diff --git a/include/sound/soc-dai.h b/include/sound/soc-dai.h
index e0c7fa7b106..ca24e7f7a3f 100644
--- a/include/sound/soc-dai.h
+++ b/include/sound/soc-dai.h
@@ -30,6 +30,7 @@ struct snd_pcm_substream;
 #define SND_SOC_DAIFMT_DSP_A		3 /* L data MSB after FRM LRC */
 #define SND_SOC_DAIFMT_DSP_B		4 /* L data MSB during FRM LRC */
 #define SND_SOC_DAIFMT_AC97		5 /* AC97 */
+#define SND_SOC_DAIFMT_PDM		6 /* Pulse density modulation */
 
 /* left and right justified also known as MSB and LSB respectively */
 #define SND_SOC_DAIFMT_MSB		SND_SOC_DAIFMT_LEFT_J