rpi-simple-soundcard: limits sample rate of Merus Amp board

Adding a dedicated hw_params function to limit the maximum sample
rate of the IFX/Merus board to 48000ksps.

Thanks to Ariel Muszkat for the support.

Signed-off-by: Joerg Schambacher <joerg@hifiberry.com>

diff --git a/sound/soc/bcm/rpi-simple-soundcard.c b/sound/soc/bcm/rpi-simple-soundcard.c
index fd1e429..85ef1a2 100644 (file)
--- a/sound/soc/bcm/rpi-simple-soundcard.c
+++ b/sound/soc/bcm/rpi-simple-soundcard.c
@@ -145,6 +145,26 @@ static struct snd_soc_ops snd_rpi_simple_ops = {
        .hw_params = snd_rpi_simple_hw_params,
 };
 
+static int snd_merus_amp_hw_params(struct snd_pcm_substream *substream,
+               struct snd_pcm_hw_params *params)
+{
+       struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+       int rate;
+
+       rate = params_rate(params);
+       if (rate > 48000) {
+               dev_err(rtd->card->dev,
+               "Unsupported samplerate %d\n",
+               rate);
+               return -EINVAL;
+       }
+       return 0;
+}
+
+static struct snd_soc_ops snd_merus_amp_ops = {
+       .hw_params = snd_merus_amp_hw_params,
+};
+
 enum adau1977_clk_id {
        ADAU1977_SYSCLK,
 };
@@ -340,13 +360,14 @@ static struct snd_rpi_simple_drvdata drvdata_rpi_dac = {
 
 SND_SOC_DAILINK_DEFS(merus_amp,
        DAILINK_COMP_ARRAY(COMP_EMPTY()),
-       DAILINK_COMP_ARRAY(COMP_CODEC("ma120x0p.1-0020","ma120x0p-amp")),
+       DAILINK_COMP_ARRAY(COMP_CODEC("ma120x0p.1-0020", "ma120x0p-amp")),
        DAILINK_COMP_ARRAY(COMP_EMPTY()));
 
 static struct snd_soc_dai_link snd_merus_amp_dai[] = {
        {
                .name           = "MerusAmp",
                .stream_name    = "Merus Audio Amp",
+               .ops            = &snd_merus_amp_ops,
                .dai_fmt        = SND_SOC_DAIFMT_I2S |
                                        SND_SOC_DAIFMT_NB_NF |
                                        SND_SOC_DAIFMT_CBS_CFS,