5 files changed, 146 insertions, 13 deletions

diff --git a/Documentation/ABI/testing/sysfs-devices-power_resources_D0 b/Documentation/ABI/testing/sysfs-devices-power_resources_D0
new file mode 100644
index 000000000000..73b77a6be196
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-power_resources_D0
@@ -0,0 +1,13 @@
+What:           /sys/devices/.../power_resources_D0/
+Date:           January 2013
+Contact:        Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Description:
+                The /sys/devices/.../power_resources_D0/ directory is only
+                present for device objects representing ACPI device nodes that
+                use ACPI power resources for power management.
+
+                If present, it contains symbolic links to device directories
+                representing ACPI power resources that need to be turned on for
+                the given device node to be in ACPI power state D0.  The names
+                of the links are the same as the names of the directories they
+                point to.
diff --git a/Documentation/ABI/testing/sysfs-devices-power_resources_D1 b/Documentation/ABI/testing/sysfs-devices-power_resources_D1
new file mode 100644
index 000000000000..30c20703fb8c
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-power_resources_D1
@@ -0,0 +1,14 @@
+What:           /sys/devices/.../power_resources_D1/
+Date:           January 2013
+Contact:        Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Description:
+                The /sys/devices/.../power_resources_D1/ directory is only
+                present for device objects representing ACPI device nodes that
+                use ACPI power resources for power management and support ACPI
+                power state D1.
+
+                If present, it contains symbolic links to device directories
+                representing ACPI power resources that need to be turned on for
+                the given device node to be in ACPI power state D1.  The names
+                of the links are the same as the names of the directories they
+                point to.
diff --git a/Documentation/ABI/testing/sysfs-devices-power_resources_D2 b/Documentation/ABI/testing/sysfs-devices-power_resources_D2
new file mode 100644
index 000000000000..fd9d84b421e1
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-power_resources_D2
@@ -0,0 +1,14 @@
+What:           /sys/devices/.../power_resources_D2/
+Date:           January 2013
+Contact:        Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Description:
+                The /sys/devices/.../power_resources_D2/ directory is only
+                present for device objects representing ACPI device nodes that
+                use ACPI power resources for power management and support ACPI
+                power state D2.
+
+                If present, it contains symbolic links to device directories
+                representing ACPI power resources that need to be turned on for
+                the given device node to be in ACPI power state D2.  The names
+                of the links are the same as the names of the directories they
+                point to.
diff --git a/Documentation/ABI/testing/sysfs-devices-power_resources_D3hot b/Documentation/ABI/testing/sysfs-devices-power_resources_D3hot
new file mode 100644
index 000000000000..3df32c20addf
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-power_resources_D3hot
@@ -0,0 +1,14 @@
+What:           /sys/devices/.../power_resources_D3hot/
+Date:           January 2013
+Contact:        Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Description:
+                The /sys/devices/.../power_resources_D3hot/ directory is only
+                present for device objects representing ACPI device nodes that
+                use ACPI power resources for power management and support ACPI
+                power state D3hot.
+
+                If present, it contains symbolic links to device directories
+                representing ACPI power resources that need to be turned on for
+                the given device node to be in ACPI power state D3hot.  The
+                names of the links are the same as the names of the directories
+                they point to.
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 946720a4db57..9466f56b938f 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -41,6 +41,7 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/pm_runtime.h>
+#include <linux/sysfs.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
 #include "sleep.h"
@@ -417,24 +418,101 @@ static void acpi_power_remove_dependent(struct acpi_power_resource *resource,
         }
 }
 
-void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
+static struct attribute *attrs[] = {
+        NULL,
+};
+
+static struct attribute_group attr_groups[] = {
+        [ACPI_STATE_D0] = {
+                .name = "power_resources_D0",
+                .attrs = attrs,
+        },
+        [ACPI_STATE_D1] = {
+                .name = "power_resources_D1",
+                .attrs = attrs,
+        },
+        [ACPI_STATE_D2] = {
+                .name = "power_resources_D2",
+                .attrs = attrs,
+        },
+        [ACPI_STATE_D3_HOT] = {
+                .name = "power_resources_D3hot",
+                .attrs = attrs,
+        },
+};
+
+static void acpi_power_hide_list(struct acpi_device *adev, int state)
+{
+        struct acpi_device_power_state *ps = &adev->power.states[state];
+        struct acpi_power_resource_entry *entry;
+
+        if (list_empty(&ps->resources))
+                return;
+
+        list_for_each_entry_reverse(entry, &ps->resources, node) {
+                struct acpi_device *res_dev = &entry->resource->device;
+
+                sysfs_remove_link_from_group(&adev->dev.kobj,
+                                             attr_groups[state].name,
+                                             dev_name(&res_dev->dev));
+        }
+        sysfs_remove_group(&adev->dev.kobj, &attr_groups[state]);
+}
+
+static void acpi_power_expose_list(struct acpi_device *adev, int state)
 {
-        if (adev->power.flags.power_resources) {
-                struct acpi_device_power_state *ps;
-                struct acpi_power_resource_entry *entry;
-
-                ps = &adev->power.states[ACPI_STATE_D0];
-                list_for_each_entry(entry, &ps->resources, node) {
-                        struct acpi_power_resource *resource = entry->resource;
-
-                        if (add)
-                                acpi_power_add_dependent(resource, adev);
-                        else
-                                acpi_power_remove_dependent(resource, adev);
+        struct acpi_device_power_state *ps = &adev->power.states[state];
+        struct acpi_power_resource_entry *entry;
+        int ret;
+
+        if (list_empty(&ps->resources))
+                return;
+
+        ret = sysfs_create_group(&adev->dev.kobj, &attr_groups[state]);
+        if (ret)
+                return;
+
+        list_for_each_entry(entry, &ps->resources, node) {
+                struct acpi_device *res_dev = &entry->resource->device;
+
+                ret = sysfs_add_link_to_group(&adev->dev.kobj,
+                                              attr_groups[state].name,
+                                              &res_dev->dev.kobj,
+                                              dev_name(&res_dev->dev));
+                if (ret) {
+                        acpi_power_hide_list(adev, state);
+                        break;
                 }
         }
 }
 
+void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
+{
+        struct acpi_device_power_state *ps;
+        struct acpi_power_resource_entry *entry;
+        int state;
+
+        if (!adev->power.flags.power_resources)
+                return;
+
+        ps = &adev->power.states[ACPI_STATE_D0];
+        list_for_each_entry(entry, &ps->resources, node) {
+                struct acpi_power_resource *resource = entry->resource;
+
+                if (add)
+                        acpi_power_add_dependent(resource, adev);
+                else
+                        acpi_power_remove_dependent(resource, adev);
+        }
+
+        for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++) {
+                if (add)
+                        acpi_power_expose_list(adev, state);
+                else
+                        acpi_power_hide_list(adev, state);
+        }
+}
+
 int acpi_power_min_system_level(struct list_head *list)
 {
         struct acpi_power_resource_entry *entry;