ACPI / PM: Expose lists of device power resources to user space

[linux-imx.git] / drivers / acpi / power.c

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 946720a4db57d7c4b745f6a5a148ba9da29d77c4..9466f56b938f66cad31f88ada412881a12b13632 100644 (file)
--- 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;