media: solo6x10: Convert to generic PCM copy ops

This patch converts the solo6x10 driver code to use the new unified
PCM copy callback.  It's a straightforward conversion from *_user() to
*_iter() variants.  As copy_to_iter() updates the internal offest at
each write, we can drop the dst counter update in the loop, too.

Note that copy_to_iter() returns the copied bytes, hence the error
condition is adjusted accordingly.
Acked-by: Ismael Luceno <ismael@iodev.co.uk>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Bluecherry Maintainers <maintainers@bluecherrydvr.com>
Cc: Anton Sviridenko <anton@corp.bluecherry.net>
Cc: Andrey Utkin <andrey_utkin@fastmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-media@vger.kernel.org
Link: https://lore.kernel.org/r/20230815190136.8987-18-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

drivers/media/pci/solo6x10/solo6x10-g723.c

@@ -204,8 +204,8 @@ static snd_pcm_uframes_t snd_solo_pcm_pointer(struct snd_pcm_substream *ss)
 	return idx * G723_FRAMES_PER_PAGE;
 }
 
-static int snd_solo_pcm_copy_user(struct snd_pcm_substream *ss, int channel,
-				  unsigned long pos, void __user *dst,
+static int snd_solo_pcm_copy(struct snd_pcm_substream *ss, int channel,
+			     unsigned long pos, struct iov_iter *dst,
 			     unsigned long count)
 {
 	struct solo_snd_pcm *solo_pcm = snd_pcm_substream_chip(ss);
@@ -223,35 +223,9 @@ static int snd_solo_pcm_copy_user(struct snd_pcm_substream *ss, int channel,
 		if (err)
 			return err;
 
-		if (copy_to_user(dst, solo_pcm->g723_buf, G723_PERIOD_BYTES))
+		if (copy_to_iter(solo_pcm->g723_buf, G723_PERIOD_BYTES, dst) !=
+		    G723_PERIOD_BYTES)
 			return -EFAULT;
-		dst += G723_PERIOD_BYTES;
-	}
-
-	return 0;
-}
-
-static int snd_solo_pcm_copy_kernel(struct snd_pcm_substream *ss, int channel,
-				    unsigned long pos, void *dst,
-				    unsigned long count)
-{
-	struct solo_snd_pcm *solo_pcm = snd_pcm_substream_chip(ss);
-	struct solo_dev *solo_dev = solo_pcm->solo_dev;
-	int err, i;
-
-	for (i = 0; i < (count / G723_FRAMES_PER_PAGE); i++) {
-		int page = (pos / G723_FRAMES_PER_PAGE) + i;
-
-		err = solo_p2m_dma_t(solo_dev, 0, solo_pcm->g723_dma,
-				     SOLO_G723_EXT_ADDR(solo_dev) +
-				     (page * G723_PERIOD_BLOCK) +
-				     (ss->number * G723_PERIOD_BYTES),
-				     G723_PERIOD_BYTES, 0, 0);
-		if (err)
-			return err;
-
-		memcpy(dst, solo_pcm->g723_buf, G723_PERIOD_BYTES);
-		dst += G723_PERIOD_BYTES;
 	}
 
 	return 0;
@@ -263,8 +237,7 @@ static const struct snd_pcm_ops snd_solo_pcm_ops = {
 	.prepare = snd_solo_pcm_prepare,
 	.trigger = snd_solo_pcm_trigger,
 	.pointer = snd_solo_pcm_pointer,
-	.copy_user = snd_solo_pcm_copy_user,
-	.copy_kernel = snd_solo_pcm_copy_kernel,
+	.copy = snd_solo_pcm_copy,
 };
 
 static int snd_solo_capture_volume_info(struct snd_kcontrol *kcontrol,