Revert "Revert "ACPI: dock driver""

This reverts 953969dd commit.

drivers/acpi/Kconfig

@@ -133,6 +133,13 @@ config ACPI_FAN
 	  This driver adds support for ACPI fan devices, allowing user-mode 
 	  applications to perform basic fan control (on, off, status).
 
+config ACPI_DOCK
+	tristate "Dock"
+	depends on !ACPI_IBM_DOCK
+	default y
+	help
+	  This driver adds support for ACPI controlled docking stations
+
 config ACPI_PROCESSOR
 	tristate "Processor"
 	default y

drivers/acpi/Makefile

@@ -42,6 +42,7 @@ obj-$(CONFIG_ACPI_BATTERY)	+= battery.o
 obj-$(CONFIG_ACPI_BUTTON)	+= button.o
 obj-$(CONFIG_ACPI_EC)		+= ec.o
 obj-$(CONFIG_ACPI_FAN)		+= fan.o
+obj-$(CONFIG_ACPI_DOCK)		+= dock.o
 obj-$(CONFIG_ACPI_VIDEO)	+= video.o 
 obj-$(CONFIG_ACPI_HOTKEY)	+= hotkey.o
 obj-y				+= pci_root.o pci_link.o pci_irq.o pci_bind.o

drivers/acpi/scan.c

@@ -663,6 +663,29 @@ static int acpi_bus_find_driver(struct acpi_device *device)
                                  Device Enumeration
    -------------------------------------------------------------------------- */
 
+acpi_status
+acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
+{
+	acpi_status status;
+	acpi_handle tmp;
+	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+	union acpi_object *obj;
+
+	status = acpi_get_handle(handle, "_EJD", &tmp);
+	if (ACPI_FAILURE(status))
+		return status;
+
+	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
+	if (ACPI_SUCCESS(status)) {
+		obj = buffer.pointer;
+		status = acpi_get_handle(NULL, obj->string.pointer, ejd);
+		kfree(buffer.pointer);
+	}
+	return status;
+}
+EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
+
+
 static int acpi_bus_get_flags(struct acpi_device *device)
 {
 	acpi_status status = AE_OK;

include/acpi/acpi_bus.h

@@ -334,7 +334,7 @@ int acpi_bus_add(struct acpi_device **child, struct acpi_device *parent,
 		 acpi_handle handle, int type);
 int acpi_bus_trim(struct acpi_device *start, int rmdevice);
 int acpi_bus_start(struct acpi_device *device);
-
+acpi_status acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd);
 int acpi_match_ids(struct acpi_device *device, char *ids);
 int acpi_create_dir(struct acpi_device *);
 void acpi_remove_dir(struct acpi_device *);

include/acpi/acpi_drivers.h

@@ -110,4 +110,21 @@ int acpi_processor_set_thermal_limit(acpi_handle handle, int type);
 
 extern int acpi_specific_hotkey_enabled;
 
+/*--------------------------------------------------------------------------
+                                  Dock Station
+  -------------------------------------------------------------------------- */
+#if defined(CONFIG_ACPI_DOCK) || defined(CONFIG_ACPI_DOCK_MODULE)
+extern int is_dock_device(acpi_handle handle);
+extern int register_dock_notifier(struct notifier_block *nb);
+extern void unregister_dock_notifier(struct notifier_block *nb);
+extern int register_hotplug_dock_device(acpi_handle handle,
+	acpi_notify_handler handler, void *context);
+extern void unregister_hotplug_dock_device(acpi_handle handle);
+#else
+#define is_dock_device(h)			(0)
+#define register_dock_notifier(nb) 		(-ENODEV)
+#define unregister_dock_notifier(nb)           	do { } while(0)
+#define register_hotplug_dock_device(h1, h2, c)	(-ENODEV)
+#define unregister_hotplug_dock_device(h)       do { } while(0)
+#endif
 #endif /*__ACPI_DRIVERS_H__*/