From 79748cdb39dbf914bc5f26c75cfd5f91d84d82c9 Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie@opensource.wolfsonmicro.com>
Date: Mon, 1 Oct 2012 15:28:30 +0100
Subject: [PATCH] ASoC: wm8994: Only enable extra BCLK cycles when required

Rather than always assuming the maximum possible BCLK rate will be
required generate BCLKs for stereo if either one or two channels is
enabled. In order to support this we also need to ensure that only
the relevant channels are enabled.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
---
 sound/soc/codecs/wm8994.c | 18 +++++++++++++++++-
 sound/soc/codecs/wm8994.h |  1 +
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/sound/soc/codecs/wm8994.c b/sound/soc/codecs/wm8994.c
index 2b2dadc54dac5..3fddc7ad1127e 100644
--- a/sound/soc/codecs/wm8994.c
+++ b/sound/soc/codecs/wm8994.c
@@ -1045,6 +1045,7 @@ static int aif1clk_ev(struct snd_soc_dapm_widget *w,
 		      struct snd_kcontrol *kcontrol, int event)
 {
 	struct snd_soc_codec *codec = w->codec;
+	struct wm8994_priv *wm8994 = snd_soc_codec_get_drvdata(codec);
 	struct wm8994 *control = codec->control_data;
 	int mask = WM8994_AIF1DAC1L_ENA | WM8994_AIF1DAC1R_ENA;
 	int i;
@@ -1063,6 +1064,10 @@ static int aif1clk_ev(struct snd_soc_dapm_widget *w,
 
 	switch (event) {
 	case SND_SOC_DAPM_PRE_PMU:
+		/* Don't enable timeslot 2 if not in use */
+		if (wm8994->channels[0] <= 2)
+			mask &= ~(WM8994_AIF1DAC2L_ENA | WM8994_AIF1DAC2R_ENA);
+
 		val = snd_soc_read(codec, WM8994_AIF1_CONTROL_1);
 		if ((val & WM8994_AIF1ADCL_SRC) &&
 		    (val & WM8994_AIF1ADCR_SRC))
@@ -2687,7 +2692,7 @@ static int wm8994_hw_params(struct snd_pcm_substream *substream,
 		return -EINVAL;
 	}
 
-	bclk_rate = params_rate(params) * 4;
+	bclk_rate = params_rate(params);
 	switch (params_format(params)) {
 	case SNDRV_PCM_FORMAT_S16_LE:
 		bclk_rate *= 16;
@@ -2708,6 +2713,17 @@ static int wm8994_hw_params(struct snd_pcm_substream *substream,
 		return -EINVAL;
 	}
 
+	wm8994->channels[id] = params_channels(params);
+	switch (params_channels(params)) {
+	case 1:
+	case 2:
+		bclk_rate *= 2;
+		break;
+	default:
+		bclk_rate *= 4;
+		break;
+	}
+
 	/* Try to find an appropriate sample rate; look for an exact match. */
 	for (i = 0; i < ARRAY_SIZE(srs); i++)
 		if (srs[i].rate == params_rate(params))
diff --git a/sound/soc/codecs/wm8994.h b/sound/soc/codecs/wm8994.h
index f142ec198db3d..ccbce5791e958 100644
--- a/sound/soc/codecs/wm8994.h
+++ b/sound/soc/codecs/wm8994.h
@@ -77,6 +77,7 @@ struct wm8994_priv {
 	int sysclk_rate[2];
 	int mclk[2];
 	int aifclk[2];
+	int channels[2];
 	struct wm8994_fll_config fll[2], fll_suspend[2];
 	struct completion fll_locked[2];
 	bool fll_locked_irq;
-- 
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