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From: Dmitry Osipenko <digetx@gmail.com>
To: Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Mark Brown <broonie@kernel.org>, Takashi Iwai <tiwai@suse.com>,
	Jaroslav Kysela <perex@perex.cz>,
	Liam Girdwood <lgirdwood@gmail.com>, Agneli <poczt@protonmail.ch>,
	Rob Herring <robh+dt@kernel.org>
Cc: linux-tegra@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
	alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org
Subject: [PATCH v1 12/20] ASoC: tegra20: spdif: Filter out unsupported rates
Date: Thu, 25 Nov 2021 01:00:49 +0300	[thread overview]
Message-ID: <20211124220057.15763-13-digetx@gmail.com> (raw)
In-Reply-To: <20211124220057.15763-1-digetx@gmail.com>

SPDIF and other SoC components share audio PLL on Tegra, thus only one
component may set the desired base clock rate. This creates problem for
HDMI audio because it uses SPDIF and audio may not work if SPDIF's clock
doesn't exactly match standard audio rate since some receivers may reject
audio in that case. Filter out audio rates which SPDIF output can't
support, assuming that other components won't change rate at runtime.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 sound/soc/tegra/tegra20_spdif.c | 61 +++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/sound/soc/tegra/tegra20_spdif.c b/sound/soc/tegra/tegra20_spdif.c
index 89f7fc5c8aad..f3e3c6df232b 100644
--- a/sound/soc/tegra/tegra20_spdif.c
+++ b/sound/soc/tegra/tegra20_spdif.c
@@ -79,6 +79,7 @@ static int tegra20_spdif_hw_params(struct snd_pcm_substream *substream,
 	struct tegra20_spdif *spdif = dev_get_drvdata(dai->dev);
 	unsigned int mask = 0, val = 0;
 	int ret, spdifclock;
+	long rate;
 
 	mask |= TEGRA20_SPDIF_CTRL_PACK |
 		TEGRA20_SPDIF_CTRL_BIT_MODE_MASK;
@@ -133,6 +134,12 @@ static int tegra20_spdif_hw_params(struct snd_pcm_substream *substream,
 		return ret;
 	}
 
+	rate = clk_get_rate(spdif->clk_spdif_out);
+	if (rate != spdifclock)
+		dev_warn(dai->dev,
+			 "SPDIF clock rate %d doesn't match requested rate %lu\n",
+			 spdifclock, rate);
+
 	return 0;
 }
 
@@ -172,6 +179,59 @@ static int tegra20_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
 	return 0;
 }
 
