/*
   * MTD primitives for XIP support
   *
   * Author:	Nicolas Pitre
   * Created:	Nov 2, 2004
   * Copyright:	(C) 2004 MontaVista Software, Inc.
   *
   * This XIP support for MTD has been loosely inspired
   * by an earlier patch authored by David Woodhouse.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *

   * $Id: xip.h,v 1.5 2005/11/07 11:14:55 gleixner Exp $

   */
  
  #ifndef __LINUX_MTD_XIP_H__
  #define __LINUX_MTD_XIP_H__

  
  #ifdef CONFIG_MTD_XIP
  
  /*

   * We really don't want gcc to guess anything.
   * We absolutely _need_ proper inlining.
   */
  #include <linux/compiler.h>
  
  /*

   * Function that are modifying the flash state away from array mode must
   * obviously not be running from flash.  The __xipram is therefore marking
   * those functions so they get relocated to ram.
   */
  #define __xipram noinline __attribute__ ((__section__ (".data")))
  
  /*

   * Each architecture has to provide the following macros.  They must access
   * the hardware directly and not rely on any other (XIP) functions since they
   * won't be available when used (flash not in array mode).
   *
   * xip_irqpending()
   *
   * 	return non zero when any hardware interrupt is pending.
   *
   * xip_currtime()
   *
   * 	return a platform specific time reference to be used with
   * 	xip_elapsed_since().
   *
   * xip_elapsed_since(x)
   *
   * 	return in usecs the elapsed timebetween now and the reference x as
   * 	returned by xip_currtime().
   *
   * 	note 1: convertion to usec can be approximated, as long as the
   * 		returned value is <= the real elapsed time.
   * 	note 2: this should be able to cope with a few seconds without
   * 		overflowing.

   *
   * xip_iprefetch()

   *

   *      Macro to fill instruction prefetch

   *	e.g. a series of nops:  asm volatile (".rep 8; nop; .endr");

   */

  #include <asm/mtd-xip.h>

  #ifndef xip_irqpending

  
  #warning "missing IRQ and timer primitives for XIP MTD support"
  #warning "some of the XIP MTD support code will be disabled"
  #warning "your system will therefore be unresponsive when writing or erasing flash"
  
  #define xip_irqpending()	(0)
  #define xip_currtime()		(0)
  #define xip_elapsed_since(x)	(0)
  
  #endif

  #ifndef xip_iprefetch
  #define xip_iprefetch()		do { } while (0)
  #endif

  /*
   * xip_cpu_idle() is used when waiting for a delay equal or larger than
   * the system timer tick period.  This should put the CPU into idle mode
   * to save power and to be woken up only when some interrupts are pending.

   * This should not rely upon standard kernel code.

   */

  #ifndef xip_cpu_idle

  #define xip_cpu_idle()  do { } while (0)
  #endif
  
  #else
  
  #define __xipram
  
  #endif /* CONFIG_MTD_XIP */
  
  #endif /* __LINUX_MTD_XIP_H__ */