[PATCH 6.1 028/131] ASoC: fsl_sai: Dont disable bitclock for i.MX8MP

Greg Kroah-Hartman
2023-10-16T08:54:01Z

From: Shengjiu Wang <shengjiu.wang@nxp.com>

[ Upstream commit 197c53c8ecb34f2cd5922f4bdcffa8f701a134eb ]

On i.MX8MP, the BCE and TERE bit are binding with mclk
enablement, if BCE and TERE are cleared the MCLK also be
disabled on output pin, that cause the external codec (wm8960)
in wrong state.

Codec (wm8960) is using the mclk to generate PLL clock,
if mclk is disabled before disabling PLL, the codec (wm8960)
won't generate bclk and frameclk when sysclk switch to
MCLK source in next test case.

The test case:
$aplay -r44100 test1.wav (PLL source)
$aplay -r48000 test2.wav (MCLK source)
aplay: pcm_write:2127: write error: Input/output error

Fixes: 269f399dc19f ("ASoC: fsl_sai: Disable bit clock with transmitter")
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://lore.kernel.org/r/1695116533-23287-1-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/soc/fsl/fsl_sai.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index 08a33832f6b3f..96fd9095e544b 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -710,10 +710,15 @@ static void fsl_sai_config_disable(struct fsl_sai *sai, int dir)
{
unsigned int ofs = sai->soc_data->reg_offset;
bool tx = dir == TX;
- u32 xcsr, count = 100;
+ u32 xcsr, count = 100, mask;
+
+ if (sai->soc_data->mclk_with_tere && sai->mclk_direction_output)
+ mask = FSL_SAI_CSR_TERE;
+ else
+ mask = FSL_SAI_CSR_TERE | FSL_SAI_CSR_BCE;

regmap_update_bits(sai->regmap, FSL_SAI_xCSR(tx, ofs),
- FSL_SAI_CSR_TERE | FSL_SAI_CSR_BCE, 0);
+ mask, 0);

/* TERE will remain set till the end of current frame */
do {
--
2.40.1