Input: add keypad driver for keys interfaced to TCA6416

This patch implements a simple Keypad driver that functions
as an I2C client. It handles key press events for keys
connected to TCA6416 I2C based IO expander.

Signed-off-by: Sriramakrishnan <srk@ti.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

include/linux/tca6416_keypad.h

@@ -0,0 +1,34 @@
+/*
+ * tca6416 keypad platform support
+ *
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * Author: Sriramakrishnan <srk@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _TCA6416_KEYS_H
+#define _TCA6416_KEYS_H
+
+#include <linux/types.h>
+
+struct tca6416_button {
+	/* Configuration parameters */
+	int code;		/* input event code (KEY_*, SW_*) */
+	int active_low;
+	int type;		/* input event type (EV_KEY, EV_SW) */
+};
+
+struct tca6416_keys_platform_data {
+	struct tca6416_button *buttons;
+	int nbuttons;
+	unsigned int rep:1;	/* enable input subsystem auto repeat */
+	uint16_t pinmask;
+	uint16_t invert;
+	int irq_is_gpio;
+	int use_polling;	/* use polling if Interrupt is not connected*/
+};
+#endif