[PATCH] Add support for fan button on Ideapad Z580

[Maxim Mikityanskiy <maxtram95@gmail.com>]

From: Maxim Mikityanskiy <maxtram95@gmail.com>

The patch adds support for fan control button on Ideapad Z580. This is
the same button as on Z570, but it raises different bit in
VPCCMD_R_SPECIAL_BUTTONS. Also add message to dmesg when unknown button
press detected, it will help adding support for new special buttons.

Signed-off-by: Maxim Mikityanskiy <maxtram95@gmail.com>
Tested-by: Ivan Vojtko <nekroman.sk@gmail.com>
---
--- ideapad-laptop.c
+++ ideapad-laptop.c
@@ -640,7 +640,8 @@
 	for (bit = 0; bit < 16; bit++) {
 		if (test_bit(bit, &value)) {
 			switch (bit) {
-			case 6:
+			case 0:	/* Z580 */
+			case 6:	/* Z570 */
 				/* Thermal Management button */
 				ideapad_input_report(priv, 65);
 				break;
@@ -648,6 +649,9 @@
 				/* OneKey Theater button */
 				ideapad_input_report(priv, 64);
 				break;
+			default:
+				pr_info("Unknown special button: %lu\n", bit);
+				break;
 			}
 		}
 	}