On Tuesday, November 12, 2013 11:24:02 AM Mika Westerberg wrote: > On Mon, Nov 11, 2013 at 02:45:39PM +0100, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > Subject: ACPI / driver core: Store an ACPI device pointer in struct acpi_dev_node > > > > Modify struct acpi_dev_node to contain a pointer to struct acpi_device > > associated with the given device object (that is, its ACPI companion > > device) instead of an ACPI handle corresponding to it. Introduce two > > new macros for manipulating that pointer in a CONFIG_ACPI-safe way, > > ACPI_COMPANION() and ACPI_COMPANION_SET(), and rework the > > ACPI_HANDLE() macro to take the above changes into account. > > Drop the ACPI_HANDLE_SET() macro entirely and rework its users to > > use ACPI_COMPANION_SET() instead. For some of them who used to > > pass the result of acpi_get_child() directly to ACPI_HANDLE_SET() > > introduce a helper routine acpi_preset_companion() doing an > > equivalent thing. > > > > The main motivation for doing this is that there are things > > represented by struct acpi_device objects that don't have valid > > ACPI handles (so called fixed ACPI hardware features, such as > > power and sleep buttons) and we would like to create platform > > device objects for them and "glue" them to their ACPI companions > > in the usual way (which currently is impossible due to the > > lack of valid ACPI handles). However, there are more reasons > > why it may be useful. > > > > First, struct acpi_device pointers allow of much better type checking > > than void pointers which are ACPI handles, so it should be more > > difficult to write buggy code using modified struct acpi_dev_node > > and the new macros. Second, the change should help to reduce (over > > time) the number of places in which the result of ACPI_HANDLE() is > > passed to acpi_bus_get_device() in order to obtain a pointer to the > > struct acpi_device associated with the given "physical" device, > > because now that pointer is returned by ACPI_COMPANION() directly. > > Finally, the change should make it easier to write generic code that > > will build both for CONFIG_ACPI set and unset without adding explicit > > compiler directives to it. > > > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > I tested this on Haswell as well and it works fine with ACPI enumerated > platform, I2C and SPI devices. > > Tested-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> (on Haswell) > Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> Thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
