ACPI: Add acpi_resource_consumer() to find device that claims a resource

[platform/kernel/linux-rpi.git] / drivers / acpi / resource.c

diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index 56241eb..cb57962 100644 (file)
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -664,3 +664,60 @@ int acpi_dev_filter_resource_type(struct acpi_resource *ares,
        return (type & types) ? 0 : 1;
 }
 EXPORT_SYMBOL_GPL(acpi_dev_filter_resource_type);
+
+static int acpi_dev_consumes_res(struct acpi_device *adev, struct resource *res)
+{
+       struct list_head resource_list;
+       struct resource_entry *rentry;
+       int ret, found = 0;
+
+       INIT_LIST_HEAD(&resource_list);
+       ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
+       if (ret < 0)
+               return 0;
+
+       list_for_each_entry(rentry, &resource_list, node) {
+               if (resource_contains(rentry->res, res)) {
+                       found = 1;
+                       break;
+               }
+
+       }
+
+       acpi_dev_free_resource_list(&resource_list);
+       return found;
+}
+
+static acpi_status acpi_res_consumer_cb(acpi_handle handle, u32 depth,
+                                        void *context, void **ret)
+{
+       struct resource *res = context;
+       struct acpi_device **consumer = (struct acpi_device **) ret;
+       struct acpi_device *adev;
+
+       if (acpi_bus_get_device(handle, &adev))
+               return AE_OK;
+
+       if (acpi_dev_consumes_res(adev, res)) {
+               *consumer = adev;
+               return AE_CTRL_TERMINATE;
+       }
+
+       return AE_OK;
+}
+
+/**
+ * acpi_resource_consumer - Find the ACPI device that consumes @res.
+ * @res: Resource to search for.
+ *
+ * Search the current resource settings (_CRS) of every ACPI device node
+ * for @res.  If we find an ACPI device whose _CRS includes @res, return
+ * it.  Otherwise, return NULL.
+ */
+struct acpi_device *acpi_resource_consumer(struct resource *res)
+{
+       struct acpi_device *consumer = NULL;
+
+       acpi_get_devices(NULL, acpi_res_consumer_cb, res, (void **) &consumer);
+       return consumer;
+}