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ACPI: scan: Add function to fetch dependent of ACPI device

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In some ACPI tables we encounter, devices use the _DEP method to assert
a dependence on other ACPI devices as opposed to the OpRegions that the
specification intends.

We need to be able to find those devices "from" the dependee, so add
a callback and a wrapper to walk over the acpi_dep_list and return
the dependent ACPI device.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Daniel Scally 2021-06-03 23:40:03 +01:00 committed by Rafael J. Wysocki
parent a9e10e5873
commit b83e2b3067
2 changed files with 36 additions and 0 deletions
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35
drivers/acpi/scan.c
View File

@ -2101,6 +2101,20 @@ static void acpi_bus_attach(struct acpi_device *device, bool first_pass)
device->handler->hotplug.notify_online(device); device->handler->hotplug.notify_online(device);
} }
static int acpi_dev_get_first_consumer_dev_cb(struct acpi_dep_data *dep, void *data)
{
struct acpi_device *adev;
adev = acpi_bus_get_acpi_device(dep->consumer);
if (!adev)
/* If we don't find an adev then we want to continue parsing */
return 0;
*(struct acpi_device **)data = adev;
return 1;
}
static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data) static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
{ {
struct acpi_device *adev; struct acpi_device *adev;
@ -2164,6 +2178,27 @@ void acpi_dev_clear_dependencies(struct acpi_device *supplier)
} }
EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies); EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);
/**
* acpi_dev_get_first_consumer_dev - Return ACPI device dependent on @supplier
* @supplier: Pointer to the dependee device
*
* Returns the first &struct acpi_device which declares itself dependent on
* @supplier via the _DEP buffer, parsed from the acpi_dep_list.
*
* The caller is responsible for putting the reference to adev when it is no
* longer needed.
*/
struct acpi_device *acpi_dev_get_first_consumer_dev(struct acpi_device *supplier)
{
struct acpi_device *adev = NULL;
acpi_walk_dep_device_list(supplier->handle,
acpi_dev_get_first_consumer_dev_cb, &adev);
return adev;
}
EXPORT_SYMBOL_GPL(acpi_dev_get_first_consumer_dev);
/** /**
* acpi_bus_scan - Add ACPI device node objects in a given namespace scope. * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
* @handle: Root of the namespace scope to scan. * @handle: Root of the namespace scope to scan.

1
include/acpi/acpi_bus.h
View File

@ -692,6 +692,7 @@ static inline bool acpi_device_can_poweroff(struct acpi_device *adev)
bool acpi_dev_hid_uid_match(struct acpi_device *adev, const char *hid2, const char *uid2); bool acpi_dev_hid_uid_match(struct acpi_device *adev, const char *hid2, const char *uid2);
void acpi_dev_clear_dependencies(struct acpi_device *supplier); void acpi_dev_clear_dependencies(struct acpi_device *supplier);
struct acpi_device *acpi_dev_get_first_consumer_dev(struct acpi_device *supplier);
struct acpi_device * struct acpi_device *
acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv); acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv);
struct acpi_device * struct acpi_device *