HID: wiimote: Add extension support stub

The wiimote supports several extensions. This adds a separate source file which
handles all extensions and can be disabled at compile-time.

The driver reacts on "plug"-events on the extension port and starts a worker
which initializes or deinitializes the extensions.

Currently, the initialization logic is not fully understood and we can only
detect and enable all extensions when all extensions are deactivated. Therefore,
we need to disable all extensions, then detect and activate them again to react
on "plug"-events.
However, deactivating extensions will generate a new "plug"-event and we will
never leave that loop. Hence, we only support extensions if they are plugged
before the wiimote is connected (or before the ext-input device is opened). In
the future we may support full extension hotplug support, but
reverse-engineering this may take a while.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 22a4a051f221..7a0c6f956d3e 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -623,6 +623,15 @@ config HID_WIIMOTE
         ---help---
         Support for the Nintendo Wii Remote bluetooth device.
 
+config HID_WIIMOTE_EXT
+        bool "Nintendo Wii Remote Extension support"
+        depends on HID_WIIMOTE
+        default HID_WIIMOTE
+        ---help---
+        Support for extension controllers of the Nintendo Wii Remote. Say yes
+        here if you want to use the Nintendo Motion+, Nunchuck or Classic
+        extension controllers with your Wii Remote.
+
 config HID_ZEROPLUS
         tristate "Zeroplus based game controller support"
         depends on USB_HID