Re: APUS bus access

[<hei...@at...>]

----- Original Message -----
From: "Geert Uytterhoeven" <ge...@li...>
To: "Arno Griffioen" <gri...@ps...>
Cc: <fh...@at...>; <lin...@li...>
Sent: Tuesday, July 18, 2000 2:18 PM
Subject: Re: APUS bus access


> On Tue, 18 Jul 2000, Arno Griffioen wrote:

> BTW, I see some things in <asm/io.h> that shouldn't be there:
>
> #if defined(CONFIG_APUS)
> #define inw(port)               in_be16((u16 *)((port)+_IO_BASE))
> #define outw(val, port)         out_be16((u16 *)((port)+_IO_BASE), (val))
> #define inl(port)               in_be32((u32 *)((port)+_IO_BASE))
> #define outl(val, port)         out_be32((u32 *)((port)+_IO_BASE), (val))
> #else
>
> Since APUS doesn't have I/O space, these should not be defined at all.
>
> [ Hmm, they are defined to in_be16() and friends. Why??? ]
>

In the MMIO 53c770 driver readw, readl, writew, writel are used when both
the driver and SCSI chip are in big endian mode.   I was just looking in
asm-ppc
and in io.h it has #define readw(addr)  in_le16((volatile unsigned short
*)addr))
and #define readl(addr)  in_le32((volatile unsigned  *)addr)).  Why is the
"le"?
Shouldn't this be "be".    The writel is also defined as out_le32().
Is APUS big endian or little endian.  Is M68K Linux big endian or little
endian?
Am I so confused about this?  Can someone explain it to me?   I always think
big endian == m68k, sparc; little endian == intel, alpha.
Is the Amiga different?  What is Power Macintosh Linux?

BTW I tried writing 0xee00ff11 to a 32 bit register on the '770 chip and got
0xff11 back.

Fred