drivers: input: sdl_touch: Associate display with instance

Make the zephyr,input-sdl-touch driver be multi instance and add the
possibility to associate it with a display. The input events are only
emitted if the events occured on this display.

Signed-off-by: Fabian Blatz <fabianblatz@gmail.com>

drivers/input/input_sdl_touch.c

@@ -41,7 +41,11 @@ static int sdl_init(const struct device *dev)
 	return 0;
 }
 
-static struct sdl_input_data sdl_data_0;
+#define INPUT_SDL_TOUCH_DEFINE(inst)                                                               \
+	static struct sdl_input_data sdl_data_##inst = {                                           \
+		.display_dev = DEVICE_DT_GET_OR_NULL(DT_INST_PHANDLE(inst, display)),              \
+	};                                                                                         \
+	DEVICE_DT_INST_DEFINE(inst, sdl_init, NULL, &sdl_data_##inst, NULL, POST_KERNEL,           \
+			      CONFIG_INPUT_INIT_PRIORITY, NULL);
 
-DEVICE_DT_INST_DEFINE(0, sdl_init, NULL, &sdl_data_0, NULL,
-		    POST_KERNEL, CONFIG_INPUT_INIT_PRIORITY, NULL);
+DT_INST_FOREACH_STATUS_OKAY(INPUT_SDL_TOUCH_DEFINE)

drivers/input/input_sdl_touch_bottom.c

@@ -8,10 +8,41 @@
 #include <SDL.h>
 #include "input_sdl_touch_bottom.h"
 
+static bool event_targets_display(SDL_Event *event, struct sdl_input_data *data)
+{
+	SDL_Window *window = NULL;
+	const void *display_dev;
+
+	if (!data->display_dev) {
+		return true;
+	}
+
+	if (event->type == SDL_MOUSEBUTTONDOWN || event->type == SDL_MOUSEBUTTONUP) {
+		window = SDL_GetWindowFromID(event->button.windowID);
+	} else if (event->type == SDL_MOUSEMOTION) {
+		window = SDL_GetWindowFromID(event->motion.windowID);
+	} else {
+		return false;
+	}
+
+	if (!window) {
+		return false;
+	}
+
+	/* Get the zephyr display associated with the window */
+	display_dev = SDL_GetWindowData(window, "zephyr_display");
+
+	return !display_dev || display_dev == data->display_dev;
+}
+
 static int sdl_filter(void *arg, SDL_Event *event)
 {
 	struct sdl_input_data *data = arg;
 
+	if (!event_targets_display(event, data)) {
+		return 1;
+	}
+
 	switch (event->type) {
 	case SDL_MOUSEBUTTONUP:
 		data->pressed = false;

drivers/input/input_sdl_touch_bottom.h

@@ -22,6 +22,7 @@ extern "C" {
 
 struct sdl_input_data {
 	const void *dev; /* device structure pointer */
+	const void *display_dev;
 	void (*callback)(struct sdl_input_data *data);
 	int x;
 	int y;

dts/bindings/input/zephyr,input-sdl-touch.yaml

@@ -4,3 +4,8 @@
 description: SDL based emulated touch panel
 
 compatible: "zephyr,input-sdl-touch"
+
+properties:
+  display:
+    type: phandle
+    description: Handle to the display that the input events are raised for