i.MX ProcessorsのトピックRe: Wakeup sources are not available in folder /dev

Wakeup sources are not available in folder /dev

aaronpadilla — Wed, 05 Oct 2016 16:17:39 GMT

I am trying to evaluate the low power modes and the wakeup time on a SCM-i.MX 6Quad but in the original image included in MMC I didn't found the files to configure the wakeup sources like an example:

/sys/devices/platform/imx-uart.1/tty/ttymxc1/power/wakeup

All that I have in the /sys/devices/platform is:

Vivante GCCore

hdmi-audio-codec

imx6q-cpufreq.0

reg-dummy

snd-soc-dummy
alarmtimer

imx-hdmi-audio

power regulatory.0

uevent

Then I have compiled a new image, including the next power management option in menuconfig:

[*] User space wakeup sources interface

But I am getting exactly the same, to compile I did the following:

$ mkdir fsl-arm-yocto-bsp

$ cd fsl-arm-yocto-bsp

$ repo init -u git://git.freescale.com/imx/fsl-arm-yocto-bsp.git -b scm-imx-3.14.52-1.1.0_ga

$ repo sync

$ DISTRO=fsl-imx-x11 MACHINE=imx6dqscm-1gb-qwks source fsl-setup-release.sh -b build-x11

$ bitbake -c menuconfig linux-imx (to activate User space wakeup sources interface)

$ bitbake fsl-image-gui

Could someone advice?

Thanks in advance

Re: Wakeup sources are not available in folder /dev

igorpadykov — Wed, 05 Oct 2016 23:57:10 GMT

Hi Aaron

please check Chapter 21 Low-level Power Management (PM) Driver

attached Linux Manual, Table 21-1. Low Power Modes, sect.21.1.5 Unit Test.

There are limited number of modules (description can be found in appropriate

chapters of reference manual) which can work without module clocks (as plls

are disabled), using only ckil.

Best regards
igor
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Re: Wakeup sources are not available in folder /dev

aaronpadilla — Thu, 06 Oct 2016 13:45:25 GMT

Thanks for the info, it is a very good manual, however my question is that in the folder /sys/devices/platform/ I don't have the folder for the uart (drivers/imx-uart/'xxxxxxx'.serial/tty/ttym does not exist) and some others, should I create this folders?? I dont think so

Could you advice?, I am a little bit hopeless

Re: Wakeup sources are not available in folder /dev

igorpadykov — Thu, 06 Oct 2016 23:23:16 GMT

one can look at linux resources how create sysfs :
https://coherentmusings.wordpress.com/2014/02/19/adding-sysfs-support-to-a-driver/
http://kroah.com/log/blog/2013/06/26/how-to-create-a-sysfs-file-correctly/