input: TSC: ti_tscadc: Add Step configuration as platform data

There are 16 programmable Step Configuration
registers which are used by the sequencer.
Program the Steps in order to configure a channel
input to be sampled. If the same step is applied
several times, the coordinate values read are more
accurate.
Hence we provide the user an option of how many steps
should be configured.

For ex: If this value is assigned as 4, This means that
4 steps are applied to read x co-ordinate and 4 steps to read
y co-ordinate. Furtheron the interrupt handler already
holds code to use delta filter and report the best value
out of these values to the input sub-system.

Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

include/linux/input/ti_tscadc.h

@@ -7,11 +7,17 @@
  *			i.e. 4/5/8 wire touchscreen support
  *			on the platform.
  * @x_plate_resistance:	X plate resistance.
+ * @steps_to_configure:	The sequencer supports a total of
+ *			16 programmable steps.
+ *			A step configured to read a single
+ *			co-ordinate value, can be applied
+ *			more number of times for better results.
  */
 
 struct tsc_data {
 	int wires;
 	int x_plate_resistance;
+	int steps_to_configure;
 };
 
 #endif