[alsa-devel][PATCH v2] ASoC: wm8960: update pll and clock setting function

[Zidan Wang]

Add sysclk auto mode. When it's sysclk auto mode, if the MCLK is
available for clock configure, using MCLK to provide sysclk directly,
otherwise, search a available pll out frequcncy and set pll.

TX and RX share the same sysclk and bclk divider register, and have
different DAC/ADC divier register. When playback and capture
simultaneously, the second stream should not set pll, should not
change the sysclk and bclk, just need set DAC/ADC divider to support
different TX and RX sample rate.

Signed-off-by: Zidan Wang <zidan.wang@xxxxxxxxxxxxx>
---
 sound/soc/codecs/wm8960.c | 256 ++++++++++++++++++++++++++++++++++++++--------
 sound/soc/codecs/wm8960.h |   1 +
 2 files changed, 214 insertions(+), 43 deletions(-)

diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index 94c5c46..e170bdf 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -48,6 +48,9 @@
 #define WM8960_DISOP     0x40
 #define WM8960_DRES_MASK 0x30
 
+static bool is_pll_freq_available(unsigned int source, unsigned int target);
+static int wm8960_set_pll(struct snd_soc_dai *codec_dai,
+		unsigned int freq_in, unsigned int freq_out);
 /*
  * wm8960 register cache
  * We can't read the WM8960 register space when we are
@@ -126,9 +129,12 @@ struct wm8960_priv {
 	struct snd_soc_dapm_widget *rout1;
 	struct snd_soc_dapm_widget *out3;
 	bool deemph;
-	int playback_fs;
-	int bclk;
 	int sysclk;
+	int clk_id;
+	int freq_in;
+	int fs[2];
+	int dac_div[2];
+	bool is_stream_in_use[2];
 	struct wm8960_data pdata;
 };
 
@@ -164,8 +170,8 @@ static int wm8960_set_deemph(struct snd_soc_codec *codec)
 	if (wm8960->deemph) {
 		best = 1;
 		for (i = 2; i < ARRAY_SIZE(deemph_settings); i++) {
-			if (abs(deemph_settings[i] - wm8960->playback_fs) <
-			    abs(deemph_settings[best] - wm8960->playback_fs))
+			if (abs(deemph_settings[i] - wm8960->fs[1]) <
+			    abs(deemph_settings[best] - wm8960->fs[1]))
 				best = i;
 		}
 
@@ -565,6 +571,9 @@ static struct {
 	{  8000, 5 },
 };
 
+/* -1 for reserved value */
+static const int sysclk_divs[] = { 1, -1, 2, -1 };
+
 /* Multiply 256 for internal 256 div */
 static const int dac_divs[] = { 256, 384, 512, 768, 1024, 1408, 1536 };
 
@@ -574,61 +583,166 @@ static const int bclk_divs[] = {
 	120, 160, 220, 240, 320, 320, 320
 };
 
-static void wm8960_configure_clocking(struct snd_soc_codec *codec,
-		bool tx, int lrclk)
+static int wm8960_configure_clocking(struct snd_pcm_substream *substream,
+		struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
 {
+	struct snd_soc_codec *codec = dai->codec;
 	struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
+	unsigned int sample_rate = params_rate(params);
+	unsigned int channels = params_channels(params);
+	unsigned int sysclk, bclk, freq_out, freq_in;
+	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 	u16 iface1 = snd_soc_read(codec, WM8960_IFACE1);
 	u16 iface2 = snd_soc_read(codec, WM8960_IFACE2);
-	u32 sysclk;
-	int i, j;
+	int i, j, k;
 
