tegra-alsa: return accurate pcm pointer position

Bug 793968

Change-Id: Ia4ee5a83d18b409dd223f70fb1a5a78fad16a08e
Reviewed-on: http://git-master/r/20403
Reviewed-by: Varun Colbert <vcolbert@nvidia.com>
Tested-by: Varun Colbert <vcolbert@nvidia.com>

2 files changed, 51 insertions, 61 deletions

diff --git a/sound/soc/tegra/tegra_pcm.c b/sound/soc/tegra/tegra_pcm.c
index c982eb6cddb4..da2d476b6886 100644
--- a/sound/soc/tegra/tegra_pcm.c
+++ b/sound/soc/tegra/tegra_pcm.c
@@ -25,31 +25,19 @@
 
 static void tegra_pcm_play(struct tegra_runtime_data *prtd)
 {
-	static int reqid = 0;
 	struct snd_pcm_substream *substream = prtd->substream;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_dma_buffer *buf = &substream->dma_buffer;
 
 	if (runtime->dma_addr) {
 		prtd->size = frames_to_bytes(runtime, runtime->period_size);
-		if (reqid == 0) {
-			if (prtd->dma_state != STATE_ABORT) {
-				prtd->dma_req1.source_addr = buf->addr +
-				frames_to_bytes(runtime,prtd->dma_pos);
-				prtd->dma_req1.size = prtd->size;
-				tegra_dma_enqueue_req(prtd->dma_chan,
-							&prtd->dma_req1);
-				reqid = 1;
-			}
-		} else {
-			if (prtd->dma_state != STATE_ABORT) {
-				prtd->dma_req2.source_addr = buf->addr +
-				frames_to_bytes(runtime,prtd->dma_pos);
-				prtd->dma_req2.size = prtd->size;
-				tegra_dma_enqueue_req(prtd->dma_chan,
-							&prtd->dma_req2);
-				reqid = 0;
-			}
+		if (prtd->dma_state != STATE_ABORT) {
+			prtd->dma_reqid_tail = (prtd->dma_reqid_tail + 1) % DMA_REQ_QCOUNT;
+			prtd->dma_req[prtd->dma_reqid_tail].source_addr = buf->addr +
+			frames_to_bytes(runtime,prtd->dma_pos);
+			prtd->dma_req[prtd->dma_reqid_tail].size = prtd->size;
+			tegra_dma_enqueue_req(prtd->dma_chan,
+						&prtd->dma_req[prtd->dma_reqid_tail]);
 		}
 	}
 
@@ -62,31 +50,19 @@ static void tegra_pcm_play(struct tegra_runtime_data *prtd)
 
 static void tegra_pcm_capture(struct tegra_runtime_data *prtd)
 {
-	static int reqid = 0;
 	struct snd_pcm_substream *substream = prtd->substream;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_dma_buffer *buf = &substream->dma_buffer;
 
 	if (runtime->dma_addr) {
 		prtd->size = frames_to_bytes(runtime, runtime->period_size);
-		if (reqid == 0) {
-			if (prtd->dma_state != STATE_ABORT) {
-				prtd->dma_req1.dest_addr = buf->addr +
-				frames_to_bytes(runtime,prtd->dma_pos);
-				prtd->dma_req1.size = prtd->size;
-				tegra_dma_enqueue_req(prtd->dma_chan,
-							&prtd->dma_req1);
-				reqid = 1;
-			}
-		} else {
-			if (prtd->dma_state != STATE_ABORT) {
-				prtd->dma_req2.dest_addr = buf->addr +
-				frames_to_bytes(runtime,prtd->dma_pos);
-				prtd->dma_req2.size = prtd->size;
-				tegra_dma_enqueue_req(prtd->dma_chan,
-							&prtd->dma_req2);
-				reqid = 0;
-			}
+		if (prtd->dma_state != STATE_ABORT) {
+			prtd->dma_reqid_tail = (prtd->dma_reqid_tail + 1) % DMA_REQ_QCOUNT;
+			prtd->dma_req[prtd->dma_reqid_tail].dest_addr = buf->addr +
+			frames_to_bytes(runtime,prtd->dma_pos);
+			prtd->dma_req[prtd->dma_reqid_tail].size = prtd->size;
+			tegra_dma_enqueue_req(prtd->dma_chan,
+						&prtd->dma_req[prtd->dma_reqid_tail]);
 		}
 	}
 
@@ -108,6 +84,7 @@ static void dma_complete_callback (struct tegra_dma_req *req)
 	}
 
 	if (prtd->dma_state != STATE_ABORT) {
+		prtd->dma_reqid_head = (prtd->dma_reqid_head + 1) % DMA_REQ_QCOUNT;
 		snd_pcm_period_elapsed(substream);
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 			tegra_pcm_play(prtd);
@@ -151,6 +128,8 @@ static int tegra_pcm_prepare(struct snd_pcm_substream *substream)
 
 	prtd->dma_pos = 0;
 	prtd->period_index = 0;
+	prtd->dma_reqid_head = 0;
+	prtd->dma_reqid_tail = DMA_REQ_QCOUNT - 1;
 
 	return 0;
 }
@@ -158,7 +137,7 @@ static int tegra_pcm_prepare(struct snd_pcm_substream *substream)
 static int tegra_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct tegra_runtime_data *prtd = substream->runtime->private_data;
-	int ret = 0;
+	int i, ret = 0;
 
