ACPI / scan: Introduce struct acpi_scan_handler

Introduce struct acpi_scan_handler for representing objects that
will do configuration tasks depending on ACPI device nodes'
hardware IDs (HIDs).

Currently, those tasks are done either directly by the ACPI namespace
scanning code or by ACPI device drivers designed specifically for
this purpose.  None of the above is desirable, however, because
doing that directly in the namespace scanning code makes that code
overly complicated and difficult to follow and doing that in
"special" device drivers leads to a great deal of confusion about
their role and to confusing interactions with the driver core (for
example, sysfs directories are created for those drivers, but they
are completely unnecessary and only increase the kernel's memory
footprint in vain).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index ad0a86ac5cce..41850cb21730 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -84,6 +84,18 @@ struct acpi_driver;
 struct acpi_device;
 
 /*
+ * ACPI Scan Handler
+ * -----------------
+ */
+
+struct acpi_scan_handler {
+        const struct acpi_device_id *ids;
+        struct list_head list_node;
+        int (*attach)(struct acpi_device *dev, const struct acpi_device_id *id);
+        void (*detach)(struct acpi_device *dev);
+};
+
+/*
  * ACPI Driver
  * -----------
  */
@@ -269,6 +281,7 @@ struct acpi_device {
         struct acpi_device_wakeup wakeup;
         struct acpi_device_perf performance;
         struct acpi_device_dir dir;
+        struct acpi_scan_handler *handler;
         struct acpi_driver *driver;
         void *driver_data;
         struct device dev;
@@ -382,6 +395,7 @@ int acpi_bus_receive_event(struct acpi_bus_event *event);
 static inline int acpi_bus_generate_proc_event(struct acpi_device *device, u8 type, int data)
         { return 0; }
 #endif
+int acpi_scan_add_handler(struct acpi_scan_handler *handler);
 int acpi_bus_register_driver(struct acpi_driver *driver);
 void acpi_bus_unregister_driver(struct acpi_driver *driver);
 int acpi_bus_scan(acpi_handle handle);