 	if (!(iface1 & (1<<6))) {
 		dev_dbg(codec->dev,
 			"Codec is slave mode, no need to configure clock\n");
-		return;
+		return 0;
+	}
+
+	/*
+	 * playback and capture using the same registers of bclk and sysclk
+	 * div, and different registers for dac/adc div. If playback and capture
+	 * simultaneously, the second should not set pll, should not change
+	 * the sysclk and bclk, only dac/adc div can be set to support different
+	 * frame clock.
+	 */
+	if (wm8960->is_stream_in_use[!tx]) {
+		/*
+		 * If ADCLRC configure as GPIO pin, DACLRC pin is used as a
+		 * frame clock for ADCs and DACs.
+		 */
+		if (iface2 & (1 << 6)) {
+			snd_soc_update_bits(codec, WM8960_CLOCK1,
+					0x7 << 3, wm8960->dac_div[!tx] << 3);
+			return 0;
+		}
+
+		/*
+		 * If the different TX and RX sample rate can be support,
+		 * setting corresponding DAC or ADC divider.
+		 */
+		for (i = 0; i < ARRAY_SIZE(dac_divs); ++i) {
+			if (wm8960->fs[!tx] * dac_divs[wm8960->dac_div[!tx]]
+					== wm8960->fs[tx] * dac_divs[i]) {
+				if (tx)
+					snd_soc_update_bits(codec,
+						WM8960_CLOCK1,
+						0x7 << 3, dac_divs[i] << 3);
+				else
+					snd_soc_update_bits(codec,
+						WM8960_CLOCK1,
+						0x7 << 6, dac_divs[i] << 6);
+				wm8960->dac_div[tx] = dac_divs[i];
+				return 0;
+			}
+		}
+		if (i == ARRAY_SIZE(dac_divs)) {
+			dev_err(codec->dev,
+				"can't support TX=%d RX=%d\n simultaneously",
+				wm8960->fs[1], wm8960->fs[0]);
+			return -EINVAL;
+		}
+	}
+
+	if (wm8960->clk_id != WM8960_SYSCLK_MCLK && !wm8960->freq_in) {
+		dev_err(codec->dev, "No MCLK configured\n");
+		return -EINVAL;
 	}
 
-	if (!wm8960->sysclk) {
-		dev_dbg(codec->dev, "No SYSCLK configured\n");
-		return;
+	freq_in = wm8960->freq_in;
+
+	bclk = snd_soc_params_to_bclk(params);
+	if (channels == 1)
+		bclk *= 2;
+
+	/*
+	 * If it's sysclk auto mode, check if the MCLK can provide sysclk or
+	 * not. If MCLK can provide sysclk, using MCLK to provide sysclk
+	 * directly. Otherwise, auto select a available pll out frequency
+	 * and set PLL.
+	 */
+	if (wm8960->clk_id == WM8960_SYSCLK_AUTO) {
+		/* disable the PLL and using MCLK to provide sysclk */
+		wm8960_set_pll(dai, 0, 0);
+		freq_out = freq_in;
+	} else if (wm8960->sysclk)
+		freq_out = wm8960->sysclk;
+	else {
+		dev_err(codec->dev, "No SYSCLK configured\n");
+		return -EINVAL;
 	}
 
-	if (!wm8960->bclk || !lrclk) {
-		dev_dbg(codec->dev, "No audio clocks configured\n");
-		return;
+	/* check if the sysclk frequency is available. */
+	for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
+		if (sysclk_divs[i] == -1)
+			continue;
+		sysclk = freq_out / sysclk_divs[i];
+		for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {
+			if (sysclk == dac_divs[j] * sample_rate) {
+				for (k = 0; k < ARRAY_SIZE(bclk_divs); ++k)
+					if (sysclk == bclk * bclk_divs[k] / 10)
+						break;
+				if (k != ARRAY_SIZE(bclk_divs))
+					break;
+			}
+		}
+		if (j != ARRAY_SIZE(dac_divs))
+			break;
 	}
 
