[PATCH 03/12] ASoC: cs42l42: Always configure both ASP TX channels

From: Richard Fitzgerald
Date: Tue Aug 10 2021 - 11:39:27 EST


An I2S frame always has two slots (left and right) even when sending
mono. The right channel (channel 2) of ASP TX will always have the
same bit width as the left channel and will always be on the high
phase of LRCLK.

The previous implementation always passed the field masks for both
channels to snd_soc_component_update_bits() but for mono the written value
only contained the settings for channel 1. The result was that for mono
channel 2 was set to 8-bit (which is an invalid configuration) with both
channels on the low phase of LRCLK.

Signed-off-by: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
Fixes: 585e7079de0e ("ASoC: cs42l42: Add Capture Support")
---
sound/soc/codecs/cs42l42.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index a43cdfb6223b..5dc3a30272a4 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/sound/soc/codecs/cs42l42.c
@@ -848,11 +848,10 @@ static int cs42l42_pcm_hw_params(struct snd_pcm_substream *substream,

switch(substream->stream) {
case SNDRV_PCM_STREAM_CAPTURE:
- if (channels == 2) {
- val |= CS42L42_ASP_TX_CH2_AP_MASK;
- val |= width << CS42L42_ASP_TX_CH2_RES_SHIFT;
- }
- val |= width << CS42L42_ASP_TX_CH1_RES_SHIFT;
+ /* channel 2 on high LRCLK */
+ val = CS42L42_ASP_TX_CH2_AP_MASK |
+ (width << CS42L42_ASP_TX_CH2_RES_SHIFT) |
+ (width << CS42L42_ASP_TX_CH1_RES_SHIFT);

snd_soc_component_update_bits(component, CS42L42_ASP_TX_CH_AP_RES,
CS42L42_ASP_TX_CH1_AP_MASK | CS42L42_ASP_TX_CH2_AP_MASK |
--
2.11.0