Re: [PATCH 1/6 v8] ARM: Add basic architecture support for VIA/WonderMedia 85xx SoC's

[Alexey Charkov <alchark@gmail.com>]

2011/7/6 Russell King - ARM Linux <linux@arm.linux.org.uk>:
> On Sun, Dec 19, 2010 at 08:40:17PM +0300, Alexey Charkov wrote:
>> +static struct map_desc vt8500_io_desc[] __initdata = {
>> +     /* SoC MMIO registers, to be filled in later */
>> +     [0] = {
>> +             .type           = MT_DEVICE
>> +     },
>> +     /* PCI I/O space, numbers tied to those in <mach/io.h> */
>> +     [1] = {
>> +             .virtual        = 0xf0000000,
>> +             .pfn            = __phys_to_pfn(0xc0000000),
>> +             .length         = SZ_64K,
>> +             .type           = MT_DEVICE
>> +     },
>> +};
> ...
>> diff --git a/arch/arm/mach-vt8500/include/mach/io.h b/arch/arm/mach-vt8500/include/mach/io.h
>> new file mode 100644
>> index 0000000..8dd55c8
>> --- /dev/null
>> +++ b/arch/arm/mach-vt8500/include/mach/io.h
>> +#ifndef __ASM_ARM_ARCH_IO_H
>> +#define __ASM_ARM_ARCH_IO_H
>> +
>> +#define IO_SPACE_LIMIT 0xffff
>> +
>> +#define __io(a)              ((void __iomem *)((a) + 0xf0000000))
>> +#define __mem_pci(a) (a)
>
> Can you explain why you seem to have PCI IO space, yet don't have CONFIG_PCI
> selected?  Do you have any drivers which use this space without CONFIG_PCI=y?

We have not yet created support for the PCI bridge (or even verified
its existence on the chip). These numbers are derived bit by bit from
vendor-published kernel sources and rather intended as a reference in
case somebody wishes to try and implement PCI support.

All the peripherals on these chips that I know of are statically
mapped platform devices programmed via MMIO registers. There may be
some boards which have support for external PCI devices, but I haven't
seen them.

Best,
Alexey