feat(profiler): add performance profiler hook (#4211)

Signed-off-by: pengyiqiang <pengyiqiang@xiaomi.com>
Co-authored-by: pengyiqiang <pengyiqiang@xiaomi.com>

docs/porting/index.rst

@@ -16,4 +16,5 @@ Porting
     sleep
     os
     log
+    profiler
     draw

docs/porting/profiler.rst

@@ -0,0 +1,42 @@
+.. _profiler:
+
+========
+Profiler
+========
+
+As the complexity of the application increases, performance issues 
+such as low FPS and frequent cache misses causing lag may arise. 
+LVGL has internally set up some hooks for performance measurement 
+to help developers analyze and locate performance issues.
+
+Porting
+*******
+
+To enable profiler, set :c:macro:`LV_USE_PROFILER` in ``lv_conf.h`` and configure the following options:
+
+- :c:macro:`LV_PROFILER_INCLUDE`: Provides a header file for the performance measurement function.
+- :c:macro:`LV_PROFILER_BEGIN`: Performance measurement start point function.
+- :c:macro:`LV_PROFILER_END`: Performance measurement end point function.
+
+Example
+*******
+
+The following is an example of output performance measurements using LVGL logging systems:
+
+Configure ``lv_conf.h``:
+
+.. code:: c
+
+   #define LV_USE_PROFILER 1
+   #define LV_PROFILER_INCLUDE "lvgl/src/hal/lv_hal_tick.h"
+   #define LV_PROFILER_BEGIN   uint32_t profiler_start = lv_tick_get()
+   #define LV_PROFILER_END     LV_LOG_USER("cost %" LV_PRIu32 "ms", lv_tick_elaps(profiler_start))
+
+
+Users can add the measured functions themselves:
+
+.. code:: c
+
+   LV_PROFILER_BEGIN;
+   my_func();
+   LV_PROFILER_END;