[PATCH v3 10/17] ACPI: add acpi_bus_get_parent() and remove "parent" arguments

Bjorn Helgaas
2009-09-21T19:31:30Z

This patch adds acpi_bus_get_parent(), which ascends the namespace until
it finds a parent with an acpi_device.

Then we use acpi_bus_get_parent() in acpi_add_single_object(), so callers
don't have to figure out or keep track of the parent acpi_device.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
---
drivers/acpi/scan.c | 50 +++++++++++++++++++++++++++++++++++++-------------
1 files changed, 37 insertions(+), 13 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index f2e2834..f205b36 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -662,6 +662,33 @@ EXPORT_SYMBOL(acpi_bus_unregister_driver);
/* --------------------------------------------------------------------------
Device Enumeration
-------------------------------------------------------------------------- */
+static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
+{
+ acpi_status status;
+ int ret;
+ struct acpi_device *device;
+
+ /*
+ * Fixed hardware devices do not appear in the namespace and do not
+ * have handles, but we fabricate acpi_devices for them, so we have
+ * to deal with them specially.
+ */
+ if (handle == NULL)
+ return acpi_root;
+
+ do {
+ status = acpi_get_parent(handle, &handle);
+ if (status == AE_NULL_ENTRY)
+ return NULL;
+ if (ACPI_FAILURE(status))
+ return acpi_root;
+
+ ret = acpi_bus_get_device(handle, &device);
+ if (ret == 0)
+ return device;
+ } while (1);
+}
+
acpi_status
acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
{
@@ -1217,10 +1244,9 @@ static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
return 0;
}

-static int
-acpi_add_single_object(struct acpi_device **child,
- struct acpi_device *parent, acpi_handle handle, int type,
- struct acpi_bus_ops *ops)
+static int acpi_add_single_object(struct acpi_device **child,
+ acpi_handle handle, int type,
+ struct acpi_bus_ops *ops)
{
int result;
struct acpi_device *device;
@@ -1234,7 +1260,7 @@ acpi_add_single_object(struct acpi_device **child,

device->device_type = type;
device->handle = handle;
- device->parent = parent;
+ device->parent = acpi_bus_get_parent(handle);
device->bus_ops = *ops; /* workround for not call .start */

acpi_device_get_busid(device);
@@ -1434,8 +1460,8 @@ static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
}

if (ops->acpi_op_add)
- status = acpi_add_single_object(&child, parent,
- chandle, type, ops);
+ status = acpi_add_single_object(&child, chandle, type,
+ ops);
else
status = acpi_bus_get_device(chandle, &child);

@@ -1488,7 +1514,7 @@ acpi_bus_add(struct acpi_device **child,
memset(&ops, 0, sizeof(ops));
ops.acpi_op_add = 1;

- result = acpi_add_single_object(child, parent, handle, type, &ops);
+ result = acpi_add_single_object(child, handle, type, &ops);
if (!result)
result = acpi_bus_scan(*child, &ops);

@@ -1584,15 +1610,13 @@ static int acpi_bus_scan_fixed(void)
* Enumerate all fixed-feature devices.
*/
if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
- result = acpi_add_single_object(&device, acpi_root,
- NULL,
+ result = acpi_add_single_object(&device, NULL,
ACPI_BUS_TYPE_POWER_BUTTON,
&ops);
}

if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
- result = acpi_add_single_object(&device, acpi_root,
- NULL,
+ result = acpi_add_single_object(&device, NULL,
ACPI_BUS_TYPE_SLEEP_BUTTON,
&ops);
}
@@ -1618,7 +1642,7 @@ int __init acpi_scan_init(void)
/*
* Create the root device in the bus's device tree
*/
- result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
+ result = acpi_add_single_object(&acpi_root, ACPI_ROOT_OBJECT,
ACPI_BUS_TYPE_SYSTEM, &ops);
if (result)
goto Done;