On 15/04/2026 10:06, Michal Simek wrote: > > > On 4/15/26 09:07, Krzysztof Kozlowski wrote: >> On 15/04/2026 08:55, Michal Simek wrote: >>>>> >>>>> Does it make sense? >>>> >>>> Yes, drop from DT. No need for generic stuff. Or describe the hardware. >>> >>> You need to describe that connection to HW. GPIOs, memory location, etc. >>> It means there must be any description. >> >> No, you can write user-space driver or pass everything through SW nodes. >> No need for DT description. > > The firmware memory typically sits behind AXI-to-AXI bridges and > > interconnect switches. The bus topology varies between FPGA designs. > > DT ranges-based address translation is the standard way to describe > > this, and pushing it into userspace would just mean hardcoding what > > ranges already provides. > > I don't think SW nodes should be used here. > >> >> But if you want a DT description, then it must be for the specific >> hardware, since the hardware is not generic. > > But there is specific HW loaded. It is loaded at power up and don't change > over > life cycle. What I am just saying that access to this fixed HW (in fpga) is > generic. At this stage memory and gpio only. > > What I was trying to say is that the hardware topology (memory window + > > reset GPIO) is the same regardless of the soft-core cpu (MicroBlaze, > RISC-V, etc.)/fpga, so naming it after the ISA architecture felt wrong to me > > too. > > When I look at other bindings. For example this one. > Documentation/devicetree/bindings/remoteproc/qcom,glink-rpm-edge.yaml
That's a subnode of other device. Not an independent device. Plus I dislike most of Qualcomm remoteproc bindings and find them way to downstreamish, written to match downstream approaches without respecting DT rules. > > the compatible describes the communication mechanism (FIFO-based G-Link), not > the specific processor behind it. > > > > Our case is similar the compatible describes the control mechanism firmware > loaded through a memory window, processor started via GPIO reset. What sits > behind that interface varies and is opaque to the binding. > > > Would something like "amd,mem-gpio-rproc" be acceptable, following the same > pattern where the compatible identifies the interface mechanism? Not for me. You have a very specific physical remote processor. That's what you write bindings for. Best regards, Krzysztof
