On Tue, Sep 7, 2021, at 22:48, Alyssa Rosenzweig wrote: > > > > + - description: > > > > + M3 mailboxes are an older variant with a slightly different MMIO > > > > + interface still found on the M1. > > > > + items: > > > > + - const: apple,t8103-m3-mailbox > > > > > > Would be nice to document an example of where an M3 mailbox is found. > > > > Sure, I can add a comment that this is used for the coprocessor controlling Thunderbolt. > > That raises another issue ... how do we know the M3 code works at all > without TB support yet? It "looks" correct but some of the IRQ handling > stuff is nontrivial. Enabling the mailbox interface just requires a few clocks to be ungated. Then I injected messages manually to verify that the code works. In addition I also brought up parts of the Thunderbolt controller which then allowed the co-processor on the other end of the mailbox to boot. After that I was also able to successfully talk to that processor using the same protocol used by most other processors. > > > > > + interrupts: > > > > + minItems: 4 > > > > + items: > > > > + - description: send fifo is empty interrupt > > > > + - description: send fifo is not empty interrupt > > > > + - description: receive fifo is empty interrupt > > > > + - description: receive fifo is not empty interrupt > > > > + > > > > + interrupt-names: > > > > + minItems: 4 > > > > + items: > > > > + - const: send-empty > > > > + - const: send-not-empty > > > > + - const: recv-empty > > > > + - const: recv-not-empty > > > > > > If the names became not-constant the asprintf thing goes away, not sure > > > that's better or worse. > > > > I'm not sure I understand your comment here. This property just gives a name > > to the interrupts so that they can be referenced by that instead of a magic > > number between 0 and 4 in the driver. > > D'oh, right, retracted. (Both this comment and the corresponding comment > on the driver itself). Sorry about that. > > > > > + clocks: > > > > + description: > > > > + Reference to the clock gate phandle(s) if required for this mailbox. > > > > + Optional since not all mailboxes are attached to a clock gate. > > > > > > Do we do anything with the clocks at this point? > > > > > > > The device tree bindings describe the hardware (as best as we can without proper > > documentation) and some of these mailboxes have clock gates which need to be turned > > on before accessing their MMIO. This driver already tries to do that and works fine > > with the downstream clock driver(s) we have. > > Good enough for me, thanks for clarifying 👍 > > Commit r-b, though Rob will surely point out problems and I'll need to > rereview 😉 > Thanks! Sven
