modules: lvgl: add multi-display input support

JarmouniA · kartben · commit 4a75a930b91c · 2025-05-08T12:24:21.000+02:00
Add support for binding LV input devs to multiple displays

Signed-off-by: Abderrahmane JARMOUNI &lt;git@jarmouni.me&gt;
diff --git a/dts/bindings/input/zephyr,lvgl-common-input.yaml b/dts/bindings/input/zephyr,lvgl-common-input.yaml
@@ -1,4 +1,5 @@
 # Copyright 2023 Fabian Blatz <fabianblatz@gmail.com>
+# Copyright 2025 Abderrahmane JARMOUNI
 # SPDX-License-Identifier: Apache-2.0
 
 # Common fields for input lvgl pseudo devices
@@ -8,3 +9,8 @@ properties:
     type: phandle
     description: |
       Input device phandle.
+  display:
+    type: phandle
+    description: |
+      Phandle of the display device to pass input commands to.
+      Used in multi-display setup.
diff --git a/modules/lvgl/include/lvgl_common_input.h b/modules/lvgl/include/lvgl_common_input.h
@@ -17,6 +17,7 @@ extern "C" {
 
 struct lvgl_common_input_config {
 	struct k_msgq *event_msgq;
+	const struct device *display_dev;
 };
 
 struct lvgl_common_input_data {
diff --git a/modules/lvgl/input/lvgl_common_input.c b/modules/lvgl/input/lvgl_common_input.c
@@ -1,14 +1,16 @@
 /*
  * Copyright 2023 Fabian Blatz <fabianblatz@gmail.com>
+ * Copyright 2025 Abderrahmane JARMOUNI
  *
  * SPDX-License-Identifier: Apache-2.0
  */
 #include "lvgl_common_input.h"
 
 #include <zephyr/device.h>
 #include <zephyr/kernel.h>
-#include <zephyr/logging/log.h>
 #include <lvgl_input_device.h>
+#include <lvgl_display.h>
+#include <zephyr/logging/log.h>
 #include "lvgl_pointer_input.h"
 #include "lvgl_button_input.h"
 #include "lvgl_encoder_input.h"
@@ -42,13 +44,42 @@ static void lvgl_input_read_cb(lv_indev_t *indev, lv_indev_data_t *data)
 	data->continue_reading = k_msgq_num_used_get(cfg->event_msgq) > 0;
 }
 
+static lv_display_t *lvgl_input_get_display(const struct device *dev)
+{
+	const struct lvgl_common_input_config *cfg = dev->config;
+	const struct device *disp_dev = cfg->display_dev;
+	struct lvgl_disp_data *lv_disp_data;
+	lv_display_t *lv_disp = NULL;
+
+	if (disp_dev == NULL) {
+		return NULL;
+	}
+
+	for (int i = 0; i < DT_ZEPHYR_DISPLAYS_COUNT; i++) {
+		lv_disp = lv_display_get_next(lv_disp);
+		if (lv_disp == NULL) {
+			LOG_ERR("Could not find LV display objects of all Zephyr displays");
+			break;
+		}
+		lv_disp_data = (struct lvgl_disp_data *)lv_display_get_user_data(lv_disp);
+		if (disp_dev == lv_disp_data->display_dev) {
+			return lv_disp;
+		}
+	}
+
+	LOG_ERR("LV display corresponding to display device %s not found", disp_dev->name);
+	__ASSERT_NO_MSG(false);
+
+	return NULL;
+}
+
 int lvgl_input_register_driver(lv_indev_type_t indev_type, const struct device *dev)
 {
-	/* Currently no indev binding has its dedicated data
-	 * if that ever changes ensure that `lvgl_common_input_data`
-	 * remains the first member
+	/* Ensure that `lvgl_common_input_data` remains the first member
+	 * of indev dedicated data
 	 */
 	struct lvgl_common_input_data *common_data = dev->data;
+	lv_display_t *disp;
 
 	if (common_data == NULL) {
 		return -EINVAL;
@@ -64,6 +95,9 @@ int lvgl_input_register_driver(lv_indev_type_t indev_type, const struct device *
 	lv_indev_set_read_cb(common_data->indev, lvgl_input_read_cb);
 	lv_indev_set_user_data(common_data->indev, (void *)dev);
 
