ACPI / platform: Initialize ACPI handles of platform devices in advance

The current platform device creation and registration code in
acpi_create_platform_device() is quite convoluted.  This function
takes an ACPI device node as an argument and eventually calls
platform_device_register_resndata() to create and register a
platform device object on the basis of the information contained
in that code.  However, it doesn't associate the new platform
device with the ACPI node directly, but instead it relies on
acpi_platform_notify(), called from within device_add(), to find
that ACPI node again with the help of acpi_platform_find_device()
and acpi_platform_match() and then attach the new platform device
to it.  This causes an additional ACPI namespace walk to happen and
is clearly suboptimal.

Use the observation that it is now possible to initialize the ACPI
handle of a device before calling device_add() for it to make this
code more straightforward.  Namely, add a new field to struct
platform_device_info allowing us to pass the ACPI handle of interest
to platform_device_register_full(), which will then use it to
initialize the new device's ACPI handle before registering it.
This will cause acpi_platform_notify() to use the ACPI handle from
the device structure directly instead of using the .find_device()
routine provided by the device's bus type.  In consequence,
acpi_platform_bus, acpi_platform_find_device(), and
acpi_platform_match() are not necessary any more, so remove them.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 5711e9525a2a..a9ded9a3c175 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -55,6 +55,7 @@ extern int platform_add_devices(struct platform_device **, int);
 
 struct platform_device_info {
 		struct device *parent;
+		struct acpi_dev_node acpi_node;
 
 		const char *name;
 		int id;