[PATCH 08/13] ASoC: ti: davinci-i2s: Add handling of BP_FC format

[Bastien Curutchet <bastien.curutchet@bootlin.com>]

McBSP is able to drive bit clock and consume frame clock but BP_FC
format is not handled by McBSP driver.

Add BP_FC format support.
When BP_FC is selected:
  - CLKX and CLKR are configured as outputs
  - The sample rate generator is configured to be able to provide bit
    clock.

Signed-off-by: Bastien Curutchet <bastien.curutchet@bootlin.com>
---
 sound/soc/ti/davinci-i2s.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/sound/soc/ti/davinci-i2s.c b/sound/soc/ti/davinci-i2s.c
index 4adaed010700..7cdd86f47ead 100644
--- a/sound/soc/ti/davinci-i2s.c
+++ b/sound/soc/ti/davinci-i2s.c
@@ -306,6 +306,12 @@ static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
 		pcr = DAVINCI_MCBSP_PCR_FSRM | DAVINCI_MCBSP_PCR_FSXM;
 		pcr |= DAVINCI_MCBSP_PCR_SCLKME;
 		break;
+	case SND_SOC_DAIFMT_BP_FC:
+		/* cpu is bitclock provider */
+		pcr = DAVINCI_MCBSP_PCR_CLKXM |
+			DAVINCI_MCBSP_PCR_CLKRM;
+		break;
+
 	case SND_SOC_DAIFMT_BC_FC:
 		/* codec is master */
 		pcr = 0;
@@ -491,6 +497,23 @@ static int davinci_i2s_hw_params(struct snd_pcm_substream *substream,
 		clk_div &= 0xFF;
 		srgr |= clk_div;
 		break;
+	case SND_SOC_DAIFMT_BP_FC:
+		if (dev->ext_clk) {
+			freq = clk_get_rate(dev->ext_clk);
+		} else {
+			freq = clk_get_rate(dev->clk);
+			srgr = DAVINCI_MCBSP_SRGR_CLKSM;
+		}
+		if (dev->tdm_slots && dev->slot_width) {
+			clk_div = freq / (params->rate_num * params->rate_den)
+				 / (dev->tdm_slots * dev->slot_width) - 1;
+		} else {
+			clk_div = freq / (mcbsp_word_length * 16) /
+				  params->rate_num * params->rate_den;
+		}
+		clk_div &= 0xFF;
+		srgr |= clk_div;
+		break;
 	case SND_SOC_DAIFMT_BC_FC:
 		/* Clock and frame sync given from external sources */
 		i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
-- 
2.43.2