[PATCH V4] ASoC: Intel: boards: Use FS as nau8825 sysclk in nau88125_* machine

From: Radoslaw Biernacki <rad@semihalf.com>
To: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
	Liam Girdwood <liam.r.girdwood@linux.intel.com>,
	Jie Yang <yang.jie@linux.intel.com>,
	Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>
Cc: Ben Zhang <benzh@chromium.org>, Marcin Wojtas <mw@semihalf.com>,
	Todd Broch <tbroch@google.com>, Alex Levin <levinale@google.com>,
	Vamshi Krishna <vamshi.krishna.gopal@intel.com>,
	Harshapriya <harshapriya.n@intel.com>,
	michal.sienkiewicz@intel.com, Lech Betlej <Lech.Betlej@intel.com>,
	Radoslaw Biernacki <rad@semihalf.com>,
	alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org,
	John Hsu <KCHSU0@nuvoton.com>, Yong Zhi <yong.zhi@intel.com>,
	Mac Chiang <mac.chiang@intel.com>
Subject: [PATCH V4] ASoC: Intel: boards: Use FS as nau8825 sysclk in nau88125_* machine
Date: Thu, 10 Sep 2020 17:40:56 +0200	[thread overview]
Message-ID: <20200910154056.30962-1-rad@semihalf.com> (raw)

Since 256xFS clocks cannot be generated by SKL, the NAU8825 is
configured to re-generate its system clock from the BCLK using the
FLL. The link is configured to use a 48kHz frame rate, and 24 bits in
25-bit slot. The SSP configuration is extracted from NHLT settings and
not dynamically changed. Listening tests and measurements do not show
any distortion or issues

Signed-off-by: John Hsu <KCHSU0@nuvoton.com>
Signed-off-by: Yong Zhi <yong.zhi@intel.com>
Signed-off-by: Mac Chiang <mac.chiang@intel.com>
Signed-off-by: Ben Zhang <benzh@chromium.org>
Signed-off-by: Radoslaw Biernacki <rad@semihalf.com>
---

Notes:
    v1 -> v2:
    - adding same changes to skl_nau88l25_max98357a.c
    v2 -> v3:
    - removing msleep() in SNDRV_PCM_TRIGGER_RESUME as it unnecessarily increase
      playback/capture latency while actually FLL does not require it.
    - simplifing commit message
    v3 -> v4:
    - simplifing the PM resume callback code for setting the FLL
    - adding comment for the stream START/RESUME sequence which prevent audio pops
    - fixing mising var initialization in platform_clock_control()

 .../soc/intel/boards/skl_nau88l25_max98357a.c | 63 ++++++++++++------
 sound/soc/intel/boards/skl_nau88l25_ssm4567.c | 65 +++++++++++++------
 2 files changed, 86 insertions(+), 42 deletions(-)

diff --git a/sound/soc/intel/boards/skl_nau88l25_max98357a.c b/sound/soc/intel/boards/skl_nau88l25_max98357a.c
index d7b8154c43a4..2f0abbd2dd8d 100644
--- a/sound/soc/intel/boards/skl_nau88l25_max98357a.c
+++ b/sound/soc/intel/boards/skl_nau88l25_max98357a.c
@@ -8,6 +8,7 @@
 
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/delay.h>
 #include <sound/core.h>
 #include <sound/jack.h>
 #include <sound/pcm.h>
@@ -47,12 +48,12 @@ enum {
 };
 
 static int platform_clock_control(struct snd_soc_dapm_widget *w,
-	struct snd_kcontrol *k, int  event)
+	struct snd_kcontrol *k, int event)
 {
 	struct snd_soc_dapm_context *dapm = w->dapm;
 	struct snd_soc_card *card = dapm->card;
 	struct snd_soc_dai *codec_dai;
-	int ret;
+	int ret = 0;
 
 	codec_dai = snd_soc_card_get_codec_dai(card, SKL_NUVOTON_CODEC_DAI);
 	if (!codec_dai) {
@@ -60,14 +61,7 @@ static int platform_clock_control(struct snd_soc_dapm_widget *w,
 		return -EIO;
 	}
 
