diff options
| author | David Brownell <david-b@pacbell.net> | 2008-02-22 21:54:24 -0800 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2008-02-23 01:32:56 -0500 |
| commit | 1071695f17daf050638e0bc550db647f8237c3bb (patch) | |
| tree | 4770e712c2293d0156fbb53bebc6fa059a8a99eb /drivers/acpi | |
| parent | 39273b58a409cd6d65c9732bdca00bacd1626672 (diff) | |
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>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/glue.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c index eda0978b57c6..06f8634fe58b 100644 --- a/drivers/acpi/glue.c +++ b/drivers/acpi/glue.c @@ -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; |