[PATCH v6 05/18] dmaengine: sh: rz-dmac: Add helper to compute the lmdesc address

[Claudiu Beznea]

From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>

Add a the rz_dmac_lmdesc_addr() helper function to compute the lmdesc
address, to make the code easier to understand. The helper will be used in
subsequent patches.

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
Tested-by: John Madieu <john.madieu.xa@xxxxxxxxxxxxxx>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
---

Changes in v6:
- updated patch description
- collected tags

Changes in v5:
- none

Changes in v4:
- none

Changes in v3:
- none, this patch is new

 drivers/dma/sh/rz-dmac.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c
index 40ddf534c094..c48858b68dee 100644
--- a/drivers/dma/sh/rz-dmac.c
+++ b/drivers/dma/sh/rz-dmac.c
@@ -259,6 +259,12 @@ static void rz_lmdesc_setup(struct rz_dmac_chan *channel,
  * Descriptors preparation
  */
 
+static u32 rz_dmac_lmdesc_addr(struct rz_dmac_chan *channel, struct rz_lmdesc *lmdesc)
+{
+	return channel->lmdesc.base_dma +
+	       (sizeof(struct rz_lmdesc) * (lmdesc - channel->lmdesc.base));
+}
+
 static void rz_dmac_lmdesc_recycle(struct rz_dmac_chan *channel)
 {
 	struct rz_lmdesc *lmdesc = channel->lmdesc.head;
@@ -284,9 +290,7 @@ static void rz_dmac_enable_hw(struct rz_dmac_chan *channel)
 
 	rz_dmac_lmdesc_recycle(channel);
 
-	nxla = channel->lmdesc.base_dma +
-		(sizeof(struct rz_lmdesc) * (channel->lmdesc.head -
-					     channel->lmdesc.base));
+	nxla = rz_dmac_lmdesc_addr(channel, channel->lmdesc.head);
 
 	chstat = rz_dmac_ch_readl(channel, CHSTAT, 1);
 	if (!(chstat & CHSTAT_EN)) {
-- 
2.43.0