UART Route setting

[Patrick Venture]

On Wed, Aug 1, 2018 at 8:33 PM, Andrew Jeffery <andrew at aj.id.au> wrote:
> On Thu, 2 Aug 2018, at 12:50, Oskar Senft wrote:
>> Interesting suggestion, that looks promising, thank you?
>>
>> What's the state of that driver? I.e. where do we expect it to land?
>
> If you think the bmc-misc-ctrl series is useful, please reply to the
> upstream thread to outline all of your use-cases. There's a lot of push-
> back on using the devicetree to describe these features, and I haven't
> had a lot of feedback on the acceptability of the rest (driver itself,
> userspace ABI).
>
> The more evidence we have of this being necessary/useful the better.

I just skimmed that message, and we're looking for a mechanism to set
in the kernel some bits in the hwstrapping and other hardware
registers to do things like restrict P2A ranges, disable lpc2ahb
stuff, etc.  Things we had hacked into the mach-aspeed.c (iirc), and I
wasn't sure it made sense to write a half dozen small drivers to
control these individual things -- would these kind of use cases fall
under this misc driver?

>
> Cheers,
>
> Andrew
>
>>
>> Thanks
>> Oskar.
>>
>> On Wed, Aug 1, 2018, 10:12 PM Lei YU <mine260309 at gmail.com> wrote:
>>
>> > On Thu, Aug 2, 2018 at 9:55 AM Oskar Senft <osk at google.com> wrote:
>> > >
>> > > Hi Andrew
>> > >
>> > > Thanks for the suggestion. I see that the register would map quite
>> > nicely to pinmux. However, the ability to change the configuration from
>> > user space is critical. How could that be done via pinmux?
>> >
>> > I believe Andrew Jeffery's [bmc-misc-ctr][1] driver is perfect for this
>> > requirement:
>> > 1. You can define related registers in dts and expose as sysfs attributes
>> > 2. User space is able to read/write the sysfs attributes to do what you
>> > need
>> >    to configure.
>> >
>> > [1]: https://patchwork.ozlabs.org/cover/942322/
>> >