ASoC: component: Add generic PCM copy ops

For following the ALSA PCM core change, a new PCM copy ops is added
toe ASoC component framework: snd_soc_component_driver receives the
copy ops, and snd_soc_pcm_component_copy() helper is provided.

This also fixes a long-standing potential bug where the ASoC driver
covers only copy_user PCM callback and misses the copy from kernel
pointers (such as OSS PCM layer), too.

As of this patch, the old copy_user is still kept, but it'll be
dropped later after all drivers are converted.

Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230815190136.8987-19-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 18 insertions, 0 deletions

diff --git a/sound/soc/soc-component.c b/sound/soc/soc-component.c
index 4356cc320fea..ffa2dd8a21ba 100644
--- a/sound/soc/soc-component.c
+++ b/sound/soc/soc-component.c
@@ -1052,6 +1052,24 @@ int snd_soc_pcm_component_sync_stop(struct snd_pcm_substream *substream)
 	return 0;
 }
 
+int snd_soc_pcm_component_copy(struct snd_pcm_substream *substream,
+			       int channel, unsigned long pos,
+			       struct iov_iter *buf, unsigned long bytes)
+{
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct snd_soc_component *component;
+	int i;
+
+	/* FIXME. it returns 1st copy now */
+	for_each_rtd_components(rtd, i, component)
+		if (component->driver->copy)
+			return soc_component_ret(component,
+				component->driver->copy(component, substream,
+					channel, pos, buf, bytes));
+
+	return -EINVAL;
+}
+
 int snd_soc_pcm_component_copy_user(struct snd_pcm_substream *substream,
 				    int channel, unsigned long pos,
 				    void __user *buf, unsigned long bytes)