[PATCH] ASoC: pcm3168a: Add option to force clock consumer

[Stephen Gordon <gordoste@iinet.net.au>]

Scenario is that DAC's clock pins are tied to ADC's clock pins, with
codec acting as clock producer for the I2S bus, and the CPU has a single
pair of I2S clock pins used for both playback and capture.

Both DAI links will have codec acting as a clock producer, but we need
to configure the codec so that only one of ADC/DAC drives the lines.

Add DT options to support this configuration. adc-force-cons/dac-force-cons
cause MSAD/MSDA to be set to 0b000.

diff --git a/sound/soc/codecs/pcm3168a.c b/sound/soc/codecs/pcm3168a.c
index 9d6431338..5e3590f2d 100644
--- a/sound/soc/codecs/pcm3168a.c
+++ b/sound/soc/codecs/pcm3168a.c
@@ -61,6 +61,7 @@ struct pcm3168a_priv {
         struct clk *scki;
         struct gpio_desc *gpio_rst;
         unsigned long sysclk;
+       bool adc_fc, dac_fc; // Force clock consumer mode

         struct pcm3168a_io_params io_params[2];
         struct snd_soc_dai_driver dai_drv[2];
@@ -479,6 +480,12 @@ static int pcm3168a_hw_params(struct 
snd_pcm_substream *substream,
                 ms = 0;
         }

+       // Force clock consumer mode if needed
+       if (pcm3168a->adc_fc && dai->id == PCM3168A_DAI_ADC)
+               ms = 0;
+       if (pcm3168a->dac_fc && dai->id == PCM3168A_DAI_DAC)
+               ms = 0;
+
         format = io_params->format;

         if (io_params->slot_width)
@@ -757,6 +764,13 @@ int pcm3168a_probe(struct device *dev, struct 
regmap *regmap)

         pcm3168a->sysclk = clk_get_rate(pcm3168a->scki);

+       if (dev->of_node) {
+               pcm3168a->adc_fc = of_property_read_bool(dev->of_node,
+                               "adc-force-cons");
+               pcm3168a->dac_fc = of_property_read_bool(dev->of_node,
+                               "dac-force-cons");
+       }
+
         for (i = 0; i < ARRAY_SIZE(pcm3168a->supplies); i++)
                 pcm3168a->supplies[i].supply = pcm3168a_supply_names[i];



Signed-off-by: Stephen Gordon <gordoste@iinet.net.au>