[PATCH 3/3] ASoC: fsl_asrc_dma: allocate memory from dma device

Shengjiu Wang
2026-01-28T07:20:11Z

As the dma device may support dma-coherent property on the i.MX952,
allocate memory from dma device to make asrc driver to be compatible with
such a case.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
sound/soc/fsl/fsl_asrc_dma.c | 48 ++++++++++++++++++++++++++++++------
1 file changed, 41 insertions(+), 7 deletions(-)

diff --git a/sound/soc/fsl/fsl_asrc_dma.c b/sound/soc/fsl/fsl_asrc_dma.c
index 7dacc06b2f02..b8fe242d53db 100644
--- a/sound/soc/fsl/fsl_asrc_dma.c
+++ b/sound/soc/fsl/fsl_asrc_dma.c
@@ -449,18 +449,52 @@ fsl_asrc_dma_pcm_pointer(struct snd_soc_component *component,
static int fsl_asrc_dma_pcm_new(struct snd_soc_component *component,
struct snd_soc_pcm_runtime *rtd)
{
- struct snd_card *card = rtd->card->snd_card;
+ struct device *dev = component->dev;
+ struct fsl_asrc *asrc = dev_get_drvdata(dev);
+ struct fsl_asrc_pair *pair;
struct snd_pcm *pcm = rtd->pcm;
+ struct dma_chan *chan;
int ret;

- ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
- if (ret) {
- dev_err(card->dev, "failed to set DMA mask\n");
- return ret;
+ pair = kzalloc(sizeof(*pair) + asrc->pair_priv_size, GFP_KERNEL);
+ if (!pair)
+ return -ENOMEM;
+
+ pair->asrc = asrc;
+ pair->private = (void *)pair + sizeof(struct fsl_asrc_pair);
+
+ /* Request a dummy pair, which will be released later.
+ * Request pair function needs channel num as input, for this
+ * dummy pair, we just request "1" channel temporarily.
+ */
+ ret = asrc->request_pair(1, pair);
+ if (ret < 0) {
+ dev_err(dev, "failed to request asrc pair\n");
+ goto req_pair_err;
}

- return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
- card->dev, FSL_ASRC_DMABUF_SIZE);
+ /* Request a dummy dma channel, which will be released later. */
+ chan = asrc->get_dma_channel(pair, IN);
+ if (!chan) {
+ dev_err(dev, "failed to get dma channel\n");
+ ret = -EINVAL;
+ goto dma_chan_err;
+ }
+
+ ret = snd_pcm_set_fixed_buffer_all(pcm,
+ SNDRV_DMA_TYPE_DEV,
+ chan->device->dev,
+ FSL_ASRC_DMABUF_SIZE);
+
+ dma_release_channel(chan);
+
+dma_chan_err:
+ asrc->release_pair(pair);
+
+req_pair_err:
+ kfree(pair);
+
+ return ret;
}

struct snd_soc_component_driver fsl_asrc_component = {
--
2.34.1