On Fri, Nov 9, 2012 at 8:45 AM, Grant Likely <grant.likely@xxxxxxxxxxxx> wrote: > On Fri, Nov 9, 2012 at 3:11 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: >> [+cc Greg, Peter, Tony since they acked the original patch [1]] >> >> On Thu, Nov 8, 2012 at 1:04 PM, Mika Westerberg >> <mika.westerberg@xxxxxxxxxxxxxxx> wrote: >>> On Thu, Nov 08, 2012 at 12:32:25PM -0700, Bjorn Helgaas wrote: >>>> Struct device_driver is a generic structure, so it seems strange to >>>> have to include non-generic things like of_device_id and now >>>> acpi_match_table there. >>> >>> Yes, but in a sense the DT and ACPI are "generic". So that they are used to >>> describe the configuration of a machine. >> >> What I meant by "generic" was "useful across all architectures." The >> new acpi_match_table and acpi_handle fields [1] are not generic in >> that sense because they're present on all architectures but used only >> on x86 and ia64. The existing of_match_table and of_node are >> similarly unused on many architectures. This doesn't seem like a >> scalable strategy to me. Are we going to add a pnpbios_node for x86 >> PNPBIOS machines without ACPI, a pdc_hpa for parisc machines with PDC, >> etc.? >> >> [1] https://patchwork.kernel.org/patch/1677221/ > > Ultimately yes, I think that is what we want to do, Just to be clear, you think we *should* add things like pnpbios_node, pdc_hpa, etc., to struct device, one field for every scheme of telling the OS about non-enumerable devices, where only one of the N fields is used on any given machine? That seems surprising to me, but maybe I just need to be educated :) > but there is first > the non-trivial problem to solve of figuring out how ACPI/DT/whatever > data maps into what the driver expects. For example, say a device uses > two GPIOs (A & B) and we have a generic get_gpio(int index) function > that works for both ACPI and DT. But what if the ACPI binding has the > gpios in the order A,B and DT orders them B,A? I do want to coordinate > between the DT and ACPI camps to avoid those situations as much as > possible, but they will happen. When they do the driver will still > need firmware specific data. It doesn't make any sense to put that > stuff outside the driver because only that specific driver needs the > extra information. Sure. This seems like just a special case of "drivers need a way to access the underlying ACPI/DT/whatever-specific functionality," e.g., gpio = get_gpio(dev, dev_is_acpi(dev) ? 1 : 0); -- 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
