ASoC: pcm512x: Allow independently overclocking PLL, DAC and DSP
When using non-standard rates, a relatively small amount of overclocking
can make a big difference to a number of cases.
- Not all rates are possible to achieve with the PLL, due to divider
restrictions.
- The higher oversampling rates that can be used by the DAC, the
simpler the analog output filters get (mirror frequencies move up,
away from the desired spectrum).
- The more work the DSP can perform per sample, the better.
For standard rates, there is little to gain as everything is
designed just right, and the needed overclocking to make a
real difference would be significant.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/pcm512x.c b/sound/soc/codecs/pcm512x.c
index f11c76f..4b5f1fe 100644
--- a/sound/soc/codecs/pcm512x.c
+++ b/sound/soc/codecs/pcm512x.c
@@ -54,6 +54,9 @@
int pll_d;
int pll_p;
unsigned long real_pll;
+ unsigned long overclock_pll;
+ unsigned long overclock_dac;
+ unsigned long overclock_dsp;
};
/*
@@ -224,6 +227,90 @@
}
}
+static int pcm512x_overclock_pll_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
+ struct pcm512x_priv *pcm512x = snd_soc_codec_get_drvdata(codec);
+
+ ucontrol->value.integer.value[0] = pcm512x->overclock_pll;
+ return 0;
+}
+
+static int pcm512x_overclock_pll_put(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
+ struct pcm512x_priv *pcm512x = snd_soc_codec_get_drvdata(codec);
+
+ switch (codec->dapm.bias_level) {
+ case SND_SOC_BIAS_OFF:
+ case SND_SOC_BIAS_STANDBY:
+ break;
+ default:
+ return -EBUSY;
+ }
+
+ pcm512x->overclock_pll = ucontrol->value.integer.value[0];
+ return 0;
+}
+
+static int pcm512x_overclock_dsp_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
+ struct pcm512x_priv *pcm512x = snd_soc_codec_get_drvdata(codec);
+
+ ucontrol->value.integer.value[0] = pcm512x->overclock_dsp;
+ return 0;
+}
+
+static int pcm512x_overclock_dsp_put(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
+ struct pcm512x_priv *pcm512x = snd_soc_codec_get_drvdata(codec);
+
+ switch (codec->dapm.bias_level) {
+ case SND_SOC_BIAS_OFF:
+ case SND_SOC_BIAS_STANDBY:
+ break;
+ default:
+ return -EBUSY;
+ }
+
+ pcm512x->overclock_dsp = ucontrol->value.integer.value[0];
+ return 0;
+}
+
+static int pcm512x_overclock_dac_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
+ struct pcm512x_priv *pcm512x = snd_soc_codec_get_drvdata(codec);
+
+ ucontrol->value.integer.value[0] = pcm512x->overclock_dac;
+ return 0;
+}
+
+static int pcm512x_overclock_dac_put(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
+ struct pcm512x_priv *pcm512x = snd_soc_codec_get_drvdata(codec);
+
+ switch (codec->dapm.bias_level) {
+ case SND_SOC_BIAS_OFF:
+ case SND_SOC_BIAS_STANDBY:
+ break;
+ default:
+ return -EBUSY;
+ }
+
+ pcm512x->overclock_dac = ucontrol->value.integer.value[0];
+ return 0;
+}
+
static const DECLARE_TLV_DB_SCALE(digital_tlv, -10350, 50, 1);
static const DECLARE_TLV_DB_SCALE(analog_tlv, -600, 600, 0);
static const DECLARE_TLV_DB_SCALE(boost_tlv, 0, 80, 0);
@@ -328,6 +415,13 @@
SOC_ENUM("Volume Ramp Up Step", pcm512x_vnus),
SOC_ENUM("Volume Ramp Down Emergency Rate", pcm512x_vedf),
SOC_ENUM("Volume Ramp Down Emergency Step", pcm512x_veds),
+
+SOC_SINGLE_EXT("Max Overclock PLL", SND_SOC_NOPM, 0, 20, 0,
+ pcm512x_overclock_pll_get, pcm512x_overclock_pll_put),
+SOC_SINGLE_EXT("Max Overclock DSP", SND_SOC_NOPM, 0, 40, 0,
+ pcm512x_overclock_dsp_get, pcm512x_overclock_dsp_put),
+SOC_SINGLE_EXT("Max Overclock DAC", SND_SOC_NOPM, 0, 40, 0,
+ pcm512x_overclock_dac_get, pcm512x_overclock_dac_put),
};
static const struct snd_soc_dapm_widget pcm512x_dapm_widgets[] = {
@@ -346,6 +440,45 @@
{ "OUTR", NULL, "DACR" },
};
+static unsigned long pcm512x_pll_max(struct pcm512x_priv *pcm512x)
+{
+ return 25000000 + 25000000 * pcm512x->overclock_pll / 100;
+}
+
+static unsigned long pcm512x_dsp_max(struct pcm512x_priv *pcm512x)
+{
+ return 50000000 + 50000000 * pcm512x->overclock_dsp / 100;
+}
+
+static unsigned long pcm512x_dac_max(struct pcm512x_priv *pcm512x,
+ unsigned long rate)
+{
+ return rate + rate * pcm512x->overclock_dac / 100;
+}
+
+static unsigned long pcm512x_sck_max(struct pcm512x_priv *pcm512x)
+{
+ if (!pcm512x->pll_out)
+ return 25000000;
+ return pcm512x_pll_max(pcm512x);
+}
+
+static unsigned long pcm512x_ncp_target(struct pcm512x_priv *pcm512x,
+ unsigned long dac_rate)
+{
+ /*
+ * If the DAC is not actually overclocked, use the good old
+ * NCP target rate...
