[PATCH v4 06/17] dmaengine: sh: rz-dmac: Add helper to compute the lmdesc address

Claudiu
2026-04-11T11:43:19Z

Add a helper function to compute the lmdesc address. This makes the
code easier to understand, and the helper will be used in subsequent
patches.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

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 943c005f52bd..6bea7c8c7053 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