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Contributor
Contributor
409 Views
Registered: ‎09-28-2019

Reset GPIO for HLS video IPs

Hello,

I'm using 2 GPIO (EMIO) from Zynq PS to reset TPG and Framebuffer write IPs in my design.

I declared them in dts file.

v_frmbuf_wr@43c10000 {
...
reset-gpios = <&gpio 54 1>;
...
}

v_tpg@43c20000 {
...
reset-gpios = <&gpio 55 1>;
...
}

In my linux app, when I want to reset each IP, (by exporting gpio under /sys/class/gpio) like described here, I get the error: 

echo: write error: Device or resource busy

 

How can I do?

 

Thanks.

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3 Replies
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Voyager
Voyager
377 Views
Registered: ‎10-21-2015

Hi 

It is not possible to use gpios, which is used by kernel driver, in userspace

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Highlighted
Contributor
Contributor
372 Views
Registered: ‎09-28-2019

Hello,

These IPs (TPG, Video FBWR) require GPIO reset. 

So, how can I reset them from userspace app?

 

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Highlighted
Voyager
Voyager
313 Views
Registered: ‎10-21-2015

Hi 

There is no way to handle them from userspace app

If you want to do it, you should modify driver code to expose gpio pin to userspace 

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