ASoC: wm8994: Lower AIFnCLK divisor when dropping to 32kHz

When lowering SYSCLK to 50kHz for accessory detection also lower the
AIFnCLK divisor to normalise the clocking configuration within the
device. This will not disrupt audio as we cannot support active audio
with such a low SYSCLK.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/wm8994.c

@@ -2258,6 +2258,18 @@ static int _wm8994_set_fll(struct snd_soc_codec *codec, int id, int src,
 
 	configure_clock(codec);
 
+	/*
+	 * If SYSCLK will be less than 50kHz adjust AIFnCLK dividers
+	 * for detection.
+	 */
+	if (max(wm8994->aifclk[0], wm8994->aifclk[1]) < 50000) {
+		dev_dbg(codec->dev, "Configuring AIFs for 128fs\n");
+		snd_soc_update_bits(codec, WM8994_AIF1_RATE,
+				    WM8994_AIF1CLK_RATE_MASK, 0x1);
+		snd_soc_update_bits(codec, WM8994_AIF2_RATE,
+				    WM8994_AIF2CLK_RATE_MASK, 0x1);
+	}
+
 	return 0;
 }