-	if (SND_SOC_DAPM_EVENT_ON(event)) {
-		ret = snd_soc_dai_set_sysclk(codec_dai,
-				NAU8825_CLK_MCLK, 24000000, SND_SOC_CLOCK_IN);
-		if (ret < 0) {
-			dev_err(card->dev, "set sysclk err = %d\n", ret);
-			return -EIO;
-		}
-	} else {
+	if (!SND_SOC_DAPM_EVENT_ON(event)) {
 		ret = snd_soc_dai_set_sysclk(codec_dai,
 				NAU8825_CLK_INTERNAL, 0, SND_SOC_CLOCK_IN);
 		if (ret < 0) {
@@ -292,24 +286,51 @@ static const struct snd_soc_ops skylake_nau8825_fe_ops = {
 	.startup = skl_fe_startup,
 };
 
-static int skylake_nau8825_hw_params(struct snd_pcm_substream *substream,
-	struct snd_pcm_hw_params *params)
+static int skylake_nau8825_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_soc_dai *codec_dai = asoc_rtd_to_codec(rtd, 0);
-	int ret;
-
-	ret = snd_soc_dai_set_sysclk(codec_dai,
-			NAU8825_CLK_MCLK, 24000000, SND_SOC_CLOCK_IN);
-
-	if (ret < 0)
-		dev_err(rtd->dev, "snd_soc_dai_set_sysclk err = %d\n", ret);
+	int ret = 0;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		/* Since 256xFS clocks cannot be generated by SKL, the NAU8825
+		 * is configured to re-generate its system clock from the BCLK
+		 * using the FLL.
+		 * We must switch system clock (FLL to use BCLK) here as it is
+		 * not given eariler by FW (like in hw_param). We let nau8825 to
+		 * use internal VCO clock till now which reduces the audiable
+		 * pop's. */
+
+		/* fall through */
+
+	case SNDRV_PCM_TRIGGER_RESUME:
+		/* Once device resumes, the system will only enable power
+		 * sequence for playback without doing hardware parameter, audio
+		 * format, and PLL configure. In the mean time, the jack
+		 * detecion sequence has changed PLL parameters and switched to
+		 * internal clock. Thus, the playback signal distorted without
+		 * correct PLL parameters. Therefore we need to configure PLL
+		 * again */
+		ret = snd_soc_dai_set_sysclk(codec_dai, NAU8825_CLK_FLL_FS, 0,
+					     SND_SOC_CLOCK_IN);
+		if (ret < 0) {
+			dev_err(codec_dai->dev, "can't set FS clock %d\n", ret);
+			break;
+		}
+		ret = snd_soc_dai_set_pll(codec_dai, 0, 0, runtime->rate,
+					  runtime->rate * 256);
+		if (ret < 0)
+			dev_err(codec_dai->dev, "can't set FLL: %d\n", ret);
+		break;
+	}
 
 	return ret;
 }
 
-static const struct snd_soc_ops skylake_nau8825_ops = {
-	.hw_params = skylake_nau8825_hw_params,
+static struct snd_soc_ops skylake_nau8825_ops = {
+	.trigger = skylake_nau8825_trigger,
 };
 
 static int skylake_dmic_fixup(struct snd_soc_pcm_runtime *rtd,
diff --git a/sound/soc/intel/boards/skl_nau88l25_ssm4567.c b/sound/soc/intel/boards/skl_nau88l25_ssm4567.c
index 4b317bcf6ea0..d076f19f9b78 100644
--- a/sound/soc/intel/boards/skl_nau88l25_ssm4567.c
+++ b/sound/soc/intel/boards/skl_nau88l25_ssm4567.c
@@ -12,6 +12,7 @@
 
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/delay.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/soc.h>
@@ -57,12 +58,12 @@ static const struct snd_kcontrol_new skylake_controls[] = {
 };
 
 static int platform_clock_control(struct snd_soc_dapm_widget *w,
-		struct snd_kcontrol *k, int  event)
+		struct snd_kcontrol *k, int event)
 {
 	struct snd_soc_dapm_context *dapm = w->dapm;
 	struct snd_soc_card *card = dapm->card;
 	struct snd_soc_dai *codec_dai;
-	int ret;
+	int ret = 0;
 
 	codec_dai = snd_soc_card_get_codec_dai(card, SKL_NUVOTON_CODEC_DAI);
 	if (!codec_dai) {
@@ -70,14 +71,7 @@ static int platform_clock_control(struct snd_soc_dapm_widget *w,
 		return -EIO;
 	}
 
