ADC with DMA in imx91

[sbmd_1234]

Hi NXP Team,


I am new to working with ADC and I wanted to implement the DMA with ADC please tell me how to implement it on the imx91 processor.


Thanks.

[Zhiming_Liu]

Hi

Default driver doesn't support DMA feature, please refer RM to configure DMA registers, DMAE, and DMARn, for different channel groups.

Best Regards
Zhiming

[sbmd_1234]

Hi,

Do you have any reference code, or document that would be helpful for the DMA implementation with ADC.

Thanks for your help!

[Zhiming_Liu]

Hello,

I don't find such reference code in doucument.

Best Regards,
Zhiming

[sbmd_1234]

Hi,

How can we know the sample rate used in ADC and also if we want to configure for 200k samples per second then how could we do that?


Thanks.

[Zhiming_Liu]

Hello,

Checked with SW team , they don't have plan to add DMA feature for ADC.

The adc driver has integrated with iio sensor framework, you can refer below link to access this device to get/set data you want with /sys/bus/iio/iio:deviceX/.

https://developer.toradex.com/linux-bsp/application-development/peripheral-access/adc-linux/

Best Regards,
Zhiming

[sbmd_1234]

Hi @Zhiming_Liu ,

Actually my concern is that I can read the ADC value as /sys/bus/iio/devices/iio:device0/in_voltage0_raw, but how can we read the desired samples per second for example I need 200k samples per second how can I read or implement.

Please help with this.

Thanks.

[Zhiming_Liu]

Hello,

The driver doesn't support iio buffer and iio scan feature, you may need refer other adc driver like drivers/iio/adc/ad7768-1.c to add them.

Best Regards,
Zhiming