1 files changed, 53 insertions, 7 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index fe9f2c926663..1453cd0672fb 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -53,6 +53,7 @@ static const struct acpi_device_id acpi_platform_device_ids[] = {
 static LIST_HEAD(acpi_device_list);
 static LIST_HEAD(acpi_bus_id_list);
 static DEFINE_MUTEX(acpi_scan_lock);
+static LIST_HEAD(acpi_scan_handlers_list);
 DEFINE_MUTEX(acpi_device_lock);
 LIST_HEAD(acpi_wakeup_device_list);
 
@@ -62,6 +63,15 @@ struct acpi_device_bus_id{
         struct list_head node;
 };
 
+int acpi_scan_add_handler(struct acpi_scan_handler *handler)
+{
+        if (!handler || !handler->attach)
+                return -EINVAL;
+
+        list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
+        return 0;
+}
+
 /*
  * Creates hid/cid(s) string needed for modalias and uevent
  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
@@ -1570,20 +1580,42 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
         return AE_OK;
 }
 
+static int acpi_scan_attach_handler(struct acpi_device *device)
+{
+        struct acpi_scan_handler *handler;
+        int ret = 0;
+
+        list_for_each_entry(handler, &acpi_scan_handlers_list, list_node) {
+                const struct acpi_device_id *id;
+
+                id = __acpi_match_device(device, handler->ids);
+                if (!id)
+                        continue;
+
+                ret = handler->attach(device, id);
+                if (ret > 0) {
+                        device->handler = handler;
+                        break;
+                } else if (ret < 0) {
+                        break;
+                }
+        }
+        return ret;
+}
+
 static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used,
                                           void *not_used, void **ret_not_used)
 {
         const struct acpi_device_id *id;
-        acpi_status status = AE_OK;
         struct acpi_device *device;
         unsigned long long sta_not_used;
-        int type_not_used;
+        int ret;
 
         /*
          * Ignore errors ignored by acpi_bus_check_add() to avoid terminating
          * namespace walks prematurely.
          */
-        if (acpi_bus_type_and_status(handle, &type_not_used, &sta_not_used))
+        if (acpi_bus_type_and_status(handle, &ret, &sta_not_used))
                 return AE_OK;
 
         if (acpi_bus_get_device(handle, &device))
@@ -1593,10 +1625,15 @@ static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used,
         if (id) {
                 /* This is a known good platform device. */
                 acpi_create_platform_device(device, id->driver_data);
-        } else if (device_attach(&device->dev) < 0) {
-                status = AE_CTRL_DEPTH;
+                return AE_OK;
         }
-        return status;
+
+        ret = acpi_scan_attach_handler(device);
+        if (ret)
+                return ret > 0 ? AE_OK : AE_CTRL_DEPTH;
+
+        ret = device_attach(&device->dev);
+        return ret >= 0 ? AE_OK : AE_CTRL_DEPTH;
 }
 
 /**
@@ -1639,8 +1676,17 @@ static acpi_status acpi_bus_device_detach(acpi_handle handle, u32 lvl_not_used,
         struct acpi_device *device = NULL;
 
         if (!acpi_bus_get_device(handle, &device)) {
+                struct acpi_scan_handler *dev_handler = device->handler;
+
                 device->removal_type = ACPI_BUS_REMOVAL_EJECT;
-                device_release_driver(&device->dev);
+                if (dev_handler) {
+                        if (dev_handler->detach)
+                                dev_handler->detach(device);
+
+                        device->handler = NULL;
+                } else {
+                        device_release_driver(&device->dev);
+                }
         }
         return AE_OK;
 }