Most of the DAPM widgets for DSP ASoC components reuse reg field
of the widgets for its internal calculations, however these are not
real registers. So read/writes to these numbers are not really
valid. However ASoC core will read these registers to get default
state during startup.
With recent changes to ASoC core, every register read/write
failures are reported very verbosely. Prior to this fails to reads
are totally ignored, so we never saw any error messages.
To fix this add dummy read/write function to return default value.
Fixes: e3a33673e845 ("ASoC: qdsp6: q6routing: Add q6routing driver")
Reported-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200811120205.21805-2-srinivas.kandagatla@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
        return 0;
 }
 
+static unsigned int q6routing_reg_read(struct snd_soc_component *component,
+                                      unsigned int reg)
+{
+       /* default value */
+       return 0;
+}
+
+static int q6routing_reg_write(struct snd_soc_component *component,
+                              unsigned int reg, unsigned int val)
+{
+       /* dummy */
+       return 0;
+}
+
 static const struct snd_soc_component_driver msm_soc_routing_component = {
        .probe = msm_routing_probe,
        .name = DRV_NAME,
        .num_dapm_widgets = ARRAY_SIZE(msm_qdsp6_widgets),
        .dapm_routes = intercon,
        .num_dapm_routes = ARRAY_SIZE(intercon),
+       .read = q6routing_reg_read,
+       .write = q6routing_reg_write,
 };
 
 static int q6pcm_routing_probe(struct platform_device *pdev)