[PATCH 06/18] dmaengine: bcm2835: make address increment platform independent

Dave Stevenson
2024-05-24T18:27:56Z

From: Stefan Wahren <stefan.wahren@i2se.com>

Actually the criteria to increment source & destination address doesn't
based on platform specific bits. It's just the DMA transfer direction which
is translated into the info bits. So introduce two new helper functions
and get the rid of these platform specifics.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
drivers/dma/bcm2835-dma.c | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index ef452ebb3c15..d6c5a2762a46 100644
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -252,6 +252,24 @@ static u32 bcm2835_dma_prepare_cb_extra(struct bcm2835_chan *c,
return result;
}

+static inline bool need_src_incr(enum dma_transfer_direction direction)
+{
+ return direction != DMA_DEV_TO_MEM;
+}
+
+static inline bool need_dst_incr(enum dma_transfer_direction direction)
+{
+ switch (direction) {
+ case DMA_MEM_TO_MEM:
+ case DMA_DEV_TO_MEM:
+ return true;
+ default:
+ break;
+ }
+
+ return false;
+}
+
static void bcm2835_dma_free_cb_chain(struct bcm2835_desc *desc)
{
size_t i;
@@ -336,10 +354,8 @@ static inline size_t bcm2835_dma_count_frames_for_sg(
* @cyclic: it is a cyclic transfer
* @info: the default info bits to apply per controlblock
* @frames: number of controlblocks to allocate
- * @src: the src address to assign (if the S_INC bit is set
- * in @info, then it gets incremented)
- * @dst: the dst address to assign (if the D_INC bit is set
- * in @info, then it gets incremented)
+ * @src: the src address to assign
+ * @dst: the dst address to assign
* @buf_len: the full buffer length (may also be 0)
* @period_len: the period length when to apply @finalextrainfo
* in addition to the last transfer
@@ -408,9 +424,9 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
d->cb_list[frame - 1].cb->next = cb_entry->paddr;

/* update src and dst and length */
- if (src && (info & BCM2835_DMA_S_INC))
+ if (src && need_src_incr(direction))
src += control_block->length;
- if (dst && (info & BCM2835_DMA_D_INC))
+ if (dst && need_dst_incr(direction))
dst += control_block->length;

/* Length of total transfer */
--
2.34.1