Re: [PATCH v5 2/2] Documentation: fpga: dfl: Add description for DFL UIO support

From: Xu Yilun
Date: Mon Jan 04 2021 - 21:06:43 EST


On Mon, Jan 04, 2021 at 09:19:24AM -0800, Russ Weight wrote:
>
>
> On 1/1/21 7:13 PM, Xu Yilun wrote:
> > This patch adds description for UIO support for dfl devices on DFL
> > bus.
> >
> > Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx>
> > ---
> > v2: no doc in v1, add it for v2.
> > v3: some documentation fixes.
> > v4: documentation change since the driver matching is changed.
> > v5: no change.
> > ---
> > Documentation/fpga/dfl.rst | 24 ++++++++++++++++++++++++
> > 1 file changed, 24 insertions(+)
> >
> > diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst
> > index 0404fe6..b8497f3 100644
> > --- a/Documentation/fpga/dfl.rst
> > +++ b/Documentation/fpga/dfl.rst
> > @@ -7,6 +7,7 @@ Authors:
> > - Enno Luebbers <enno.luebbers@xxxxxxxxx>
> > - Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
> > - Wu Hao <hao.wu@xxxxxxxxx>
> > +- Xu Yilun <yilun.xu@xxxxxxxxx>
> >
> > The Device Feature List (DFL) FPGA framework (and drivers according to
> > this framework) hides the very details of low layer hardwares and provides
> > @@ -502,6 +503,29 @@ FME Partial Reconfiguration Sub Feature driver (see drivers/fpga/dfl-fme-pr.c)
> > could be a reference.
> >
> >
> > +UIO support for DFL devices
> > +===========================
> > +The purpose of an FPGA is to be reprogrammed with newly developed hardware
> > +components. New hardware can instantiate a new private feature in the DFL, and
> > +then get a DFL device in their system. In some cases users may need a userspace
> > +driver for the DFL device:
> > +
> > +* Users may need to run some diagnostic test for their hardwares.
> > +* Users may prototype the kernel driver in user space.
> > +* Some hardware is designed for specific purposes and does not fit into one of
> > + the standard kernel subsystems.
> > +
> > +This requires the direct access to the MMIO space and interrupt handling in
> This may be better stated as:
>
> "This requires direct access to MMIO space and interrupt handling from userspace."

Thanks for the correction, I'll change it.

Yilun