ASoC: atmel: Remove system clock tree configuration for at91sam9g20ek

The MCLK of the WM8731 on the AT91SAM9G20-EK board is connected to the
PCK0 output of the SoC, intended in the reference software to be supplied
using PLLB and programmed to 12MHz. As originally written for use with a
board file the audio driver was responsible for configuring the entire tree
but in the conversion to the common clock framework the registration of
the named pck0 and pllb clocks was removed so the driver has failed to
instantiate ever since.

Since the WM8731 driver has had support for managing a MCLK provided via
the common clock framework for some time we can simply drop all the clock
management code from the machine driver other than configuration of the
sysclk rate, the CODEC driver still respects that configuration from the
machine driver.

Fixes: ff78a189 ("ARM: at91: remove old at91-specific clock driver")
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Link: https://lore.kernel.org/r/20220325154241.1600757-2-broonie@kernel.org

sound/soc/atmel/sam9g20_wm8731.c

@@ -46,35 +46,6 @@
  */
 #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),
@@ -135,7 +106,6 @@ static struct snd_soc_card snd_soc_at91sam9g20ek = {
 	.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),
@@ -148,7 +118,6 @@ static int at91sam9g20ek_audio_probe(struct platform_device *pdev)
 {
 	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;
 
@@ -162,31 +131,6 @@ static int at91sam9g20ek_audio_probe(struct platform_device *pdev)
 		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 */
@@ -230,9 +174,6 @@ static int at91sam9g20ek_audio_probe(struct platform_device *pdev)
 
 	return ret;
 
-err_mclk:
-	clk_put(mclk);
-	mclk = NULL;
 err:
 	atmel_ssc_put_audio(0);
 	return ret;
@@ -242,8 +183,6 @@ static int at91sam9g20ek_audio_remove(struct platform_device *pdev)
 {
 	struct snd_soc_card *card = platform_get_drvdata(pdev);
 
-	clk_disable(mclk);
-	mclk = NULL;
 	snd_soc_unregister_card(card);
 	atmel_ssc_put_audio(0);