[PATCH 5.4 142/194] Revert "ASoC: atmel: Remove system clock tree configuration for at91sam9g20ek"

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

5.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

This reverts commit 6a20bf46c6254e4e99613309c334519a5f54be53 which is
commit c775cbf62ed4911e4f0f23880f01815753123690 upstream.

It is reported to cause problems, so drop it from the 5.4.y tree for now.

Link: https://lore.kernel.org/r/845b3053-d47b-4717-9665-79b120da133b@xxxxxxxxxxxxx
Reported-by: Mark Brown <broonie@xxxxxxxxxx>
Cc: Codrin Ciubotariu <codrin.ciubotariu@xxxxxxxxxxxxx>
Cc: Sasha Levin <sashal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 sound/soc/atmel/sam9g20_wm8731.c |   61 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

--- a/sound/soc/atmel/sam9g20_wm8731.c
+++ b/sound/soc/atmel/sam9g20_wm8731.c
@@ -46,6 +46,35 @@
  */
 #undef ENABLE_MIC_INPUT
 
+static struct clk *mclk;
+
+static int at91sam9g20ek_set_bias_level(struct snd_soc_card *card,
+					struct snd_soc_dapm_context *dapm,
+					enum snd_soc_bias_level level)
+{
+	static int mclk_on;
+	int ret = 0;
+
+	switch (level) {
+	case SND_SOC_BIAS_ON:
+	case SND_SOC_BIAS_PREPARE:
+		if (!mclk_on)
+			ret = clk_enable(mclk);
+		if (ret == 0)
+			mclk_on = 1;
+		break;
+
+	case SND_SOC_BIAS_OFF:
+	case SND_SOC_BIAS_STANDBY:
+		if (mclk_on)
+			clk_disable(mclk);
+		mclk_on = 0;
+		break;
+	}
+
+	return ret;
+}
+
 static const struct snd_soc_dapm_widget at91sam9g20ek_dapm_widgets[] = {
 	SND_SOC_DAPM_MIC("Int Mic", NULL),
 	SND_SOC_DAPM_SPK("Ext Spk", NULL),
@@ -106,6 +135,7 @@ static struct snd_soc_card snd_soc_at91s
 	.owner = THIS_MODULE,
 	.dai_link = &at91sam9g20ek_dai,
 	.num_links = 1,
+	.set_bias_level = at91sam9g20ek_set_bias_level,
 
 	.dapm_widgets = at91sam9g20ek_dapm_widgets,
 	.num_dapm_widgets = ARRAY_SIZE(at91sam9g20ek_dapm_widgets),
@@ -118,6 +148,7 @@ static int at91sam9g20ek_audio_probe(str
 {
 	struct device_node *np = pdev->dev.of_node;
 	struct device_node *codec_np, *cpu_np;
+	struct clk *pllb;
 	struct snd_soc_card *card = &snd_soc_at91sam9g20ek;
 	int ret;
 
@@ -131,6 +162,31 @@ static int at91sam9g20ek_audio_probe(str
 		return -EINVAL;
 	}
 
+	/*
+	 * Codec MCLK is supplied by PCK0 - set it up.
+	 */
+	mclk = clk_get(NULL, "pck0");
+	if (IS_ERR(mclk)) {
+		dev_err(&pdev->dev, "Failed to get MCLK\n");
+		ret = PTR_ERR(mclk);
+		goto err;
+	}
+
+	pllb = clk_get(NULL, "pllb");
+	if (IS_ERR(pllb)) {
+		dev_err(&pdev->dev, "Failed to get PLLB\n");
+		ret = PTR_ERR(pllb);
+		goto err_mclk;
+	}
+	ret = clk_set_parent(mclk, pllb);
+	clk_put(pllb);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "Failed to set MCLK parent\n");
+		goto err_mclk;
+	}
+
+	clk_set_rate(mclk, MCLK_RATE);
+
 	card->dev = &pdev->dev;
 
 	/* Parse device node info */
@@ -174,6 +230,9 @@ static int at91sam9g20ek_audio_probe(str
 
 	return ret;
 
+err_mclk:
+	clk_put(mclk);
+	mclk = NULL;
 err:
 	atmel_ssc_put_audio(0);
 	return ret;
@@ -183,6 +242,8 @@ static int at91sam9g20ek_audio_remove(st
 {
 	struct snd_soc_card *card = platform_get_drvdata(pdev);
 
+	clk_disable(mclk);
+	mclk = NULL;
 	snd_soc_unregister_card(card);
 	atmel_ssc_put_audio(0);