-	for (i = 0; i < ARRAY_SIZE(dac_divs); ++i) {
-		if (wm8960->sysclk == lrclk * dac_divs[i]) {
-			for (j = 0; j < ARRAY_SIZE(bclk_divs); ++j) {
-				sysclk = wm8960->bclk * bclk_divs[j] / 10;
-				if (wm8960->sysclk == sysclk)
+	if (i != ARRAY_SIZE(sysclk_divs))
+		goto configure_clock;
+	else if (wm8960->clk_id != WM8960_SYSCLK_AUTO) {
+		dev_err(codec->dev, "failed to configure clock\n");
+		return -EINVAL;
+	}
+	/* get a available pll out frequency and set pll */
+	for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
+		if (sysclk_divs[i] == -1)
+			continue;
+		for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {
+			sysclk = sample_rate * dac_divs[j];
+			freq_out = sysclk * sysclk_divs[i];
+
+			for (k = 0; k < ARRAY_SIZE(bclk_divs); ++k) {
+				if (sysclk == bclk * bclk_divs[k] / 10 &&
+				    is_pll_freq_available(freq_in, freq_out)) {
+					wm8960_set_pll(dai, freq_in, freq_out);
 					break;
+				} else
+					continue;
 			}
-			if(j != ARRAY_SIZE(bclk_divs))
+			if (k != ARRAY_SIZE(bclk_divs))
 				break;
 		}
+		if (j != ARRAY_SIZE(dac_divs))
+			break;
 	}
 
-	if (i == ARRAY_SIZE(dac_divs)) {
-		dev_err(codec->dev, "Unsupported sysclk %d\n", wm8960->sysclk);
-		return;
+	if (i == ARRAY_SIZE(sysclk_divs)) {
+		dev_err(codec->dev, "failed to configure clock\n");
+		return -EINVAL;
 	}
 
-	/*
-	 * configure frame clock. If ADCLRC configure as GPIO pin, DACLRC
-	 * pin is used as a frame clock for ADCs and DACs.
-	 */
-	if (iface2 & (1<<6))
-		snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 3, i << 3);
+configure_clock:
+	snd_soc_update_bits(codec, WM8960_CLOCK1, 3 << 1, i << 1);
+
+	if (iface2 & (1 << 6))
+		snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 3, j << 3);
 	else if (tx)
-		snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 3, i << 3);
+		snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 3, j << 3);
 	else if (!tx)
-		snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 6, i << 6);
+		snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 6, j << 6);
 
 	/* configure bit clock */
-	snd_soc_update_bits(codec, WM8960_CLOCK2, 0xf, j);
+	snd_soc_update_bits(codec, WM8960_CLOCK2, 0xf, k);
+
+	wm8960->dac_div[tx] = j;
+
+	return 0;
 }
 
 static int wm8960_hw_params(struct snd_pcm_substream *substream,
@@ -641,10 +755,6 @@ static int wm8960_hw_params(struct snd_pcm_substream *substream,
 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 	int i;
 
-	wm8960->bclk = snd_soc_params_to_bclk(params);
-	if (params_channels(params) == 1)
-		wm8960->bclk *= 2;
-
 	/* bit size */
 	switch (params_width(params)) {
 	case 16:
@@ -667,11 +777,11 @@ static int wm8960_hw_params(struct snd_pcm_substream *substream,
 		return -EINVAL;
 	}
 
+	wm8960->fs[tx] = params_rate(params);
 	/* Update filters for the new rate */
-	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
-		wm8960->playback_fs = params_rate(params);
+	if (tx)
 		wm8960_set_deemph(codec);
-	} else {
+	else {
 		for (i = 0; i < ARRAY_SIZE(alc_rates); i++)
 			if (alc_rates[i].rate == params_rate(params))
 				snd_soc_update_bits(codec,
@@ -682,7 +792,27 @@ static int wm8960_hw_params(struct snd_pcm_substream *substream,
 	/* set iface */
 	snd_soc_write(codec, WM8960_IFACE1, iface);
 
-	wm8960_configure_clocking(codec, tx, params_rate(params));
+	wm8960->is_stream_in_use[tx] = true;
+
+	return wm8960_configure_clocking(substream, params, dai);
+}
+
+static int wm8960_hw_free(struct snd_pcm_substream *substream,
+		struct snd_soc_dai *dai)
+{
+	struct snd_soc_codec *codec = dai->codec;
+	struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
+	u16 clock1 = snd_soc_read(codec, WM8960_CLOCK1);
+	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+
+	wm8960->is_stream_in_use[tx] = false;
+	/*
+	 * If it's sysclk auto mode, no stream in use, and the pll is enabled,
+	 * disable the pll
+	 */
+	if (wm8960->clk_id == WM8960_SYSCLK_AUTO && (clock1 & 0x1) &&
+	    !wm8960->is_stream_in_use[!tx])
+		wm8960_set_pll(dai, 0, 0);
 
 	return 0;
 }
@@ -892,6 +1022,28 @@ struct _pll_div {
 	u32 k:24;
 };
 
