Merge tag 'microblaze-v5.5-rc1' of git://git.monstr.eu/linux-2.6-microblaze

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

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index a916417b9e70f69b4d022196eb25ba372ad781e6..fe1e7bc91a5ea24009c541d0387d2f62d18ea7f7 100644 (file)
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -42,6 +42,11 @@ ACPI_MODULE_NAME("power");
 #define ACPI_POWER_RESOURCE_STATE_ON   0x01
 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
 
+struct acpi_power_dependent_device {
+       struct device *dev;
+       struct list_head node;
+};
+
 struct acpi_power_resource {
        struct acpi_device device;
        struct list_head list_node;
@@ -51,6 +56,7 @@ struct acpi_power_resource {
        unsigned int ref_count;
        bool wakeup_enabled;
        struct mutex resource_lock;
+       struct list_head dependents;
 };
 
 struct acpi_power_resource_entry {
@@ -232,8 +238,121 @@ static int acpi_power_get_list_state(struct list_head *list, int *state)
        return 0;
 }
 
+static int
+acpi_power_resource_add_dependent(struct acpi_power_resource *resource,
+                                 struct device *dev)
+{
+       struct acpi_power_dependent_device *dep;
+       int ret = 0;
+
+       mutex_lock(&resource->resource_lock);
+       list_for_each_entry(dep, &resource->dependents, node) {
+               /* Only add it once */
+               if (dep->dev == dev)
+                       goto unlock;
+       }
+
+       dep = kzalloc(sizeof(*dep), GFP_KERNEL);
+       if (!dep) {
+               ret = -ENOMEM;
+               goto unlock;
+       }
+
+       dep->dev = dev;
+       list_add_tail(&dep->node, &resource->dependents);
+       dev_dbg(dev, "added power dependency to [%s]\n", resource->name);
+
+unlock:
+       mutex_unlock(&resource->resource_lock);
+       return ret;
+}
+
+static void
+acpi_power_resource_remove_dependent(struct acpi_power_resource *resource,
+                                    struct device *dev)
+{
+       struct acpi_power_dependent_device *dep;
+
+       mutex_lock(&resource->resource_lock);
+       list_for_each_entry(dep, &resource->dependents, node) {
+               if (dep->dev == dev) {
+                       list_del(&dep->node);
+                       kfree(dep);
+                       dev_dbg(dev, "removed power dependency to [%s]\n",
+                               resource->name);
+                       break;
+               }
+       }
+       mutex_unlock(&resource->resource_lock);
+}
+
+/**
+ * acpi_device_power_add_dependent - Add dependent device of this ACPI device
+ * @adev: ACPI device pointer
+ * @dev: Dependent device
+ *
+ * If @adev has non-empty _PR0 the @dev is added as dependent device to all
+ * power resources returned by it. This means that whenever these power
+ * resources are turned _ON the dependent devices get runtime resumed. This
+ * is needed for devices such as PCI to allow its driver to re-initialize
+ * it after it went to D0uninitialized.
+ *
+ * If @adev does not have _PR0 this does nothing.
+ *
+ * Returns %0 in case of success and negative errno otherwise.
+ */
+int acpi_device_power_add_dependent(struct acpi_device *adev,
+                                   struct device *dev)
+{
+       struct acpi_power_resource_entry *entry;
+       struct list_head *resources;
+       int ret;
+
+       if (!adev->flags.power_manageable)
+               return 0;
+
+       resources = &adev->power.states[ACPI_STATE_D0].resources;
+       list_for_each_entry(entry, resources, node) {
+               ret = acpi_power_resource_add_dependent(entry->resource, dev);
+               if (ret)
+                       goto err;
+       }
+
+       return 0;
+
+err:
+       list_for_each_entry(entry, resources, node)
+               acpi_power_resource_remove_dependent(entry->resource, dev);
+
+       return ret;
+}
+
+/**
+ * acpi_device_power_remove_dependent - Remove dependent device
+ * @adev: ACPI device pointer
+ * @dev: Dependent device
+ *
+ * Does the opposite of acpi_device_power_add_dependent() and removes the
+ * dependent device if it is found. Can be called to @adev that does not
+ * have _PR0 as well.
+ */
+void acpi_device_power_remove_dependent(struct acpi_device *adev,
+                                       struct device *dev)
+{
+       struct acpi_power_resource_entry *entry;
+       struct list_head *resources;
+
+       if (!adev->flags.power_manageable)
+               return;
+
+       resources = &adev->power.states[ACPI_STATE_D0].resources;
+       list_for_each_entry_reverse(entry, resources, node)
+               acpi_power_resource_remove_dependent(entry->resource, dev);
+}
+
 static int __acpi_power_on(struct acpi_power_resource *resource)
 {
+       struct acpi_power_dependent_device *dep;
        acpi_status status = AE_OK;
 
        status = acpi_evaluate_object(resource->device.handle, "_ON", NULL, NULL);
@@ -243,6 +362,21 @@ static int __acpi_power_on(struct acpi_power_resource *resource)
        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
                          resource->name));
 
+       /*
+        * If there are other dependents on this power resource we need to
+        * resume them now so that their drivers can re-initialize the
+        * hardware properly after it went back to D0.
+        */
+       if (list_empty(&resource->dependents) ||
+           list_is_singular(&resource->dependents))
+               return 0;
+
+       list_for_each_entry(dep, &resource->dependents, node) {
+               dev_dbg(dep->dev, "runtime resuming because [%s] turned on\n",
+                       resource->name);
+               pm_request_resume(dep->dev);
+       }
+
        return 0;
 }
 
@@ -810,6 +944,7 @@ int acpi_add_power_resource(acpi_handle handle)
                                ACPI_STA_DEFAULT);
        mutex_init(&resource->resource_lock);
        INIT_LIST_HEAD(&resource->list_node);
+       INIT_LIST_HEAD(&resource->dependents);
        resource->name = device->pnp.bus_id;
        strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
        strcpy(acpi_device_class(device), ACPI_POWER_CLASS);