MLK-19154-3: ASoC: fsl_spdif: Add support for PLL switch at runtime.

iMX8 platforms typically have 2 AUDIO PLLs being configured to handle
8k and 11k audio rates. The patch implements the functionality to
select at runtime the appropriate AUDIO PLL as function of audio
file rate.

Signed-off-by: Viorel Suman <viorel.suman@nxp.com>

1 files changed, 188 insertions, 103 deletions

diff --git a/sound/soc/fsl/fsl_spdif.c b/sound/soc/fsl/fsl_spdif.c
index 4111f4a5107f..bb5713f8c4fe 100644
--- a/sound/soc/fsl/fsl_spdif.c
+++ b/sound/soc/fsl/fsl_spdif.c
@@ -15,6 +15,7 @@
 
 #include <linux/bitrev.h>
 #include <linux/clk.h>
+#include <linux/clk-provider.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_device.h>
@@ -128,6 +129,9 @@ struct fsl_spdif_priv {
 	struct snd_dmaengine_dai_dma_data dma_params_rx;
 	/* regcache for SRPC */
 	u32 regcache_srpc;
+	struct clk *pll8k_clk;
+	struct clk *pll11k_clk;
+	u8 streams;
 };
 
 static struct fsl_spdif_soc_data fsl_spdif_vf610 = {
@@ -634,6 +638,9 @@ static int fsl_spdif_hw_params(struct snd_pcm_substream *substream,
 		ret = spdif_set_rx_clksrc(spdif_priv, SPDIF_DEFAULT_GAINSEL, 1);
 	}
 
+	if (!ret)
+		spdif_priv->streams |= BIT(substream->stream);
+
 	return ret;
 }
 
@@ -676,18 +683,190 @@ static int fsl_spdif_hw_free(struct snd_pcm_substream *substream,
 	if (spdif_priv->soc->dma_workaround)
 		clear_gpt_dma(substream, spdif_priv->dma_info);
 
