[U-Boot] [PATCH 1/1] serial: ns16550: Read reg-io-type from device tree

[Park, Aiden]

Hi Andy/Bin,

> -----Original Message-----
> From: Bin Meng [mailto:bmeng.cn at gmail.com]
> Sent: Wednesday, August 21, 2019 2:45 AM
> To: Andy Shevchenko <andy.shevchenko at gmail.com>
> Cc: Park, Aiden <aiden.park at intel.com>; u-boot at lists.denx.de
> Subject: Re: [U-Boot] [PATCH 1/1] serial: ns16550: Read reg-io-type from
> device tree
> 
> On Wed, Aug 21, 2019 at 3:26 PM Andy Shevchenko
> <andy.shevchenko at gmail.com> wrote:
> >
> > On Wed, Aug 21, 2019 at 3:43 AM Park, Aiden <aiden.park at intel.com>
> wrote:
> > >
> > > ns16550 can select register access type from device tree.
> > > This also allows an inherited serial driver of ns16550 to configure
> > > register access type at run-time by overriding ofdata_to_platdata.
> > >
> >
> > Can you elaborate more on this?
> >
> > For now it looks like a hack due to misunderstanding of the design.
> 
Right, this is a just hack. As Bin said, we may need refactor whole codes.
By the way, do we need to keep current design which selects I/O port or MMIO
at compile time by defining CONFIG_SYS_NS16550_PORT_MAPPED
or CONFIG_SYS_NS16550_MEM32?

> The reg-io-type is not a standard DTS property for 8250
> (Documentation/devicetree/bindings/serial/8250.txt) so I guess we may
> need refactor the ns16550 codes to support both I/O port and memory-
> mapped variants.
> 
Thanks for letting me know 8250.txt(doc/device-tree-bindings/serial/8250.txt).
I agree that ns16550 codes may need refactor. Let me abandon this patch.

> Regards,
> Bin

Best Regards,
Aiden