add disp_drv->wait_cb

src/lv_core/lv_refr.c

@@ -458,7 +458,9 @@ static void lv_refr_area_part(const lv_area_t * area_p)
     /*In non double buffered mode, before rendering the next part wait until the previous image is
      * flushed*/
     if(lv_disp_is_double_buf(disp_refr) == false) {
-        while(vdb->flushing) ;
+        while(vdb->flushing) {
+            if(disp_refr->driver.wait_cb) disp_refr->driver.wait_cb(&disp_refr->driver);
+        }
     }
 
     lv_obj_t * top_p;
@@ -654,7 +656,9 @@ static void lv_refr_vdb_flush(void)
     /*In double buffered mode wait until the other buffer is flushed before flushing the current
      * one*/
     if(lv_disp_is_double_buf(disp_refr)) {
-        while(vdb->flushing);
+        while(vdb->flushing) {
+            if(disp_refr->driver.wait_cb) disp_refr->driver.wait_cb(&disp_refr->driver);
+        }
     }
 
     vdb->flushing = 1;

src/lv_gpu/lv_gpu_stm32_dma2d.c

@@ -33,6 +33,7 @@
 /**********************
  *  STATIC PROTOTYPES
  **********************/
+static void dma2d_wait(void);
 
 /**********************
  *  STATIC VARIABLES
@@ -70,12 +71,10 @@ void lv_gpu_stm32_dma2d_fill(lv_color_t * buf, lv_coord_t buf_w, lv_color_t colo
     hdma2d.LayerCfg[1].InputOffset = 0;
 
     /* DMA2D Initialization */
-    if (HAL_DMA2D_Init(&hdma2d) == HAL_OK) {
+    HAL_DMA2D_Init(&hdma2d) {
-        if (HAL_DMA2D_ConfigLayer(&hdma2d, 1) == HAL_OK) {
+    HAL_DMA2D_ConfigLayer(&hdma2d, 1)
     HAL_DMA2D_Start(&hdma2d, (uint32_t)lv_color_to32(color), (uint32_t)buf, fill_w, fill_h);
-            HAL_DMA2D_PollForTransfer(&hdma2d, HAL_MAX_DELAY);
+    dma2d_wait();
-        }
-    }
 }
 
 /**
@@ -119,7 +118,7 @@ void lv_gpu_stm32_dma2d_fill_mask(lv_color_t * buf, lv_coord_t buf_w, lv_color_t
     HAL_DMA2D_ConfigLayer(&hdma2d, 0);
     HAL_DMA2D_ConfigLayer(&hdma2d, 1);
     HAL_DMA2D_BlendingStart(&hdma2d, (uint32_t) mask, (uint32_t) buf,  (uint32_t)buf, fill_w, fill_h);
-    HAL_DMA2D_PollForTransfer(&hdma2d, HAL_MAX_DELAY);
+    dma2d_wait();
 }
 
 /**
@@ -150,13 +149,11 @@ void lv_gpu_stm32_dma2d_copy(lv_color_t * buf, lv_coord_t buf_w, const lv_color_
     hdma2d.LayerCfg[1].AlphaInverted = DMA2D_REGULAR_ALPHA;
 
     /* DMA2D Initialization */
-    if (HAL_DMA2D_Init(&hdma2d) == HAL_OK) {
+    HAL_DMA2D_Init(&hdma2d);
     HAL_DMA2D_ConfigLayer(&hdma2d, 0);
-        if (HAL_DMA2D_ConfigLayer(&hdma2d, 1) == HAL_OK) {
+    HAL_DMA2D_ConfigLayer(&hdma2d, 1);
     HAL_DMA2D_Start(&hdma2d, (uint32_t)map, (uint32_t)buf, copy_w, copy_h);
-            HAL_DMA2D_PollForTransfer(&hdma2d, HAL_MAX_DELAY);
+    dma2d_wait();
-        }
-    }
 }
 
 /**
@@ -194,18 +191,23 @@ void lv_gpu_stm32_dma2d_blend(lv_color_t * buf, lv_coord_t buf_w, const lv_color
     hdma2d.LayerCfg[1].AlphaInverted = DMA2D_REGULAR_ALPHA;
 
     /* DMA2D Initialization */
-    if (HAL_DMA2D_Init(&hdma2d) == HAL_OK) {
+    HAL_DMA2D_Init(&hdma2d); {
     HAL_DMA2D_ConfigLayer(&hdma2d, 0);
-        if (HAL_DMA2D_ConfigLayer(&hdma2d, 1) == HAL_OK) {
+    HAL_DMA2D_ConfigLayer(&hdma2d, 1);
     HAL_DMA2D_BlendingStart(&hdma2d, (uint32_t)map, (uint32_t)buf, (uint32_t)buf, copy_w, copy_h);
-            HAL_DMA2D_PollForTransfer(&hdma2d, HAL_MAX_DELAY);
+    dma2d_wait();
-        }
-    }
 }
 
 /**********************
  *   STATIC FUNCTIONS
  **********************/
 
+static void dma2d_wait(void)
+{
+    lv_disp_t * disp = lv_refr_get_disp_refreshing();
+    while(HAL_DMA2D_PollForTransfer(&hdma2d, 0) == HAL_BUSY) {
+        if(disp->driver.wait_cb) disp->driver.wait_cb(&disp->driver);
+    }
+}
 
 #endif

src/lv_hal/lv_hal_disp.h

@@ -104,6 +104,11 @@ typedef struct _disp_drv_t {
      * number of flushed pixels */
     void (*monitor_cb)(struct _disp_drv_t * disp_drv, uint32_t time, uint32_t px);
 
+    /** OPTIONAL: Called periodically while lvgl waits for operation to be completed.
+     * For example flushing or GPU
+     * User can execute very simple tasks here or yield the task */
+    void (*wait_cb)(struct _disp_drv_t * disp_drv);
+
 #if LV_USE_GPU
     /** OPTIONAL: Blend two memories using opacity (GPU only)*/
     void (*gpu_blend_cb)(struct _disp_drv_t * disp_drv, lv_color_t * dest, const lv_color_t * src, uint32_t length,