Re: [PATCH v2 5/6] gpio-exar/8250-exar: Make set of exported GPIOs configurable

[Andy Shevchenko]

On Sun, May 21, 2017 at 2:43 PM, Jan Kiszka <jan.kiszka@xxxxxxxxxxx> wrote:
> On 2017-05-18 19:43, Andy Shevchenko wrote:
>> On Thu, May 18, 2017 at 5:59 PM, Jan Kiszka <jan.kiszka@xxxxxxxxxxx> wrote:
>>> On the SIMATIC, IOT2040 only a single pin is exportable as GPIO, the

>>> +       pdata.first_gpio = first_gpio;
>>> +       pdata.ngpio = ngpio;
>>
>> Still thinking about device properties ("ngpios" and something like
>> "exar8250,gpio-start").
>
> Changed back to properties, removing all platform data.
>
> But what's the purpose of prefixing the name here? This does not have
> anything to do with device trees. It's a private parameter channel
> between the creating device driver and the gpio driver, and there will
> be no other bindings.

To avoid potential collision with registered official property, that's
why better to use prefix.
(I didn't find anything like GPIO start / pin in registered
properties, maybe there is one)

>>> +       unsigned int first_gpio;
>>> +       unsigned int ngpio;
>>
>> u16 ?

> If we do that, then we would rather have to choose u8. But this is
> pointless restriction. I prefer to stay with the native type.

Still for properties it would be u32, wouldn't it?

-- 
With Best Regards,
Andy Shevchenko