[PATCH] ASoC: fsl_esai: Support synchronous mode

In ESAI synchronous mode, the clock is generated by Tx, So
we should always set registers of Tx which relate with the
bit clock and frame clock generation (TCCR, TCR, ECR), even
there is only Rx is working.

Signed-off-by: Shengjiu Wang <redacted>
---
 sound/soc/fsl/fsl_esai.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/sound/soc/fsl/fsl_esai.c b/sound/soc/fsl/fsl_esai.c
index 3623aa9a6f2e..d9fcddd55c02 100644
--- a/sound/soc/fsl/fsl_esai.c
+++ b/sound/soc/fsl/fsl_esai.c

@@ -230,6 +230,21 @@ static int fsl_esai_set_dai_sysclk(struct snd_soc_dai *dai, int clk_id,
 		return -EINVAL;
 	}
 
+	if (esai_priv->synchronous && !tx) {
+		switch (clk_id) {
+		case ESAI_HCKR_FSYS:
+			fsl_esai_set_dai_sysclk(dai, ESAI_HCKT_FSYS,
+								freq, dir);
+			break;
+		case ESAI_HCKR_EXTAL:
+			fsl_esai_set_dai_sysclk(dai, ESAI_HCKT_EXTAL,
+								freq, dir);
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
 	/* Bypass divider settings if the requirement doesn't change */
 	if (freq == esai_priv->hck_rate[tx] && dir == esai_priv->hck_dir[tx])
 		return 0;

@@ -537,10 +552,21 @@ static int fsl_esai_hw_params(struct snd_pcm_substream *substream,
 
 	bclk = params_rate(params) * slot_width * esai_priv->slots;
 
-	ret = fsl_esai_set_bclk(dai, tx, bclk);
+	ret = fsl_esai_set_bclk(dai, esai_priv->synchronous ? true : tx, bclk);
 	if (ret)
 		return ret;
 
+	if (esai_priv->synchronous && !tx) {
+		/* Use Normal mode to support monaural audio */
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR,
+			   ESAI_xCR_xMOD_MASK, params_channels(params) > 1 ?
+			   ESAI_xCR_xMOD_NETWORK : 0);
+
+		mask = ESAI_xCR_xSWS_MASK | ESAI_xCR_PADC;
+		val = ESAI_xCR_xSWS(slot_width, width) | ESAI_xCR_PADC;
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR, mask, val);
+	}
+
 	/* Use Normal mode to support monaural audio */
 	regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx),
 			   ESAI_xCR_xMOD_MASK, params_channels(params) > 1 ?

-- 
1.9.1

Shengjiu,

On Mon, Apr 01, 2019 at 11:39:10AM +0000, S.j. Wang wrote:

Not sure why you call set_dai_sysclk inside set_dai_sysclk again. It
feels very confusing to do so, especially without a comments.

Does synchronous mode require to set both TCR and RCR? or just TCR?
The code behind this part is doing the same setting to RCR. If that
is not needed any more for a synchronous recording, we should reuse
it instead of inserting a piece of redundant code. Otherwise, if we
need to set both, we should have two regmap_update_bits operations
back-to-back for TCR and RCR (and other registers too).

+
 	/* Use Normal mode to support monaural audio */
 	regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx),
 			   ESAI_xCR_xMOD_MASK, params_channels(params) > 1 ?

In case that we only need to set TCR (more likely I feel), it would
feel less confusing to me, if we changed REG_ESAI_xCR(tx) here, for
example, to REG_ESAI_xCR(tx || sync). Yea, please add to the top a
'bool sync = esai_priv->synchronous;'.

Similarly, for ECR_ETO and ECR_ERO:
	(tx || sync) ? ESAI_ECR_ETO : ESAI_ECR_ERO;

Hi

Shengjiu,

On Mon, Apr 01, 2019 at 11:39:10AM +0000, S.j. Wang wrote:

quoted

In ESAI synchronous mode, the clock is generated by Tx, So we should
always set registers of Tx which relate with the bit clock and frame
clock generation (TCCR, TCR, ECR), even there is only Rx is working.

