[alsa-devel] [PATCH 12/14] ASoC: Intel: Skylake: Add DMA resume position in Trigger resume/suspend

[Vinod Koul]

From: Jeeja KP <jeeja.kp at intel.com>

Use the DMA resume capability to resume the DMA position when
stream is suspended/resumed.

In suspend we save the position and when stream is resumed the stream needs
to be started from the position when the stream was suspended using the new
DMA resume capabilities

Signed-off-by: Jeeja KP <jeeja.kp at intel.com>
Signed-off-by: Vinod Koul <vinod.koul at intel.com>
---
 sound/soc/intel/skylake/skl-pcm.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/sound/soc/intel/skylake/skl-pcm.c b/sound/soc/intel/skylake/skl-pcm.c
index 95fd2210bd86..4a437e3c918c 100644
--- a/sound/soc/intel/skylake/skl-pcm.c
+++ b/sound/soc/intel/skylake/skl-pcm.c
@@ -393,6 +393,15 @@ static int skl_pcm_trigger(struct snd_pcm_substream *substream, int cmd,
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_RESUME:
 		skl_pcm_prepare(substream, dai);
+		/*
+		 * enable DMA Resume enable bit for the stream, set the dpib
+		 * & lpib position to resune before starting the DMA
+		 */
+		snd_hdac_ext_stream_drsm_enable(ebus, true,
+					hdac_stream(stream)->index);
+		snd_hdac_ext_stream_set_dpibr(ebus, stream, stream->dpib);
+		snd_hdac_ext_stream_set_lpib(stream, stream->lpib);
+
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		/*
@@ -421,8 +430,17 @@ static int skl_pcm_trigger(struct snd_pcm_substream *substream, int cmd,
 			return ret;
 
 		ret = skl_decoupled_trigger(substream, cmd);
-		if (cmd == SNDRV_PCM_TRIGGER_SUSPEND)
+		if (cmd == SNDRV_PCM_TRIGGER_SUSPEND) {
+			/* save the dpib and lpib positions */
+			stream->dpib = readl(ebus->bus.remap_addr +
+					AZX_REG_VS_SDXDPIB_XBASE +
+					(AZX_REG_VS_SDXDPIB_XINTERVAL *
+					hdac_stream(stream)->index));
+
+			stream->lpib = snd_hdac_stream_get_pos_lpib(
+							hdac_stream(stream));
 			snd_hdac_ext_stream_decouple(ebus, stream, false);
+		}
 		break;
 
 	default:
-- 
1.9.1