On Tuesday 02 September 2014 16:15:05 Ashwin Chaugule wrote: > > > >> > The "index" in mbox_request_channel() picks > >> > up one set of strings. How should this work with PCC? Should we use > >> > the PCC client platform_device->dev->platform_data to store mailbox > >> > controller strings? > > > > I didn't think there was more than one PCC provider, why do you even > > need a string? > > > > For the general case in ACPI, there should be a similar way of looking > > up mailbox providers to what we have in DT, but if I understand you > > correctly, the PCC specification does not allow that. > > Right. At least not in a way DT does. PCC clients know if something > needs to be written/read via PCC mailbox and can identify a PCC > subspace. (i.e. Mailbox channel). The PCC mailbox is uniquely > identified/defined in the spec. > > #define ACPI_ADR_SPACE_PLATFORM_COMM (acpi_adr_space_type) 10 > > So we could use this ID instead of a string and use that to look up > the PCC controller for a PCC client. I didn't realize this was the case. Does that mean we can treat pcc as a linearly accessible address space the way we do for system memory, pci-config etc? If that works, we should probably just have a regmap for it rather than expose the mailbox API to client drivers. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
