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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: David Brownell <dbrownell@users.sourceforge.net>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
hifive-unleashed-5.1
David Brownell 2008-02-22 21:54:24 -08:00 committed by Len Brown
parent 39273b58a4
commit 1071695f17
1 changed files with 20 additions and 0 deletions
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20
drivers/acpi/glue.c
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@ -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;