GPIO Muxing

GPIO Muxing

[Vignesh Radhakrishnan]

Hi ,

I have one driver that calls gpio_request and holds on to it. When another
driver requests for the same gpio, it failes giving EBUSY. Anyway i can
force the gpio request in 2nd driver?

Thanks and regards,
Vignesh

-- 
http://vigneshradhakrishnan.blogspot.com/
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GPIO Muxing

[Vishwanath Govind]

Unless your driver should free it using gpio_free function.


On Wed, Jan 22, 2014 at 12:19 AM, Vignesh Radhakrishnan <
vignesh1192@gmail.com> wrote:

> Hi ,
>
> I have one driver that calls gpio_request and holds on to it. When another
> driver requests for the same gpio, it failes giving EBUSY. Anyway i can
> force the gpio request in 2nd driver?
>
> Thanks and regards,
> Vignesh
>
> --
> http://vigneshradhakrishnan.blogspot.com/
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
>
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GPIO Muxing

[Sudip Mukherjee]

> Hi ,
>
> I have one driver that calls gpio_request and holds on to it. When another
> driver requests for the same gpio, it failes giving EBUSY. Anyway i can
> force the gpio request in 2nd driver?
>

You can modify the GPIO driver to do what you are asking. But that is not
recommended.
If you want to multiplex same GPIO pin between two drivers , then I will
suggest you make a middle layer driver which will actually register the
GPIO. Your other drivers will send the GPIO requests to this middle layer
driver. And your middle layer driver should receive the requests and
forward the requests to the GPIO , but again take care to use semaphores in
proper places otherwise , you will never get the desired output.

Regards
Sudip
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GPIO Muxing

[Ali]

This should not have happened at first place. Got to fix the ebusy thing.
Thats the idea to have _ebusy_.


On Wed, Jan 22, 2014 at 3:52 PM, Vishwanath Govind <
vishwanath.govind@gmail.com> wrote:

> Unless your driver should free it using gpio_free function.
>
>
> On Wed, Jan 22, 2014 at 12:19 AM, Vignesh Radhakrishnan <
> vignesh1192 at gmail.com> wrote:
>
>> Hi ,
>>
>> I have one driver that calls gpio_request and holds on to it. When
>> another driver requests for the same gpio, it failes giving EBUSY. Anyway i
>> can force the gpio request in 2nd driver?
>>
>> Thanks and regards,
>> Vignesh
>>
>> --
>> http://vigneshradhakrishnan.blogspot.com/
>>
>> _______________________________________________
>> Kernelnewbies mailing list
>> Kernelnewbies at kernelnewbies.org
>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>>
>>
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
>
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