On 09/10/17 14:52, Rob Herring wrote: > On Fri, Oct 6, 2017 at 9:26 PM, Jassi Brar <jassisinghbrar@xxxxxxxxx> wrote: >> On Fri, Oct 6, 2017 at 9:24 PM, Rob Herring <robh@xxxxxxxxxx> wrote: >>> On Fri, Oct 6, 2017 at 6:01 AM, Jassi Brar <jassisinghbrar@xxxxxxxxx> wrote: >>>> On Fri, Oct 6, 2017 at 4:50 AM, Rob Herring <robh@xxxxxxxxxx> wrote: >>>>> On Thu, Sep 28, 2017 at 02:11:27PM +0100, Sudeep Holla wrote: >> >>>>> >>>>>> +- mbox-data : For each phandle listed in mboxes property, an unsigned 32-bit >>>>>> + data as expected by the mailbox controller >>>>> >>>>> Shouldn't that be cells as part of mboxes property? >>>>> >>>> A MHU client can send any number of commands (such u32 values) over a channel. >>>> This client (SCMI) sends just one command over a channel, but other >>>> clients may/do send two or more. > > The above definition doesn't support 2 or more as it is 1-1 with channels. > In case of MHU, we just need one u32 per channel in SCMI context. >>> Okay, then I guess I don't understand why this is in DT. >>> >> Yeah the client has to provide code (u32 value) for the commands it >> sends, and that value is going to be platform specific. For example, >> on Juno the ITS_AN_SCMI_COMMAND may be defined as BIT(7) while on my >> platform it may be 0x4567 >> >> For MHU based platforms, it becomes easy if the u32 is passed from DT. >> And that should be ok since that is like a h/w parameter - a value >> chosen/expected by the remote firmware. > > Could it ever be more than 1 cell? > No, as mentioned above. > I guess being in DT is fine, but I'm still not sure about the naming. > The current name suggests it is part of the mbox binding. Do we want > that or should it be SCMI specific? Then "data" is vague. Perhaps > "scmi-commands"? > How about "scmi-mhu-commands" ? As scmi-commands sounds too generic and part of SCMI specification. But they are rather MHU specific to make use of each 32 bit in physical channel for a virtual channel. IOW, it's just different way of representing the doorbell bits I proposed previously as a 32-bit command expected by the driver. -- Regards, Sudeep -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
