dmaengine: at_hdmac: specialize AHB interfaces to optimize transfers

DMA controller has two AHB interfaces on the SOC internal
matrix.
It is more efficient to specialize each interface as the
access to memory can introduce latencies that are not compatible
with peripheral accesses requirements.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 65bd52a..f52c9e3 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -37,8 +37,8 @@
 
 #define	ATC_DEFAULT_CFG		(ATC_FIFOCFG_HALFFIFO)
 #define	ATC_DEFAULT_CTRLA	(0)
-#define	ATC_DEFAULT_CTRLB	(ATC_SIF(0)	\
-				|ATC_DIF(1))
+#define	ATC_DEFAULT_CTRLB	(ATC_SIF(AT_DMA_MEM_IF) \
+				|ATC_DIF(AT_DMA_MEM_IF))
 
 /*
  * Initial number of descriptors to allocate for each channel. This could
@@ -693,14 +693,15 @@
 	reg_width = atslave->reg_width;
 
 	ctrla = ATC_DEFAULT_CTRLA | atslave->ctrla;
-	ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN;
+	ctrlb = ATC_IEN;
 
 	switch (direction) {
 	case DMA_TO_DEVICE:
 		ctrla |=  ATC_DST_WIDTH(reg_width);
 		ctrlb |=  ATC_DST_ADDR_MODE_FIXED
 			| ATC_SRC_ADDR_MODE_INCR
-			| ATC_FC_MEM2PER;
+			| ATC_FC_MEM2PER
+			| ATC_SIF(AT_DMA_MEM_IF) | ATC_DIF(AT_DMA_PER_IF);
 		reg = atslave->tx_reg;
 		for_each_sg(sgl, sg, sg_len, i) {
 			struct at_desc	*desc;
@@ -741,7 +742,8 @@
 		ctrla |=  ATC_SRC_WIDTH(reg_width);
 		ctrlb |=  ATC_DST_ADDR_MODE_INCR
 			| ATC_SRC_ADDR_MODE_FIXED
-			| ATC_FC_PER2MEM;
+			| ATC_FC_PER2MEM
+			| ATC_SIF(AT_DMA_PER_IF) | ATC_DIF(AT_DMA_MEM_IF);
 
 		reg = atslave->rx_reg;
 		for_each_sg(sgl, sg, sg_len, i) {
@@ -846,20 +848,22 @@
 		desc->lli.saddr = buf_addr + (period_len * period_index);
 		desc->lli.daddr = atslave->tx_reg;
 		desc->lli.ctrla = ctrla;
-		desc->lli.ctrlb = ATC_DEFAULT_CTRLB
-				| ATC_DST_ADDR_MODE_FIXED
+		desc->lli.ctrlb = ATC_DST_ADDR_MODE_FIXED
 				| ATC_SRC_ADDR_MODE_INCR
-				| ATC_FC_MEM2PER;
+				| ATC_FC_MEM2PER
+				| ATC_SIF(AT_DMA_MEM_IF)
+				| ATC_DIF(AT_DMA_PER_IF);
 		break;
 
 	case DMA_FROM_DEVICE:
 		desc->lli.saddr = atslave->rx_reg;
 		desc->lli.daddr = buf_addr + (period_len * period_index);
 		desc->lli.ctrla = ctrla;
-		desc->lli.ctrlb = ATC_DEFAULT_CTRLB
-				| ATC_DST_ADDR_MODE_INCR
+		desc->lli.ctrlb = ATC_DST_ADDR_MODE_INCR
 				| ATC_SRC_ADDR_MODE_FIXED
-				| ATC_FC_PER2MEM;
+				| ATC_FC_PER2MEM
+				| ATC_SIF(AT_DMA_PER_IF)
+				| ATC_DIF(AT_DMA_MEM_IF);
 		break;
 
 	default: