drivers: input: add driver for stmpe811 i2c touch controller

This commit adds STMPE811 I2C touch controller driver.

Signed-off-by: Brunon Blok <bblok@internships.antmicro.com>
Signed-off-by: Mateusz Sierszulski <msierszulski@antmicro.com>

drivers/input/CMakeLists.txt

@@ -10,6 +10,7 @@ zephyr_library_sources_ifdef(CONFIG_INPUT_GPIO_KEYS input_gpio_keys.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_GPIO_QDEC input_gpio_qdec.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_GT911 input_gt911.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_NPCX_KBD input_npcx_kbd.c)
+zephyr_library_sources_ifdef(CONFIG_INPUT_STMPE811 input_stmpe811.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_XPT2046 input_xpt2046.c)
 
 if (CONFIG_INPUT_SDL_TOUCH)

drivers/input/Kconfig

@@ -13,6 +13,7 @@ source "drivers/input/Kconfig.gpio_qdec"
 source "drivers/input/Kconfig.gt911"
 source "drivers/input/Kconfig.npcx"
 source "drivers/input/Kconfig.sdl"
+source "drivers/input/Kconfig.stmpe811"
 source "drivers/input/Kconfig.xpt2046"
 
 endmenu # Input Drivers

drivers/input/Kconfig.stmpe811

@@ -0,0 +1,10 @@
+# Copyright (c) 2023 Antmicro <www.antmicro.com>
+# SPDX-License-Identifier: Apache-2.0
+
+config INPUT_STMPE811
+	bool "STMPE811 touch driver"
+	default y
+	depends on DT_HAS_ST_STMPE811_ENABLED
+	select I2C
+	help
+	  Enable driver for STMPE811 touch panel.

dts/bindings/input/st,stmpe811.yaml

@@ -0,0 +1,127 @@
+# Copyright (c) 2023 Antmicro <www.antmicro.com>
+# SPDX-License-Identifier: Apache-2.0
+
+description: STMPE811 I2C touchscreen controller
+
+compatible: "st,stmpe811"
+
+include: i2c-device.yaml
+
+properties:
+  int-gpios:
+    type: phandle-array
+    description: |
+      Interrupt GPIO. Used by the controller to signal touch data is
+      available. Active low.
+
+  screen-width:
+    type: int
+    default: 0
+    description: |
+      Screen width for scaling the reported coordinates.
+      Default: raw touchscreen resolution.
+
+  screen-height:
+    type: int
+    default: 0
+    description: |
+      Screen height for scaling the reported coordinates.
+      Default: raw touchscreen resolution.
+
+  raw-x-min:
+    type: int
+    description: |
+      Signed raw X axis start for scaling the reported coordinates.
+      No effect if screen size is not set.
+
+  raw-y-min:
+    type: int
+    description: |
+      Signed raw Y axis start for scaling the reported coordinates.
+      No effect if screen size is not set.
+
+  raw-x-max:
+    type: int
+    description: |
+      Raw X axis end for scaling the reported coordinates.
+      No effect if screen size is not set.
+
+  raw-y-max:
+    type: int
+    description: |
+      Raw Y axis end for scaling the reported coordinates.
+      No effect if screen size is not set.
+
+  panel-driver-settling-time-us:
+    type: int
+    enum:
+      - 10
+      - 100
+      - 500
+      - 1000
+      - 5000
+      - 10000
+      - 50000
+      - 100000
+    required: true
+    description: |
+      Panel driver settling time (microseconds). For large panels (> 6"), a capacitor of 10 nF
+      is recommended at the touchscreen terminals for noise filtering.
+      As a general rule, 1-5 nF capacitors require around 500 us settling time, and 5-10 nF need
+      around 1 ms. When a larger capacitor is used, this value should be changed, as it can
+      lead to inaccuracy of the measurement.
+
+  touch-detect-delay-us:
+    type: int
+    enum:
+      - 10
+      - 50
+      - 100
+      - 500
+      - 1000
+      - 5000
+      - 10000
+      - 50000
+    required: true
+    description: |
+      Touch detect delay (microseconds) is the delay from the activation of the pull-up resistor
+      in the X+ line to the time the device performs touch detection.
+      If no capacitor, or a smaller capacitor is used, this value can be lowered to
+      minimize detection latency, but it could lower the position stability.
+
+  touch-average-control:
+    type: int
+    enum:
+      - 1
+      - 2
+      - 4
+      - 8
+    required: true
+    description: |
+      Average control (number of samples).
+      This parameter can be set to any of the possible values.
+      Higher values result in more filtering of noise, but also introduce
+      more latency in the touch detection process.
+
+      Use cases that require low touch detection latency
+      may benefit from using a lower value for this parameter,
+      at the cost of less noise filtering.
+
+  tracking-index:
+    type: int
+    enum:
+      - 0
+      - 4
+      - 8
+      - 16
+      - 32
+      - 64
+      - 92
+      - 127
+    required: true
+    description: |
+      Tracking index determines the minimal distance between
+      the current touch position and the previous touch position.
+      If the distance is shorter than the tracking index, it is discarded.
+      Lowering the tracking index increases the frequency of touch events,
+      but also increases the load on the system.

tests/drivers/build_all/input/app.overlay

@@ -78,6 +78,16 @@
 				int-gpios = <&gpio0 0 0>;
 				input-codes = <0 1 2>;
 			};
+
+			stmpe811@4 {
+				compatible = "st,stmpe811";
+				reg = <0x4>;
+				int-gpios = <&gpio0 0 0>;
+				panel-driver-settling-time-us = <10>;
+				touch-detect-delay-us = <10>;
+				touch-average-control = <1>;
+				tracking-index = <0>;
+			};
 		};
 
 		spi@2 {