Re: [RFC PATCH 0/3] Add support of busfreq

[Alexandre Bailon]

Hi Aisheng

On 3/15/19 3:39 AM, Aisheng Dong wrote:
> +Jacky and Leonard, Ranjani
>
> Hi Alexandre,
>
> > From: Alexandre Bailon [mailto:abailon@xxxxxxxxxxxx]
> >
> > This series implements busfreq, a framework used in MXP's tree to scale the
> > interconnect and dram frequencies.
> > In the vendor tree, device's driver request for a performance level, which is
> > used to scale the frequencies.
> > This series implements it using the interconnect framework.
> > Devices' driver request for bandwidth which is use by busfreq to determine a
> > performance level, and then scale the frequency.
> >
> > Busfreq is quite generic. It could be used for any i.MX SoC.
> > A busfreq platform driver just have to define a list of interconnect nodes, and
> > some OPPs.
>
> It's really great to see this patch series.
> And it should be the correct direction we're heading to upstream busfreq support.
>
> > This series is sent as RFC mostly because the current support of i.MX SoC won't
> > benefit of busfreq framework, because the clocks' driver don't support
> > interconnect / dram frequency scaling.
> > As exemple, this series implements busfreq for i.MX8MM whose upstreaming
> > is in progress. Because this relies on ATF to do the frequency scaling, it won't
> > be hard make it work.
>
> How can I test this patch series?
> Any additional patches you can share with us?
> Or what else we need to do to test it? We can help with it.
Many other patches will be required to test the series.
There are a couple of patches that updates i.MX device drivers to 
request for bandwidth (does similar thing as bus_freq_request and 
bus_freq_release).
In addition, a patch to that allow to scale the DRAM
frequency using CCF is required. I'm still working on this patch. It 
works correctly on 4.14, but since I rebased it on linux-next/master, it 
stopped to work. I'm trying to fix it now.
I will share all this patches ASAP.

Best Regards,
Alexandre
> Regards
> Dong Aisheng
>
> > As exemple, this series implements busfreq for Alexandre Bailon (3):
> >    drivers: interconnect: Add a driver for i.MX SoC
> >    drivers: interconnect: imx: Add support of i.MX8MM
> >    dt-bindings: interconnect: Document fsl,busfreq-imx8mm bindings
> >
> >   .../bindings/interconnect/imx8mm.txt          |  24 +
> >   drivers/interconnect/Kconfig                  |   1 +
> >   drivers/interconnect/Makefile                 |   1 +
> >   drivers/interconnect/imx/Kconfig              |  17 +
> >   drivers/interconnect/imx/Makefile             |   2 +
> >   drivers/interconnect/imx/busfreq-imx8mm.c     | 132 ++++
> >   drivers/interconnect/imx/busfreq.c            | 570
> > ++++++++++++++++++
> >   drivers/interconnect/imx/busfreq.h            | 123 ++++
> >   include/dt-bindings/interconnect/imx8mm.h     |  37 ++
> >   9 files changed, 907 insertions(+)
> >   create mode 100644
> > Documentation/devicetree/bindings/interconnect/imx8mm.txt
> >   create mode 100644 drivers/interconnect/imx/Kconfig  create mode
> > 100644 drivers/interconnect/imx/Makefile  create mode 100644
> > drivers/interconnect/imx/busfreq-imx8mm.c
> >   create mode 100644 drivers/interconnect/imx/busfreq.c
> >   create mode 100644 drivers/interconnect/imx/busfreq.h
> >   create mode 100644 include/dt-bindings/interconnect/imx8mm.h
> >
> > --
> > 2.19.2