lv_disp: add clean_dcache_cb callback

src/lv_core/lv_disp.c

@@ -352,6 +352,21 @@ void lv_disp_trig_activity(lv_disp_t * disp)
     disp->last_activity_time = lv_tick_get();
 }
 
+/**
+ * Invalidate any CPU cache that is related to the display.
+ * @param disp pointer to an display (NULL to use the default display)
+ */
+void lv_disp_invalidate_cache(lv_disp_t * disp)
+{
+    if(!disp) disp = lv_disp_get_default();
+    if(!disp) {
+      LV_LOG_WARN("lv_disp_invalidate_cache: no display registered");
+      return;
+    }
+
+    if(disp->driver.clean_dcache_cb)
+      disp->driver.clean_dcache_cb(&disp->driver);
+}
 
 /**
  * Get a pointer to the screen refresher task to

src/lv_core/lv_disp.h

@@ -133,6 +133,12 @@ uint32_t lv_disp_get_inactive_time(const lv_disp_t * disp);
  */
 void lv_disp_trig_activity(lv_disp_t * disp);
 
+/**
+ * Invalidate any CPU cache that is related to the display.
+ * @param disp pointer to an display (NULL to use the default display)
+ */
+void lv_disp_invalidate_cache(lv_disp_t * disp);
+
 /**
  * Get a pointer to the screen refresher task to
  * modify its parameters with `lv_task_...` functions.

src/lv_gpu/lv_gpu_stm32_dma2d.c

@@ -7,6 +7,7 @@
  *      INCLUDES
  *********************/
 #include "lv_gpu_stm32_dma2d.h"
+#include "../lv_core/lv_disp.h"
 #include "../lv_core/lv_refr.h"
 
 #if LV_USE_GPU_STM32_DMA2D
@@ -41,7 +42,6 @@
 /**********************
  *  STATIC PROTOTYPES
  **********************/
-static void invalidate_cache(void);
 static void dma2d_wait(void);
 
 /**********************
@@ -82,7 +82,7 @@ void lv_gpu_stm32_dma2d_init(void)
  */
 void lv_gpu_stm32_dma2d_fill(lv_color_t * buf, lv_coord_t buf_w, lv_color_t color, lv_coord_t fill_w, lv_coord_t fill_h)
 {
-    invalidate_cache();
+    lv_disp_invalidate_cache(NULL);
 
     DMA2D->CR = 0x30000;
     DMA2D->OMAR = (uint32_t)buf;
@@ -112,7 +112,7 @@ void lv_gpu_stm32_dma2d_fill_mask(lv_color_t * buf, lv_coord_t buf_w, lv_color_t
                                   lv_opa_t opa, lv_coord_t fill_w, lv_coord_t fill_h)
 {
 #if 0
-    invalidate_cache();
+    lv_disp_invalidate_cache(NULL);
 
     /* Configure the DMA2D Mode, Color Mode and line output offset */
     hdma2d.Init.Mode         = DMA2D_M2M_BLEND;
@@ -156,7 +156,7 @@ void lv_gpu_stm32_dma2d_fill_mask(lv_color_t * buf, lv_coord_t buf_w, lv_color_t
 void lv_gpu_stm32_dma2d_copy(lv_color_t * buf, lv_coord_t buf_w, const lv_color_t * map, lv_coord_t map_w,
                              lv_coord_t copy_w, lv_coord_t copy_h)
 {
-    invalidate_cache();
+    lv_disp_invalidate_cache(NULL);
 
     DMA2D->CR = 0;
     /* copy output colour mode, this register controls both input and output colour format */
@@ -186,7 +186,7 @@ void lv_gpu_stm32_dma2d_copy(lv_color_t * buf, lv_coord_t buf_w, const lv_color_
 void lv_gpu_stm32_dma2d_blend(lv_color_t * buf, lv_coord_t buf_w, const lv_color_t * map, lv_opa_t opa,
                               lv_coord_t map_w, lv_coord_t copy_w, lv_coord_t copy_h)
 {
-    invalidate_cache();
+    lv_disp_invalidate_cache(NULL);
     DMA2D->CR = 0x20000;
 
     DMA2D->BGPFCCR = LV_DMA2D_COLOR_FORMAT;
@@ -214,15 +214,6 @@ void lv_gpu_stm32_dma2d_blend(lv_color_t * buf, lv_coord_t buf_w, const lv_color
  *   STATIC FUNCTIONS
  **********************/
 
-static void invalidate_cache(void)
-{
-#if __DCACHE_PRESENT
-    if(SCB->CCR & (uint32_t)SCB_CCR_DC_Msk) {
-        SCB_CleanInvalidateDCache();
-    }
-#endif
-}
-
 static void dma2d_wait(void)
 {
     lv_disp_t * disp = _lv_refr_get_disp_refreshing();

src/lv_hal/lv_hal_disp.h

@@ -111,6 +111,9 @@ typedef struct _disp_drv_t {
      * User can execute very simple tasks here or yield the task */
     void (*wait_cb)(struct _disp_drv_t * disp_drv);
 
+    /** OPTIONAL: Called when lvgl needs any CPU cache that affects rendering to be cleaned */
+    void (*clean_dcache_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,