doc: peripherals: KSCAN API documentation

Append KSCAN API to the list of peripherals

Signed-off-by: Francisco Munoz <[email protected]>

Author: franciscomunoz

doc/reference/peripherals/index.rst

@@ -16,6 +16,7 @@ Peripherals
    i2c.rst
    i2s.rst
    ipm.rst
+   kscan.rst
    pinmux.rst
    pwm.rst
    ps2.rst

doc/reference/peripherals/kscan.rst

@@ -0,0 +1,32 @@
+.. _kscan:
+
+
+KSCAN
+#####
+
+Overview
+********
+The kscan driver (keyboard scan matrix) is used for detecting a key press in a
+connected matrix keyboard or any device with buttons such as joysticks.
+Typically, matrix keyboards are implemented using a two-dimensional
+configuration in order to sense several keys.  This allows interfacing to
+many keys through fewer physical pins. Keyboard matrix
+drivers read the rows while applying power through the columns one at a time
+with the purpose of detecting key events.
+There is no correlation between the physical and electrical layout of keys.
+For, example, the physical layout may be one array of 16 or fewer keys, which
+may be electrically connected to a 4 x 4 array. In addition, key values are
+defined by a keymap provided by the keyboard manufacturer.
+
+Configuration Options
+*********************
+
+Related configuration options:
+
+* :option:`CONFIG_KSCAN`
+
+API Reference
+*************
+
+.. doxygengroup:: kscan_interface
+   :project: Zephyr