Re: [PATCH v16 0/9] LPC: legacy ISA I/O support

[John Garry]

On 06/03/2018 11:21, Andy Shevchenko wrote:
> On Tue, 2018-03-06 at 18:47 +0800, John Garry wrote:
> > This patchset supports the IPMI-bt device attached to the Low-Pin-
> > Count
> > interface implemented on Hisilicon Hip06/Hip07 SoC.
> >                         -----------
> >                         | LPC host|
> >                         |         |
> >                         -----------
> >                              |
> >                 _____________V_______________LPC
> >                   |                       |
> >                   V                       V
> >                                      ------------
> >                                      |  BT(ipmi)|
> >                                      ------------
> >
> > When master accesses those peripherals beneath the Hip06/Hip07 LPC, a
> > specific
> > LPC driver is needed to make LPC host generate the standard LPC I/O
> > cycles with
> > the target peripherals'I/O port addresses. But on curent arm64 world,
> > there is
> > no real I/O accesses. All the I/O operations through in/out accessors
> > are based
> > on MMIO ranges; on Hip06/Hip07 LPC the I/O accesses are performed
> > through driver
> > specific accessors rather than MMIO.
> > To solve this issue and keep the relevant existing peripherals'
> > drivers untouched,
> > this patchset:
> >    - introduces a generic I/O space management framework, logical PIO,
> > to support
> >       I/O operations on host controllers operating either on MMIO
> > buses or on buses
> >      requiring specific driver I/O accessors;
> >    - redefines the in/out accessors to provide a unified interface for
> > both MMIO
> >      and driver specific I/O operations. Using logical PIO, th call of
> > in/out() from
> >      the host children drivers, such as ipmi-si, will be redirected to
> > the
> >      corresponding device-specific I/O hooks to perform the I/O
> > accesses.
> >
> > Based on this patch-set, all the I/O accesses to Hip06/Hip07 LPC
> > peripherals can
> > be supported without any changes on the existing ipmi-si driver.
> >
> > The whole patchset has been tested on Hip07 D05 board both using DTB
> > and ACPI.
>
> > V15 thread here: https://lkml.org/lkml/2018/2/26/584
>
> Thanks for an update.
> Though I answered to previous thread.
>
> Summary: I'm fine with the series as long as maintainers are fine
> (Rafael et al.). On personal side I think that the handler approach is
> better. Details are in v15 thread.

Hi Andy,

Thanks for your input and continued support. As I mentioned in reply in 
v15, the handler support would (or has) faced issues. And Rafael seems 
fine with deferring the probe to the LLDD in Patch #7/9

Anyway, let's wait for any more input.

Much appreciated,
John

>