topic Re: Power Management in i.MX Processors

Power Management

vinothkumars — Fri, 22 May 2020 09:23:49 GMT

Hi All,

We are implementing the Power Management for Android Automotive on NXP IMX8QM-MEK board.

As a part of the implementation, we want to know:
Does schematic of IMX8QM-MEK board is matching with the way Android is described?

Please have a look at the following Hardware block diagram.

https://source.android.com/devices/automotive/power

Does IMX8QM-MEK board have any specific way of handling Power management? If there is any reference for implementation please share.

Thanks & Regards,

VinothS,

Re: Power Management

gusarambula — Fri, 22 May 2020 21:18:25 GMT

Hello VinothS,

The implementation mentioned on the link you shared would refer to a vehicle implementation.

The i.MX8QM-MEK uses PMICs and instead of using the Linux Power management like other i.MX processors, power is handled by the System Controller. You can find more information on the i.MX8QM Documentation. The Android Automotive BSP for the i.MX8QM does integrate the Android Power HAL.

I hope this helps!
Regards,

Re: Power Management

vinothkumars — Mon, 25 May 2020 13:02:46 GMT

Hi Gusarambula thank you for the reply,

Will you please provide IMX8QM-MEK power management document for sleep and wake up A35 from M4.

Thanks & Regards,

VinothS,

Re: Power Management

gusarambula — Thu, 04 Jun 2020 20:10:49 GMT

Hello VinothS,

Some of the i.MX8QM documentation is not publicly available, like the Reference Manual, so you may open a case and request to sign an NDA to request access.

As for the SCFW documentation, please search for the SCFW Porting Kit under the Linux BSPs on the Prereleases BSP page on the link below (you may need to login to download this file):

https://www.nxp.com/pages/alpha-beta-bsps-for-microprocessors:IMXPRERELEASES

My apologies for the inconvenience!

Regards,

Re: Power Management

vinothkumars — Fri, 05 Jun 2020 05:07:21 GMT

Thank you Gusarambula thank you for the reply.

Thanks & Regards,

VinothS,

Re: Power Management

vinothkumars — Fri, 19 Jun 2020 07:40:46 GMT

Hi,

I configured System Control Register for Deep sleep but system is not going to deep sleep.

status = ASMC_SetPowerModeStop(BBS_SIM, kASMC_PartialStop1);

/*!
* brief Configure the system to Stop power mode.
*
* param base ASMC peripheral base address.
* param option Partial Stop mode option.
* return ASMC configuration error code.
*/
status_t ASMC_SetPowerModeStop(ASMC_Type *base, asmc_partial_stop_option_t option)
{
    uint32_t reg;
    PRINTF("%s ++++++++++++++++++++++++++\r\n", __func__);
    /* configure the Partial Stop mode in Normal Stop mode */
    reg = base->STOPCTRL;
    reg &= ~ASMC_STOPCTRL_PSTOPO_MASK;
    reg |= ((uint32_t)option << ASMC_STOPCTRL_PSTOPO_SHIFT);
    base->STOPCTRL = reg;
    /* configure Normal Stop mode */
    reg = base->PMCTRL;
    reg &= ~ASMC_PMCTRL_STOPM_MASK;
    reg |= (kASMC_StopNormal << ASMC_PMCTRL_STOPM_SHIFT);
    base->PMCTRL = reg;
    /* Set the SLEEPDEEP bit to enable deep sleep mode (stop mode) */
    SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk;
    PRINTF("%s ++++++++++++++++++++++++++ SCB->SCR: 0x%x\r\n", __func__, SCB->SCR);
    /* read back to make sure the configuration valid before entering stop mode */
    (void)base->PMCTRL;
    __DSB();
    __WFI();
    __ISB();
    PRINTF("%s ------------------------\r\n", __func__);
    return kStatus_Success;
}

Ref: https://static.docs.arm.com/dui0553/a/DUI0553A_cortex_m4_dgug.pdf

Thanks & Regards,

VinothS,

Re: Power Management

vinothkumars — Sat, 18 Jul 2020 02:28:41 GMT

Solution here,

https://community.nxp.com/thread/536002

Regards,

VinothS.