[LinuxPPS] PPS echo implementation

[Rodolfo Giometti]

On 16/09/18 05:26, tom burkart wrote:
> Quoting Rodolfo Giometti <giometti at enneenne.com>:
> 
>> Patches must always be against __latest__ __vanilla__ kernel. Also
> 
> I wanted to make it as simple as possible for people to try out the patch hence 
> I provided all the information required which included device tree items, none 
> of which are in the vanilla kernel.

If you want a patch against Raspberry Pi kernel you should send that patch to 
Raspberry Pi kernel's maintainers and not to me. I'm a vanilla kernel maintainer 
and I apply patches to vanilla kernel only.

However, you can add extra Raspberry Pi kernel information to our new LinuxPPS's 
wiki! :-)

>>> +        if (of_get_property(np, "enable-pps-echo", NULL)) {
>>
>> I think we can safely drop property "enable-pps-echo" and considering the EHO 
>> functionality activated if property "echo-gpios" is present.
> 
> I elected to provide this functionality as I felt it conceivable that someone 
> might want the PPS signal but does not want or require the ECHO functionality.

If I well understand this patch when "enable-pps-echo" is enabled you do a 
devm_request_threaded_irq(), which in turn calls pps_gpio_irq_threaded() which 
requires a GPIO line to work...

Ciao,

Rodolfo

-- 

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