+/* powerdown bits */
+#define AC97_PD_ADC_STATUS 0x0001 /* ADC status (RO) */
+#define AC97_PD_DAC_STATUS 0x0002 /* DAC status (RO) */
+#define AC97_PD_MIXER_STATUS 0x0004 /* Analog mixer status (RO) */
+#define AC97_PD_VREF_STATUS 0x0008 /* Vref status (RO) */
+#define AC97_PD_PR0 0x0100 /* Power down PCM ADCs and input MUX */
+#define AC97_PD_PR1 0x0200 /* Power down PCM front DAC */
+#define AC97_PD_PR2 0x0400 /* Power down Mixer (Vref still on) */
+#define AC97_PD_PR3 0x0800 /* Power down Mixer (Vref off) */
+#define AC97_PD_PR4 0x1000 /* Power down AC-Link */
+#define AC97_PD_PR5 0x2000 /* Disable internal clock usage */
+#define AC97_PD_PR6 0x4000 /* Headphone amplifier */
+#define AC97_PD_EAPD 0x8000 /* External Amplifer Power Down (EAPD) */
+