+static bool is_pll_freq_available(unsigned int source, unsigned int target)
+{
+	unsigned int Ndiv;
+
+	if (source == 0 || target == 0)
+		return false;
+
+	/* Scale up target to PLL operating frequency */
+	target *= 4;
+	Ndiv = target / source;
+
+	if (Ndiv < 6) {
+		source >>= 1;
+		Ndiv = target / source;
+	}
+
+	if ((Ndiv < 6) || (Ndiv > 12))
+		return false;
+
+	return true;
+}
+
 /* The size in bits of the pll divide multiplied by 10
  * to allow rounding later */
 #define FIXED_PLL_SIZE ((1 << 24) * 10)
@@ -943,8 +1095,8 @@ static int pll_factors(unsigned int source, unsigned int target,
 	return 0;
 }
 
-static int wm8960_set_dai_pll(struct snd_soc_dai *codec_dai, int pll_id,
-		int source, unsigned int freq_in, unsigned int freq_out)
+static int wm8960_set_pll(struct snd_soc_dai *codec_dai,
+		unsigned int freq_in, unsigned int freq_out)
 {
 	struct snd_soc_codec *codec = codec_dai->codec;
 	u16 reg;
@@ -986,6 +1138,20 @@ static int wm8960_set_dai_pll(struct snd_soc_dai *codec_dai, int pll_id,
 	return 0;
 }
 
+static int wm8960_set_dai_pll(struct snd_soc_dai *codec_dai, int pll_id,
+		int source, unsigned int freq_in, unsigned int freq_out)
+{
+	struct snd_soc_codec *codec = codec_dai->codec;
+	struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
+
+	wm8960->freq_in = freq_in;
+
+	if (wm8960->clk_id == WM8960_SYSCLK_AUTO)
+		return 0;
+
+	return wm8960_set_pll(codec_dai, freq_in, freq_out);
+}
+
 static int wm8960_set_dai_clkdiv(struct snd_soc_dai *codec_dai,
 		int div_id, int div)
 {
@@ -1043,11 +1209,14 @@ static int wm8960_set_dai_sysclk(struct snd_soc_dai *dai, int clk_id,
 		snd_soc_update_bits(codec, WM8960_CLOCK1,
 					0x1, WM8960_SYSCLK_PLL);
 		break;
+	case WM8960_SYSCLK_AUTO:
+		break;
 	default:
 		return -EINVAL;
 	}
 
 	wm8960->sysclk = freq;
+	wm8960->clk_id = clk_id;
 
 	return 0;
 }
@@ -1060,6 +1229,7 @@ static int wm8960_set_dai_sysclk(struct snd_soc_dai *dai, int clk_id,
 
 static const struct snd_soc_dai_ops wm8960_dai_ops = {
 	.hw_params = wm8960_hw_params,
+	.hw_free = wm8960_hw_free,
 	.digital_mute = wm8960_mute,
 	.set_fmt = wm8960_set_dai_fmt,
 	.set_clkdiv = wm8960_set_dai_clkdiv,
diff --git a/sound/soc/codecs/wm8960.h b/sound/soc/codecs/wm8960.h
index 2d8163d..ab3220d 100644
--- a/sound/soc/codecs/wm8960.h
+++ b/sound/soc/codecs/wm8960.h
@@ -82,6 +82,7 @@
 
 #define WM8960_SYSCLK_MCLK		(0 << 0)
 #define WM8960_SYSCLK_PLL		(1 << 0)
+#define WM8960_SYSCLK_AUTO		(2 << 0)
 
 #define WM8960_DAC_DIV_1		(0 << 3)
 #define WM8960_DAC_DIV_1_5		(1 << 3)
-- 
1.9.1

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