ASoC: rsnd: update pointer more accurate

Current rsnd driver updates pointer when DMA transfer was finished
in DMA transfer mode. But PulseAudio requests more accurate
pointer update when timer mode.
This patch consider about DMA transfer residue and update more
accurate pointer.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sh/rcar/core.c

@@ -968,12 +968,14 @@ static int rsnd_hw_params(struct snd_pcm_substream *substream,
 
 static snd_pcm_uframes_t rsnd_pointer(struct snd_pcm_substream *substream)
 {
-	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_soc_dai *dai = rsnd_substream_to_dai(substream);
 	struct rsnd_dai *rdai = rsnd_dai_to_rdai(dai);
 	struct rsnd_dai_stream *io = rsnd_rdai_to_io(rdai, substream);
+	snd_pcm_uframes_t pointer = 0;
 
-	return bytes_to_frames(runtime, io->byte_pos);
+	rsnd_dai_call(pointer, io, &pointer);
+
+	return pointer;
 }
 
 static struct snd_pcm_ops rsnd_pcm_ops = {

sound/soc/sh/rcar/dma.c

@@ -25,6 +25,7 @@
 
 struct rsnd_dmaen {
 	struct dma_chan		*chan;
+	dma_cookie_t		cookie;
 	dma_addr_t		dma_buf;
 	unsigned int		dma_len;
 	unsigned int		dma_period;
@@ -292,7 +293,8 @@ static int rsnd_dmaen_start(struct rsnd_mod *mod,
 	for (i = 0; i < 2; i++)
 		rsnd_dmaen_sync(dmaen, io, i);
 
-	if (dmaengine_submit(desc) < 0) {
+	dmaen->cookie = dmaengine_submit(desc);
+	if (dmaen->cookie < 0) {
 		dev_err(dev, "dmaengine_submit() fail\n");
 		return -EIO;
 	}
@@ -348,12 +350,34 @@ static int rsnd_dmaen_attach(struct rsnd_dai_stream *io,
 	return 0;
 }
 
+static int rsnd_dmaen_pointer(struct rsnd_mod *mod,
+			      struct rsnd_dai_stream *io,
+			      snd_pcm_uframes_t *pointer)
+{
+	struct snd_pcm_runtime *runtime = rsnd_io_to_runtime(io);
+	struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
+	struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);
+	struct dma_tx_state state;
+	enum dma_status status;
+	unsigned int pos = 0;
+
+	status = dmaengine_tx_status(dmaen->chan, dmaen->cookie, &state);
+	if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
+		if (state.residue > 0 && state.residue <= dmaen->dma_len)
+			pos = dmaen->dma_len - state.residue;
+	}
+	*pointer = bytes_to_frames(runtime, pos);
+
+	return 0;
+}
+
 static struct rsnd_mod_ops rsnd_dmaen_ops = {
 	.name	= "audmac",
 	.nolock_start = rsnd_dmaen_nolock_start,
 	.nolock_stop  = rsnd_dmaen_nolock_stop,
 	.start	= rsnd_dmaen_start,
 	.stop	= rsnd_dmaen_stop,
+	.pointer= rsnd_dmaen_pointer,
 };
 
 /*

sound/soc/sh/rcar/rsnd.h

@@ -269,6 +269,9 @@ struct rsnd_mod_ops {
 			 struct rsnd_dai_stream *io,
 			 struct snd_pcm_substream *substream,
 			 struct snd_pcm_hw_params *hw_params);
+	int (*pointer)(struct rsnd_mod *mod,
+		       struct rsnd_dai_stream *io,
+		       snd_pcm_uframes_t *pointer);
 	int (*fallback)(struct rsnd_mod *mod,
 			struct rsnd_dai_stream *io,
 			struct rsnd_priv *priv);
@@ -306,6 +309,7 @@ struct rsnd_mod {
  * H	0: pcm_new
  * H	0: fallback
  * H	0: hw_params
+ * H	0: pointer
  */
 #define __rsnd_mod_shift_nolock_start	0
 #define __rsnd_mod_shift_nolock_stop	0
@@ -319,6 +323,7 @@ struct rsnd_mod {
 #define __rsnd_mod_shift_pcm_new	28 /* always called */
 #define __rsnd_mod_shift_fallback	28 /* always called */
 #define __rsnd_mod_shift_hw_params	28 /* always called */
+#define __rsnd_mod_shift_pointer	28 /* always called */
 
 #define __rsnd_mod_add_probe		0
 #define __rsnd_mod_add_remove		0
@@ -332,6 +337,7 @@ struct rsnd_mod {
 #define __rsnd_mod_add_pcm_new		0
 #define __rsnd_mod_add_fallback		0
 #define __rsnd_mod_add_hw_params	0
+#define __rsnd_mod_add_pointer		0
 
 #define __rsnd_mod_call_probe		0
 #define __rsnd_mod_call_remove		0
@@ -343,6 +349,7 @@ struct rsnd_mod {
 #define __rsnd_mod_call_pcm_new		0
 #define __rsnd_mod_call_fallback	0
 #define __rsnd_mod_call_hw_params	0
+#define __rsnd_mod_call_pointer		0
 #define __rsnd_mod_call_nolock_start	0
 #define __rsnd_mod_call_nolock_stop	1
 

sound/soc/sh/rcar/ssi.c

@@ -685,6 +685,17 @@ static int rsnd_ssi_common_probe(struct rsnd_mod *mod,
 	return ret;
 }
 
+static int rsnd_ssi_pointer(struct rsnd_mod *mod,
+			    struct rsnd_dai_stream *io,
+			    snd_pcm_uframes_t *pointer)
+{
+	struct snd_pcm_runtime *runtime = rsnd_io_to_runtime(io);
+
+	*pointer = bytes_to_frames(runtime, io->byte_pos);
+
+	return 0;
+}
+
 static struct rsnd_mod_ops rsnd_ssi_pio_ops = {
 	.name	= SSI_NAME,
 	.probe	= rsnd_ssi_common_probe,
@@ -693,6 +704,7 @@ static struct rsnd_mod_ops rsnd_ssi_pio_ops = {
 	.start	= rsnd_ssi_start,
 	.stop	= rsnd_ssi_stop,
 	.irq	= rsnd_ssi_irq,
+	.pointer= rsnd_ssi_pointer,
 	.pcm_new = rsnd_ssi_pcm_new,
 	.hw_params = rsnd_ssi_hw_params,
 };