i.MX ProcessorsのトピックHow to set continues mclk ON in processor?

How to set continues mclk ON in processor?

parth_modi — Thu, 22 Nov 2018 14:03:39 GMT

Hi,

I am using imx8mq and 4.9.51 Linux distribution. I have connected processor's SAI1 to analog devices'ADAU1361 codec.(I2S interface)

My codec is working with external oscillator(12.288Mhz)MCLK. But i need to change clock source form external to internal.(i.e from processor's mclk pin).

The MCLK is generated from processor when i play audio.

Actually i need continues MCLK.

My query is

1) How to set continues mclk on in processor side?

Let me know if you need further information.

Thanks & regards,
Parth

Re: How to set continues mclk ON in processor?

igorpadykov — Fri, 23 Nov 2018 11:14:58 GMT

Hi Parth

unfortunately there is no such option in dts file for such case, seems

driver modifications are needed. One can try to analyze driver sources in

linux/sound/soc/fsl/fsl_sai.c

fsl_sai.c\fsl\soc\sound - linux-imx - i.MX Linux kernel

use alsa tutorial:

Writing an ALSA Driver

Best regards
igor
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Re: How to set continues mclk ON in processor?

parth_modi — Mon, 26 Nov 2018 12:30:38 GMT

Hi Igor,

Thanks for the reference.

This take lots of time to learn and We have little urgency to do this.

So,Can you please point out the exact function to set a mclk frequency and where to call?

Thanks & regards,

Parth

Re: How to set continues mclk ON in processor?

igorpadykov — Tue, 27 Nov 2018 00:21:55 GMT

Hi Parth

I am afraid there are no ready patches for that.

If you have some project requiring this feature, suggest to proceed with

Professional Services to develop solution:

NXP Professional Services|NXP

As simple workaround one can consider CCM_CLKO1,2 for outputting

continuous clock.

Best regards
igor

Re: How to set continues mclk ON in processor?

传策薛 — Tue, 27 Nov 2018 05:42:07 GMT

May be you can use GPIO1_IO14 or GPIO1_IO15 pin ,iomux it as CLK