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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/mtd/xip.h | |
download | linux-fsl-qoriq-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/linux/mtd/xip.h')
-rw-r--r-- | include/linux/mtd/xip.h | 107 |
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 0000000..fc07112 --- /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__ */ |