Re: [PATCH v7 2/2] Documentation: fpga: dfl: Add description for DFL UIO support

From: Xu Yilun
Date: Tue Jan 19 2021 - 22:19:28 EST


On Tue, Jan 19, 2021 at 07:12:24PM -0800, Randy Dunlap wrote:
> Doc suggestions:
>
> On 1/19/21 6:43 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.
> > v6: improve the title of the userspace driver support section.
> > some word improvement.
> > v7: rebased to next-20210119
> > ---
> > Documentation/fpga/dfl.rst | 25 +++++++++++++++++++++++++
> > 1 file changed, 25 insertions(+)
> >
> > diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst
> > index c41ac76..f96a6fb 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
> > @@ -530,6 +531,30 @@ Being able to specify more than one DFL per BAR has been considered, but it
> > was determined the use case did not provide value. Specifying a single DFL
> > per BAR simplifies the implementation and allows for extra error checking.
> >
> > +
> > +Userspace driver 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
>
> then present a DFL device in the system.
>
> > +driver for the DFL device:
> > +
> > +* Users may need to run some diagnostic test for their hardwares.
>
> hardware.
>
> > +* 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 direct access to MMIO space and interrupt handling from
> > +userspace. The dfl-uio-pdev module exposes the UIO device interfaces for this
> > +purpose. It adds the uio_pdrv_genirq platform device with the resources of
> > +the DFL feature, and lets the generic UIO platform device driver provide UIO
> > +support to userspace.
> > +
> > +FPGA_DFL_UIO_PDEV should be selected to enable the dfl-uio-pdev module driver.
> > +To support a new DFL feature been directly accessed via UIO, its feature id
>
> To support a new DFL feature via UIO direct access, its feature id

Thanks for the fixes. Will fix them all.

Yilun