2 files changed, 96 insertions, 27 deletions

diff --git a/sound/soc/codecs/pcm512x.c b/sound/soc/codecs/pcm512x.c
index 66dd036f0141..8b474196d52a 100644
--- a/sound/soc/codecs/pcm512x.c
+++ b/sound/soc/codecs/pcm512x.c
@@ -105,6 +105,7 @@ static const struct reg_default pcm512x_reg_defaults[] = {
         { PCM512x_VCOM_CTRL_2,       0x01 },
         { PCM512x_BCLK_LRCLK_CFG,    0x00 },
         { PCM512x_MASTER_MODE,       0x7c },
+        { PCM512x_GPIO_DACIN,        0x00 },
         { PCM512x_GPIO_PLLIN,        0x00 },
         { PCM512x_SYNCHRONIZE,       0x10 },
         { PCM512x_PLL_COEFF_0,       0x00 },
@@ -138,6 +139,7 @@ static bool pcm512x_readable(struct device *dev, unsigned int reg)
         case PCM512x_MASTER_MODE:
         case PCM512x_PLL_REF:
         case PCM512x_DAC_REF:
+        case PCM512x_GPIO_DACIN:
         case PCM512x_GPIO_PLLIN:
         case PCM512x_SYNCHRONIZE:
         case PCM512x_PLL_COEFF_0:
@@ -659,6 +661,37 @@ done:
         return 0;
 }
 
+static unsigned long pcm512x_pllin_dac_rate(struct snd_soc_dai *dai,
+                                            unsigned long osr_rate,
+                                            unsigned long pllin_rate)
+{
+        struct snd_soc_codec *codec = dai->codec;
+        struct pcm512x_priv *pcm512x = snd_soc_codec_get_drvdata(codec);
+        unsigned long dac_rate;
+
+        if (!pcm512x->pll_out)
+                return 0; /* no PLL to bypass, force SCK as DAC input */
+
+        if (pllin_rate % osr_rate)
+                return 0; /* futile, quit early */
+
+        /* run DAC no faster than 6144000 Hz */
+        for (dac_rate = rounddown(6144000, osr_rate);
+             dac_rate;
+             dac_rate -= osr_rate) {
+
+                if (pllin_rate / dac_rate > 128)
+                        return 0; /* DAC divider would be too big */
+
+                if (!(pllin_rate % dac_rate))
+                        return dac_rate;
+
+                dac_rate -= osr_rate;
+        }
+
+        return 0;
+}
+
 static int pcm512x_set_dividers(struct snd_soc_dai *dai,
                                 struct snd_pcm_hw_params *params)
 {
@@ -672,6 +705,7 @@ static int pcm512x_set_dividers(struct snd_soc_dai *dai,
         unsigned long bclk_rate;
         unsigned long sample_rate;
         unsigned long osr_rate;
+        unsigned long dacsrc_rate;
         int bclk_div;
         int lrclk_div;
         int dsp_div;
@@ -679,11 +713,10 @@ static int pcm512x_set_dividers(struct snd_soc_dai *dai,
         unsigned long dac_rate;
         int ncp_div;
         int osr_div;
-        unsigned long dac_mul;
-        unsigned long sck_mul;
         int ret;
         int idac;
         int fssp;
+        int gpio;
 
         lrclk_div = snd_soc_params_to_frame_size(params);
         if (lrclk_div == 0) {
@@ -772,31 +805,72 @@ static int pcm512x_set_dividers(struct snd_soc_dai *dai,
         /* run DSP no faster than 50 MHz */
         dsp_div = mck_rate > 50000000 ? 2 : 1;
 
-        /* run DAC no faster than 6144000 Hz */
-        dac_mul = 6144000 / osr_rate;
-        sck_mul = sck_rate / osr_rate;
-        for (; dac_mul; dac_mul--) {
-                if (!(sck_mul % dac_mul))
-                        break;
-        }
-        if (!dac_mul) {
-                dev_err(dev, "Failed to find DAC rate\n");
-                return -EINVAL;
-        }
+        dac_rate = pcm512x_pllin_dac_rate(dai, osr_rate, pllin_rate);
+        if (dac_rate) {
+                /* the desired clock rate is "compatible" with the pll input
+                 * clock, so use that clock as dac input instead of the pll
+                 * output clock since the pll will introduce jitter and thus
+                 * noise.
+                 */
+                dev_dbg(dev, "using pll input as dac input\n");
+                ret = regmap_update_bits(pcm512x->regmap, PCM512x_DAC_REF,
+                                         PCM512x_SDAC, PCM512x_SDAC_GPIO);
+                if (ret != 0) {
+                        dev_err(codec->dev,
+                                "Failed to set gpio as dacref: %d\n", ret);
+                        return ret;
+                }
 
