[PATCH RFC 05/11] dmaengine: bcm2835: move CB final extra info generation into function

Stefan Wahren stefan.wahren at i2se.com
Mon Dec 27 04:05:39 PST 2021


Similar to the info generation, generate the final extra info with a
separate function. This is necessary to introduce other platforms
with different info bits.

Signed-off-by: Stefan Wahren <stefan.wahren at i2se.com>
---
 drivers/dma/bcm2835-dma.c | 34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index 10c9ba2..863792e 100644
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -230,6 +230,29 @@ static u32 bcm2835_dma_prepare_cb_info(struct bcm2835_chan *c,
 	return result;
 }
 
+static u32 bcm2835_dma_prepare_cb_extra(struct bcm2835_chan *c,
+					enum dma_transfer_direction direction,
+					bool cyclic, bool final,
+					unsigned long flags)
+{
+	u32 result = 0;
+
+	if (cyclic) {
+		if (flags & DMA_PREP_INTERRUPT)
+			result |= BCM2835_DMA_INT_EN;
+	} else {
+		if (!final)
+			return 0;
+
+		result |= BCM2835_DMA_INT_EN;
+
+		if (direction == DMA_MEM_TO_MEM)
+			result |= BCM2835_DMA_WAIT_RESP;
+	}
+
+	return result;
+}
+
 static void bcm2835_dma_free_cb_chain(struct bcm2835_desc *desc)
 {
 	size_t i;
@@ -645,7 +668,8 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_memcpy(
 	struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
 	struct bcm2835_desc *d;
 	u32 info = bcm2835_dma_prepare_cb_info(c, DMA_MEM_TO_MEM, false);
-	u32 extra = BCM2835_DMA_INT_EN | BCM2835_DMA_WAIT_RESP;
+	u32 extra = bcm2835_dma_prepare_cb_extra(c, DMA_MEM_TO_MEM, false,
+						 true, 0);
 	size_t max_len = bcm2835_dma_max_frame_length(c);
 	size_t frames;
 
@@ -676,7 +700,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg(
 	struct bcm2835_desc *d;
 	dma_addr_t src = 0, dst = 0;
 	u32 info = bcm2835_dma_prepare_cb_info(c, direction, false);
-	u32 extra = BCM2835_DMA_INT_EN;
+	u32 extra = bcm2835_dma_prepare_cb_extra(c, direction, false, true, 0);
 	size_t frames;
 
 	if (!is_slave_direction(direction)) {
@@ -724,7 +748,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(
 	dma_addr_t src, dst;
 	u32 info = bcm2835_dma_prepare_cb_info(c, direction,
 					       buf_addr == od->zero_page);
-	u32 extra = 0;
+	u32 extra = bcm2835_dma_prepare_cb_extra(c, direction, true, true, 0);
 	size_t max_len = bcm2835_dma_max_frame_length(c);
 	size_t frames;
 
@@ -740,9 +764,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(
 		return NULL;
 	}
 
-	if (flags & DMA_PREP_INTERRUPT)
-		extra |= BCM2835_DMA_INT_EN;
-	else
+	if (!(flags & DMA_PREP_INTERRUPT))
 		period_len = buf_len;
 
 	/*
-- 
2.7.4




More information about the linux-arm-kernel mailing list