soundwire: stream: add helper to startup/shutdown streams

To handle streams at the dailink level, expose two helpers that will
be called from machine drivers.

Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200630184356.24939-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 98 insertions, 0 deletions

diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
index a9a72574b34a..6bc2ff29c202 100644
--- a/drivers/soundwire/stream.c
+++ b/drivers/soundwire/stream.c
@@ -13,6 +13,7 @@
 #include <linux/slab.h>
 #include <linux/soundwire/sdw_registers.h>
 #include <linux/soundwire/sdw.h>
+#include <sound/soc.h>
 #include "bus.h"
 
 /*
@@ -1826,3 +1827,100 @@ state_err:
 	return ret;
 }
 EXPORT_SYMBOL(sdw_deprepare_stream);
+
+static int set_stream(struct snd_pcm_substream *substream,
+		      struct sdw_stream_runtime *sdw_stream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *dai;
+	int ret = 0;
+	int i;
+
+	/* Set stream pointer on all DAIs */
+	for_each_rtd_dais(rtd, i, dai) {
+		ret = snd_soc_dai_set_sdw_stream(dai, sdw_stream, substream->stream);
+		if (ret < 0) {
+			dev_err(rtd->dev, "failed to set stream pointer on dai %s", dai->name);
+			break;
+		}
+	}
+
+	return ret;
+}
+
+/**
+ * sdw_startup_stream() - Startup SoundWire stream
+ *
+ * @stream: Soundwire stream
+ *
+ * Documentation/driver-api/soundwire/stream.rst explains this API in detail
+ */
+int sdw_startup_stream(void *sdw_substream)
+{
+	struct snd_pcm_substream *substream = sdw_substream;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct sdw_stream_runtime *sdw_stream;
+	char *name;
+	int ret;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		name = kasprintf(GFP_KERNEL, "%s-Playback", substream->name);
+	else
+		name = kasprintf(GFP_KERNEL, "%s-Capture", substream->name);
+
+	if (!name)
+		return -ENOMEM;
+
+	sdw_stream = sdw_alloc_stream(name);
+	if (!sdw_stream) {
+		dev_err(rtd->dev, "alloc stream failed for substream DAI %s", substream->name);
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	ret = set_stream(substream, sdw_stream);
+	if (ret < 0)
+		goto release_stream;
+	return 0;
+
+release_stream:
+	sdw_release_stream(sdw_stream);
+	set_stream(substream, NULL);
+error:
+	kfree(name);
+	return ret;
+}
+EXPORT_SYMBOL(sdw_startup_stream);
+
+/**
+ * sdw_shutdown_stream() - Shutdown SoundWire stream
+ *
+ * @stream: Soundwire stream
+ *
+ * Documentation/driver-api/soundwire/stream.rst explains this API in detail
+ */
+void sdw_shutdown_stream(void *sdw_substream)
+{
+	struct snd_pcm_substream *substream = sdw_substream;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct sdw_stream_runtime *sdw_stream;
+	struct snd_soc_dai *dai;
+
+	/* Find stream from first CPU DAI */
+	dai = asoc_rtd_to_cpu(rtd, 0);
+
+	sdw_stream = snd_soc_dai_get_sdw_stream(dai, substream->stream);
+
+	if (!sdw_stream) {
+		dev_err(rtd->dev, "no stream found for DAI %s", dai->name);
+		return;
+	}
+
+	/* release memory */
+	kfree(sdw_stream->name);
+	sdw_release_stream(sdw_stream);
+
+	/* clear DAI data */
+	set_stream(substream, NULL);
+}
+EXPORT_SYMBOL(sdw_shutdown_stream);