-        dac_rate = dac_mul * osr_rate;
-        dev_dbg(dev, "dac_rate %lu sample_rate %lu\n", dac_rate, sample_rate);
+                gpio = PCM512x_GREF_GPIO1 + pcm512x->pll_in - 1;
+                ret = regmap_update_bits(pcm512x->regmap, PCM512x_GPIO_DACIN,
+                                         PCM512x_GREF, gpio);
+                if (ret != 0) {
+                        dev_err(codec->dev,
+                                "Failed to set gpio %d as dacin: %d\n",
+                                pcm512x->pll_in, ret);
+                        return ret;
+                }
+
+                dacsrc_rate = pllin_rate;
+        } else {
+                /* run DAC no faster than 6144000 Hz */
+                unsigned long dac_mul = 6144000 / osr_rate;
+                unsigned long sck_mul = sck_rate / osr_rate;
+
+                for (; dac_mul; dac_mul--) {
+                        if (!(sck_mul % dac_mul))
+                                break;
+                }
+                if (!dac_mul) {
+                        dev_err(dev, "Failed to find DAC rate\n");
+                        return -EINVAL;
+                }
 
-        dac_div = DIV_ROUND_CLOSEST(sck_rate, dac_rate);
+                dac_rate = dac_mul * osr_rate;
+                dev_dbg(dev, "dac_rate %lu sample_rate %lu\n",
+                        dac_rate, sample_rate);
+
+                ret = regmap_update_bits(pcm512x->regmap, PCM512x_DAC_REF,
+                                         PCM512x_SDAC, PCM512x_SDAC_SCK);
+                if (ret != 0) {
+                        dev_err(codec->dev,
+                                "Failed to set sck as dacref: %d\n", ret);
+                        return ret;
+                }
+
+                dacsrc_rate = sck_rate;
+        }
+
+        dac_div = DIV_ROUND_CLOSEST(dacsrc_rate, dac_rate);
         if (dac_div > 128) {
                 dev_err(dev, "Failed to find DAC divider\n");
                 return -EINVAL;
         }
 
-        ncp_div = DIV_ROUND_CLOSEST(sck_rate / dac_div, 1536000);
-        if (ncp_div > 128 || sck_rate / dac_div / ncp_div > 2048000) {
+        ncp_div = DIV_ROUND_CLOSEST(dacsrc_rate / dac_div, 1536000);
+        if (ncp_div > 128 || dacsrc_rate / dac_div / ncp_div > 2048000) {
                 /* run NCP no faster than 2048000 Hz, but why? */
-                ncp_div = DIV_ROUND_UP(sck_rate / dac_div, 2048000);
+                ncp_div = DIV_ROUND_UP(dacsrc_rate / dac_div, 2048000);
                 if (ncp_div > 128) {
                         dev_err(dev, "Failed to find NCP divider\n");
                         return -EINVAL;
@@ -1011,13 +1085,6 @@ static int pcm512x_hw_params(struct snd_pcm_substream *substream,
         if (ret != 0)
                 return ret;
 
-        ret = regmap_update_bits(pcm512x->regmap, PCM512x_DAC_REF,
-                                 PCM512x_SDAC, PCM512x_SDAC_SCK);
-        if (ret != 0) {
-                dev_err(codec->dev, "Failed to set sck as dacref: %d\n", ret);
-                return ret;
-        }
-
         if (pcm512x->pll_out) {
                 ret = regmap_update_bits(pcm512x->regmap, PCM512x_PLL_REF,
                                          PCM512x_SREF, PCM512x_SREF_GPIO);
diff --git a/sound/soc/codecs/pcm512x.h b/sound/soc/codecs/pcm512x.h
index eba5adc2cdb1..b7c310207223 100644
--- a/sound/soc/codecs/pcm512x.h
+++ b/sound/soc/codecs/pcm512x.h
@@ -38,6 +38,7 @@
 #define PCM512x_MASTER_MODE       (PCM512x_PAGE_BASE(0) +  12)
 #define PCM512x_PLL_REF           (PCM512x_PAGE_BASE(0) +  13)
 #define PCM512x_DAC_REF           (PCM512x_PAGE_BASE(0) +  14)
+#define PCM512x_GPIO_DACIN        (PCM512x_PAGE_BASE(0) +  16)
 #define PCM512x_GPIO_PLLIN        (PCM512x_PAGE_BASE(0) +  18)
 #define PCM512x_SYNCHRONIZE       (PCM512x_PAGE_BASE(0) +  19)
 #define PCM512x_PLL_COEFF_0       (PCM512x_PAGE_BASE(0) +  20)
@@ -162,8 +163,9 @@
 #define PCM512x_SDAC_PLL    (1 << 4)
 #define PCM512x_SDAC_SCK    (3 << 4)
 #define PCM512x_SDAC_BCK    (4 << 4)
+#define PCM512x_SDAC_GPIO   (5 << 4)
 
-/* Page 0, Register 18 - GPIO source for PLL */
+/* Page 0, Register 16, 18 - GPIO source for DAC, PLL */
 #define PCM512x_GREF        (7 << 0)
 #define PCM512x_GREF_SHIFT  0
 #define PCM512x_GREF_GPIO1  (0 << 0)