ASoC: fsl_sai: Enable BCI bit if SAI works on synchronous mode with BYP asserted

There's an issue on SAI synchronous mode that TX/RX side can't get BCLK
from RX/TX it sync with if BYP bit is asserted. It's a workaround to
fix it that enable SION of IOMUX pad control and assert BCI.

For example if TX sync with RX which means both TX and RX are using clk
form RX and BYP=1. TX can get BCLK only if the following two conditions
are valid:
1. SION of RX BCLK IOMUX pad is set to 1
2. BCI of TX is set to 1

Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
Acked-by: Shengjiu Wang <shengjiu.wang@gmail.com>
Link: https://lore.kernel.org/r/20230530103012.3448838-1-chancel.liu@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index abdaffb00fbdc978509538b3b667d0c2fad78c73..e3105d48fb651eddd39342b0b8dfbbd989ed1685 100644 (file)
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -491,14 +491,21 @@ static int fsl_sai_set_bclk(struct snd_soc_dai *dai, bool tx, u32 freq)
        regmap_update_bits(sai->regmap, reg, FSL_SAI_CR2_MSEL_MASK,
                           FSL_SAI_CR2_MSEL(sai->mclk_id[tx]));
 
-       if (savediv == 1)
+       if (savediv == 1) {
                regmap_update_bits(sai->regmap, reg,
                                   FSL_SAI_CR2_DIV_MASK | FSL_SAI_CR2_BYP,
                                   FSL_SAI_CR2_BYP);
-       else
+               if (fsl_sai_dir_is_synced(sai, adir))
+                       regmap_update_bits(sai->regmap, FSL_SAI_xCR2(tx, ofs),
+                                          FSL_SAI_CR2_BCI, FSL_SAI_CR2_BCI);
+               else
+                       regmap_update_bits(sai->regmap, FSL_SAI_xCR2(tx, ofs),
+                                          FSL_SAI_CR2_BCI, 0);
+       } else {
                regmap_update_bits(sai->regmap, reg,
                                   FSL_SAI_CR2_DIV_MASK | FSL_SAI_CR2_BYP,
                                   savediv / 2 - 1);
+       }
 
        if (sai->soc_data->max_register >= FSL_SAI_MCTL) {
                /* SAI is in master mode at this point, so enable MCLK */

diff --git a/sound/soc/fsl/fsl_sai.h b/sound/soc/fsl/fsl_sai.h
index 197748a888d5fce91ae3ddf2047559adfcb88577..a53c4f0e25faf85b97d1cd04936a4bf076652564 100644 (file)
--- a/sound/soc/fsl/fsl_sai.h
+++ b/sound/soc/fsl/fsl_sai.h
@@ -116,6 +116,7 @@
 
 /* SAI Transmit and Receive Configuration 2 Register */
 #define FSL_SAI_CR2_SYNC       BIT(30)
+#define FSL_SAI_CR2_BCI                BIT(28)
 #define FSL_SAI_CR2_MSEL_MASK  (0x3 << 26)
 #define FSL_SAI_CR2_MSEL_BUS   0
 #define FSL_SAI_CR2_MSEL_MCLK1 BIT(26)