Signed-off-by: Shengjiu Wang <redacted>
---
 sound/soc/fsl/fsl_esai.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/sound/soc/fsl/fsl_esai.c b/sound/soc/fsl/fsl_esai.c index

3623aa9a6f2e..d9fcddd55c02 100644

--- a/sound/soc/fsl/fsl_esai.c
+++ b/sound/soc/fsl/fsl_esai.c

@@ -230,6 +230,21 @@ static int fsl_esai_set_dai_sysclk(struct

snd_soc_dai *dai, int clk_id,

quoted

 		return -EINVAL;
 	}

+	if (esai_priv->synchronous && !tx) {
+		switch (clk_id) {
+		case ESAI_HCKR_FSYS:
+			fsl_esai_set_dai_sysclk(dai, ESAI_HCKT_FSYS,
+								freq, dir);
+			break;
+		case ESAI_HCKR_EXTAL:
+			fsl_esai_set_dai_sysclk(dai, ESAI_HCKT_EXTAL,
+								freq, dir);

Not sure why you call set_dai_sysclk inside set_dai_sysclk again. It feels very
confusing to do so, especially without a comments.

For sync mode, only RX is enabled,  the register of tx should be set, so call the
Set_dai_sysclk again.

quoted

+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
 	/* Bypass divider settings if the requirement doesn't change */
 	if (freq == esai_priv->hck_rate[tx] && dir == esai_priv->hck_dir[tx])
 		return 0;

@@ -537,10 +552,21 @@ static int fsl_esai_hw_params(struct

snd_pcm_substream *substream,

 	bclk = params_rate(params) * slot_width * esai_priv->slots;

-	ret = fsl_esai_set_bclk(dai, tx, bclk);
+	ret = fsl_esai_set_bclk(dai, esai_priv->synchronous ? true : tx,
+bclk);
 	if (ret)
 		return ret;

+	if (esai_priv->synchronous && !tx) {
+		/* Use Normal mode to support monaural audio */
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR,
+			   ESAI_xCR_xMOD_MASK,

params_channels(params) > 1 ?

quoted

+			   ESAI_xCR_xMOD_NETWORK : 0);
+
+		mask = ESAI_xCR_xSWS_MASK | ESAI_xCR_PADC;
+		val = ESAI_xCR_xSWS(slot_width, width) | ESAI_xCR_PADC;
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR,

mask, val);

quoted

+	}

Does synchronous mode require to set both TCR and RCR? or just TCR?
The code behind this part is doing the same setting to RCR. If that is not
needed any more for a synchronous recording, we should reuse it instead
of inserting a piece of redundant code. Otherwise, if we need to set both,
we should have two regmap_update_bits operations back-to-back for TCR
and RCR (and other registers too).

Both TCR and RCR.  RCR will be set in normal flow.

quoted

+
 	/* Use Normal mode to support monaural audio */
 	regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx),
 			   ESAI_xCR_xMOD_MASK,

params_channels(params) > 1 ?

In case that we only need to set TCR (more likely I feel), it would feel less
confusing to me, if we changed REG_ESAI_xCR(tx) here, for example, to
REG_ESAI_xCR(tx || sync). Yea, please add to the top a 'bool sync =
esai_priv->synchronous;'.

Similarly, for ECR_ETO and ECR_ERO:
	(tx || sync) ? ESAI_ECR_ETO : ESAI_ECR_ERO;

Both TCR and RCR should be set.
 

quoted

On Mon, Apr 01, 2019 at 11:39:10AM +0000, S.j. Wang wrote:

quoted

In ESAI synchronous mode, the clock is generated by Tx, So we should
always set registers of Tx which relate with the bit clock and frame
clock generation (TCCR, TCR, ECR), even there is only Rx is working.

Signed-off-by: Shengjiu Wang <redacted>
---
 sound/soc/fsl/fsl_esai.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/sound/soc/fsl/fsl_esai.c b/sound/soc/fsl/fsl_esai.c index

3623aa9a6f2e..d9fcddd55c02 100644

--- a/sound/soc/fsl/fsl_esai.c
+++ b/sound/soc/fsl/fsl_esai.c

@@ -230,6 +230,21 @@ static int fsl_esai_set_dai_sysclk(struct

snd_soc_dai *dai, int clk_id,

quoted

 		return -EINVAL;
 	}

+	if (esai_priv->synchronous && !tx) {
+		switch (clk_id) {
+		case ESAI_HCKR_FSYS:
+			fsl_esai_set_dai_sysclk(dai, ESAI_HCKT_FSYS,
+								freq, dir);
+			break;
+		case ESAI_HCKR_EXTAL:
+			fsl_esai_set_dai_sysclk(dai, ESAI_HCKT_EXTAL,
+								freq, dir);

Not sure why you call set_dai_sysclk inside set_dai_sysclk again. It feels very
confusing to do so, especially without a comments.

