+static snd_pcm_sframes_t dac33_dai_delay(
+ 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);
+ unsigned long long t0, t1, t_now;
+ unsigned int time_delta;
+ int samples_out, samples_in, samples;
+ snd_pcm_sframes_t delay = 0;
+
+ switch (dac33->fifo_mode) {
+ case DAC33_FIFO_BYPASS:
+ break;
+ case DAC33_FIFO_MODE1:
+ spin_lock(&dac33->lock);
+ t0 = dac33->t_stamp1;
+ t1 = dac33->t_stamp2;
+ spin_unlock(&dac33->lock);
+ t_now = ktime_to_us(ktime_get());
+
+ /* We have not started to fill the FIFO yet, delay is 0 */
+ if (!t1)
+ goto out;
+
+ if (t0 > t1) {
+ /*
+ * Phase 1:
+ * After Alarm threshold, and before nSample write
+ */
+ time_delta = t_now - t0;
+ samples_out = time_delta ? US_TO_SAMPLES(
+ substream->runtime->rate,
+ time_delta) : 0;
+
+ if (likely(dac33->alarm_threshold > samples_out))
+ delay = dac33->alarm_threshold - samples_out;
+ else
+ delay = 0;
+ } else if ((t_now - t1) <= dac33->mode1_us_burst) {
+ /*
+ * Phase 2:
+ * After nSample write (during burst operation)
+ */
+ time_delta = t_now - t0;
+ samples_out = time_delta ? US_TO_SAMPLES(
+ substream->runtime->rate,
+ time_delta) : 0;
+
+ time_delta = t_now - t1;
+ samples_in = time_delta ? US_TO_SAMPLES(
+ dac33->burst_rate,
+ time_delta) : 0;
+
+ samples = dac33->alarm_threshold;
+ samples += (samples_in - samples_out);
+
+ if (likely(samples > 0))
+ delay = samples;
+ else
+ delay = 0;
+ } else {
+ /*
+ * Phase 3:
+ * After burst operation, before next alarm threshold
+ */
+ time_delta = t_now - t0;
+ samples_out = time_delta ? US_TO_SAMPLES(
+ substream->runtime->rate,
+ time_delta) : 0;
+
+ samples_in = dac33->nsample;
+ samples = dac33->alarm_threshold;
+ samples += (samples_in - samples_out);
+
+ if (likely(samples > 0))
+ delay = samples > DAC33_BUFFER_SIZE_SAMPLES ?
+ DAC33_BUFFER_SIZE_SAMPLES : samples;
+ else
+ delay = 0;
+ }
+ break;
+ case DAC33_FIFO_MODE7:
+ spin_lock(&dac33->lock);
+ t0 = dac33->t_stamp1;
+ spin_unlock(&dac33->lock);
+ t_now = ktime_to_us(ktime_get());
+
+ /* We have not started to fill the FIFO yet, delay is 0 */
+ if (!t0)
+ goto out;
+
+ if (t_now <= t0) {
+ /*
+ * Either the timestamps are messed or equal. Report
+ * maximum delay
+ */
+ delay = MODE7_UTHR;
+ goto out;
+ }
+
+ time_delta = t_now - t0;
+ if (time_delta <= dac33->mode7_us_to_lthr) {
+ /*
+ * Phase 1:
+ * After burst (draining phase)
+ */
+ samples_out = US_TO_SAMPLES(
+ substream->runtime->rate,
+ time_delta);
+
+ if (likely(MODE7_UTHR > samples_out))
+ delay = MODE7_UTHR - samples_out;
+ else
+ delay = 0;
+ } else {
+ /*
+ * Phase 2:
+ * During burst operation
+ */
+ time_delta = time_delta - dac33->mode7_us_to_lthr;
+
+ samples_out = US_TO_SAMPLES(
+ substream->runtime->rate,
+ time_delta);
+ samples_in = US_TO_SAMPLES(
+ dac33->burst_rate,
+ time_delta);
+ delay = MODE7_LTHR + samples_in - samples_out;
+
+ if (unlikely(delay > MODE7_UTHR))
+ delay = MODE7_UTHR;
+ }
+ break;
+ default:
+ dev_warn(codec->dev, "Unhandled FIFO mode: %d\n",
+ dac33->fifo_mode);
+ break;
+ }
+out:
+ return delay;
+}
+