Re: [PATCH 07/12] ARM: s3c24xx: remove support for ISA drivers on BAST PC/104

From: Krzysztof Kozlowski
Date: Thu Apr 07 2022 - 03:27:38 EST


On 05/04/2022 11:17, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> BAST is the one machine that theoretically supports unmodified ISA
> drivers for hardware on its PC/104 connector, using a custom version of
> the inb()/outb() and inw()/outw() macros.
>
> This is incompatible with the generic version used in asm/io.h, and
> can't easily be used in a multiplatform kernel.
>
> Removing the special case for 16-bit I/O port access on BAST gets us
> closer to multiplatform, at the expense of any PC/104 users with 16-bit
> cards having to either use an older kernel or modify their ISA drivers
> to manually ioremap() the area and use readw()/write() in place of
> inw()/outw(). Either way is probably ok, given that all of s3c24xx is
> already on the way out next year, and many traditional ISA drivers are
> already gone.
>
> Machines other than BAST already have no support for ISA drivers, though a
> couple of them do map one of the external chip-selects into the ISA port
> range, using the same address for 8-bit and 16-bit I/O. It is unlikely
> that anything actually uses this mapping, but it's also easy to keep
> this working by mapping it to the normal platform-independent PCI I/O
> base that is otherwise unused on s3c24xx.
>
> The mach/map-base.h file is no longer referenced in global headers and
> can be moved into the platform directory.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---


Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>


Best regards,
Krzysztof