Forums - QCA9377 SCO Data routing

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QCA9377 SCO Data routing
saisreekartheek...
Join Date: 30 Jun 21
Posts: 8
Posted: Sat, 2021-08-21 06:41

Hi,

We are running Linux on pico-imx8mm which has a QCA9377-3 connected for Bluetooth with UART & PCM.
ACL Data and Event Packets are received correctly to the hci_core and we are able to use A2DP without any issue. But we are unable to receive SCO data packets in the case of HSP/HFP.

I have 3 queries regarding this:

1. What is the default routing for SCO data in this chip? HCI UART or PCM pins?

2. Are there any HCI commands that need to be given to enable SCO data over that default interface?

3. Is there a possibility to switch between UART and PCM interfaces for SCO data using any HCI commands?

 

Thank you in advance for your response.

S S Kartheek Adivi.

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matadeen
Join Date: 12 Oct 17
Posts: 29
Posted: Wed, 2021-09-01 00:11

Hi S S Kartheek Adivi,

Please find the inline comment:

1. What is the default routing for SCO data in this chip? HCI UART or PCM pins?

[QC] using PCM PINs.

2. Are there any HCI commands that need to be given to enable SCO data over that default interface?

[QC] no it won't requrie any command to enable SCO.

3. Is there a possibility to switch between UART and PCM interfaces for SCO data using any HCI commands?

[QC] No We don't have any command to switch, what is your usecase? why you want to switch kind of mechanism?

Regards,

Matadeen Mishra

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saisreekartheek...
Join Date: 30 Jun 21
Posts: 8
Posted: Wed, 2021-09-01 06:37

Hi Matadeen,

We are trying to enable HSP/HFP on this device. We are unable to receive SCO Data from the PCM SAI interface.
I asked for the command to switch the interface so that if it can be switched and if with that command we are able to receive SCO data on UART, Our use case will be served and we will know that something is wrong regarding the PCM SAI configuration on our side.

Also we want to know how the QCA9377-3 PCM is configured? I2S Slave or Master? We initially kept imx8mm as Slave, and we were unable to read pcm data with that configuration. When imx8mm is set as Master, we are able to read data but it's all 0's.
We are using scotest in bluez tools to get this data.

Can you recommend any reference platform on which SCO data from QCA9377-3 is tested or a platform in general in which this chip is used?

Thank you,
S S Kartheek Adivi

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matadeen
Join Date: 12 Oct 17
Posts: 29
Posted: Wed, 2021-09-01 21:26

Hi S S Kartheek,

Got the point let me share the details you can try that loopback is working fine or not. this way we can test the PCM interface.

will update you with the FW chagnes.

 

Regards,

Matadeen Mishra

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matadeen
Join Date: 12 Oct 17
Posts: 29
Posted: Thu, 2021-09-02 08:34

Hi SS Kartheek,

From NVM, DUT as PCM Slave.

Please confirm below points with Audio team:

1. Audio Modules as PCM Master?

2. What is the frequency of Bit CLK and Frame Sync CLK?

Note:

The frequency of Frame Sync should be:

When use CVSD Codec, it should be 8K

When use MSBC codec, it should be 16K

 
Please have a try if still you get any issue, we need snoop logs and OTA logs to check the issue.
 
Regards,
Matadeen Mishra
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saisreekartheek...
Join Date: 30 Jun 21
Posts: 8
Posted: Thu, 2021-09-02 22:11

Hi Matadeen,

I will have to check with my team regarding your queries. Meanwhile here are our new observations.

We have created a dummy codec to read and write the PCM SAI interface, Set imx8mm as master. Then, with the dummy codec alsa PCM, we tried to play and record a wav file. Recording gave 0's. But when we played a local audio file, we were able to hear it on the other end of the call. So it looks like TXD is working fine and the problem is only with RXD pin. Hope this will help narrow down the issue.

Thanks,

S S Kartheek Adivi

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matadeen
Join Date: 12 Oct 17
Posts: 29
Posted: Fri, 2021-09-03 07:48

Hi Kartheek,

once you get clarification from the team, please share recorded file and OTA with snoop logs.

 

Regards,

Matadeen Mishra

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saisreekartheek...
Join Date: 30 Jun 21
Posts: 8
Posted: Tue, 2021-09-07 03:48

Hi Matadeen,

Here are the answers for your queries.

  1. Yes we configure pico-imx8mm as I2S Master.
  2. Bit Clk is 512k and Frame Sync Clk is 8k. Using CVSD.

I've sent you the attachments in mail.

- S S Kartheek Adivi

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matadeen
Join Date: 12 Oct 17
Posts: 29
Posted: Wed, 2021-09-08 23:05

Hi Kartheek, 

Could you please share the OTA as well.

Regards,

Matadeen Mishra

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saisreekartheek...
Join Date: 30 Jun 21
Posts: 8
Posted: Thu, 2021-09-16 22:03

Hi matadeen,

We were able to transmit and receive data but the received data is interfered with too much noise and the hexdump of the received audio looks like a following a pattern/mask. It might be a configuration mismatch between QCA9377-3 and Our side.
Could you please share the datasheet of QCA9377-3 so that we can get a little more understanding on the configurations on your end.

Thanks & Regards,
S S Kartheek Adivi.

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