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
@@ -185,17 +164,19 @@ static int tegra_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 		tegra_dma_cancel(prtd->dma_chan);
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 			if (prtd->dma_chan) {
-				tegra_dma_dequeue_req(prtd->dma_chan,
-							&prtd->dma_req1);
-				tegra_dma_dequeue_req(prtd->dma_chan,
-							&prtd->dma_req2);
+				for (i = 0; i < DMA_REQ_QCOUNT; i++)
+					tegra_dma_dequeue_req(prtd->dma_chan,
+							&prtd->dma_req[i]);
+				prtd->dma_reqid_head = 0;
+				prtd->dma_reqid_tail = DMA_REQ_QCOUNT - 1;
 			}
 		} else {
 			if (prtd->dma_chan) {
-				tegra_dma_dequeue_req(prtd->dma_chan,
-							&prtd->dma_req1);
-				tegra_dma_dequeue_req(prtd->dma_chan,
-							&prtd->dma_req2);
+				for (i = 0; i < DMA_REQ_QCOUNT; i++)
+					tegra_dma_dequeue_req(prtd->dma_chan,
+							&prtd->dma_req[i]);
+				prtd->dma_reqid_head = 0;
+				prtd->dma_reqid_tail = DMA_REQ_QCOUNT - 1;
 			}
 		}
 		break;
@@ -211,7 +192,13 @@ static snd_pcm_uframes_t tegra_pcm_pointer(struct snd_pcm_substream *substream)
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct tegra_runtime_data *prtd = runtime->private_data;
 	int size;
-	size = prtd->period_index * runtime->period_size;
+
+	size = (prtd->period_index * runtime->period_size) +
+		 bytes_to_frames(runtime,
+				tegra_dma_get_transfer_count(
+					prtd->dma_chan,
+					&prtd->dma_req[prtd->dma_reqid_head],
+					false));
 	return (size);
 }
 
@@ -219,7 +206,7 @@ static int tegra_pcm_open(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct tegra_runtime_data *prtd = 0;
-	int ret=0;
+	int i, ret=0;
 
 	/* Ensure period size is multiple of minimum DMA step size */
 	ret = snd_pcm_hw_constraint_step(runtime, 0,
@@ -249,15 +236,12 @@ static int tegra_pcm_open(struct snd_pcm_substream *substream)
 
 	prtd->state = STATE_INVALID;
 
-	setup_dma_request(substream,
-			&prtd->dma_req1,
-			dma_complete_callback,
-			prtd);
-
-	setup_dma_request(substream,
-			&prtd->dma_req2,
-			dma_complete_callback,
-			prtd);
+	for (i = 0; i < DMA_REQ_QCOUNT; i++) {
+		setup_dma_request(substream,
+				&prtd->dma_req[i],
+				dma_complete_callback,
+				prtd);
+	}
 
 	prtd->dma_chan = tegra_dma_allocate_channel(TEGRA_DMA_MODE_CONTINUOUS_DOUBLE);
 	if (IS_ERR(prtd->dma_chan)) {
@@ -291,6 +275,7 @@ static int tegra_pcm_close(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct tegra_runtime_data *prtd = runtime->private_data;
+	int i;
 
 	if (!prtd) {
 		printk(KERN_ERR "tegra_pcm_close called with prtd == NULL\n");
@@ -301,11 +286,13 @@ static int tegra_pcm_close(struct snd_pcm_substream *substream)
 
 	if (prtd->dma_chan) {
 		prtd->dma_state = STATE_EXIT;
-		tegra_dma_dequeue_req(prtd->dma_chan, &prtd->dma_req1);
-		tegra_dma_dequeue_req(prtd->dma_chan, &prtd->dma_req2);
+		for (i = 0; i < DMA_REQ_QCOUNT; i++)
+			tegra_dma_dequeue_req(prtd->dma_chan, &prtd->dma_req[i]);
 		tegra_dma_flush(prtd->dma_chan);
 		tegra_dma_free_channel(prtd->dma_chan);
 		prtd->dma_chan = NULL;
+		prtd->dma_reqid_head = 0;
+		prtd->dma_reqid_tail = DMA_REQ_QCOUNT - 1;
 	}
 	kfree(prtd);
 
diff --git a/sound/soc/tegra/tegra_soc.h b/sound/soc/tegra/tegra_soc.h
index 1510d6dbee76..215b4c580edb 100644
--- a/sound/soc/tegra/tegra_soc.h
+++ b/sound/soc/tegra/tegra_soc.h
@@ -76,6 +76,7 @@
 #define TEGRA_VOICE_SAMPLE_RATES SNDRV_PCM_RATE_8000
 
 #define DMA_STEP_SIZE_MIN 8
+#define DMA_REQ_QCOUNT 2
 
 struct tegra_dma_channel;
 
@@ -83,7 +84,9 @@ struct tegra_runtime_data {
 	struct snd_pcm_substream *substream;
 	int size;
 	int dma_pos;
-	struct tegra_dma_req dma_req1, dma_req2;
+	struct tegra_dma_req dma_req[DMA_REQ_QCOUNT];
+	int dma_reqid_head;
+	int dma_reqid_tail;
 	volatile int state;
 	int period_index;
 	int i2s_shutdown;