topic Re: System Controller API in IMX8QM-MEK in i.MX Processors

System Controller API in IMX8QM-MEK

vinothkumars — Wed, 10 Jun 2020 16:36:51 GMT

Hi All,

I am working on Power Management - IMX8QM MEK board. I have to integrate system controller API to put system low power mode.

I integrated successfully and I got the following response,

M4F and A53, A72 is OFF
                       sc_pm_set_sys_power_mode(ipc_handle, SC_PM_PW_MODE_OFF)
Board Reboot
                        sc_pm_set_sys_power_mode(ipc_handle, SC_PM_PW_MODE_STBY)
No response
                       sc_pm_set_resource_power_mode(ipc_handle, SC_R_A53_0, SC_PM_PW_MODE_OFF)
                       sc_pm_set_resource_power_mode(ipc_handle, SC_R_A53_0, SC_PM_PW_MODE_STBY)

I don't the perfect the perfect API to suspend resume the A53, A72 CPU's

I am following the following reference,

https://community.nxp.com/docs/DOC-345249

Will you please provide proper SCU API for control Application Processor in Suspend and Wakeup from MCU.

Thanks & Regards,

VinothS,

Re: System Controller API in IMX8QM-MEK

igorpadykov — Wed, 10 Jun 2020 23:08:57 GMT

Hi VinothS

additional examples can be found in linux sources, one can look at

sect.2.5.1 Low Level Power Management (PM) Linux Manual

in Linux 5.4.3_1.0.0 Documentation

atf sources:

imx\plat - imx-atf - i.MX ARM Trusted firmware

Best regards
igor
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Re: System Controller API in IMX8QM-MEK

vinothkumars — Thu, 11 Jun 2020 07:49:48 GMT

Thank you Igor for the reply.

I am following same API for Suspend the CPU-A35 and CPU-A72. But, I don't know my implementation is not giving any effect.

This is my implementation for power off CPU's from M4 MCU,

RTN_ERR(sc_pm_req_low_power_mode(ipc_handle, SC_R_A53, SC_PM_PW_MODE_OFF));
RTN_ERR(sc_pm_req_low_power_mode(ipc_handle, SC_R_A53_0, SC_PM_PW_MODE_OFF));
RTN_ERR(sc_pm_req_low_power_mode(ipc_handle, SC_R_A53_1, SC_PM_PW_MODE_OFF));
RTN_ERR(sc_pm_req_low_power_mode(ipc_handle, SC_R_A53_2, SC_PM_PW_MODE_OFF));
RTN_ERR(sc_pm_req_low_power_mode(ipc_handle, SC_R_A53_3, SC_PM_PW_MODE_OFF));
RTN_ERR(sc_pm_req_low_power_mode(ipc_handle, SC_R_A53_0, SC_PM_PW_MODE_OFF));
RTN_ERR(sc_pm_req_low_power_mode(ipc_handle, SC_R_A72, SC_PM_PW_MODE_OFF));
RTN_ERR(sc_pm_req_low_power_mode(ipc_handle, SC_R_A72_0, SC_PM_PW_MODE_OFF));
RTN_ERR(sc_pm_req_low_power_mode(ipc_handle, SC_R_A72_1, SC_PM_PW_MODE_OFF));
RTN_ERR(sc_pm_req_cpu_low_power_mode(ipc_handle, SC_R_A53, SC_PM_PW_MODE_OFF, SC_PM_WAKE_SRC_NONE));
RTN_ERR(sc_pm_req_cpu_low_power_mode(ipc_handle, SC_R_A53_0, SC_PM_PW_MODE_OFF, SC_PM_WAKE_SRC_NONE));
RTN_ERR(sc_pm_req_cpu_low_power_mode(ipc_handle, SC_R_A53_1, SC_PM_PW_MODE_OFF, SC_PM_WAKE_SRC_NONE));
RTN_ERR(sc_pm_req_cpu_low_power_mode(ipc_handle, SC_R_A53_2, SC_PM_PW_MODE_OFF, SC_PM_WAKE_SRC_NONE));
RTN_ERR(sc_pm_req_cpu_low_power_mode(ipc_handle, SC_R_A53_3, SC_PM_PW_MODE_OFF, SC_PM_WAKE_SRC_NONE));
RTN_ERR(sc_pm_req_cpu_low_power_mode(ipc_handle, SC_R_A72, SC_PM_PW_MODE_OFF, SC_PM_WAKE_SRC_NONE));
RTN_ERR(sc_pm_req_cpu_low_power_mode(ipc_handle, SC_R_A72_0, SC_PM_PW_MODE_OFF, SC_PM_WAKE_SRC_NONE));
RTN_ERR(sc_pm_req_cpu_low_power_mode(ipc_handle, SC_R_A72_1, SC_PM_PW_MODE_OFF, SC_PM_WAKE_SRC_NONE));

Thanks & Regards,

VinothS,

Re: System Controller API in IMX8QM-MEK

igorpadykov — Thu, 11 Jun 2020 08:24:40 GMT

one can look at imx_pwr_domain_off() in

imx8qm_psci.c\imx8qm\imx\plat - imx-atf - i.MX ARM Trusted firmware

Best regards
igor

Re: System Controller API in IMX8QM-MEK

vinothkumars — Thu, 11 Jun 2020 10:49:01 GMT

Hi Igor,

Yes I am using the same API (sc_pm_req_low_power_mode, sc_pm_req_cpu_low_power_mode) only.

Thanks & Regards,

VinothS,

Re: System Controller API in IMX8QM-MEK

vinothkumars — Thu, 11 Jun 2020 12:11:51 GMT

Hi Igor,

from this document,

System Controller Firmware 101 - Power management service

A cores and GPUs are the only ones with a dedicated external power supplies

So, I unable to handle the power mode of A cores by using SCF API.

Thanks & Regards,

VinothS,

Re: System Controller API in IMX8QM-MEK

vinothkumars — Fri, 19 Jun 2020 06:39:41 GMT

Hi,

When I execute I got the error for the API,

err = sc_pm_set_resource_power_mode(ipc_handle, SC_R_A53_0, SC_PM_PW_MODE_OFF)
err = sc_pm_set_resource_power_mode(ipc_handle, SC_R_A53_0, SC_PM_PW_MODE_STBY)

SC_ERR_NOACCESS

#define SC_ERR_NOACCESS 4U /*!< Permission error (no access) */

How to resolve the this error?

Thanks & Regards,

VinothS,

Re: System Controller API in IMX8QM-MEK

vinothkumars — Sat, 18 Jul 2020 02:34:19 GMT

Solution here,

IMX8QM-MEK Power Management difference between Linux and Android

Regards,

VinothS.