Input: pxa27x_keypad add choice to set direct_key_mask

Direct keys usage may not start from KP_DKIN0, add a msk option
to configure the specifics for platforms that can skip some keys.
Signed-off-by: Chao Xie <chao.xie@marvell.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>

arch/arm/plat-pxa/include/plat/pxa27x_keypad.h

@@ -46,6 +46,8 @@ struct pxa27x_keypad_platform_data {
 	unsigned int	direct_key_map[MAX_DIRECT_KEY_NUM];
 	/* the key output may be low active */
 	int		direct_key_low_active;
+	/* give board a chance to choose the start direct key */
+	unsigned int	direct_key_mask;
 
 	/* rotary encoders 0 */
 	int		enable_rotary0;

drivers/input/keyboard/pxa27x_keypad.c

@@ -391,7 +391,14 @@ static void pxa27x_keypad_config(struct pxa27x_keypad *keypad)
 	if (pdata->direct_key_num > direct_key_num)
 		direct_key_num = pdata->direct_key_num;
 
-	keypad->direct_key_mask = ((1 << direct_key_num) - 1) & ~mask;
+	/*
+	 * Direct keys usage may not start from KP_DKIN0, check the platfrom
+	 * mask data to config the specific.
+	 */
+	if (pdata->direct_key_mask)
+		keypad->direct_key_mask = pdata->direct_key_mask;
+	else
+		keypad->direct_key_mask = ((1 << direct_key_num) - 1) & ~mask;
 
 	/* enable direct key */
 	if (direct_key_num)