[PATCH] ASoC: fsl_spdif: implement bypass mode from in to out

[PATCH] ASoC: fsl_spdif: implement bypass mode from in to out

[Shengjiu Wang]

From: Viorel Suman <viorel.suman@nxp.com>

Implement SPDIF bypass mode. It implies internal SoC
routing of SPDIF input signal to SPDIF output signal. The
test bed requires two boards: B1 configured in bypass mode,
and B2 to feed B1 SPDIF RX port and read B1 SPDIF TX port:
   B2 TX -> B1 RX,
   B2 RX <- B1 TX.
The test procedure:
 a) Boot both boards
 b) B2: start "arecord <spdifcard> -r 48kHz | aplay <local DAC>"
 c) B2: start "aplay <spdifcard> -r 48kHz <2ch 48kHz audio file>"
 d) B1: enable bypass mode:
	amixer -cimxspdif cset numid=8,iface=PCM,name='Bypass Mode' on
 e) B2: check DAC audio, make sure the same sample rate is used at
	steps b) and c), in example above the rate is 48kHz.
 f) B1: try to run "aplay" or "arecord" on imxspdif card while in
	bypass mode - both must fail until bypass mode is disabled
 g) B1: disable bypass mode:
	amixer -cimxspdif cset numid=8,iface=PCM,name='Bypass Mode' off
 h) B1: check the usual playback and capture on imxspdif card.
	During this test try to set bypass mode - must not be allowed
	while playback or capture is running.

Signed-off-by: Viorel Suman <viorel.suman@nxp.com>
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 sound/soc/fsl/fsl_spdif.c | 74 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/sound/soc/fsl/fsl_spdif.c b/sound/soc/fsl/fsl_spdif.c
index 928b59069283..d178b479c8bd 100644
--- a/sound/soc/fsl/fsl_spdif.c
+++ b/sound/soc/fsl/fsl_spdif.c
@@ -111,6 +111,7 @@ struct spdif_mixer_control {
  * @dma_params_tx: DMA parameters for transmit channel
  * @dma_params_rx: DMA parameters for receive channel
  * @regcache_srpc: regcache for SRPC
+ * @bypass: status of bypass input to output
  */
 struct fsl_spdif_priv {
 	const struct fsl_spdif_soc_data *soc;
@@ -133,6 +134,7 @@ struct fsl_spdif_priv {
 	struct snd_dmaengine_dai_dma_data dma_params_rx;
 	/* regcache for SRPC */
 	u32 regcache_srpc;
+	bool bypass;
 };
 
 static struct fsl_spdif_soc_data fsl_spdif_vf610 = {
@@ -905,6 +907,69 @@ static int fsl_spdif_rx_rcm_put(struct snd_kcontrol *kcontrol,
 	return 0;
 }
 
