[PATCH] ASoC: codecs: ad193x: Add support to disable on-chip PLL

From: Codrin Ciubotariu
Date: Mon Feb 18 2019 - 11:10:36 EST


The on-chip PLL can be disabled if on the MCLKI pin we have an external
clock at 512 x fs. This clock can be used as direct internal clock for
ADCs or DACs.
To support this, we add an extra clock id that can be configured
using the set_sysclk() callback.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@xxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
sound/soc/codecs/ad193x.c | 26 +++++++++++++++++++++++++-
sound/soc/codecs/ad193x.h | 8 ++++++++
2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/sound/soc/codecs/ad193x.c b/sound/soc/codecs/ad193x.c
index f8cf182518a3..96d7cb2e4a56 100644
--- a/sound/soc/codecs/ad193x.c
+++ b/sound/soc/codecs/ad193x.c
@@ -100,6 +100,15 @@ static const struct snd_soc_dapm_widget ad193x_adc_widgets[] = {
SND_SOC_DAPM_INPUT("ADC2IN"),
};

+static int ad193x_check_pll(struct snd_soc_dapm_widget *source,
+ struct snd_soc_dapm_widget *sink)
+{
+ struct snd_soc_component *component = snd_soc_dapm_to_component(source->dapm);
+ struct ad193x_priv *ad193x = snd_soc_component_get_drvdata(component);
+
+ return !!ad193x->sysclk;
+}
+
static const struct snd_soc_dapm_route audio_paths[] = {
{ "DAC", NULL, "SYSCLK" },
{ "DAC Output", NULL, "DAC" },
@@ -108,7 +117,7 @@ static const struct snd_soc_dapm_route audio_paths[] = {
{ "DAC2OUT", NULL, "DAC Output" },
{ "DAC3OUT", NULL, "DAC Output" },
{ "DAC4OUT", NULL, "DAC Output" },
- { "SYSCLK", NULL, "PLL_PWR" },
+ { "SYSCLK", NULL, "PLL_PWR", &ad193x_check_pll },
};

static const struct snd_soc_dapm_route ad193x_adc_audio_paths[] = {
@@ -276,7 +285,22 @@ static int ad193x_set_dai_sysclk(struct snd_soc_dai *codec_dai,
int clk_id, unsigned int freq, int dir)
{
struct snd_soc_component *component = codec_dai->component;
+ struct snd_soc_dapm_context *dapm = snd_soc_component_get_dapm(component);
struct ad193x_priv *ad193x = snd_soc_component_get_drvdata(component);
+
+ if (clk_id == AD193X_SYSCLK_MCLK) {
+ /* MCLK must be 512 x fs */
+ if (dir == SND_SOC_CLOCK_OUT || freq != 24576000)
+ return -EINVAL;
+
+ regmap_update_bits(ad193x->regmap, AD193X_PLL_CLK_CTRL1,
+ AD193X_PLL_SRC_MASK,
+ AD193X_PLL_DAC_SRC_MCLK |
+ AD193X_PLL_CLK_SRC_MCLK);
+
+ snd_soc_dapm_sync(dapm);
+ return 0;
+ }
switch (freq) {
case 12288000:
case 18432000:
diff --git a/sound/soc/codecs/ad193x.h b/sound/soc/codecs/ad193x.h
index 8b1e65f928d2..27d6afbd7dfb 100644
--- a/sound/soc/codecs/ad193x.h
+++ b/sound/soc/codecs/ad193x.h
@@ -31,6 +31,11 @@ int ad193x_probe(struct device *dev, struct regmap *regmap,
#define AD193X_PLL_INPUT_512 (2 << 1)
#define AD193X_PLL_INPUT_768 (3 << 1)
#define AD193X_PLL_CLK_CTRL1 0x01
+#define AD193X_PLL_SRC_MASK 0x03
+#define AD193X_PLL_DAC_SRC_PLL 0
+#define AD193X_PLL_DAC_SRC_MCLK 1
+#define AD193X_PLL_CLK_SRC_PLL (0 << 1)
+#define AD193X_PLL_CLK_SRC_MCLK (1 << 1)
#define AD193X_DAC_CTRL0 0x02
#define AD193X_DAC_POWERDOWN 0x01
#define AD193X_DAC_SERFMT_MASK 0xC0
@@ -96,4 +101,7 @@ int ad193x_probe(struct device *dev, struct regmap *regmap,

#define AD193X_NUM_REGS 17

+#define AD193X_SYSCLK_PLL 0
+#define AD193X_SYSCLK_MCLK 1
+
#endif
--
2.20.1