ASoC: davinci-mcasp: dai format runtime reconfiguration

In case when the dai format is set via the dai_link the format
configuration happens once when the links are probed. If the McASP lose
context after this, the information will be lost and McASP will not going
to work correctly.
To overcome this issue, we save the fmt and set it within hw_params as
well.
Reported-by: NMisael Lopez Cruz <misael.lopez@ti.com>
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

sound/soc/davinci/davinci-mcasp.c

@@ -77,6 +77,7 @@ struct davinci_mcasp {
 	u32 fifo_base;
 	struct device *dev;
 	struct snd_pcm_substream *substreams[2];
+	unsigned int dai_fmt;
 
 	/* McASP specific data */
 	int	tdm_slots;
@@ -398,6 +399,9 @@ static int davinci_mcasp_set_dai_fmt(struct snd_soc_dai *cpu_dai,
 	bool fs_pol_rising;
 	bool inv_fs = false;
 
+	if (!fmt)
+		return 0;
+
 	pm_runtime_get_sync(mcasp->dev);
 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_DSP_A:
@@ -529,6 +533,8 @@ static int davinci_mcasp_set_dai_fmt(struct snd_soc_dai *cpu_dai,
 		mcasp_set_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG, FSXPOL);
 		mcasp_set_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG, FSRPOL);
 	}
+
+	mcasp->dai_fmt = fmt;
 out:
 	pm_runtime_put(mcasp->dev);
 	return ret;
@@ -1026,6 +1032,10 @@ static int davinci_mcasp_hw_params(struct snd_pcm_substream *substream,
 	int period_size = params_period_size(params);
 	int ret;
 
+	ret = davinci_mcasp_set_dai_fmt(cpu_dai, mcasp->dai_fmt);
+	if (ret)
+		return ret;
+
 	/*
 	 * If mcasp is BCLK master, and a BCLK divider was not provided by
 	 * the machine driver, we need to calculate the ratio.