[U-Boot] [PATCH 2/2] gpio: tegra: use named constants

Simon Glass sjg at chromium.org
Sat Oct 3 16:14:35 CEST 2015


Hi Stephen,

On 2 October 2015 at 00:29, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 10/01/2015 05:00 PM, Simon Glass wrote:
>>
>> On Friday, 25 September 2015, Stephen Warren <swarren at wwwdotorg.org>
>> wrote:
>>>
>>> From: Stephen Warren <swarren at nvidia.com>
>>>
>>> In order to make it clear what the parameters to set_config() and
>>> set_direction() mean, and similarly for the return values from the
>>> respective get_*(), define named constants for these values.
>>>
>>> Disassembly shows no diff in the generated code, except that the
>>> order of the code in the branches of tegra_gpio_get_function() gets
>>> modified without affecting behaviour.
>
>
>>> diff --git a/drivers/gpio/tegra_gpio.c b/drivers/gpio/tegra_gpio.c
>
>
>>> +static const int CONFIG_SFIO = 0;
>>> +static const int CONFIG_GPIO = 1;
>>> +static const int DIRECTION_INPUT = 0;
>>> +static const int DIRECTION_OUTPUT = 1;
>>
>>
>> Why not use an enum?
>
>
> I don't think it gives any benefit does it?
>
> Doing so would entail 5 extra lines of overhead for the enum { and } lines.
> I'd want to define two separate enum blocks since I dislike putting
> logically unrelated enum values into a single enum definition. Even if I
> didn't do that, it's still 2 lines of useless overhead to add everything
> into a single enum.

It's just odd to use const int instead of enum I think. Particularly
as you are using capital letters.

Since it's Tegra code I'll leave it up to you.

Regards,
Simon


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