1 files changed, 107 insertions, 0 deletions

diff --git a/include/linux/mtd/xip.h b/include/linux/mtd/xip.h
new file mode 100644
index 000000000000..fc071125cbcc
--- /dev/null
+++ b/include/linux/mtd/xip.h
@@ -0,0 +1,107 @@
+/*
+ * 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 1.2 2004/12/01 15:49:10 nico Exp $
+ */
+
+#ifndef __LINUX_MTD_XIP_H__
+#define __LINUX_MTD_XIP_H__
+
+#include <linux/config.h>
+
+#ifdef CONFIG_MTD_XIP
+
+/*
+ * 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 __attribute__ ((__section__ (".data")))
+
+/*
+ * We really don't want gcc to guess anything.
+ * We absolutely _need_ proper inlining.
+ */
+#include <linux/compiler.h>
+
+/*
+ * 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.
+ */
+
+#if defined(CONFIG_ARCH_SA1100) || defined(CONFIG_ARCH_PXA)
+
+#include <asm/hardware.h>
+#ifdef CONFIG_ARCH_PXA
+#include <asm/arch/pxa-regs.h>
+#endif
+
+#define xip_irqpending()        (ICIP & ICMR)
+
+/* we sample OSCR and convert desired delta to usec (1/4 ~= 1000000/3686400) */
+#define xip_currtime()          (OSCR)
+#define xip_elapsed_since(x)    (signed)((OSCR - (x)) / 4)
+
+#else
+
+#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
+
+/*
+ * 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.
+ * As above, this should not rely upon standard kernel code.
+ */
+
+#if defined(CONFIG_CPU_XSCALE)
+#define xip_cpu_idle()  asm volatile ("mcr p14, 0, %0, c7, c0, 0" :: "r" (1))
+#else
+#define xip_cpu_idle()  do { } while (0)
+#endif
+
+#else
+
+#define __xipram
+
+#endif /* CONFIG_MTD_XIP */
+
+#endif /* __LINUX_MTD_XIP_H__ */