reset in %lu seconds\n",
- iop_watchdog_timeout());
- }
-
- clear_bit(WDT_IN_USE, &wdt_status);
- clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
-
- return 0;
-}
-
-static const struct file_operations iop_wdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .write = iop_wdt_write,
- .unlocked_ioctl = iop_wdt_ioctl,
- .compat_ioctl = compat_ptr_ioctl,
- .open = iop_wdt_open,
- .release = iop_wdt_release,
-};
-
-static struct miscdevice iop_wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &iop_wdt_fops,
-};
-
-static int __init iop_wdt_init(void)
-{
- int ret;
-
- /* check if the reset was caused by the watchdog timer */
- boot_status = (read_rcsr() & IOP_RCSR_WDT) ? WDIOF_CARDRESET : 0;
-
- /* Configure Watchdog Timeout to cause an Internal Bus (IB) Reset
- * NOTE: An IB Reset will Reset both cores in the IOP342
- */
- write_wdtsr(IOP13XX_WDTCR_IB_RESET);
-
- /* Register after we have the device set up so we cannot race
- with an open */
- ret = misc_register(&iop_wdt_miscdev);
- if (ret == 0)
- pr_info("timeout %lu sec\n", iop_watchdog_timeout());
-
- return ret;
-}
-
-static void __exit iop_wdt_exit(void)
-{
- misc_deregister(&iop_wdt_miscdev);
-}
-
-module_init(iop_wdt_init);
-module_exit(iop_wdt_exit);
-
-module_param(nowayout, bool, 0);
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
-
-MODULE_AUTHOR("Curt E Bruns <curt.e.bruns@intel.com>");
-MODULE_DESCRIPTION("iop watchdog timer driver");
-MODULE_LICENSE("GPL");
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