ASoC: Implement WM8903 high pass filter support

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>

sound/soc/codecs/wm8903.c

@@ -474,6 +474,13 @@ static const DECLARE_TLV_DB_SCALE(drc_tlv_min, 0, 600, 0);
 static const DECLARE_TLV_DB_SCALE(drc_tlv_max, 1200, 600, 0);
 static const DECLARE_TLV_DB_SCALE(drc_tlv_startup, -300, 50, 0);
 
+static const char *hpf_mode_text[] = {
+	"Hi-fi", "Voice 1", "Voice 2", "Voice 3"
+};
+
+static const struct soc_enum hpf_mode =
+	SOC_ENUM_SINGLE(WM8903_ADC_DIGITAL_0, 5, 4, hpf_mode_text);
+
 static const char *drc_slope_text[] = {
 	"1", "1/2", "1/4", "1/8", "1/16", "0"
 };
@@ -612,6 +619,8 @@ SOC_SINGLE("Right Input PGA Common Mode Switch", WM8903_ANALOGUE_RIGHT_INPUT_1,
 	   6, 1, 0),
 
 /* ADCs */
+SOC_SINGLE("HPF Switch", WM8903_ADC_DIGITAL_0, 4, 1, 0),
+SOC_ENUM("HPF Mode", hpf_mode),
 SOC_SINGLE("DRC Switch", WM8903_DRC_0, 15, 1, 0),
 SOC_ENUM("DRC Compressor Slope R0", drc_slope_r0),
 SOC_ENUM("DRC Compressor Slope R1", drc_slope_r1),