+ */
+ if (dac_rate <= 6144000)
+ return 1536000;
+ /*
+ * ...but if the DAC is in fact overclocked, bump the NCP target
+ * rate to get the recommended dividers even when overclocking.
+ */
+ return pcm512x_dac_max(pcm512x, 1536000);
+}
+
static const u32 pcm512x_dai_rates[] = {
8000, 11025, 16000, 22050, 32000, 44100, 48000, 64000,
88200, 96000, 176400, 192000, 384000,
@@ -359,6 +492,7 @@
static int pcm512x_hw_rule_rate(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)
{
+ struct pcm512x_priv *pcm512x = rule->private;
struct snd_interval ranges[2];
int frame_size;
@@ -377,7 +511,7 @@
*/
memset(ranges, 0, sizeof(ranges));
ranges[0].min = 8000;
- ranges[0].max = 25000000 / frame_size / 2;
+ ranges[0].max = pcm512x_sck_max(pcm512x) / frame_size / 2;
ranges[1].min = DIV_ROUND_UP(16000000, frame_size);
ranges[1].max = 384000;
break;
@@ -408,7 +542,7 @@
return snd_pcm_hw_rule_add(substream->runtime, 0,
SNDRV_PCM_HW_PARAM_RATE,
pcm512x_hw_rule_rate,
- NULL,
+ pcm512x,
SNDRV_PCM_HW_PARAM_FRAME_BITS,
SNDRV_PCM_HW_PARAM_CHANNELS, -1);
@@ -517,6 +651,8 @@
unsigned long bclk_rate)
{
struct device *dev = dai->dev;
+ struct snd_soc_codec *codec = dai->codec;
+ struct pcm512x_priv *pcm512x = snd_soc_codec_get_drvdata(codec);
unsigned long sck_rate;
int pow2;
@@ -527,9 +663,10 @@
* as many factors of 2 as possible, as that makes it easier
* to find a fast DAC rate
*/
- pow2 = 1 << fls((25000000 - 16000000) / bclk_rate);
+ pow2 = 1 << fls((pcm512x_pll_max(pcm512x) - 16000000) / bclk_rate);
for (; pow2; pow2 >>= 1) {
- sck_rate = rounddown(25000000, bclk_rate * pow2);
+ sck_rate = rounddown(pcm512x_pll_max(pcm512x),
+ bclk_rate * pow2);
if (sck_rate >= 16000000)
break;
}
@@ -678,7 +815,7 @@
return 0; /* futile, quit early */
/* run DAC no faster than 6144000 Hz */
- for (dac_rate = rounddown(6144000, osr_rate);
+ for (dac_rate = rounddown(pcm512x_dac_max(pcm512x, 6144000), osr_rate);
dac_rate;
dac_rate -= osr_rate) {
@@ -805,7 +942,7 @@
osr_rate = 16 * sample_rate;
/* run DSP no faster than 50 MHz */
- dsp_div = mck_rate > 50000000 ? 2 : 1;
+ dsp_div = mck_rate > pcm512x_dsp_max(pcm512x) ? 2 : 1;
dac_rate = pcm512x_pllin_dac_rate(dai, osr_rate, pllin_rate);
if (dac_rate) {
@@ -836,7 +973,8 @@
dacsrc_rate = pllin_rate;
} else {
/* run DAC no faster than 6144000 Hz */
- unsigned long dac_mul = 6144000 / osr_rate;
+ unsigned long dac_mul = pcm512x_dac_max(pcm512x, 6144000)
+ / osr_rate;
unsigned long sck_mul = sck_rate / osr_rate;
for (; dac_mul; dac_mul--) {
@@ -876,7 +1014,8 @@
}
dac_rate = dacsrc_rate / dac_div;
- ncp_div = DIV_ROUND_CLOSEST(dac_rate, 1536000);
+ ncp_div = DIV_ROUND_CLOSEST(dac_rate,
+ pcm512x_ncp_target(pcm512x, dac_rate));
if (ncp_div > 128 || dac_rate / ncp_div > 2048000) {
/* run NCP no faster than 2048000 Hz, but why? */
ncp_div = DIV_ROUND_UP(dac_rate, 2048000);
@@ -938,11 +1077,11 @@
return ret;
}
- if (sample_rate <= 48000)
+ if (sample_rate <= pcm512x_dac_max(pcm512x, 48000))
fssp = PCM512x_FSSP_48KHZ;
- else if (sample_rate <= 96000)
+ else if (sample_rate <= pcm512x_dac_max(pcm512x, 96000))
fssp = PCM512x_FSSP_96KHZ;
- else if (sample_rate <= 192000)
+ else if (sample_rate <= pcm512x_dac_max(pcm512x, 192000))
fssp = PCM512x_FSSP_192KHZ;
else
fssp = PCM512x_FSSP_384KHZ;