text: /*	$NetBSD: i80321_wdog.c,v 1.6 2003/07/15 00:24:54 lukem Exp $	*/
  
  /*-
   * Copyright (c) 2005 Olivier Houchard
   * Copyright (c) 2002 Wasabi Systems, Inc.
   * All rights reserved.
   *
   * Written by Jason R. Thorpe for Wasabi Systems, Inc.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed for the NetBSD Project by
   *	Wasabi Systems, Inc.
   * 4. The name of Wasabi Systems, Inc. may not be used to endorse
   *    or promote products derived from this software without specific prior
   *    written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
   * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  /*
   * Watchdog timer support for the Intel i80321 I/O processor.
   */
  
  #include <sys/cdefs.h>
  __FBSDID("$FreeBSD: src/sys/arm/xscale/i80321/i80321_wdog.c,v 1.2 2005/01/15 18:38:10 cognet Exp $");
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/watchdog.h>
  #include <sys/bus.h>
  #include <sys/kernel.h>
  #include <sys/module.h>
  
  #include <machine/bus.h>
  #include <machine/cpufunc.h>
  #include <machine/machdep.h>
  
  #include <arm/xscale/i80321/i80321reg.h>
  #include <arm/xscale/i80321/i80321var.h>
  
  
  struct iopwdog_softc {
  	device_t dev;
  	int armed;
  	int wdog_period;
  	struct callout_handle wdog_callout;
  };
  
  static __inline void
  wdtcr_write(uint32_t val)
  {
  
  	__asm __volatile("mcr p6, 0, %0, c7, c1, 0"
  		:
  		: "r" (val));
  }
  
  static void
  iopwdog_tickle(void *arg)
  {
  	struct iopwdog_softc *sc = arg;
  
  	if (!sc->armed)
  		return;
  	wdtcr_write(WDTCR_ENABLE1);
  	wdtcr_write(WDTCR_ENABLE2);
  	sc->wdog_callout = timeout(iopwdog_tickle, sc,
  	    hz * (sc->wdog_period - 1));
  }
  
  static int
  iopwdog_probe(device_t dev)
  {
  	struct iopwdog_softc *sc = device_get_softc(dev);
  	char buf[128];
  
  	/*
  	 * XXX Should compute the period based on processor speed.
  	 * For a 600MHz XScale core, the wdog must be tickled approx.
  	 * every 7 seconds.
  	 */
  
  	sc->wdog_period = 7;
  	sprintf(buf, "i80321 Watchdog, must be tickled every %d seconds",
  	    sc->wdog_period);
  	device_set_desc_copy(dev, buf);
  
  	return (0);
  }
  
  static void
  iopwdog_watchdog_fn(void *private, u_int cmd, int *error)
  {
  	struct iopwdog_softc *sc = private;
  
  	if (cmd == 0)
  		return;
  	if ((((uint64_t)1 << (cmd & WD_INTERVAL))) >
  	    (uint64_t)sc->wdog_period * 1000000000)
  		return;
  	sc->armed = 1;
  	iopwdog_tickle(sc);
  	*error = 0;
  }
  
  static int
  iopwdog_attach(device_t dev)
  {
  	struct iopwdog_softc *sc = device_get_softc(dev);
  	
  	sc->dev = dev;
  	sc->armed = 0;
  	EVENTHANDLER_REGISTER(watchdog_list, iopwdog_watchdog_fn, sc, 0);
  	return (0);
  }
  
  static device_method_t iopwdog_methods[] = {
  	DEVMETHOD(device_probe, iopwdog_probe),
  	DEVMETHOD(device_attach, iopwdog_attach),
  	{0, 0},
  };
  
  static driver_t iopwdog_driver = {
  	"iopwdog",
  	iopwdog_methods,
  	sizeof(struct iopwdog_softc),
  };
  static devclass_t iopwdog_devclass;
  
  DRIVER_MODULE(iopwdog, iq, iopwdog_driver, iopwdog_devclass, 0, 0);
  