SOme displays needs to adjust CS_post for speed

components/display/SH1106.c

@@ -86,6 +86,10 @@ static void SetContrast( struct GDS_Device* Device, uint8_t Contrast ) {
     Device->WriteCommand( Device, Contrast );
 }
 
+static void SPIParams(int Speed, uint8_t *mode, uint8_t *CS_pre, uint8_t *CS_post) {
+	*CS_post = Speed / (8*1000*1000);
+}
+
 static bool Init( struct GDS_Device* Device ) {
 #ifdef SHADOW_BUFFER	
 	struct PrivateSpace *Private = (struct PrivateSpace*) Device->Private;
@@ -140,7 +144,7 @@ static const struct GDS_Device SH1106 = {
 	.SetLayout = SetLayout,
 	.Update = Update, .Init = Init,
 	.Depth = 1,
-	.CS_post = 2,
+	.SPIParams = SPIParams,
 #if !defined SHADOW_BUFFER && defined USE_IRAM	
 	.Alloc = GDS_ALLOC_IRAM_SPI;
 #endif		

components/display/core/gds_private.h

@@ -86,7 +86,6 @@ struct GDS_Device {
 		struct {
 			spi_device_handle_t SPIHandle;
 			int8_t CSPin;
-			int8_t CS_pre, CS_post, SPI_mode;
 		};
 	};	
 	
@@ -125,6 +124,8 @@ struct GDS_Device {
 	// may provide for optimization
 	void (*DrawRGB)( struct GDS_Device* Device, uint8_t *Image,int x, int y, int Width, int Height, int RGB_Mode );
 	void (*ClearWindow)( struct GDS_Device* Device, int x1, int y1, int x2, int y2, int Color );
+	// may provide for tweaking
+	void (*SPIParams)(int Speed, uint8_t *mode, uint8_t *CS_pre, uint8_t *CS_post);
 		    
 	// interface-specific methods	
     WriteCommandProc WriteCommand;

components/display/core/ifaces/default_if_spi.c

@@ -51,10 +51,9 @@ bool GDS_SPIAttachDevice( struct GDS_Device* Device, int Width, int Height, int
     SPIDeviceConfig.spics_io_num = CSPin;
     SPIDeviceConfig.queue_size = 1;
 	SPIDeviceConfig.flags = SPI_DEVICE_NO_DUMMY;
-	SPIDeviceConfig.cs_ena_pretrans = Device->CS_pre;
-	SPIDeviceConfig.cs_ena_posttrans = Device->CS_post;
-	SPIDeviceConfig.mode = Device->SPI_mode;
-
+	if (Device->SPIParams) Device->SPIParams(SPIDeviceConfig.clock_speed_hz, &SPIDeviceConfig.mode, 
+											 &SPIDeviceConfig.cs_ena_pretrans, &SPIDeviceConfig.cs_ena_posttrans);
+	
     ESP_ERROR_CHECK_NONFATAL( spi_bus_add_device( SPIHost, &SPIDeviceConfig, &SPIDevice ), return false );
 	
 	Device->WriteCommand = SPIDefaultWriteCommand;