For sync mode, only RX is enabled,  the register of tx should be set, so call the
Set_dai_sysclk again.

Yea, I understood that. But why not just replace RX with TX on the
register-writing level? Do we need to set both TCCR and RCCR? Your
change in hw_params() only sets TCCR inside fsl_esai_set_bclk(), so
we probably only need to change TCCR for recordings running in sync
mode, right?

From the commit message, it feels like that only the clock-related
fields in the TX registers need to be set. Things like calculation
and setting the direction of HCKx pin don't need to run again.

quoted

quoted

@@ -537,10 +552,21 @@ static int fsl_esai_hw_params(struct

snd_pcm_substream *substream,

 	bclk = params_rate(params) * slot_width * esai_priv->slots;

-	ret = fsl_esai_set_bclk(dai, tx, bclk);
+	ret = fsl_esai_set_bclk(dai, esai_priv->synchronous ? true : tx,
+bclk);
 	if (ret)
 		return ret;

+	if (esai_priv->synchronous && !tx) {
+		/* Use Normal mode to support monaural audio */
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR,
+			   ESAI_xCR_xMOD_MASK,

params_channels(params) > 1 ?

quoted

+			   ESAI_xCR_xMOD_NETWORK : 0);
+
+		mask = ESAI_xCR_xSWS_MASK | ESAI_xCR_PADC;
+		val = ESAI_xCR_xSWS(slot_width, width) | ESAI_xCR_PADC;
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR,

mask, val);

quoted

+	}

Does synchronous mode require to set both TCR and RCR? or just TCR?

Both TCR and RCR.  RCR will be set in normal flow.

OK. Settings both xCRs makes sense. Would you please try this:

===============

@@ -537,14 +552,20 @@ static int fsl_esai_hw_params(struct snd_pcm_substream *substream,

        bclk = params_rate(params) * slot_width * esai_priv->slots;

-       ret = fsl_esai_set_bclk(dai, tx, bclk);
+       /* Synchronous mode uses TX clock generator */
+       ret = fsl_esai_set_bclk(dai, esai_priv->synchronous || tx, bclk);
        if (ret)
                return ret;

+       mask = ESAI_xCR_xMOD_MASK | ESAI_xCR_xSWS_MASK;
+       val = ESAI_xCR_xSWS(slot_width, width);
        /* Use Normal mode to support monaural audio */
-       regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx),
-                          ESAI_xCR_xMOD_MASK, params_channels(params) > 1 ?
-                          ESAI_xCR_xMOD_NETWORK : 0);
+       val |= params_channels(params) > 1 ? ESAI_xCR_xMOD_NETWORK : 0;
+
+       regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx), mask, val);
+       /* Recording in synchronous mode needs to set TCR also */
+       if (!tx && esai_priv->synchronous)
+               regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR, mask, val);

        regmap_update_bits(esai_priv->regmap, REG_ESAI_xFCR(tx),
                           ESAI_xFCR_xFR_MASK, ESAI_xFCR_xFR);

@@ -556,10 +577,10 @@ static int fsl_esai_hw_params(struct snd_pcm_substream *substream,

        regmap_update_bits(esai_priv->regmap, REG_ESAI_xFCR(tx), mask, val);

-       mask = ESAI_xCR_xSWS_MASK | (tx ? ESAI_xCR_PADC : 0);
-       val = ESAI_xCR_xSWS(slot_width, width) | (tx ? ESAI_xCR_PADC : 0);
-
-       regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx), mask, val);
+       /* Only TCR has padding bit and needs to be set for synchronous mode */
+       if (tx || esai_priv->synchronous)
+               regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR,
+                                  ESAI_xCR_PADC, ESAI_xCR_PADC);

        /* Remove ESAI personal reset by configuring ESAI_PCRC and ESAI_PRRC */
        regmap_update_bits(esai_priv->regmap, REG_ESAI_PRRC,

===============

It merges those plain settings so we won't need to change both
sides if there's a modification of xCR settings in the future.

Hi

Thanks for reviewing,  will send v2.  And the ESAI_xCR_PADC, ESAI_xCR_xMOD_NETWORK
Is not needed in sync mode.