Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1071695f authored by David Brownell's avatar David Brownell Committed by Len Brown
Browse files

ACPI: crosslink ACPI and "real" device nodes 



Add cross-links between ACPI device and "real" devices in sysfs,
exposing otherwise-hidden interrelationships between the various
device nodes for ACPI stuff.  As a representative example, one
hardware device is exposed as two logical devices (PNP and ACPI):

  .../pnp0/00:06/
  .../LNXSYSTM:00/device:00/PNP0A03:00/device:15/PNP0B00:00/

The PNP device gets a "firmware_node" link pointing to the ACPI device,
and is what a Linux device driver binds to.  The ACPI device has instead
a "physical_node" link pointing back to the PNP device.  Other firmware
frameworks, like OpenFirmware, could do the same thing to couple their
firmware tables to the rest of the system.

(Based on a patch from Zhang Rui.  This version is modified to not
depend on the patch makig ACPI initialize driver model wakeup flags.)

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 39273b58

drivers/acpi/glue.c

+20 −0
Original line number Diff line number Diff line
@@ -142,6 +142,7 @@ EXPORT_SYMBOL(acpi_get_physical_device); 


static int acpi_bind_one(struct device *dev, acpi_handle handle)

{

	struct acpi_device *acpi_dev;

	acpi_status status;



	if (dev->archdata.acpi_handle) {
@@ -157,6 +158,16 @@ static int acpi_bind_one(struct device *dev, acpi_handle handle) 
	}

	dev->archdata.acpi_handle = handle;



	status = acpi_bus_get_device(handle, &acpi_dev);

	if (!ACPI_FAILURE(status)) {

		int ret;



		ret = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,

				"firmware_node");

		ret = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,

				"physical_node");

	}



	return 0;

}
@@ -165,8 +176,17 @@ static int acpi_unbind_one(struct device *dev) 
	if (!dev->archdata.acpi_handle)

		return 0;

	if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) {

		struct acpi_device *acpi_dev;



		/* acpi_get_physical_device increase refcnt by one */

		put_device(dev);



		if (!acpi_bus_get_device(dev->archdata.acpi_handle,

					&acpi_dev)) {

			sysfs_remove_link(&dev->kobj, "firmware_node");

			sysfs_remove_link(&acpi_dev->dev.kobj, "physical_node");

		}



		acpi_detach_data(dev->archdata.acpi_handle,

				 acpi_glue_data_handler);

		dev->archdata.acpi_handle = NULL;