[PATCH 1/2] ASoC: qcom: Add helper for allocating Soundwire stream runtime

[Krzysztof Kozlowski]

Newer Qualcomm SoC soundcards will need to allocate Soundwire stream
runtime in their startup op.  The code will be exactly the same for all
soundcards, so add a helper for that.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
---
 sound/soc/qcom/sdw.c | 45 +++++++++++++++++++++++++++++++++++++++++++-
 sound/soc/qcom/sdw.h |  1 +
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/sound/soc/qcom/sdw.c b/sound/soc/qcom/sdw.c
index dd275123d31d..77dbe0c28b29 100644
--- a/sound/soc/qcom/sdw.c
+++ b/sound/soc/qcom/sdw.c
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-// Copyright (c) 2018, Linaro Limited.
+// Copyright (c) 2018-2023, Linaro Limited.
 // Copyright (c) 2018, The Linux Foundation. All rights reserved.
 
 #include <dt-bindings/sound/qcom,q6afe.h>
@@ -7,6 +7,49 @@
 #include <sound/soc.h>
 #include "sdw.h"
 
+/**
+ * qcom_snd_sdw_startup() - Helper to start Soundwire stream for SoC audio card
+ * @substream: The PCM substream from audio, as passed to snd_soc_ops->startup()
+ *
+ * Helper for the SoC audio card (snd_soc_ops->startup()) to allocate and set
+ * Soundwire stream runtime to each codec DAI.
+ *
+ * The shutdown() callback should call sdw_release_stream() on the same
+ * sdw_stream_runtime.
+ *
+ * Return: 0 or errno
+ */
+int qcom_snd_sdw_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
+	struct sdw_stream_runtime *sruntime;
+	struct snd_soc_dai *codec_dai;
+	int ret, i;
+
+	sruntime = sdw_alloc_stream(cpu_dai->name);
+	if (!sruntime)
+		return -ENOMEM;
+
+	for_each_rtd_codec_dais(rtd, i, codec_dai) {
+		ret = snd_soc_dai_set_stream(codec_dai, sruntime,
+					     substream->stream);
+		if (ret < 0 && ret != -ENOTSUPP) {
+			dev_err(rtd->dev, "Failed to set sdw stream on %s\n",
+				codec_dai->name);
+			goto err_set_stream;
+		}
+	}
+
+	return 0;
+
+err_set_stream:
+	sdw_release_stream(sruntime);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(qcom_snd_sdw_startup);
+
 int qcom_snd_sdw_prepare(struct snd_pcm_substream *substream,
 			 struct sdw_stream_runtime *sruntime,
 			 bool *stream_prepared)
diff --git a/sound/soc/qcom/sdw.h b/sound/soc/qcom/sdw.h
index d74cbb84da13..392e3455f1b1 100644
--- a/sound/soc/qcom/sdw.h
+++ b/sound/soc/qcom/sdw.h
@@ -6,6 +6,7 @@
 
 #include <linux/soundwire/sdw.h>
 
+int qcom_snd_sdw_startup(struct snd_pcm_substream *substream);
 int qcom_snd_sdw_prepare(struct snd_pcm_substream *substream,
 			 struct sdw_stream_runtime *runtime,
 			 bool *stream_prepared);
-- 
2.34.1