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From:   Pintu Agarwal <pintu.ping@gmail.com>
Date:   Tue, 9 Jun 2020 23:06:10 +0530
Message-ID: <CAOuPNLj4m_jvs90YpAq5r4gAP9o8Y1Uck3HN+MbsTPb3zP=4eA@mail.gmail.com>
Subject: Generic way for verifying GPIO wakeup capability
To:     Kernelnewbies <kernelnewbies@kernelnewbies.org>,
        open list <linux-kernel@vger.kernel.org>,
        linux-pm@vger.kernel.org,
        "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>, linux-gpio@vger.kernel.org,
        zonque@gmail.com
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Hi All,

I am looking for ways to wakeup any devices (from sleep) using any
arbitrary gpio wakeup method in a generic way (either from user space
or kernel space) that should work on any kernel version (starting from
4.14 onwards).

What are the options available right now ?
I wanted to experiment with all of them and decide which is best for us.

Is /sys/class/gpio/ method still valid with the latest kernel ?
Or is there any other method to do it from user space ?

One option I know is to use enable/disable_irq_wake() API from kernel
driver suspend/resume path.
Just like this:
https://lwn.net/Articles/569027/

But this requires an additional kernel driver and device-tree changes
for each gpio wakeup, which the end-user needs to implement on their
own.

Is there any other existing generic mechanism?


Thanks,
Pintu