1 files changed, 49 insertions, 6 deletions

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 63fdbf09b044..e0b241bd3070 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -212,6 +212,18 @@ static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
 }
 
 /*
+ * Concatenate usage which defines 16 bits or less with the
+ * currently defined usage page to form a 32 bit usage
+ */
+
+static void complete_usage(struct hid_parser *parser, unsigned int index)
+{
+	parser->local.usage[index] &= 0xFFFF;
+	parser->local.usage[index] |=
+		(parser->global.usage_page & 0xFFFF) << 16;
+}
+
+/*
  * Add a usage to the temporary parser table.
  */
 
@@ -222,6 +234,14 @@ static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size)
 		return -1;
 	}
 	parser->local.usage[parser->local.usage_index] = usage;
+
+	/*
+	 * If Usage item only includes usage id, concatenate it with
+	 * currently defined usage page
+	 */
+	if (size <= 2)
+		complete_usage(parser, parser->local.usage_index);
+
 	parser->local.usage_size[parser->local.usage_index] = size;
 	parser->local.collection_index[parser->local.usage_index] =
 		parser->collection_stack_ptr ?
@@ -543,13 +563,32 @@ static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
  * usage value."
  */
 
-static void hid_concatenate_usage_page(struct hid_parser *parser)
+static void hid_concatenate_last_usage_page(struct hid_parser *parser)
 {
 	int i;
+	unsigned int usage_page;
+	unsigned int current_page;
+
+	if (!parser->local.usage_index)
+		return;
 
-	for (i = 0; i < parser->local.usage_index; i++)
-		if (parser->local.usage_size[i] <= 2)
-			parser->local.usage[i] += parser->global.usage_page << 16;
+	usage_page = parser->global.usage_page;
+
+	/*
+	 * Concatenate usage page again only if last declared Usage Page
+	 * has not been already used in previous usages concatenation
+	 */
+	for (i = parser->local.usage_index - 1; i >= 0; i--) {
+		if (parser->local.usage_size[i] > 2)
+			/* Ignore extended usages */
+			continue;
+
+		current_page = parser->local.usage[i] >> 16;
+		if (current_page == usage_page)
+			break;
+
+		complete_usage(parser, i);
+	}
 }
 
 /*
@@ -561,7 +600,7 @@ static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
 	__u32 data;
 	int ret;
 
-	hid_concatenate_usage_page(parser);
+	hid_concatenate_last_usage_page(parser);
 
 	data = item_udata(item);
 
@@ -742,6 +781,10 @@ static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
 	if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
 	    parser->global.report_size == 8)
 		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
+
+	if (usage == 0xff0000c6 && parser->global.report_count == 1 &&
+	    parser->global.report_size == 8)
+		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 }
 
 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
@@ -772,7 +815,7 @@ static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 	__u32 data;
 	int i;
 
-	hid_concatenate_usage_page(parser);
+	hid_concatenate_last_usage_page(parser);
 
 	data = item_udata(item);