The port_window_size is a struct member of dma slave channel runtime
config. It's the length of the register area in words the data need to
be accessed on the device side. It is only used for devices which is
using an area instead of a single register to send or receive the data.
Typically the DMA loops in this area in order to transfer the data.

It's useful for cases that reading/writing multiple registers in DMA
transactions.

Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
---
 include/sound/dmaengine_pcm.h | 5 +++++
 sound/core/pcm_dmaengine.c    | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/include/sound/dmaengine_pcm.h b/include/sound/dmaengine_pcm.h
index 1ef13bcdc43f9..9472f0a966a27 100644
--- a/include/sound/dmaengine_pcm.h
+++ b/include/sound/dmaengine_pcm.h
@@ -69,6 +69,10 @@ struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
  * @peripheral_config: peripheral configuration for programming peripheral
  * for dmaengine transfer
  * @peripheral_size: peripheral configuration buffer size
+ * @port_window_size: The length of the register area in words the data need
+ * to be accessed on the device side. It is only used for devices which is using
+ * an area instead of a single register to send/receive the data. Typically the
+ * DMA loops in this area in order to transfer the data.
  */
 struct snd_dmaengine_dai_dma_data {
 	dma_addr_t addr;
@@ -80,6 +84,7 @@ struct snd_dmaengine_dai_dma_data {
 	unsigned int flags;
 	void *peripheral_config;
 	size_t peripheral_size;
+	u32 port_window_size;
 };
 
 void snd_dmaengine_pcm_set_config_from_dai_data(
diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c
index 72040964b6fd6..f0c17503df425 100644
--- a/sound/core/pcm_dmaengine.c
+++ b/sound/core/pcm_dmaengine.c
@@ -111,6 +111,7 @@ void snd_dmaengine_pcm_set_config_from_dai_data(
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		slave_config->dst_addr = dma_data->addr;
 		slave_config->dst_maxburst = dma_data->maxburst;
+		slave_config->dst_port_window_size = dma_data->port_window_size;
 		if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
 			slave_config->dst_addr_width =
 				DMA_SLAVE_BUSWIDTH_UNDEFINED;
@@ -119,6 +120,7 @@ void snd_dmaengine_pcm_set_config_from_dai_data(
 	} else {
 		slave_config->src_addr = dma_data->addr;
 		slave_config->src_maxburst = dma_data->maxburst;
+		slave_config->src_port_window_size = dma_data->port_window_size;
 		if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
 			slave_config->src_addr_width =
 				DMA_SLAVE_BUSWIDTH_UNDEFINED;
-- 
2.50.1

On Fri, 08 Aug 2025 15:17:41 +0900, Chancel Liu wrote:
> The port_window_size is a struct member of dma slave channel runtime
> config. It's the length of the register area in words the data need to
> be accessed on the device side. It is only used for devices which is
> using an area instead of a single register to send or receive the data.
> Typically the DMA loops in this area in order to transfer the data.
> 
> It's useful for cases that reading/writing multiple registers in DMA
> transactions.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: dmaengine_pcm: Add port_window_size to DAI dma data struct
      commit: 32dffd4c3e3129e3d9bb378af8d80bb57dc3038b

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark