modules: lvgl: Sync display rotation to LVGL

LVGL supports the `rotated` flag on its display drivers. It is used
during input device coordinate processing to translate the physical
touch points to the points in (rendered) GUI space. Previously this was
done by the Zephyr gluecode on system init. With this change it is now
possible to perform runtime rotation of the display, the
`lvgl_reload_display_capabilities` method should be called right after
`display_set_orientation`.

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

modules/lvgl/input/lvgl_pointer_input.c

@@ -61,65 +61,46 @@ static void lvgl_pointer_process_event(const struct device *dev, struct input_ev
 		return;
 	}
 
-	lv_point_t tmp_point = {
-		.x = data->point_x,
-		.y = data->point_y,
-	};
+	point->x = data->point_x;
+	point->y = data->point_y;
 
 	if (cfg->invert_x) {
 		if (cap->current_orientation == DISPLAY_ORIENTATION_NORMAL ||
 		    cap->current_orientation == DISPLAY_ORIENTATION_ROTATED_180) {
-			tmp_point.x = cap->x_resolution - tmp_point.x;
+			point->x = cap->x_resolution - point->x;
 		} else {
-			tmp_point.x = cap->y_resolution - tmp_point.x;
+			point->x = cap->y_resolution - point->x;
 		}
 	}
 
 	if (cfg->invert_y) {
 		if (cap->current_orientation == DISPLAY_ORIENTATION_NORMAL ||
 		    cap->current_orientation == DISPLAY_ORIENTATION_ROTATED_180) {
-			tmp_point.y = cap->y_resolution - tmp_point.y;
+			point->y = cap->y_resolution - point->y;
 		} else {
-			tmp_point.y = cap->x_resolution - tmp_point.y;
+			point->y = cap->x_resolution - point->y;
 		}
 	}
 
-	/* rotate touch point to match display rotation */
+	/* Compensate off-by-one error in LVGL rotation code (lv_indev.c) */
 	switch (cap->current_orientation) {
 	case DISPLAY_ORIENTATION_NORMAL:
-		point->x = tmp_point.x;
-		point->y = tmp_point.y;
 		break;
 	case DISPLAY_ORIENTATION_ROTATED_90:
-		point->x = tmp_point.y;
-		point->y = cap->y_resolution - tmp_point.x;
+		point->y -= 1;
 		break;
 	case DISPLAY_ORIENTATION_ROTATED_180:
-		point->x = cap->x_resolution - tmp_point.x;
-		point->y = cap->y_resolution - tmp_point.y;
+		point->x -= 1;
+		point->y -= 1;
 		break;
 	case DISPLAY_ORIENTATION_ROTATED_270:
-		point->x = cap->x_resolution - tmp_point.y;
-		point->y = tmp_point.x;
+		point->x -= 1;
 		break;
 	default:
 		LOG_ERR("Invalid display orientation");
 		break;
 	}
 
-	/* filter readings within display */
-	if (point->x <= 0) {
-		point->x = 0;
-	} else if (point->x >= cap->x_resolution) {
-		point->x = cap->x_resolution - 1;
-	}
-
-	if (point->y <= 0) {
-		point->y = 0;
-	} else if (point->y >= cap->y_resolution) {
-		point->y = cap->y_resolution - 1;
-	}
-
 	if (k_msgq_put(cfg->common_config.event_msgq, &data->common_data.pending_event,
 		       K_NO_WAIT) != 0) {
 		LOG_WRN("Could not put input data into queue");

modules/lvgl/lvgl_display.c

@@ -157,6 +157,23 @@ int lvgl_reload_display_capabilities(void)
 
 		display_get_capabilities(disp_data->display_dev, &disp_data->cap);
 
+		switch (disp_data->cap.current_orientation) {
+		case DISPLAY_ORIENTATION_NORMAL:
+			disp->driver->rotated = LV_DISP_ROT_NONE;
+			break;
+		case DISPLAY_ORIENTATION_ROTATED_90:
+			disp->driver->rotated = LV_DISP_ROT_90;
+			break;
+		case DISPLAY_ORIENTATION_ROTATED_180:
+			disp->driver->rotated = LV_DISP_ROT_180;
+			break;
+		case DISPLAY_ORIENTATION_ROTATED_270:
+			disp->driver->rotated = LV_DISP_ROT_270;
+			break;
+		default:
+			return -EINVAL;
+		}
+
 		disp = lv_disp_get_next(disp);
 	}