+	spdif_priv->streams &= ~BIT(substream->stream);
+
+	return 0;
+}
+
+static u32 fsl_spdif_txclk_caldiv(struct fsl_spdif_priv *spdif_priv,
+				struct clk *clk, u64 savesub,
+				enum spdif_txrate index, bool round)
+{
+	const u32 rate[] = { 32000, 44100, 48000, 96000, 192000 };
+	bool is_sysclk = clk_is_match(clk, spdif_priv->sysclk);
+	u64 rate_actual, sub;
+	u32 arate;
+	u16 sysclk_dfmin, sysclk_dfmax, sysclk_df;
+	u8 txclk_df;
+
+	/* The sysclk has an extra divisor [2, 512] */
+	sysclk_dfmin = is_sysclk ? 2 : 1;
+	sysclk_dfmax = is_sysclk ? 512 : 1;
+
+	for (sysclk_df = sysclk_dfmin; sysclk_df <= sysclk_dfmax; sysclk_df++) {
+		for (txclk_df = 1; txclk_df <= 128; txclk_df++) {
+			rate_actual = clk_get_rate(clk);
+
+			arate = rate_actual / 64;
+			arate /= txclk_df * sysclk_df;
+
+			if (arate == rate[index]) {
+				/* We are lucky */
+				savesub = 0;
+				spdif_priv->txclk_df[index] = txclk_df;
+				spdif_priv->sysclk_df[index] = sysclk_df;
+				spdif_priv->txrate[index] = arate;
+				goto out;
+			} else if (arate / rate[index] == 1) {
+				/* A little bigger than expect */
+				sub = (u64)(arate - rate[index]) * 100000;
+				do_div(sub, rate[index]);
+				if (sub >= savesub)
+					continue;
+				savesub = sub;
+				spdif_priv->txclk_df[index] = txclk_df;
+				spdif_priv->sysclk_df[index] = sysclk_df;
+				spdif_priv->txrate[index] = arate;
+			} else if (rate[index] / arate == 1) {
+				/* A little smaller than expect */
+				sub = (u64)(rate[index] - arate) * 100000;
+				do_div(sub, rate[index]);
+				if (sub >= savesub)
+					continue;
+				savesub = sub;
+				spdif_priv->txclk_df[index] = txclk_df;
+				spdif_priv->sysclk_df[index] = sysclk_df;
+				spdif_priv->txrate[index] = arate;
+			}
+		}
+	}
+
+out:
+	return savesub;
+}
+
+static int fsl_spdif_probe_txclk(struct fsl_spdif_priv *spdif_priv,
+				enum spdif_txrate index)
+{
+	const u32 rate[] = { 32000, 44100, 48000, 96000, 192000 };
+	struct platform_device *pdev = spdif_priv->pdev;
+	struct device *dev = &pdev->dev;
+	u64 savesub = 100000, ret;
+	struct clk *clk;
+	int i;
+
+	for (i = 0; i < STC_TXCLK_SRC_MAX; i++) {
+		clk = spdif_priv->txclk[i];
+		if (IS_ERR(clk)) {
+			dev_err(dev, "no rxtx%d clock in devicetree\n", i);
+			return PTR_ERR(clk);
+		}
+		if (!clk_get_rate(clk))
+			continue;
+
+		ret = fsl_spdif_txclk_caldiv(spdif_priv, clk, savesub, index,
+					     i == STC_TXCLK_SPDIF_ROOT);
+		if (savesub == ret)
+			continue;
+
+		savesub = ret;
+		spdif_priv->txclk_src[index] = i;
+
+		/* To quick catch a divisor, we allow a 0.1% deviation */
+		if (savesub < 100)
+			break;
+	}
+
+	dev_dbg(&pdev->dev, "use rxtx%d as tx clock source for %dHz sample rate\n",
+			spdif_priv->txclk_src[index], rate[index]);
+	dev_dbg(&pdev->dev, "use txclk df %d for %dHz sample rate\n",
+			spdif_priv->txclk_df[index], rate[index]);
+	if (clk_is_match(spdif_priv->txclk[spdif_priv->txclk_src[index]], spdif_priv->sysclk))
+		dev_dbg(&pdev->dev, "use sysclk df %d for %dHz sample rate\n",
+				spdif_priv->sysclk_df[index], rate[index]);
+	dev_dbg(&pdev->dev, "the best rate for %dHz sample rate is %dHz\n",
+			rate[index], spdif_priv->txrate[index]);
+
+	return 0;
+}
+
+static int fsl_spdif_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
+		int clk_id, unsigned int freq, int dir)
+{
+	struct fsl_spdif_priv *data = snd_soc_dai_get_drvdata(cpu_dai);
+	struct platform_device *pdev = data->pdev;
+	struct device *dev = &pdev->dev;
+	struct clk *clk, *p, *pll = 0, *npll = 0;
+	u64 ratio = freq;
+	int ret, i;
+
+	if (dir != SND_SOC_CLOCK_OUT || freq == 0 || clk_id != STC_TXCLK_SPDIF_ROOT)
+		return 0;
+
+	if (data->pll8k_clk == NULL || data->pll11k_clk == NULL)
+		return 0;
+
+	clk = data->txclk[clk_id];
+	if (IS_ERR_OR_NULL(clk)) {
+		dev_err(dev, "no rxtx%d clock in devicetree\n", clk_id);
+		return PTR_ERR(clk);
+	}
+
+	p = clk;
+	while (p && data->pll8k_clk && data->pll11k_clk) {
+		struct clk *pp = clk_get_parent(p);
+
+		if (clk_is_match(pp, data->pll8k_clk) ||
+		    clk_is_match(pp, data->pll11k_clk)) {
+			pll = pp;
+			break;
+		}
+		p = pp;
+	}
+
+	if (pll) {
+		npll = (do_div(ratio, 8000) ? data->pll11k_clk : data->pll8k_clk);
+		if (!clk_is_match(pll, npll)) {
+			if (!data->streams) {
+				ret = clk_set_parent(p, npll);
+				if (ret < 0)
+					dev_warn(cpu_dai->dev,
+						"failed to set parent %s: %d\n",
+						__clk_get_name(npll), ret);
+			} else {
+				dev_err(cpu_dai->dev,
+					"PLL %s is in use by a running stream.\n",
+					__clk_get_name(pll));
+				return -EINVAL;
+			}
+		}
+	}
+
+	ret = clk_set_rate(clk, freq);
+	if (ret < 0) {
+		dev_err(cpu_dai->dev, "failed to set clock rate (%u): %d\n",
+			freq, ret);
+		return ret;
+	}
+
+	for (i = 0; i < SPDIF_TXRATE_MAX; i++) {
+		ret = fsl_spdif_probe_txclk(data, i);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
 static struct snd_soc_dai_ops fsl_spdif_dai_ops = {
 	.startup = fsl_spdif_startup,
+	.set_sysclk = fsl_spdif_set_dai_sysclk,
 	.hw_params = fsl_spdif_hw_params,
 	.trigger = fsl_spdif_trigger,
 	.shutdown = fsl_spdif_shutdown,
 	.hw_free = fsl_spdif_hw_free,
 };
 
-
 /*
  * FSL SPDIF IEC958 controller(mixer) functions
  *
@@ -1219,108 +1398,6 @@ static const struct regmap_config fsl_spdif_regmap_config = {
 	.cache_type = REGCACHE_FLAT,
 };
 
