ASoC: wm8960: Let wm8960 driver configure its bit clock and frame clock

wm8960 codec driver missing configure its bit clock and frame clock for codec
master mode, so add support for it. It will calculate a appropriate frequency
dividing ratio according to the system clock, bit clock and frame clock, then
set the corresponding registers.

Signed-off-by: Zidan Wang <zidan.wang@freescale.com>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wm8960.c

@@ -127,6 +127,8 @@ struct wm8960_priv {
 	struct snd_soc_dapm_widget *out3;
 	bool deemph;
 	int playback_fs;
+	int bclk;
+	int sysclk;
 	struct wm8960_data pdata;
 };
 
@@ -563,15 +565,86 @@ static struct {
 	{  8000, 5 },
 };
 
+/* Multiply 256 for internal 256 div */
+static const int dac_divs[] = { 256, 384, 512, 768, 1024, 1408, 1536 };
+
+/* Multiply 10 to eliminate decimials */
+static const int bclk_divs[] = {
+	10, 15, 20, 30, 40, 55, 60, 80, 110,
+	120, 160, 220, 240, 320, 320, 320
+};
+
+static void wm8960_configure_clocking(struct snd_soc_codec *codec,
+		bool tx, int lrclk)
+{
+	struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
+	u16 iface1 = snd_soc_read(codec, WM8960_IFACE1);
+	u16 iface2 = snd_soc_read(codec, WM8960_IFACE2);
+	u32 sysclk;
+	int i, j;
+
+	if (!(iface1 & (1<<6))) {
+		dev_dbg(codec->dev,
+			"Codec is slave mode, no need to configure clock\n");
+		return;
+	}
+
+	if (!wm8960->sysclk) {
+		dev_dbg(codec->dev, "No SYSCLK configured\n");
+		return;
+	}
+
+	if (!wm8960->bclk || !lrclk) {
+		dev_dbg(codec->dev, "No audio clocks configured\n");
+		return;
+	}
+
+	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)
+					break;
+			}
+			if(j != ARRAY_SIZE(bclk_divs))
+				break;
+		}
+	}
+
+	if (i == ARRAY_SIZE(dac_divs)) {
+		dev_err(codec->dev, "Unsupported sysclk %d\n", wm8960->sysclk);
+		return;
+	}
+
+	/*
+	 * 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);
+	else if (tx)
+		snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 3, i << 3);
+	else if (!tx)
+		snd_soc_update_bits(codec, WM8960_CLOCK1, 0x7 << 6, i << 6);
+
+	/* configure bit clock */
+	snd_soc_update_bits(codec, WM8960_CLOCK2, 0xf, j);
+}
+
 static int wm8960_hw_params(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);
 	u16 iface = snd_soc_read(codec, WM8960_IFACE1) & 0xfff3;
+	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:
@@ -602,6 +675,9 @@ 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));
+
 	return 0;
 }
 
@@ -950,6 +1026,30 @@ static int wm8960_set_bias_level(struct snd_soc_codec *codec,
 	return wm8960->set_bias_level(codec, level);
 }
 
+static int wm8960_set_dai_sysclk(struct snd_soc_dai *dai, int clk_id,
+					unsigned int freq, int dir)
+{
+	struct snd_soc_codec *codec = dai->codec;
+	struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
+
+	switch (clk_id) {
+	case WM8960_SYSCLK_MCLK:
+		snd_soc_update_bits(codec, WM8960_CLOCK1,
+					0x1, WM8960_SYSCLK_MCLK);
+		break;
+	case WM8960_SYSCLK_PLL:
+		snd_soc_update_bits(codec, WM8960_CLOCK1,
+					0x1, WM8960_SYSCLK_PLL);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	wm8960->sysclk = freq;
+
+	return 0;
+}
+
 #define WM8960_RATES SNDRV_PCM_RATE_8000_48000
 
 #define WM8960_FORMATS \
@@ -962,6 +1062,7 @@ static const struct snd_soc_dai_ops wm8960_dai_ops = {
 	.set_fmt = wm8960_set_dai_fmt,
 	.set_clkdiv = wm8960_set_dai_clkdiv,
 	.set_pll = wm8960_set_dai_pll,
+	.set_sysclk = wm8960_set_dai_sysclk,
 };
 
 static struct snd_soc_dai_driver wm8960_dai = {