[PATCH 3/3] ASoC: imx-card: improve the sound quality for low rate

Shengjiu Wang shengjiu.wang at nxp.com
Tue Jan 4 21:40:35 AEDT 2022


According to RM, on auto mode:
For codec AK4458 and AK4497, the lowest ratio of MLCK/FS is 256
if sample rate is 8kHz-48kHz,
For codec AK5558, the lowest ratio of MLCK/FS is 512 if sample
rate is 8kHz-48kHz.

With these setting the sound quality for 8kHz-48kHz can be improved.

Fixes: aa736700f42f ("ASoC: imx-card: Add imx-card machine driver")
Signed-off-by: Shengjiu Wang <shengjiu.wang at nxp.com>
---
 sound/soc/fsl/imx-card.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/sound/soc/fsl/imx-card.c b/sound/soc/fsl/imx-card.c
index f9196fb7e833..6f8efd838fcc 100644
--- a/sound/soc/fsl/imx-card.c
+++ b/sound/soc/fsl/imx-card.c
@@ -120,7 +120,7 @@ struct imx_card_data {
 
 static struct imx_akcodec_fs_mul ak4458_fs_mul[] = {
 	/* Normal, < 32kHz */
-	{ .rmin = 8000,   .rmax = 24000,  .wmin = 1024, .wmax = 1024, },
+	{ .rmin = 8000,   .rmax = 24000,  .wmin = 256,  .wmax = 1024, },
 	/* Normal, 32kHz */
 	{ .rmin = 32000,  .rmax = 32000,  .wmin = 256,  .wmax = 1024, },
 	/* Normal */
@@ -151,8 +151,8 @@ static struct imx_akcodec_fs_mul ak4497_fs_mul[] = {
 	 * Table 7      - mapping multiplier and speed mode
 	 * Tables 8 & 9 - mapping speed mode and LRCK fs
 	 */
-	{ .rmin = 8000,   .rmax = 32000,  .wmin = 1024, .wmax = 1024, }, /* Normal, <= 32kHz */
-	{ .rmin = 44100,  .rmax = 48000,  .wmin = 512,  .wmax = 512, }, /* Normal */
+	{ .rmin = 8000,   .rmax = 32000,  .wmin = 256,  .wmax = 1024, }, /* Normal, <= 32kHz */
+	{ .rmin = 44100,  .rmax = 48000,  .wmin = 256,  .wmax = 512, }, /* Normal */
 	{ .rmin = 88200,  .rmax = 96000,  .wmin = 256,  .wmax = 256, }, /* Double */
 	{ .rmin = 176400, .rmax = 192000, .wmin = 128,  .wmax = 128, }, /* Quad */
 	{ .rmin = 352800, .rmax = 384000, .wmin = 128,  .wmax = 128, }, /* Oct */
@@ -164,7 +164,7 @@ static struct imx_akcodec_fs_mul ak4497_fs_mul[] = {
  * (Table 4 from datasheet)
  */
 static struct imx_akcodec_fs_mul ak5558_fs_mul[] = {
-	{ .rmin = 8000,   .rmax = 32000,  .wmin = 1024, .wmax = 1024, },
+	{ .rmin = 8000,   .rmax = 32000,  .wmin = 512,  .wmax = 1024, },
 	{ .rmin = 44100,  .rmax = 48000,  .wmin = 512,  .wmax = 512, },
 	{ .rmin = 88200,  .rmax = 96000,  .wmin = 256,  .wmax = 256, },
 	{ .rmin = 176400, .rmax = 192000, .wmin = 128,  .wmax = 128, },
-- 
2.17.1



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