Update LVGL to v9.1.0

lib/lvgl/docs/libs/barcode.rst

@@ -0,0 +1,50 @@
+.. _barcode:
+
+=======
+Barcode
+=======
+
+Barcode generation with LVGL. Uses
+`code128 <https://github.com/fhunleth/code128>`__ by
+`fhunleth <https://github.com/fhunleth>`__.
+
+.. _barcode_usage:
+
+Usage
+-----
+
+Enable :c:macro:`LV_USE_BARCODE` in ``lv_conf.h``.
+
+Use :cpp:func:`lv_barcode_create` to create a barcode object, and use
+:cpp:func:`lv_barcode_update` to generate a barcode.
+
+Call :cpp:func:`lv_barcode_set_scale` to adjust scaling,
+call :cpp:func:`lv_barcode_set_dark_color` and :cpp:func:`lv_barcode_set_light_color`
+adjust color, call :cpp:func:`lv_barcode_set_direction` will set 
+direction to display, and call :cpp:func:`lv_barcode_update` again to regenerate 
+the barcode.
+
+Notes
+-----
+
+-  It is best not to manually set the width of the barcode, because when
+   the width of the object is lower than the width of the barcode, the
+   display will be incomplete due to truncation.
+-  The scale adjustment can only be an integer multiple, for example,
+   :cpp:expr:`lv_barcode_set_scale(barcode, 2)` means 2x scaling.
+-  The direction adjustment can be :cpp:enumerator:`LV_DIR_HOR` or :cpp:enumerator:`LV_DIR_VER`
+
+.. _barcode_example:
+
+Example
+-------
+
+.. include:: ../examples/libs/barcode/index.rst
+
+.. _barcode_api:
+
+API
+---
+
+:ref:`code128`
+