CS42888 8000 sampling rate support

[Babu]

Dear NXP Team, 

we are developing IVI system based on IMX8QM and connected BT module "BCM4356". BT A2DP works fine but HFP is not working. As per logs from alsa layer, input sampling rate is 8000 and output is 48000.

 Line 6109: 04-07 03:45:52.760  1829  3601 I audio_hw_primary: create_resampler rsmpl_sco_rx, in rate 8000, out rate 48000

tinypcminfor output for CS42888:

mek_8q:/sdcard/Download # tinypcminfo -D 0
Info for card 0, device 0:

PCM out:
      Access:   0x000009
   Format[0]:   0x000044
   Format[1]:   00000000
 Format Name:   S16_LE, S24_LE
   Subformat:   0x000001
        Rate:   min=48000Hz     max=192000Hz
    Channels:   min=1           max=8
 Sample bits:   min=16          max=32
 Period size:   min=16          max=16384
Period count:   min=2           max=255

PCM in:
      Access:   0x000009
   Format[0]:   0x000044
   Format[1]:   00000000
 Format Name:   S16_LE, S24_LE
   Subformat:   0x000001
        Rate:   min=48000Hz     max=192000Hz
    Channels:   min=1           max=4
 Sample bits:   min=16          max=32
 Period size:   min=16          max=16384
Period count:   min=2           max=255

Can any one help us to enable 8000 sampling rate in CS42888 codec ..?

[igorpadykov]

Hi Babu

in general 8000 sampling rate should work fine,

one can test it in latest Linux 5.4.3_1.0.0 linux:

imx8q-val.dtsi\freescale\dts\boot\arm64\arch - linux-imx - i.MX Linux kernel 

check that asrc was used. Cs42888 driver is described in

sect.7.1.2.2 7.1 Audio Codec Features attached Linux Manual.

Best regards
igor
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[Babu]

Dear Igor, 

Is is possible to enable software sampling rate converter in android (convert from 8k to 48k ) in sync with 8K in C42888 .. ? if yes, can you help how we can enable in android ..?

Best Regards

Babu A

[Babu]

Thank you Igor, 

I will verify in Linux for 8k sampling rate. if any help required i will pose here.

Best Regards

Babu A