@@ -1062,6 +1062,42 @@ static int davinci_mcasp_calc_clk_div(struct davinci_mcasp *mcasp,
return error_ppm;
}
+static inline u32 davinci_mcasp_tx_delay(struct davinci_mcasp *mcasp)
+{
+ if (!mcasp->txnumevt)
+ return 0;
+
+ return mcasp_get_reg(mcasp, mcasp->fifo_base + MCASP_WFIFOSTS_OFFSET);
+}
+
+static inline u32 davinci_mcasp_rx_delay(struct davinci_mcasp *mcasp)
+{
+ if (!mcasp->rxnumevt)
+ return 0;
+
+ return mcasp_get_reg(mcasp, mcasp->fifo_base + MCASP_RFIFOSTS_OFFSET);
+}
+
+static snd_pcm_sframes_t davinci_mcasp_delay(
+ struct snd_pcm_substream *substream,
+ struct snd_soc_dai *cpu_dai)
+{
+ struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(cpu_dai);
+ u32 fifo_use;
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+ fifo_use = davinci_mcasp_tx_delay(mcasp);
+ else
+ fifo_use = davinci_mcasp_rx_delay(mcasp);
+
+ /*
+ * Divide the used locations with the channel count to get the
+ * FIFO usage in samples (don't care about partial samples in the
+ * buffer).
+ */
+ return fifo_use / substream->runtime->channels;
+}
+
static int davinci_mcasp_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params,
struct snd_soc_dai *cpu_dai)
@@ -1386,6 +1422,7 @@ static const struct snd_soc_dai_ops davinci_mcasp_dai_ops = {
.startup = davinci_mcasp_startup,
.shutdown = davinci_mcasp_shutdown,
.trigger = davinci_mcasp_trigger,
+ .delay = davinci_mcasp_delay,
.hw_params = davinci_mcasp_hw_params,
.set_fmt = davinci_mcasp_set_dai_fmt,
.set_clkdiv = davinci_mcasp_set_clkdiv,
McASP have write and read FIFO, each 64 words deep. From the WFIFOS/RFIFOS registers we can read the amount of data currently in the FIFO which can be directly reported as delay. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> --- sound/soc/davinci/davinci-mcasp.c | 37 +++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+)