> Subject: [PATCH v10 2/2] Documentation: fpga: dfl: Add description for DFL UIO > support > > This patch adds description for UIO support for dfl devices on DFL > bus. > > Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx> > Reviewed-by: Tom Rix <trix@xxxxxxxxxx> > --- > 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 > v8: some doc fixes. > v9: some doc change since we switch to the driver in drivers/uio. > v10: no change. > --- > Documentation/fpga/dfl.rst | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst > index c41ac76..e35cf87 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 +531,28 @@ 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 present a DFL device in the system. In some cases users may need a > +userspace driver for the DFL device: > + > +* Users may need to run some diagnostic test for their 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 uio_dfl module exposes the UIO device interfaces for this > +purpose. Current uio_dfl doesn't have interrupt handling support, right? I guess we need to make sure no confusion on the description here. other place looks good to me. Hao > + > +UIO_DFL should be selected to enable the uio_dfl module driver. To support a > +new DFL feature via UIO direct access, its feature id should be added to the > +driver's id_table. > + > + > Open discussion > =============== > FME driver exports one ioctl (DFL_FPGA_FME_PORT_PR) for partial > reconfiguration > -- > 2.7.4