+static int fsl_spdif_bypass_get(struct snd_kcontrol *kcontrol,
+				struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_dai *dai = snd_kcontrol_chip(kcontrol);
+	struct fsl_spdif_priv *priv = snd_soc_dai_get_drvdata(dai);
+
+	ucontrol->value.integer.value[0] = priv->bypass ? 1 : 0;
+
+	return 0;
+}
+
+static int fsl_spdif_bypass_put(struct snd_kcontrol *kcontrol,
+				struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_dai *dai = snd_kcontrol_chip(kcontrol);
+	struct fsl_spdif_priv *priv = snd_soc_dai_get_drvdata(dai);
+	struct snd_soc_card *card = dai->component->card;
+	bool set = (ucontrol->value.integer.value[0] != 0);
+	struct regmap *regmap = priv->regmap;
+	struct snd_soc_pcm_runtime *rtd;
+	u32 scr, mask;
+	int stream;
+
+	rtd = snd_soc_get_pcm_runtime(card, card->dai_link);
+
+	if (priv->bypass == set)
+		return 0; /* nothing to do */
+
+	if (snd_soc_dai_active(dai)) {
+		dev_err(dai->dev, "Cannot change BYPASS mode while stream is running.\n");
+		return -EBUSY;
+	}
+
+	pm_runtime_get_sync(dai->dev);
+
+	if (set) {
+		/* Disable interrupts */
+		regmap_update_bits(regmap, REG_SPDIF_SIE, 0xffffff, 0);
+
+		/* Configure BYPASS mode */
+		scr = SCR_TXSEL_RX | SCR_RXFIFO_OFF;
+		mask = SCR_RXFIFO_FSEL_MASK | SCR_RXFIFO_AUTOSYNC_MASK |
+			SCR_RXFIFO_CTL_MASK | SCR_RXFIFO_OFF_MASK | SCR_TXSEL_MASK;
+		/* Power up SPDIF module */
+		mask |= SCR_LOW_POWER;
+	} else {
+		/* Power down SPDIF module, disable TX */
+		scr = SCR_LOW_POWER | SCR_TXSEL_OFF;
+		mask = SCR_LOW_POWER | SCR_TXSEL_MASK;
+	}
+
+	regmap_update_bits(regmap, REG_SPDIF_SCR, mask, scr);
+
+	/* Disable playback & capture if BYPASS mode is enabled, enable otherwise */
+	for_each_pcm_streams(stream)
+		rtd->pcm->streams[stream].substream_count = (set ? 0 : 1);
+
+	priv->bypass = set;
+	pm_runtime_put_sync(dai->dev);
+
+	return 0;
+}
+
 /* DPLL lock information */
 static int fsl_spdif_rxrate_info(struct snd_kcontrol *kcontrol,
 				struct snd_ctl_elem_info *uinfo)
@@ -1075,6 +1140,15 @@ static struct snd_kcontrol_new fsl_spdif_ctrls[] = {
 		.info = fsl_spdif_rxrate_info,
 		.get = fsl_spdif_rxrate_get,
 	},
+	/* RX bypass controller */
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
+		.name = "Bypass Mode",
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+		.info = snd_ctl_boolean_mono_info,
+		.get = fsl_spdif_bypass_get,
+		.put = fsl_spdif_bypass_put,
+	},
 	/* User bit sync mode set/get controller */
 	{
 		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
-- 
2.17.1

Re: [PATCH] ASoC: fsl_spdif: implement bypass mode from in to out

[Mark Brown]

On Sun, 26 Sep 2021 17:49:20 +0800, Shengjiu Wang wrote:
> From: Viorel Suman <viorel.suman@nxp.com>
> 
> Implement SPDIF bypass mode. It implies internal SoC
> routing of SPDIF input signal to SPDIF output signal. The
> test bed requires two boards: B1 configured in bypass mode,
> and B2 to feed B1 SPDIF RX port and read B1 SPDIF TX port:
>    B2 TX -> B1 RX,
>    B2 RX <- B1 TX.
> The test procedure:
>  a) Boot both boards
>  b) B2: start "arecord <spdifcard> -r 48kHz | aplay <local DAC>"
>  c) B2: start "aplay <spdifcard> -r 48kHz <2ch 48kHz audio file>"
>  d) B1: enable bypass mode:
> 	amixer -cimxspdif cset numid=8,iface=PCM,name='Bypass Mode' on
>  e) B2: check DAC audio, make sure the same sample rate is used at
> 	steps b) and c), in example above the rate is 48kHz.
>  f) B1: try to run "aplay" or "arecord" on imxspdif card while in
> 	bypass mode - both must fail until bypass mode is disabled
>  g) B1: disable bypass mode:
> 	amixer -cimxspdif cset numid=8,iface=PCM,name='Bypass Mode' off
>  h) B1: check the usual playback and capture on imxspdif card.
> 	During this test try to set bypass mode - must not be allowed
> 	while playback or capture is running.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: fsl_spdif: implement bypass mode from in to out
      commit: 83bea088f976a289bc2efe4e404af47ab79d6639

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark