Ralf Baechle wrote:
>
> On Wed, Feb 20, 2002 at 06:05:21PM -0800, Matthew Dharm wrote:
>
> > If it works as I think it does, then is the code in
> > linux/arch/mips/gt64120/momenco_ocelot/setup.c correct? Specifically,
> > it calls ioremap() and then calls set_io_port_base() with a very
> > strange value -- it's the value from ioremap()
>
> > modified by the I/O physical address base...
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
> I was reading too fast and missed that part.
>
> > That doesn't look right to me... or I just don't quite understand how
> > this is supposed to work.
>
> That's definately looks fishy.
This is actually right. This way if you pass an virtual at (mips_io_port_base
+ delta), you will get a physical address (GT_PCI_IO_BASE + delta), the
desired place.
Most boards don't need this funky ioremap() and base addr substraction trick,
but ocelot has the IO address placed beyond normal kseg1 addressing range.
Jun
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