ASoC: SOF: compress: Add copy function for capture case

Added a new copy function used to copy data to user buffer
in the case of compress capture.
Reviewed-by: Paul Olaru <paul.olaru@nxp.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
Link: https://lore.kernel.org/r/20220822101502.17644-3-laurentiu.mihalcea@nxp.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/compress.c

@@ -318,6 +318,27 @@ static int sof_compr_copy_playback(struct snd_compr_runtime *rtd,
 	return count - ret;
 }
 
+static int sof_compr_copy_capture(struct snd_compr_runtime *rtd,
+				  char __user *buf, size_t count)
+{
+	void *ptr;
+	unsigned int offset, n;
+	int ret;
+
+	div_u64_rem(rtd->total_bytes_transferred, rtd->buffer_size, &offset);
+	ptr = rtd->dma_area + offset;
+	n = rtd->buffer_size - offset;
+
+	if (count < n) {
+		ret = copy_to_user(buf, ptr, count);
+	} else {
+		ret = copy_to_user(buf, ptr, n);
+		ret += copy_to_user(buf + n, rtd->dma_area, count - n);
+	}
+
+	return count - ret;
+}
+
 static int sof_compr_copy(struct snd_soc_component *component,
 			  struct snd_compr_stream *cstream,
 			  char __user *buf, size_t count)
@@ -327,7 +348,10 @@ static int sof_compr_copy(struct snd_soc_component *component,
 	if (count > rtd->buffer_size)
 		count = rtd->buffer_size;
 
-	return sof_compr_copy_playback(rtd, buf, count);
+	if (cstream->direction == SND_COMPRESS_PLAYBACK)
+		return sof_compr_copy_playback(rtd, buf, count);
+	else
+		return sof_compr_copy_capture(rtd, buf, count);
 }
 
 static int sof_compr_pointer(struct snd_soc_component *component,