[PATCH 02/12] ASoC: cs42l42: Don't claim to support 192k

Richard Fitzgerald rf at opensource.cirrus.com
Tue Aug 10 17:37:49 CEST 2021


The driver currently only supports configuring for sample rates <= 96k
and it isn't possible to setup a configuration that will support all
sample rates up to 192k.

For sample rates up to 96k MCLK is in the 12MHz group.
However, although 192k only requires an I2S clock in the 12MHz group,
the cs42l42 audio path is not natively 192k so the audio must be
resampled. But for 192k the SRC requires a 24MHz MCLK.

It is not possible to switch MCLK between 12MHz and 24MHz groups
on-the-fly. The 12MHz group supports all sample rates up to 96k.

Signed-off-by: Richard Fitzgerald <rf at opensource.cirrus.com>
---
 sound/soc/codecs/cs42l42.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index 3c1609865440..a43cdfb6223b 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/sound/soc/codecs/cs42l42.c
@@ -819,7 +819,7 @@ static int cs42l42_dai_startup(struct snd_pcm_substream *substream, struct snd_s
 	/* Machine driver has not set a SCLK, limit bottom end to 44.1 kHz */
 	return snd_pcm_hw_constraint_minmax(substream->runtime,
 					    SNDRV_PCM_HW_PARAM_RATE,
-					    44100, 192000);
+					    44100, 96000);
 }
 
 static int cs42l42_pcm_hw_params(struct snd_pcm_substream *substream,
@@ -1026,14 +1026,14 @@ static struct snd_soc_dai_driver cs42l42_dai = {
 			.stream_name = "Playback",
 			.channels_min = 1,
 			.channels_max = 2,
-			.rates = SNDRV_PCM_RATE_8000_192000,
+			.rates = SNDRV_PCM_RATE_8000_96000,
 			.formats = CS42L42_FORMATS,
 		},
 		.capture = {
 			.stream_name = "Capture",
 			.channels_min = 1,
 			.channels_max = 2,
-			.rates = SNDRV_PCM_RATE_8000_192000,
+			.rates = SNDRV_PCM_RATE_8000_96000,
 			.formats = CS42L42_FORMATS,
 		},
 		.symmetric_rate = 1,
-- 
2.11.0



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