+	disp = lvgl_input_get_display(dev);
+	lv_indev_set_display(common_data->indev, disp);
+
 	return 0;
 }
 
diff --git a/modules/lvgl/input/lvgl_encoder_input.c b/modules/lvgl/input/lvgl_encoder_input.c
@@ -65,6 +65,8 @@ int lvgl_encoder_input_init(const struct device *dev)
 			  lvgl_encoder_process_event);                                             \
 	static const struct lvgl_encoder_input_config lvgl_encoder_input_config_##inst = {         \
 		.common_config.event_msgq = &LVGL_INPUT_EVENT_MSGQ(inst, encoder),                 \
+		.common_config.display_dev =                                                       \
+			DEVICE_DT_GET_OR_NULL(DT_INST_PHANDLE(inst, display)),                     \
 		.rotation_input_code = ROTATION_CODE(inst),                                        \
 		.button_input_code = BUTTON_CODE(inst),                                            \
 	};                                                                                         \
diff --git a/modules/lvgl/input/lvgl_keypad_input.c b/modules/lvgl/input/lvgl_keypad_input.c
@@ -63,6 +63,8 @@ int lvgl_keypad_input_init(const struct device *dev)
 	static const uint16_t lvgl_keypad_lvgl_codes_##inst[] = DT_INST_PROP(inst, lvgl_codes);    \
 	static const struct lvgl_keypad_input_config lvgl_keypad_input_config_##inst = {           \
 		.common_config.event_msgq = &LVGL_INPUT_EVENT_MSGQ(inst, keypad),                  \
+		.common_config.display_dev =                                                       \
+			DEVICE_DT_GET_OR_NULL(DT_INST_PHANDLE(inst, display)),                     \
 		.input_codes = lvgl_keypad_input_codes_##inst,                                     \
 		.lvgl_codes = lvgl_keypad_lvgl_codes_##inst,                                       \
 		.num_codes = DT_INST_PROP_LEN(inst, input_codes),                                  \
diff --git a/modules/lvgl/input/lvgl_pointer_input.c b/modules/lvgl/input/lvgl_pointer_input.c
@@ -1,5 +1,6 @@
 /*
  * Copyright 2023 Fabian Blatz <fabianblatz@gmail.com>
+ * Copyright 2025 Abderrahmane JARMOUNI
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -32,7 +33,7 @@ static void lvgl_pointer_process_event(struct input_event *evt, void *user_data)
 	const struct device *dev = user_data;
 	const struct lvgl_pointer_input_config *cfg = dev->config;
 	struct lvgl_pointer_input_data *data = dev->data;
-	lv_display_t *disp = lv_display_get_default();
+	lv_display_t *disp = lv_indev_get_display(data->common_data.indev);
 	struct lvgl_disp_data *disp_data = (struct lvgl_disp_data *)lv_display_get_user_data(disp);
 	struct display_capabilities *cap = &disp_data->cap;
 	lv_point_t *point = &data->common_data.pending_event.point;
@@ -137,6 +138,8 @@ int lvgl_pointer_input_init(const struct device *dev)
 			  lvgl_pointer_process_event);                                             \
 	static const struct lvgl_pointer_input_config lvgl_pointer_input_config_##inst = {         \
 		.common_config.event_msgq = &LVGL_INPUT_EVENT_MSGQ(inst, pointer),                 \
+		.common_config.display_dev =                                                       \
+			DEVICE_DT_GET_OR_NULL(DT_INST_PHANDLE(inst, display)),                     \
 		.swap_xy = DT_INST_PROP(inst, swap_xy),                                            \
 		.invert_x = DT_INST_PROP(inst, invert_x),                                          \
 		.invert_y = DT_INST_PROP(inst, invert_y),                                          \
