aboutsummaryrefslogtreecommitdiff
path: root/drivers/acpi/scan.c
diff options
context:
space:
mode:
authorBjorn Helgaas <bjorn.helgaas@hp.com>2009-09-21 19:29:50 +0000
committerLen Brown <len.brown@intel.com>2009-09-25 14:24:29 -0400
commit859ac9a4be0c753cece0e30a2e4a65fd2cdcaeee (patch)
tree10962790433ee0865ab6506c69981e8248368e46 /drivers/acpi/scan.c
parentadc08e2035f1859d4b129f42b2c2305ef090d226 (diff)
downloadlinux-linaro-android-859ac9a4be0c753cece0e30a2e4a65fd2cdcaeee.tar.gz
ACPI: identify device tree root by null parent pointer, not ACPI_BUS_TYPE
We can identify the root of the ACPI device tree by the fact that it has no parent. This is simpler than passing around ACPI_BUS_TYPE_SYSTEM and will help remove special treatment of the device tree root. Currently, we add the root by hand with ACPI_BUS_TYPE_SYSTEM. If we traverse the tree treating the root as just another device and use acpi_get_type(), the root shows up as ACPI_TYPE_DEVICE. Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/scan.c')
-rw-r--r--drivers/acpi/scan.c20
1 files changed, 13 insertions, 7 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 27d2dec55c6..0b5aaf059c9 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -22,6 +22,8 @@ extern struct acpi_device *acpi_root;
#define ACPI_BUS_HID "LNXSYBUS"
#define ACPI_BUS_DEVICE_NAME "System Bus"
+#define ACPI_IS_ROOT_DEVICE(device) (!(device)->parent)
+
static LIST_HEAD(acpi_device_list);
static LIST_HEAD(acpi_bus_id_list);
DEFINE_MUTEX(acpi_device_lock);
@@ -955,10 +957,12 @@ static void acpi_device_get_busid(struct acpi_device *device)
* The device's Bus ID is simply the object name.
* TBD: Shouldn't this value be unique (within the ACPI namespace)?
*/
- switch (device->device_type) {
- case ACPI_BUS_TYPE_SYSTEM:
+ if (ACPI_IS_ROOT_DEVICE(device)) {
strcpy(device->pnp.bus_id, "ACPI");
- break;
+ return;
+ }
+
+ switch (device->device_type) {
case ACPI_BUS_TYPE_POWER_BUTTON:
strcpy(device->pnp.bus_id, "PWRF");
break;
@@ -1093,6 +1097,11 @@ static void acpi_device_set_id(struct acpi_device *device)
switch (device->device_type) {
case ACPI_BUS_TYPE_DEVICE:
+ if (ACPI_IS_ROOT_DEVICE(device)) {
+ hid = ACPI_SYSTEM_HID;
+ break;
+ }
+
status = acpi_get_object_info(device->handle, &info);
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);
@@ -1129,9 +1138,6 @@ static void acpi_device_set_id(struct acpi_device *device)
case ACPI_BUS_TYPE_PROCESSOR:
hid = ACPI_PROCESSOR_OBJECT_HID;
break;
- case ACPI_BUS_TYPE_SYSTEM:
- hid = ACPI_SYSTEM_HID;
- break;
case ACPI_BUS_TYPE_THERMAL:
hid = ACPI_THERMAL_HID;
break;
@@ -1643,7 +1649,7 @@ int __init acpi_scan_init(void)
* Create the root device in the bus's device tree
*/
result = acpi_add_single_object(&acpi_root, ACPI_ROOT_OBJECT,
- ACPI_BUS_TYPE_SYSTEM, &ops);
+ ACPI_BUS_TYPE_DEVICE, &ops);
if (result)
goto Done;