Re: [PATCH 0/4] use BIT() macro instead manually shifting bits

[Alexandre Courbot <gnurou@gmail.com>]

On Sun, Apr 27, 2014 at 9:00 AM, Javier Martinez Canillas
<javier@dowhile0.org> wrote:
> Hello Linus and Alexandre,
>
> While learning coccinelle towards doing the big gpio_chip/gpio_chip_ops
> split refactoring I wrote this trivial semantic patch that replaces a
> manual bit shift by using the BIT macro from <linux/bitops.h>
>
>     @hasbitops@
>     @@
>
>     #include <linux/bitops.h>
>
>     @depends on hasbitops@
>     expression E;
>     @@
>
>     - 1 << E
>     + BIT(E)
>
>     @depends on hasbitops@
>     expression E;
>     @@
>
>     - BIT((E))
>     + BIT(E)
>
> When applying to the drivers/gpio subdirectory I got
> the following clean up patches for some GPIO drivers.

I personally find "1 << n" easier to read than a macro, but you are
right that the macro is less error-prone. Nice use of Coccinelle btw,
I should really spend the time to learn it.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>