+static int tegra20_spdif_filter_rates(struct snd_pcm_hw_params *params,
+				      struct snd_pcm_hw_rule *rule)
+{
+	struct snd_interval *r = hw_param_interval(params, rule->var);
+	struct snd_soc_dai *dai = rule->private;
+	struct tegra20_spdif *spdif = dev_get_drvdata(dai->dev);
+	struct clk *parent = clk_get_parent(spdif->clk_spdif_out);
+	const unsigned int rates[] = { 32000, 44100, 48000 };
+	long i, parent_rate, valid_rates = 0;
+
+	parent_rate = clk_get_rate(parent);
+	if (parent_rate <= 0) {
+		dev_err(dai->dev, "Can't get parent clock rate: %ld\n",
+			parent_rate);
+		return parent_rate ?: -EINVAL;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(rates); i++) {
+		if (parent_rate % (rates[i] * 128) == 0)
+			valid_rates |= BIT(i);
+	}
+
+	/*
+	 * At least one rate must be valid, otherwise the parent clock isn't
+	 * audio PLL. Nothing should be filtered in this case.
+	 */
+	if (!valid_rates)
+		valid_rates = BIT(ARRAY_SIZE(rates)) - 1;
+
+	return snd_interval_list(r, ARRAY_SIZE(rates), rates, valid_rates);
+}
+
+static int tegra20_spdif_startup(struct snd_pcm_substream *substream,
+				 struct snd_soc_dai *dai)
+{
+	if (!device_property_read_bool(dai->dev, "nvidia,fixed-parent-rate"))
+		return 0;
+
+	/*
+	 * SPDIF and I2S share audio PLL. HDMI takes audio packets from SPDIF
+	 * and audio may not work on some TVs if clock rate isn't precise.
+	 *
+	 * PLL rate is controlled by I2S side. Filter out audio rates that
+	 * don't match PLL rate at the start of stream to allow both SPDIF
+	 * and I2S work simultaneously, assuming that PLL rate won't be
+	 * changed later on.
+	 */
+	return snd_pcm_hw_rule_add(substream->runtime, 0,
+				   SNDRV_PCM_HW_PARAM_RATE,
+				   tegra20_spdif_filter_rates, dai,
+				   SNDRV_PCM_HW_PARAM_RATE, -1);
+}
+
 static int tegra20_spdif_probe(struct snd_soc_dai *dai)
 {
 	struct tegra20_spdif *spdif = dev_get_drvdata(dai->dev);
@@ -185,6 +245,7 @@ static int tegra20_spdif_probe(struct snd_soc_dai *dai)
 static const struct snd_soc_dai_ops tegra20_spdif_dai_ops = {
 	.hw_params = tegra20_spdif_hw_params,
 	.trigger = tegra20_spdif_trigger,
+	.startup = tegra20_spdif_startup,
 };
 
 static struct snd_soc_dai_driver tegra20_spdif_dai = {
-- 
2.33.1


  parent reply	other threads:[~2021-11-24 22:07 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-24 22:00 [PATCH v1 00/20] Support HDMI audio on NVIDIA Tegra20 Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 01/20] ASoC: dt-bindings: Add binding for Tegra20 S/PDIF Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 02/20] ASoC: dt-bindings: tegra20-i2s: Convert to schema Dmitry Osipenko
2021-11-25 21:26   ` Rob Herring
2021-11-26  1:08     ` Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 03/20] ASoC: dt-bindings: tegra20-i2s: Document new nvidia,fixed-parent-rate property Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 04/20] dt-bindings: host1x: Document optional HDMI sound-dai-cells Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 05/20] ASoC: tegra20-spdif: stop setting slave_id Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 06/20] ASoC: tegra20: spdif: Support device-tree Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 07/20] ASoC: tegra20: spdif: Set FIFO trigger level Dmitry Osipenko
2021-11-25 12:02   ` Mark Brown
2021-11-25 12:04     ` Dmitry Osipenko
2021-11-25 12:28       ` Mark Brown
2021-11-25 12:53         ` Dmitry Osipenko
2021-11-25 13:18           ` Mark Brown
2021-11-25 13:36             ` Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 08/20] ASoC: tegra20: spdif: Improve driver's code Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 09/20] ASoC: tegra20: spdif: Use more resource-managed helpers Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 10/20] ASoC: tegra20: spdif: Reset hardware Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 11/20] ASoC: tegra20: spdif: Support system suspend Dmitry Osipenko
2021-11-24 22:00 ` Dmitry Osipenko [this message]
2021-11-24 22:00 ` [PATCH v1 13/20] ASoC: tegra20: i2s: Filter out unsupported rates Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 14/20] drm/tegra: hdmi: Unwind tegra_hdmi_init() errors Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 15/20] drm/tegra: hdmi: Register audio CODEC on Tegra20 Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 16/20] ARM: tegra_defconfig: Enable S/PDIF driver Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 17/20] ARM: tegra: Add S/PDIF node to Tegra20 device-tree Dmitry Osipenko
2021-11-25 11:43   ` Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 18/20] ARM: tegra: Add HDMI audio graph " Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 19/20] ARM: tegra: acer-a500: Enable S/PDIF and HDMI audio Dmitry Osipenko
2021-11-24 22:00 ` [PATCH v1 20/20] ARM: tegra: paz00: " Dmitry Osipenko

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