dmaengine: Move icg helpers to global header

Now that we can have ICGs set for both the source and destination (using
the icg field of struct data_chunk) or for only the source or the
destination (using the dst_icg or src_icg respectively), and that these
fields can be ignored depending on other parameters (src_inc, src_sgl,
etc.), the logic to get the actual ICG value can be quite tricky.

The XDMAC driver was already implementing it, but since we will need it in
other drivers, we can move it to the main header file.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 9b602a6..80e46e5 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -862,20 +862,8 @@
 
 	desc->lld.mbr_sa = src;
 	desc->lld.mbr_da = dst;
-
-	if (xt->src_inc && xt->src_sgl) {
-		if (chunk->src_icg)
-			desc->lld.mbr_sus = chunk->src_icg;
-		else
-			desc->lld.mbr_sus = chunk->icg;
-	}
-
-	if (xt->dst_inc && xt->dst_sgl) {
-		if (chunk->dst_icg)
-			desc->lld.mbr_dus = chunk->dst_icg;
-		else
-			desc->lld.mbr_dus = chunk->icg;
-	}
+	desc->lld.mbr_sus = dmaengine_get_src_icg(xt, chunk);
+	desc->lld.mbr_dus = dmaengine_get_dst_icg(xt, chunk);
 
 	desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV3
 		| AT_XDMAC_MBR_UBC_NDEN
@@ -895,32 +883,6 @@
 	return desc;
 }
 
-static size_t at_xdmac_get_icg(bool inc, bool sgl, size_t icg, size_t dir_icg)
-{
-	if (inc) {
-		if (dir_icg)
-			return dir_icg;
-		else if (sgl)
-			return icg;
-	}
-
-	return 0;
-}
-
-static size_t at_xdmac_get_dst_icg(struct dma_interleaved_template *xt,
-				   struct data_chunk *chunk)
-{
-	return at_xdmac_get_icg(xt->dst_inc, xt->dst_sgl,
-				chunk->icg, chunk->dst_icg);
-}
-
-static size_t at_xdmac_get_src_icg(struct dma_interleaved_template *xt,
-				   struct data_chunk *chunk)
-{
-	return at_xdmac_get_icg(xt->src_inc, xt->src_sgl,
-				chunk->icg, chunk->src_icg);
-}
-
 static struct dma_async_tx_descriptor *
 at_xdmac_prep_interleaved(struct dma_chan *chan,
 			  struct dma_interleaved_template *xt,
@@ -950,8 +912,8 @@
 
 		chunk = xt->sgl + i;
 
-		dst_icg = at_xdmac_get_dst_icg(xt, chunk);
-		src_icg = at_xdmac_get_src_icg(xt, chunk);
+		dst_icg = dmaengine_get_dst_icg(xt, chunk);
+		src_icg = dmaengine_get_src_icg(xt, chunk);
 
 		src_skip = chunk->size + src_icg;
 		dst_skip = chunk->size + dst_icg;