samples: drivers: added a simple touch controller sample

The sample is supposed to help examine the issues with touchscreen.
It draws a plus in last touched position.

Signed-off-by: Dominik Lau <dlau@internships.antmicro.com>
Signed-off-by: Filip Kokosinski <fkokosinski@antmicro.com>

samples/drivers/touch/CMakeLists.txt

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+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(touch)
+
+target_sources(app PRIVATE src/main.c)

samples/drivers/touch/README.rst

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+.. zephyr:code-sample:: touch
+   :name: touchs
+   :relevant-api: io_interfaces
+
+   Basic touchscreen sample.
+
+Overview
+********
+This sample will draw a small plus in the last touched coordinates, that way you can check
+if the touch screen works for a board, examine its parameters such as inverted/swapped axes.
+
+Building and Running
+********************
+While this is a generic sample and it should work with any boards with both display controllers
+and touch controllers supported by Zephyr (provided the corresponding /chosen node properties
+are set i.e. `zephyr,touch` and `zephyr,display`).
+Below is an example on how to build the sample for :ref:`stm327f746g_disco`;
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/drivers/touch
+   :board: stm32f746g_disco
+   :goals: build
+   :compact:
+
+For testing purpose without the need of any hardware, the :ref:`native_sim <native_sim>`
+board is also supported and can be built as follows;
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/drivers/touch
+   :board: native_sim
+   :goals: build
+   :compact:

samples/drivers/touch/boards/native_posix_64.overlay

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+/ {
+	chosen {
+		zephyr,display = &sdl_dc;
+		zephyr,touch = &input_sdl_touch;
+	};
+};

samples/drivers/touch/boards/stm32f429i_disc1.overlay

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+/ {
+	chosen {
+		zephyr,touch = &stmpe811;
+	};
+};

samples/drivers/touch/boards/stm32f746g_disco.overlay

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+/ {
+	chosen {
+		zephyr,touch = &ft5336;
+	};
+};

samples/drivers/touch/prj.conf

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+CONFIG_HEAP_MEM_POOL_SIZE=16384
+CONFIG_LOG=y
+CONFIG_INPUT=y
+CONFIG_DISPLAY=y

samples/drivers/touch/sample.yaml

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+sample:
+  description: Sample application for touch controllers
+  name: touch_sample
+tests:
+  sample.touch.ft5336:
+    platform_allow:
+      - stm32f429i_disc1
+      - stm32f746g_disco
+    tags:
+      - touch
+    harness: none

samples/drivers/touch/src/main.c

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+/*
+ * Copyright (c) 2024 Antmicro <www.antmicro.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(sample, LOG_LEVEL_INF);
+
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/input/input.h>
+#include <zephyr/drivers/display.h>
+
+#define CROSS_WIDTH  20
+#define CROSS_HEIGHT 20
+#define BUFFER_SIZE  ((CROSS_WIDTH) * (CROSS_HEIGHT) * 4)
+#define REFRESH_RATE 100
+
+#ifndef DT_CHOSEN_zephyr_touch
+#error "Unsupported board: zephyr,touch is not assigned"
+#endif
+
+#ifndef DT_CHOSEN_zephyr_display
+#error "Unsupported board: zephyr,display is not assigned"
+#endif
+
+static const struct device *const display_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_display));
+static const struct device *const touch_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_touch));
+static struct display_capabilities capabilities;
+static struct display_buffer_descriptor buf_desc = {.buf_size = BUFFER_SIZE,
+						    .pitch = CROSS_WIDTH,
+						    .width = CROSS_WIDTH,
+						    .height = CROSS_HEIGHT};
+
+static uint8_t buffer_cross[BUFFER_SIZE] = {0};
+static const uint8_t buffer_cross_empty[BUFFER_SIZE] = {0};
+static struct k_sem sync_x, sync_y;
+
+static struct {
+	size_t x;
+	size_t y;
+} touch_point, touch_point_drawn;
+
+static void touch_event_callback(struct input_event *evt, void *user_data)
+{
+	if (evt->code == INPUT_ABS_X) {
+		touch_point.x = evt->value;
+		k_sem_give(&sync_x);
+	}
+	if (evt->code == INPUT_ABS_Y) {
+		touch_point.y = evt->value;
+		k_sem_give(&sync_y);
+	}
+}
+
+static void clear_screen(void)
+{
+	int x;
+	int y;
+
+	for (x = 0; x < capabilities.x_resolution; x += CROSS_WIDTH) {
+		for (y = 0; y < capabilities.y_resolution; y += CROSS_HEIGHT) {
+			display_write(display_dev, x, y, &buf_desc, buffer_cross_empty);
+		}
+	}
+}
+
+static void fill_cross_buffer(int bpp)
+{
+	int i;
+	int x;
+	int y;
+	int index;
+
+	for (i = 0; i < bpp; i++) {
+		for (x = 0; x < CROSS_WIDTH; x++) {
+			index = bpp * (CROSS_HEIGHT / 2 * CROSS_WIDTH + x);
+			buffer_cross[index + i] = -1;
+		}
+		for (y = 0; y < CROSS_HEIGHT; y++) {
+			index = bpp * (y * CROSS_WIDTH + CROSS_WIDTH / 2);
+			buffer_cross[index + i] = -1;
+		}
+	}
+}
+
+int main(void)
+{
+	size_t tick_count;
+	size_t bpp;
+
+	LOG_INF("Touch sample for touchscreen: %s, dc: %s", touch_dev->name, display_dev->name);
+
+	if (!device_is_ready(touch_dev)) {
+		LOG_ERR("Device %s not found. Aborting sample.", display_dev->name);
+		return 1;
+	}
+
+	if (!device_is_ready(display_dev)) {
+		LOG_ERR("Device %s not found. Aborting sample.", display_dev->name);
+		return 1;
+	}
+
+	display_get_capabilities(display_dev, &capabilities);
+	bpp = DISPLAY_BITS_PER_PIXEL(capabilities.current_pixel_format) / 8u;
+
+	if (bpp == 0 || bpp > 4) {
+		LOG_ERR("Unsupported BPP=%d", bpp);
+		return 1;
+	}
+	fill_cross_buffer(bpp);
+	display_blanking_off(display_dev);
+
+	clear_screen();
+	tick_count = 0;
+	touch_point_drawn.x = CROSS_WIDTH / 2;
+	touch_point_drawn.y = CROSS_HEIGHT / 2;
+	touch_point.x = -1;
+	touch_point.y = -1;
+
+	k_sem_init(&sync_x, 0, 1);
+	k_sem_init(&sync_y, 0, 1);
+	INPUT_CALLBACK_DEFINE(NULL, touch_event_callback, NULL);
+
+	while (1) {
+		k_msleep(REFRESH_RATE);
+		k_sem_take(&sync_x, K_FOREVER);
+		k_sem_take(&sync_y, K_FOREVER);
+		LOG_INF("TOUCH X, Y: (%d, %d)", touch_point.x, touch_point.y);
+
+		display_write(display_dev, touch_point_drawn.x - CROSS_WIDTH / 2,
+			      touch_point_drawn.y - CROSS_HEIGHT / 2, &buf_desc,
+			      buffer_cross_empty);
+		display_write(display_dev, touch_point.x - CROSS_WIDTH / 2,
+			      touch_point.y - CROSS_HEIGHT / 2, &buf_desc, buffer_cross);
+
+		touch_point_drawn.x = touch_point.x;
+		touch_point_drawn.y = touch_point.y;
+	}
+	return 0;
+}