CLK1 and CLK2 enable in i.MX8M

[yashavanthashet]

Hi,

Kindly let us know how to enable CLK1 and CLK2 (CCM instance) coming from CPU in Linux kernel.

We are using i.MX8M custom board with Linux4.9.51_ga release.

Thanks in advance.

Regards,

Yashavantha

[art]

The CLK1_P/N and CLK2_P/N differential clock signals are intended to be used for internal/factory test purposes only. They should not be used for regular operation.

Have a great day,
Artur

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[yashavanthashet]

Hi Arut,

Thank you for the reply.

We are not intended to use CLK1 and CLK2 for regular operation, just we wanted to check whether its enabled or not.

When we probe the respective pins we are not getting any clock pulse. So we wanted to enable it, if it is not enabled.

Best Regards,

Yashavantha

[art]

As I told before, this is not required for normal operation. CLK1_P/N is the debug clock input only, and the CLK2_P/N debug clock output is disabled by default.

Best Regards,

Artur

[plentod]

Artur,

The IMX8M HW Dev Guide (IMX8MDQLQHDG, section 3.9) talks about using CLK2 as a source for the PCIe interface (when not using an external clock generator).  Can CLK2 still be enabled as a 100MHz ref clk for this purpose?  If so, is there an updated ref manual/app_note that describes how to configure/enable CLK2 output?

Thanks, David Plentovich