Hi Yilun, > -----Original Message----- > From: Xu Yilun <yilun.xu@xxxxxxxxxxxxxxx> > Sent: Monday, July 29, 2024 9:27 PM > To: Manne, Nava kishore <nava.kishore.manne@xxxxxxx> > Cc: git (AMD-Xilinx) <git@xxxxxxx>; mdf@xxxxxxxxxx; hao.wu@xxxxxxxxx; > yilun.xu@xxxxxxxxx; trix@xxxxxxxxxx; robh@xxxxxxxxxx; > saravanak@xxxxxxxxxx; linux-fpga@xxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx > Subject: Re: [RFC 1/1] of-fpga-region: Add sysfs interface support for FPGA > configuration > > On Fri, Jul 26, 2024 at 12:08:19PM +0530, Nava kishore Manne wrote: > > Adds sysfs interface as part of the of-fpga-region. This newly added > > sysfs interface uses Device Tree Overlay (DTO) files to > > configure/reprogram an FPGA while an operating system is running.This > > solution will not change the existing sequence When a DT overlay that > > targets an FPGA Region is applied. > > - Disable appropriate FPGA bridges. > > - Program the FPGA using the FPGA manager. > > - Enable the FPGA bridges. > > - The Device Tree overlay is accepted into the live tree. > > - Child devices are populated. > > > > When the overlay is removed, the child nodes will be removed, and the > > FPGA Region will disable the bridges. > > > > Usage: > > To configure/reprogram an FPGA region: > > echo "fpga.dtbo" > /sys/class/fpga_region/<region>/device/load > > IIRC, last time we are considering some generic interface for both OF & non- > OF FPGA region, but this is still OF specific. > At AMD, we exclusively use OF for FPGA configuration/reconfiguration, utilizing overlay files as outlined in the fpga-region.txt documentation. However, some devices, like dfl.c those relying solely on the FPGA region, do not use OF. For these non-OF devices, should we expect them to follow the fpga-region.txt guidelines for FPGA configuration/reconfiguration? If so, it may be advantageous to develop a common interface for both OF and non-OF. If not, it might be more appropriate to establish distinct interfaces to cater to their specific requirements. Regards, Navakishore.