-static u32 fsl_spdif_txclk_caldiv(struct fsl_spdif_priv *spdif_priv,
-				struct clk *clk, u64 savesub,
-				enum spdif_txrate index, bool round)
-{
-	const u32 rate[] = { 32000, 44100, 48000, 96000, 192000 };
-	bool is_sysclk = clk_is_match(clk, spdif_priv->sysclk);
-	u64 rate_actual, sub;
-	u32 arate;
-	u16 sysclk_dfmin, sysclk_dfmax, sysclk_df;
-	u8 txclk_df;
-
-	/* The sysclk has an extra divisor [2, 512] */
-	sysclk_dfmin = is_sysclk ? 2 : 1;
-	sysclk_dfmax = is_sysclk ? 512 : 1;
-
-	for (sysclk_df = sysclk_dfmin; sysclk_df <= sysclk_dfmax; sysclk_df++) {
-		for (txclk_df = 1; txclk_df <= 128; txclk_df++) {
-			rate_actual = clk_get_rate(clk);
-
-			arate = rate_actual / 64;
-			arate /= txclk_df * sysclk_df;
-
-			if (arate == rate[index]) {
-				/* We are lucky */
-				savesub = 0;
-				spdif_priv->txclk_df[index] = txclk_df;
-				spdif_priv->sysclk_df[index] = sysclk_df;
-				spdif_priv->txrate[index] = arate;
-				goto out;
-			} else if (arate / rate[index] == 1) {
-				/* A little bigger than expect */
-				sub = (u64)(arate - rate[index]) * 100000;
-				do_div(sub, rate[index]);
-				if (sub >= savesub)
-					continue;
-				savesub = sub;
-				spdif_priv->txclk_df[index] = txclk_df;
-				spdif_priv->sysclk_df[index] = sysclk_df;
-				spdif_priv->txrate[index] = arate;
-			} else if (rate[index] / arate == 1) {
-				/* A little smaller than expect */
-				sub = (u64)(rate[index] - arate) * 100000;
-				do_div(sub, rate[index]);
-				if (sub >= savesub)
-					continue;
-				savesub = sub;
-				spdif_priv->txclk_df[index] = txclk_df;
-				spdif_priv->sysclk_df[index] = sysclk_df;
-				spdif_priv->txrate[index] = arate;
-			}
-		}
-	}
-
-out:
-	return savesub;
-}
-
-static int fsl_spdif_probe_txclk(struct fsl_spdif_priv *spdif_priv,
-				enum spdif_txrate index)
-{
-	const u32 rate[] = { 32000, 44100, 48000, 96000, 192000 };
-	struct platform_device *pdev = spdif_priv->pdev;
-	struct device *dev = &pdev->dev;
-	u64 savesub = 100000, ret;
-	struct clk *clk;
-	int i;
-
-	for (i = 0; i < STC_TXCLK_SRC_MAX; i++) {
-		clk = spdif_priv->txclk[i];
-		if (IS_ERR(clk)) {
-			dev_err(dev, "no rxtx%d clock in devicetree\n", i);
-			return PTR_ERR(clk);
-		}
-		if (!clk_get_rate(clk))
-			continue;
-
-		ret = fsl_spdif_txclk_caldiv(spdif_priv, clk, savesub, index,
-					     i == STC_TXCLK_SPDIF_ROOT);
-		if (savesub == ret)
-			continue;
-
-		savesub = ret;
-		spdif_priv->txclk_src[index] = i;
-
-		/* To quick catch a divisor, we allow a 0.1% deviation */
-		if (savesub < 100)
-			break;
-	}
-
-	dev_dbg(&pdev->dev, "use rxtx%d as tx clock source for %dHz sample rate\n",
-			spdif_priv->txclk_src[index], rate[index]);
-	dev_dbg(&pdev->dev, "use txclk df %d for %dHz sample rate\n",
-			spdif_priv->txclk_df[index], rate[index]);
-	if (clk_is_match(spdif_priv->txclk[spdif_priv->txclk_src[index]], spdif_priv->sysclk))
-		dev_dbg(&pdev->dev, "use sysclk df %d for %dHz sample rate\n",
-				spdif_priv->sysclk_df[index], rate[index]);
-	dev_dbg(&pdev->dev, "the best rate for %dHz sample rate is %dHz\n",
-			rate[index], spdif_priv->txrate[index]);
-
-	return 0;
-}
-
 static const struct of_device_id fsl_spdif_dt_ids[] = {
 	{ .compatible = "fsl,imx8qxp-v1-spdif", .data = &fsl_spdif_imx8qxp_v1, },
 	{ .compatible = "fsl,imx8mm-spdif", .data = &fsl_spdif_imx8mm, },
@@ -1441,6 +1518,14 @@ static int fsl_spdif_probe(struct platform_device *pdev)
 	}
 	spdif_priv->rxclk_src = DEFAULT_RXCLK_SRC;
 
+	spdif_priv->pll8k_clk = devm_clk_get(&pdev->dev, "pll8k");
+	if (IS_ERR(spdif_priv->pll8k_clk))
+		spdif_priv->pll8k_clk = NULL;
+
+	spdif_priv->pll11k_clk = devm_clk_get(&pdev->dev, "pll11k");
+	if (IS_ERR(spdif_priv->pll11k_clk))
+		spdif_priv->pll11k_clk = NULL;
+
 	for (i = 0; i < SPDIF_TXRATE_MAX; i++) {
 		ret = fsl_spdif_probe_txclk(spdif_priv, i);
 		if (ret)