2014-11-06 9:03 GMT+03:00 Mark Brown [off-list ref]:

On Thu, Nov 06, 2014 at 01:33:24AM +0400, Dmitry Eremin-Solenikov wrote:

quoted

2014-11-03 16:43 GMT+03:00 Linus Walleij [off-list ref]:

quoted

quoted

Yes that's the point: if you use regmap mmio you get the RMW-locking
for free, with the regmap implementation.

quoted

Just to be more concrete. Currently locomo_gpio_ack_irq() function uses
one lock and one unlock for doing 3 consecutive RMW I I convert locomo
to regmap, will that be 3 lock/unlock calls or still one? (Or maybe I'm
trying to be over-protective here and adding more lock/unlock cycles
won't matter that much?)

You'll get three lock/unlocks, we could add an interface for bulk
updates under one lock if it's important though.

quoted

Next question: if I have to export regmap to several subdrivers, is it better
to have one big regmap or to have one-map-per-driver approach?

One regmap for the physical register map which is shared between all the
users.

Mark, Linus,

Just to better understand your suggestions: do you want me to convert
to regmap only gpio driver or do you suggest to convert all LoCoMo drivers?
That is doable, of course, but the amount of changes is overwhelming.
Also I'm concerned about the performance impact from going through
regmap layers.


-- 
With best wishes
Dmitry