Re: [PATCH v1 4/5] gpio: xilinx: Switch to use bitmap APIs

Andy Shevchenko
2021-04-08T15:08:23Z

On Thu, Apr 08, 2021 at 05:56:00PM +0300, Andy Shevchenko wrote:
> It seems that Xilinx GPIO driver operates with bit arrays longer than 32 and
> thus can leverage bitmap APIs for that. It makes code better to understand.
>
> The ->probe() function is modified to try read properties for both channels
> since is_dual check makes only sense for the amount of pins used for the second
> channel. On top of that kzalloc() guarantees zero initial values for the fields
> in the private data structure, hence drop unneeded conditionals and assignments.
>
> The change is inspired by Syed Nayyar Waris' ideas about bitmap API extension.

As I was afraid in the cover letter, I found some mistakes already.
In any case, I'll wait for the comments and test of other patches if possible.

Out of curiosity, below I point out the issues.

...

> + return bitmap_bitremap(gpio, chip->sw_map, chip->hw_map, chip->gc.ngpio);

Seems we have to use 64 instead of ngpio here.

...

> + bitmap_replace(state, chip->state, hw_bits, hw_mask, gc->ngpio);

Ditto.

...

> + bitmap_copy(chip->state, state, gc->ngpio);

Ditto.

...

> + for_each_set_bit(bit, all, 64)
> + generic_handle_irq(irq_find_mapping(gc->irq.domain, bit));

Here should be used gpio actually and ngpio IIUC.

--
With Best Regards,
Andy Shevchenko