On 25/07/2022 18:55, Frank Li wrote: >>>> Not minItems but maxItems in general, but anyway you need to actually >>>> list and describe the items (and then skip min/max) >>> [Frank Li] >>> I am not sure format. Any example? >>> >>> Reg: >>> Items: >>> - description: a side register >>> - description: b side register >> >> Yes, but then explain what is A and B in bindings description. > > [Frank Li] How about "A(B) side base register address." > Any other description need? In top-level description you have: "The MU also provides the ability for one processor to signal the other processor using interrupts." so maybe: "The MU also provides the ability for one processor (A side) to signal the other processor (B side) using interrupts." > >> >> Why MU, which sits on A side needs to access other side (B) registers? > > [Frank Li] MU work as MSI controller for PCI EP. So driver need provide > B side register to PCI EP by msi_msg. PCI EP driver use this address to set > PCI bar<n>. Then PCI host can write this address to trigger PCIe EP side irq > As doorbell. > > MU MSI driver also need A side register > To get irq status. So MU MSI need both side registers. OK. Best regards, Krzysztof