-	if (SND_SOC_DAPM_EVENT_ON(event)) {
-		ret = snd_soc_dai_set_sysclk(codec_dai,
-				NAU8825_CLK_MCLK, 24000000, SND_SOC_CLOCK_IN);
-		if (ret < 0) {
-			dev_err(card->dev, "set sysclk err = %d\n", ret);
-			return -EIO;
-		}
-	} else {
+	if (!SND_SOC_DAPM_EVENT_ON(event)) {
 		ret = snd_soc_dai_set_sysclk(codec_dai,
 				NAU8825_CLK_INTERNAL, 0, SND_SOC_CLOCK_IN);
 		if (ret < 0) {
@@ -85,6 +79,7 @@ static int platform_clock_control(struct snd_soc_dapm_widget *w,
 			return -EIO;
 		}
 	}
+
 	return ret;
 }
 
@@ -344,24 +339,51 @@ static int skylake_dmic_fixup(struct snd_soc_pcm_runtime *rtd,
 	return 0;
 }
 
-static int skylake_nau8825_hw_params(struct snd_pcm_substream *substream,
-	struct snd_pcm_hw_params *params)
+static int skylake_nau8825_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_soc_dai *codec_dai = asoc_rtd_to_codec(rtd, 0);
-	int ret;
-
-	ret = snd_soc_dai_set_sysclk(codec_dai,
-			NAU8825_CLK_MCLK, 24000000, SND_SOC_CLOCK_IN);
-
-	if (ret < 0)
-		dev_err(rtd->dev, "snd_soc_dai_set_sysclk err = %d\n", ret);
+	int ret = 0;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		/* Since 256xFS clocks cannot be generated by SKL, the NAU8825
+		 * is configured to re-generate its system clock from the BCLK
+		 * using the FLL.
+		 * We must switch system clock (FLL to use BCLK) here as it is
+		 * not given eariler by FW (like in hw_param). We let nau8825 to
+		 * use internal VCO clock till now which reduces the audiable
+		 * pop's. */
+
+		/* fall through */
+
+	case SNDRV_PCM_TRIGGER_RESUME:
+		/* Once device resumes, the system will only enable power
+		 * sequence for playback without doing hardware parameter, audio
+		 * format, and PLL configure. In the mean time, the jack
+		 * detecion sequence has changed PLL parameters and switched to
+		 * internal clock. Thus, the playback signal distorted without
+		 * correct PLL parameters. Therefore we need to configure PLL
+		 * again */
+		ret = snd_soc_dai_set_sysclk(codec_dai, NAU8825_CLK_FLL_FS, 0,
+					     SND_SOC_CLOCK_IN);
+		if (ret < 0) {
+			dev_err(codec_dai->dev, "can't set FS clock %d\n", ret);
+			break;
+		}
+		ret = snd_soc_dai_set_pll(codec_dai, 0, 0, runtime->rate,
+					  runtime->rate * 256);
+		if (ret < 0)
+			dev_err(codec_dai->dev, "can't set FLL: %d\n", ret);
+		break;
+	}
 
 	return ret;
 }
 
-static const struct snd_soc_ops skylake_nau8825_ops = {
-	.hw_params = skylake_nau8825_hw_params,
+static struct snd_soc_ops skylake_nau8825_ops = {
+	.trigger = skylake_nau8825_trigger,
 };
 
 static const unsigned int channels_dmic[] = {
@@ -582,6 +604,7 @@ static struct snd_soc_dai_link skylake_dais[] = {
 		.init = skylake_ssm4567_codec_init,
 		.ignore_pmdown_time = 1,
 		.be_hw_params_fixup = skylake_ssp_fixup,
+		.ops = &skylake_nau8825_ops,
 		.dpcm_playback = 1,
 		.dpcm_capture = 1,
 		SND_SOC_DAILINK_REG(ssp0_pin, ssp0_codec, platform),
-- 
2.17.1

