0x0003,     /* R35 - ClassD1 */
        0x0000,     /* R36 */
        0x0100,     /* R37 - ClassD3 */
-       0x0000,     /* R38 */
+       0x0079,     /* R38 - ClassD4 */
        0x0000,     /* R39 - Input Mixer1 */
        0x0000,     /* R40 - Input Mixer2 */
        0x0000,     /* R41 - Input Mixer3 */
        WM8990_CDMODE_BIT, 1, 0),
 
 SOC_SINGLE("Speaker Output Attenuation Volume", WM8990_SPEAKER_VOLUME,
-       WM8990_SPKVOL_SHIFT, WM8990_SPKVOL_MASK, 0),
+       WM8990_SPKATTN_SHIFT, WM8990_SPKATTN_MASK, 0),
 SOC_SINGLE("Speaker DC Boost Volume", WM8990_CLASSD3,
        WM8990_DCGAIN_SHIFT, WM8990_DCGAIN_MASK, 0),
 SOC_SINGLE("Speaker AC Boost Volume", WM8990_CLASSD3,
        WM8990_ACGAIN_SHIFT, WM8990_ACGAIN_MASK, 0),
+SOC_SINGLE_TLV("Speaker Volume", WM8990_CLASSD4,
+       WM8990_SPKVOL_SHIFT, WM8990_SPKVOL_MASK, 0, out_pga_tlv),
+SOC_SINGLE("Speaker ZC Switch", WM8990_CLASSD4,
+       WM8990_SPKZC_SHIFT, WM8990_SPKZC_MASK, 0),
 
 SOC_WM899X_OUTPGA_SINGLE_R_TLV("Left DAC Digital Volume",
        WM8990_LEFT_DAC_DIGITAL_VOLUME,
 
 #define WM8990_SPEAKER_VOLUME                   0x22
 #define WM8990_CLASSD1                          0x23
 #define WM8990_CLASSD3                          0x25
+#define WM8990_CLASSD4                          0x26
 #define WM8990_INPUT_MIXER1                     0x27
 #define WM8990_INPUT_MIXER2                     0x28
 #define WM8990_INPUT_MIXER3                     0x29
 /*
  * R34 (0x22) - Speaker Volume
  */
-#define WM8990_SPKVOL_MASK                      0x0003  /* SPKVOL - [1:0] */
-#define WM8990_SPKVOL_SHIFT                    0
+#define WM8990_SPKATTN_MASK                      0x0003  /* SPKATTN - [1:0] */
+#define WM8990_SPKATTN_SHIFT                    0
 
 /*
  * R35 (0x23) - ClassD1
 #define WM8990_DCGAIN_SHIFT                    3
 #define WM8990_ACGAIN_MASK                      0x0007  /* ACGAIN - [2:0] */
 #define WM8990_ACGAIN_SHIFT                    0
+
+/*
+ * R38 (0x26) - ClassD4
+ */
+#define WM8990_SPKZC_MASK                       0x0001  /* SPKZC */
+#define WM8990_SPKZC_SHIFT                           7  /* SPKZC */
+#define WM8990_SPKVOL_MASK                      0x007F  /* SPKVOL - [6:0] */
+#define WM8990_SPKVOL_SHIFT                          0  /* SPKVOL - [6:0] */
+
 /*
  * R39 (0x27) - Input Mixer1
  */