IMX6 powermanagement in linux

anoopmm — Wed, 24 Dec 2014 11:50:19 GMT

Hi,

We are doing power management in Linux(L3.0.35_4.1.0_130816_source) for imx6 board.

As part of power management, we want to power off arm core or gate off arm core during suspend.

But we cannot find the code portion to do this in Linux source. Is this feature is implemented in Linux code?

In one portion (mxc_cpu_lp_set function) ARM_POWER_OFF case, we can see the code to power off the arm core.

But I am not seeing arm power down request bit similar to VPU/GPU(gpu_vpu_pdn_req) to switch off the arm core in imx6.

Can you please help to identify the arm power down request bit?

Regards

Anoop

Re: IMX6 powermanagement in linux

igorpadykov — Wed, 24 Dec 2014 13:54:39 GMT

Hi anoop

actually mxc_cpu_lp_set function ARM_POWER_OFF case is

pdn_req to switch off the arm core, it is implemented in

IMX6DQRM sect.27.6 Power Gating Control (PGC) gives usage :

PGC power down sequence:

• CCM sends power down request when the chip is about to enter stop mode. The user

should define which modules will be powered down (PGCR registers of

corresponding PGC module, bit 0).

Best regards

igor

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