HID: add feature_mapping callback

Currently hid doesn't export the features it knows to the specific modules.
Some information can be really important in such features: MosArt and
Cypress devices are by default not in a multitouch mode.
We have to send the value 2 on the right feature.

This patch exports to the module the features report so they can find the
right feature to set up the correct mode.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Acked-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/include/linux/hid.h b/include/linux/hid.h
index bb0f56f..96bd792 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -593,6 +593,7 @@
  * @report_fixup: called before report descriptor parsing (NULL means nop)
  * @input_mapping: invoked on input registering before mapping an usage
  * @input_mapped: invoked on input registering after mapping an usage
+ * @feature_mapping: invoked on feature registering
  * @suspend: invoked on suspend (NULL means nop)
  * @resume: invoked on resume if device was not reset (NULL means nop)
  * @reset_resume: invoked on resume if device was reset (NULL means nop)
@@ -636,6 +637,9 @@
 	int (*input_mapped)(struct hid_device *hdev,
 			struct hid_input *hidinput, struct hid_field *field,
 			struct hid_usage *usage, unsigned long **bit, int *max);
+	void (*feature_mapping)(struct hid_device *hdev,
+			struct hid_input *hidinput, struct hid_field *field,
+			struct hid_usage *usage);
 #ifdef CONFIG_PM
 	int (*suspend)(struct hid_device *hdev, pm_message_t message);
 	int (*resume)(struct hid_device *hdev);