i.MX ProcessorsのトピックRe: How to enable system clock from MCU M4

How to enable system clock from MCU M4

vinothkumars — Thu, 28 May 2020 06:40:32 GMT

Hi All,

I am working on IMX8QM-MEK with Android 9 Automotive. These are the observation I found with default Power Management behavior.

These are the observation

1, No interrupt triggered for Wake-up

mek_8q:/ $ cat /sys/power/pm_wakeup_irq
cat: /sys/power/pm_wakeup_irq: No data available

2, Only timer expires concept is integrate

system/core/libsuspend/autosuspend.c
int autosuspend_force_suspend(int timeout_ms) {
    int ret;
    ret = autosuspend_init();
    if (ret) {
        return ret;
    }
    return autosuspend_ops->force_suspend(timeout_ms);
}

3, Deep sleep due to disable the following

source/vendor/nxp-opensource/kernel_imx/kernel/power
disable_nonboot_cpus
oom_killer_disable
arch_suspend_disable_irqs

4, Wake up is done due to enable the system clock and peripherals

source/vendor/nxp-opensource/kernel_imx/kernel/power
enable_nonboot_cpus
oom_killer_enable
arch_suspend_enable_irqs

I needs to implement enable clocks from m4 MCU.

Is there any per-defined API for enable clocks from M4 MCU ?

Thanks & Regards,

Vinoth S,

Re: How to enable system clock from MCU M4

igorpadykov — Thu, 28 May 2020 08:29:41 GMT

Hi Vinoth

opposite to previous i.MX products, for i.MX8(X) there is no CCM Chapter in

Reference Manual and no direct access to CCM registers (and PLLs) are allowed.

All access is performed using Linux SCFW APIs :

SCFW Porting Kit

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

Re: How to enable system clock from MCU M4

vinothkumars — Thu, 28 May 2020 10:22:00 GMT

Thank you Igor for the quick reply,

Thanks & Regards,

VinothS,

Re: How to enable system clock from MCU M4

vinothkumars — Sat, 18 Jul 2020 02:37:24 GMT

Solution here,

IMX8QM-MEK Power Management difference between Linux and Android

Regards,

VinothS.