Input: add driver FSL MPR121 capacitive touch sensor

This patch adds basic support for Freescale MPR121 capacitive touch
sensor.  It's an i2c controller with up to 12 capacitance sensing inputs.

Product information (data sheet, application notes) can be found here:
http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MPR121

Signed-off-by: Zhang Jiejing <jiejing.zhang@freescale.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/include/linux/i2c/mpr121_touchkey.h b/include/linux/i2c/mpr121_touchkey.h
new file mode 100644
index 0000000..f0bcc38
--- /dev/null
+++ b/include/linux/i2c/mpr121_touchkey.h
@@ -0,0 +1,20 @@
+/* Header file for Freescale MPR121 Capacitive Touch Sensor */
+
+#ifndef _MPR121_TOUCHKEY_H
+#define _MPR121_TOUCHKEY_H
+
+/**
+ * struct mpr121_platform_data - platform data for mpr121 sensor
+ * @keymap: pointer to array of KEY_* values representing keymap
+ * @keymap_size: size of the keymap
+ * @wakeup: configure the button as a wake-up source
+ * @vdd_uv: VDD voltage in uV
+ */
+struct mpr121_platform_data {
+	const unsigned short *keymap;
+	unsigned int keymap_size;
+	bool wakeup;
+	int vdd_uv;
+};
+
+#endif /* _MPR121_TOUCHKEY_H */