Re: [PATCH v3 1/3] iio: add struct declarations for iio types

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Michael Riesch <michael.riesch@wolfvision.net>
Cc: Gerald Loacker <gerald.loacker@wolfvision.net>,
	linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, Jonathan Cameron <jic23@kernel.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Jakob Hauser <jahau@rocketmail.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Subject: Re: [PATCH v3 1/3] iio: add struct declarations for iio types
Date: Mon, 28 Nov 2022 16:05:11 +0200	[thread overview]
Message-ID: <Y4TAF1hn0l1CziUh@smile.fi.intel.com> (raw)
In-Reply-To: <4d1b0054-efd4-e10e-17a6-d236052afa49@wolfvision.net>

On Mon, Nov 28, 2022 at 02:48:48PM +0100, Michael Riesch wrote:
> On 11/28/22 14:27, Andy Shevchenko wrote:
> > On Mon, Nov 28, 2022 at 01:18:04PM +0100, Gerald Loacker wrote:
> >> Am 25.11.2022 um 12:01 schrieb Andy Shevchenko:

...

> > It's a rule to use _t for typedef:s in the kernel. That's why
> > I suggested to leave struct definition and only typedef the same structures
> > (existing) to new names (if needed).
> 
> Andy, excuse our ignorance but we are not sure how this typedef approach
> is supposed to look like...
> 
> >> or
> > 
> >> 	typedef iio_val_int_plus_micro iio_val_int_plus_micro_db;
> 
> ... because
> 
> #include <stdio.h>
> 
> struct iio_val_int_plus_micro {
> 	int integer;
> 	int micro;
> };
> 
> typedef iio_val_int_plus_micro iio_val_int_plus_micro_db;
> 
> int main()
> {
>   struct iio_val_int_plus_micro a = { .integer = 100, .micro = 10, };
>   struct iio_val_int_plus_micro_db b = { .integer = 20, .micro = 10, };
>   return 0;
> }
> 
> won't compile.

I see. Thanks for pointing this out.

Then the question is why do we need the two same structures with different
names?

-- 
With Best Regards,
Andy Shevchenko