struct work_struct work;
        struct snd_soc_codec codec;
        struct regulator_bulk_data supplies[DAC33_NUM_SUPPLIES];
+       struct snd_pcm_substream *substream;
        int power_gpio;
        int chip_power;
        int irq;
                        "internal oscillator calibration failed\n");
 }
 
+static int dac33_startup(struct snd_pcm_substream *substream,
+                          struct snd_soc_dai *dai)
+{
+       struct snd_soc_pcm_runtime *rtd = substream->private_data;
+       struct snd_soc_device *socdev = rtd->socdev;
+       struct snd_soc_codec *codec = socdev->card->codec;
+       struct tlv320dac33_priv *dac33 = snd_soc_codec_get_drvdata(codec);
+
+       /* Stream started, save the substream pointer */
+       dac33->substream = substream;
+
+       return 0;
+}
+
+static void dac33_shutdown(struct snd_pcm_substream *substream,
+                            struct snd_soc_dai *dai)
+{
+       struct snd_soc_pcm_runtime *rtd = substream->private_data;
+       struct snd_soc_device *socdev = rtd->socdev;
+       struct snd_soc_codec *codec = socdev->card->codec;
+       struct tlv320dac33_priv *dac33 = snd_soc_codec_get_drvdata(codec);
+
+       dac33->substream = NULL;
+}
+
 static int dac33_hw_params(struct snd_pcm_substream *substream,
                           struct snd_pcm_hw_params *params,
                           struct snd_soc_dai *dai)
 #define DAC33_FORMATS  SNDRV_PCM_FMTBIT_S16_LE
 
 static struct snd_soc_dai_ops dac33_dai_ops = {
+       .startup        = dac33_startup,
+       .shutdown       = dac33_shutdown,
        .hw_params      = dac33_hw_params,
        .prepare        = dac33_pcm_prepare,
        .trigger        = dac33_pcm_trigger,