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committed 2874c5fd284/* [01] Time-out = 496 us (with 33 Mhz clk). */// SPDX-License-Identifier: GPL-2.0-or-later/* * AMD Elan SC520 processor Watchdog Timer driver * * Based on acquirewdt.c by Alan Cox, * and sbc60xxwdt.c by Jakob Oestergaard <jakob@unthought.net> * * The authors do NOT admit liability nor provide warranty for * any of this software. This material is provided "AS-IS" in * the hope that it may be useful for others. * * (c) Copyright 2001 Scott Jennings <linuxdrivers@oro.net> * 9/27 - 2001 [Initial release] * * Additional fixes Alan Cox * - Fixed formatting * - Removed debug printks * - Fixed SMP built kernel deadlock * - Switched to private locks not lock_kernel * - Used ioremap/writew/readw * - Added NOWAYOUT support * 4/12 - 2002 Changes by Rob Radez <rob@osinvestor.com> * - Change comments * - Eliminate fop_llseek * - Change CONFIG_WATCHDOG_NOWAYOUT semantics * - Add KERN_* tags to printks * - fix possible wdt_is_open race * - Report proper capabilities in watchdog_info * - Add WDIOC_{GETSTATUS, GETBOOTSTATUS, SETTIMEOUT, * GETTIMEOUT, SETOPTIONS} ioctls * 09/8 - 2003 Changes by Wim Van Sebroeck <wim@iguana.be> * - cleanup of trailing spaces * - added extra printk's for startup problems * - use module_param * - made timeout (the emulated heartbeat) a module_param * - made the keepalive ping an internal subroutine * 3/27 - 2004 Changes by Sean Young <sean@mess.org> * - set MMCR_BASE to 0xfffef000 * - CBAR does not need to be read * - removed debugging printks * * This WDT driver is different from most other Linux WDT * drivers in that the driver will ping the watchdog by itself, * because this particular WDT has a very short timeout (1.6 * seconds) and it would be insane to count on any userspace * daemon always getting scheduled within that time frame. * * This driver uses memory mapped IO, and spinlock. */