HID: input: generic hidinput_input_event handler

The hidinput_input_event() callback converts input events written from
userspace into HID reports and sends them to the device. We currently
implement this in every HID transport driver, even though most of them do
the same.

This provides a generic hidinput_input_event() implementation which is
mostly copied from usbhid. It uses a delayed worker to allow multiple LED
events to be collected into a single output event.
We use the custom ->request() transport driver callback to allow drivers
to adjust the outgoing report and handle the request asynchronously. If no
custom ->request() callback is available, we fall back to the generic raw
output report handler (which is synchronous).

Drivers can still provide custom hidinput_input_event() handlers (see
logitech-dj) if the generic implementation doesn't fit their needs.

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

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/hid.h b/include/linux/hid.h
index b8058c5c5594..ea4b828cb9cd 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -456,6 +456,7 @@ struct hid_device {							/* device report descriptor */
         enum hid_type type;                                             /* device type (mouse, kbd, ...) */
         unsigned country;                                               /* HID country */
         struct hid_report_enum report_enum[HID_REPORT_TYPES];
+        struct work_struct led_work;                                    /* delayed LED worker */
 
         struct semaphore driver_lock;                                   /* protects the current driver, except during input */
         struct semaphore driver_input_lock;                             /* protects the current driver */