Add documentation for TT21100 touchscreen component (#2916)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>

components/touchscreen/index.rst

@@ -81,6 +81,7 @@ See Also
 - :doc:`Inkplate 6 Plus </components/display/inkplate6>`
 - :doc:`EKTF2232 </components/touchscreen/ektf2232>`
 - :doc:`XPT2046 </components/touchscreen/xpt2046>`
+- :doc:`TT21100 </components/touchscreen/tt21100>`
 - :apiref:`touchscreen/touchscreen.h`
 - :apiref:`touchscreen/binary_sensor/touchscreen_binary_sensor.h`
 - :ghedit:`Edit`

components/touchscreen/tt21100.rst

@@ -0,0 +1,85 @@
+TT21100 Touch Screen Controller
+===============================
+
+.. seo::
+    :description: Instructions for setting up TT21100 touch screen controller with ESPHome
+    :image: esp32-s3-korvo-2-lcd.png
+    :keywords: TT21100, ESP32-S3-BOX, ESP32-S3-Korvo-2-LCD
+
+The ``tt21100`` touchscreen platform allows using the touch screen controllers based on the TT21100 chip with ESPHome.
+The :ref:`I²C <i2c>` is required to be set up in your configuration for this touchscreen to work.
+
+This controller is used in the Espressif ESP32-S3-BOX and the ESP32-S3-Korvo-2-LCD extension board for the ESP32-S3-Korvo-2.
+
+.. figure:: images/esp32-s3-box.png
+    :align: center
+    :width: 50.0%
+
+    TT21100 touchscreen on ESP32-S3-BOX
+
+.. figure:: images/esp32-s3-korvo-2.png
+    :align: center
+    :width: 50.0%
+
+    TT21100 touchscreen on ESP32-S3-Korvo-2
+
+Base Touchscreen Configuration
+------------------------------
+
+.. code-block:: yaml
+
+    # Example configuration entry
+    touchscreen:
+      platform: tt21100
+      id: my_touchscreen
+      interrupt_pin: GPIO3
+      reset_pin: GPIO48
+
+Configuration variables:
+************************
+
+- **id** (*Optional*, :ref:`config-id`): Manually set the ID of this touchscreen.
+- **interrupt_pin** (*Required*, :ref:`Pin Schema <config-pin_schema>`): The touch detection pin.
+- **reset_pin** (*Optional*, :ref:`Pin Schema <config-pin_schema>`): The reset pin of the controller.
+
+- All other options from :ref:`Touchscreen <config-touchscreen>`.
+
+.. warning::
+
+    If the reset pin is shared between the display and TT21100 touchscreen
+    (as is the case for the ESP32-S3-BOX and the ESP32-S3-Korvo-2-LCD),
+    only configure the reset pin for the display and remove the **reset_pin** variable for the TT21100 touchscreen.
+    The display component should be initialized before the touchscreen component, which has then already performed the reset.
+
+Additional Buttons
+------------------
+
+In addition to touch areas on the screen configured through the :ref:`Touchscreen <config-touchscreen>` component,
+the TT21100 supports up to four buttons located outside of the normal touchscreen area.
+On the ESP32-S3-BOX and the ESP32-S3-Korvo-2-LCD, the red circle below the display is such a button.
+A binary sensor can be configured to react to touching these buttons.
+
+.. code-block:: yaml
+
+    # Example configuration entry
+    binary_sensor:
+      - platform: tt21100
+        name: "Home"
+        index: 0
+
+Configuration variables:
+************************
+
+- **tt21100_id** (*Optional*, :ref:`config-id`): Manually specify the ID of the touchscreen.
+- **index** (**Required**, int): Internal index of the touch button, between 0 and 3.
+
+- All other options from :ref:`Binary Sensor <config-binary_sensor>`.
+
+
+See Also
+--------
+
+- :ref:`Binary Sensor Filters <binary_sensor-filters>`
+- :apiref:`tt21100/touchscreen/tt21100.h`
+- :apiref:`tt21100/binary_sensor/tt21100_button.h`
+- :ghedit:`Edit`

index.rst

@@ -462,6 +462,7 @@ Touchscreen
 
     Nextion Binary Sensor, components/binary_sensor/nextion, nextion.jpg
     Touchscreen, components/touchscreen/index, touch.svg, dark-invert
+    TT21100, components/touchscreen/tt21100, esp32-s3-korvo-2-lcd.png
     XPT2046, components/binary_sensor/xpt2046, xpt2046.jpg
 
 Miscellaneous
@@ -633,6 +634,7 @@ Touchscreen Components
     Touchscreen Core, components/touchscreen/index, folder-open.svg, dark-invert
     EKTF2232, components/touchscreen/ektf2232, ektf2232.svg, Inkplate 6 Plus
     Lilygo T5 4.7", components/touchscreen/lilygo_t5_47, lilygo_t5_47_touch.jpg
+    TT21100, components/touchscreen/tt21100, esp32-s3-korvo-2-lcd.png
 
 Cover Components
 ----------------