ASoC: soc-component: Add snd_soc_pcm_component_ack

Add snd_soc_pcm_component_ack back, which can be used to get an
updated buffer pointer in the platform driver.
On Asymmetric multiprocessor, this pointer can be sent to Cortex-M
core for audio processing.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://lore.kernel.org/r/1615516725-4975-2-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc-component.h

@@ -146,6 +146,8 @@ struct snd_soc_component_driver {
 	int (*mmap)(struct snd_soc_component *component,
 		    struct snd_pcm_substream *substream,
 		    struct vm_area_struct *vma);
+	int (*ack)(struct snd_soc_component *component,
+		   struct snd_pcm_substream *substream);
 
 	const struct snd_compress_ops *compress_ops;
 
@@ -498,5 +500,6 @@ int snd_soc_pcm_component_pm_runtime_get(struct snd_soc_pcm_runtime *rtd,
 					 void *stream);
 void snd_soc_pcm_component_pm_runtime_put(struct snd_soc_pcm_runtime *rtd,
 					  void *stream, int rollback);
+int snd_soc_pcm_component_ack(struct snd_pcm_substream *substream);
 
 #endif /* __SOC_COMPONENT_H */

sound/soc/soc-component.c

@@ -1212,3 +1212,17 @@ void snd_soc_pcm_component_pm_runtime_put(struct snd_soc_pcm_runtime *rtd,
 		soc_component_mark_pop(component, stream, pm);
 	}
 }
+
+int snd_soc_pcm_component_ack(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct snd_soc_component *component;
+	int i;
+
+	/* FIXME: use 1st pointer */
+	for_each_rtd_components(rtd, i, component)
+		if (component->driver->ack)
+			return component->driver->ack(component, substream);
+
+	return 0;
+}

sound/soc/soc-pcm.c

@@ -2772,6 +2772,8 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
 			rtd->ops.page		= snd_soc_pcm_component_page;
 		if (drv->mmap)
 			rtd->ops.mmap		= snd_soc_pcm_component_mmap;
+		if (drv->ack)
+			rtd->ops.ack            = snd_soc_pcm_component_ack;
 	}
 
 	if (playback)