ASoC: simple-card: set cpu dai clk in hw_params

The simple-card driver currently accepts a clock node in the cpu dai sub-node and only uses it as an alternative to the 'system-clock-frequency' property to get the current frequency.

This patch adds another use of the passed clock node. If mclk-fs is specified, the clocks in cpu and codec dai sub-nodes will be set to the calculated rate (stream rate * mclk_fs) in hw_params.

This allows platforms to pass tuneable clocks as phandle that will automatically be set to the right rates.

---

This is the only patch that's left from the series of three that I posted earlier.

v1 → v2:

* Apply the setting to both the codec and the cpu dai
* Check for errors from clk_set_rate() and avoid unnecessary rate changes.

 .../devicetree/bindings/sound/simple-card.txt       |  5 +++++
 sound/soc/generic/simple-card.c                     | 21 +++++++++++++++++++++
 2 files changed, 26 insertions(+)

index 17c13e74667d..a4c72d09cd45 100644
@@ -86,6 +86,11 @@ Optional CPU/CODEC subnodes properties:
 					  in dai startup() and disabled with
 					  clk_disable_unprepare() in dai
 					  shutdown().
+					  If a clock is specified and a
+					  multiplication factor is given with
+					  mclk-fs, the clock will be set to the
+					  calculated mclk frequency when the
+					  stream starts.
 - system-clock-direction-out		: specifies clock direction as 'out' on
 					  initialization. It is useful for some aCPUs with
 					  fixed clocks.

index 6959a74a6f49..4a516c428b3d 100644
@@ -135,6 +135,18 @@ static void asoc_simple_card_shutdown(struct snd_pcm_substream *substream)
 	asoc_simple_card_clk_disable(&dai_props->codec_dai);
 }
 
+static int asoc_simple_set_clk_rate(struct asoc_simple_dai *simple_dai,
+				    unsigned long rate)
+{
+	if (!simple_dai->clk)
+		return 0;
+
+	if (clk_get_rate(simple_dai->clk) == rate)
+		return 0;
+
+	return clk_set_rate(simple_dai->clk, rate);
+}
+
 static int asoc_simple_card_hw_params(struct snd_pcm_substream *substream,
 				      struct snd_pcm_hw_params *params)
 {

@@ -154,6 +166,15 @@ static int asoc_simple_card_hw_params(struct snd_pcm_substream *substream,
 
 	if (mclk_fs) {
 		mclk = params_rate(params) * mclk_fs;
+
+		ret = asoc_simple_set_clk_rate(&dai_props->codec_dai, mclk);
+		if (ret < 0)
+			return ret;
+
+		ret = asoc_simple_set_clk_rate(&dai_props->cpu_dai, mclk);
+		if (ret < 0)
+			return ret;
+
 		ret = snd_soc_dai_set_sysclk(codec_dai, 0, mclk,
 					     SND_SOC_CLOCK_IN);
 		if (ret && ret != -ENOTSUPP)

2.14.3

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The patch

ASoC: simple-card: set cpu dai clk in hw_params

has been applied to the asoc tree at

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

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

From: Daniel Mack <[email protected]>
Date: Wed, 30 May 2018 21:45:56 +0200
Subject: [PATCH] ASoC: simple-card: set cpu dai clk in hw_params

The simple-card driver currently accepts a clock node in the cpu dai sub-node and only uses it as an alternative to the 'system-clock-frequency' property to get the current frequency.

This patch adds another use of the passed clock node. If mclk-fs is specified, the clocks in cpu and codec dai sub-nodes will be set to the calculated rate (stream rate * mclk_fs) in hw_params.

This allows platforms to pass tuneable clocks as phandle that will automatically be set to the right rates.

---
 .../devicetree/bindings/sound/simple-card.txt |  5 +++++
 sound/soc/generic/simple-card.c               | 21 +++++++++++++++++++
 2 files changed, 26 insertions(+)

index 17c13e74667d..a4c72d09cd45 100644
@@ -86,6 +86,11 @@ Optional CPU/CODEC subnodes properties:
 					  in dai startup() and disabled with
 					  clk_disable_unprepare() in dai
 					  shutdown().
+					  If a clock is specified and a
+					  multiplication factor is given with
+					  mclk-fs, the clock will be set to the
+					  calculated mclk frequency when the
+					  stream starts.
 - system-clock-direction-out		: specifies clock direction as 'out' on
 					  initialization. It is useful for some aCPUs with
 					  fixed clocks.

index 6959a74a6f49..4a516c428b3d 100644
@@ -135,6 +135,18 @@ static void asoc_simple_card_shutdown(struct snd_pcm_substream *substream)
 	asoc_simple_card_clk_disable(&dai_props->codec_dai);
 }
 
+static int asoc_simple_set_clk_rate(struct asoc_simple_dai *simple_dai,
+				    unsigned long rate)
+{
+	if (!simple_dai->clk)
+		return 0;
+
+	if (clk_get_rate(simple_dai->clk) == rate)
+		return 0;
+
+	return clk_set_rate(simple_dai->clk, rate);
+}
+
 static int asoc_simple_card_hw_params(struct snd_pcm_substream *substream,
 				      struct snd_pcm_hw_params *params)
 {

@@ -154,6 +166,15 @@ static int asoc_simple_card_hw_params(struct snd_pcm_substream *substream,
 
 	if (mclk_fs) {
 		mclk = params_rate(params) * mclk_fs;
+
+		ret = asoc_simple_set_clk_rate(&dai_props->codec_dai, mclk);
+		if (ret < 0)
+			return ret;
+
+		ret = asoc_simple_set_clk_rate(&dai_props->cpu_dai, mclk);
+		if (ret < 0)
+			return ret;
+
 		ret = snd_soc_dai_set_sysclk(codec_dai, 0, mclk,
 					     SND_SOC_CLOCK_IN);
 		if (ret && ret != -ENOTSUPP)

2.17.0