+static void twl4030_constraints(struct twl4030_priv *twl4030,
+ struct snd_pcm_substream *mst_substream)
+{
+ struct snd_pcm_substream *slv_substream;
+
+ /* Pick the stream, which need to be constrained */
+ if (mst_substream == twl4030->master_substream)
+ slv_substream = twl4030->slave_substream;
+ else if (mst_substream == twl4030->slave_substream)
+ slv_substream = twl4030->master_substream;
+ else /* This should not happen.. */
+ return;
+
+ /* Set the constraints according to the already configured stream */
+ snd_pcm_hw_constraint_minmax(slv_substream->runtime,
+ SNDRV_PCM_HW_PARAM_RATE,
+ twl4030->rate,
+ twl4030->rate);
+
+ snd_pcm_hw_constraint_minmax(slv_substream->runtime,
+ SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
+ twl4030->sample_bits,
+ twl4030->sample_bits);
+
+ snd_pcm_hw_constraint_minmax(slv_substream->runtime,
+ SNDRV_PCM_HW_PARAM_CHANNELS,
+ twl4030->channels,
+ twl4030->channels);
+}
+
+/* In case of 4 channel mode, the RX1 L/R for playback and the TX2 L/R for
+ * capture has to be enabled/disabled. */
+static void twl4030_tdm_enable(struct snd_soc_codec *codec, int direction,
+ int enable)
+{
+ u8 reg, mask;
+
+ reg = twl4030_read_reg_cache(codec, TWL4030_REG_OPTION);
+
+ if (direction == SNDRV_PCM_STREAM_PLAYBACK)
+ mask = TWL4030_ARXL1_VRX_EN | TWL4030_ARXR1_EN;
+ else
+ mask = TWL4030_ATXL2_VTXL_EN | TWL4030_ATXR2_VTXR_EN;
+
+ if (enable)
+ reg |= mask;
+ else
+ reg &= ~mask;
+
+ twl4030_write(codec, TWL4030_REG_OPTION, reg);
+}
+
+static int twl4030_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 twl4030_priv *twl4030 = codec->private_data;
+
+ if (twl4030->master_substream) {
+ twl4030->slave_substream = substream;
+ /* The DAI has one configuration for playback and capture, so
+ * if the DAI has been already configured then constrain this
+ * substream to match it. */
+ if (twl4030->configured)
+ twl4030_constraints(twl4030, twl4030->master_substream);
+ } else {
+ if (!(twl4030_read_reg_cache(codec, TWL4030_REG_CODEC_MODE) &
+ TWL4030_OPTION_1)) {
+ /* In option2 4 channel is not supported, set the
+ * constraint for the first stream for channels, the
+ * second stream will 'inherit' this cosntraint */
+ snd_pcm_hw_constraint_minmax(substream->runtime,
+ SNDRV_PCM_HW_PARAM_CHANNELS,
+ 2, 2);
+ }
+ twl4030->master_substream = substream;
+ }
+
+ return 0;
+}
+
+static void twl4030_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 twl4030_priv *twl4030 = codec->private_data;
+
+ if (twl4030->master_substream == substream)
+ twl4030->master_substream = twl4030->slave_substream;
+
+ twl4030->slave_substream = NULL;
+
+ /* If all streams are closed, or the remaining stream has not yet
+ * been configured than set the DAI as not configured. */
+ if (!twl4030->master_substream)
+ twl4030->configured = 0;
+ else if (!twl4030->master_substream->runtime->channels)
+ twl4030->configured = 0;
+
+ /* If the closing substream had 4 channel, do the necessary cleanup */
+ if (substream->runtime->channels == 4)
+ twl4030_tdm_enable(codec, substream->stream, 0);
+}
+