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List:       linux-arm-kernel
Subject:    Re: Direct-mapped Compact Flash on ARM9
From:       Kenneth Crudup <kenny () panix ! com>
Date:       2004-07-01 21:26:39
Message-ID: Pine.LNX.4.60.0407011418160.26924 () Dell8K ! localdomain
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On Thu, 1 Jul 2004, James Graves wrote:

> Instead the CF slot is directly hooked up to the memory bus, with chip
> selects, I/O strobes, interrupt, and such.

> As far as I can tell, there is no support for this currently, so I was
> hoping that someone out there would have some code which does this
> already.

I have something similar for the LH79520-based board I was working with.

It's easy- essentially just register the address of the I/O port, and a CF
"drive" just looks like an IDE drive:

.../linux/include/asm-arm/arch-lh79520/ide.h

----
	<snip>
#include <asm/hardware.h>
	<snip>

/*
 * This registers the standard ports for this architecture with the IDE
 * driver.
 */
static __inline__ void
ide_init_default_hwifs(void)
{
    hw_regs_t hw;

        /*
         * The IDE data ports are mapped in at IDE_BASE, and are aligined on 32 bit boundaries
         * The IDE control port (usually found at port 0x3f6 on a PC, e.g.) is 6 ints into IDE_BASE2.
         */
    ide_init_hwif_ports( &hw, IDE_BASE, (char *)IDE2_BASE + 6*sizeof(int), NULL);
    hw.irq = IRQ_CF;
    ide_register_hw( &hw, NULL);
}
----

... where "IDE_BASE", "IDE_BASE2" and "IRQ_CF" match your hardware.


Let me know if you need more help.

	-Kenny

-- 
Kenneth R. Crudup  Sr. SW Engineer, Scott County Consulting, Los Angeles
H: 3630 S. Sepulveda Blvd. #138, L.A., CA 90034-6809      (888) 454-8181

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