Messages in this thread | | | Date | Wed, 28 Apr 2021 17:07:55 +0200 | From | Michael Walle <> | Subject | Re: [PATCH v4 1/2] gpio: Add support for IDT 79RC3243x GPIO controller |
| |
Am 2021-04-28 17:02, schrieb Andy Shevchenko: > On Wed, Apr 28, 2021 at 5:48 PM Michael Walle <michael@walle.cc> wrote: >> >> [Adding Mark here, too] >> >> Am 2021-04-28 16:32, schrieb Andy Shevchenko: >> > On Wed, Apr 28, 2021 at 5:04 PM Michael Walle <michael@walle.cc> wrote: >> >> Am 2021-04-28 15:44, schrieb Andy Shevchenko: >> >> > On Wed, Apr 28, 2021 at 2:57 PM Michael Walle <michael@walle.cc> wrote: >> >> >> >> >> >> Am 2021-04-28 13:07, schrieb Andy Shevchenko: >> >> >> > On Wed, Apr 28, 2021 at 1:51 AM Michael Walle <michael@walle.cc> wrote: >> >> >> >> Am 2021-04-26 12:29, schrieb Andy Shevchenko: >> >> >> >> > On Mon, Apr 26, 2021 at 12:55 PM Thomas Bogendoerfer >> >> >> >> > <tsbogend@alpha.franken.de> wrote: >> >> >> >> > >> >> >> >> > 2) there is gpio-regmap generic code, that may be worth >> >> >> >> > considering. >> >> >> >> >> >> >> >> This driver uses memory mapped registers. While that is >> >> >> >> also possible with gpio-regmap, there is one drawback: >> >> >> >> it assumes gpiochip->can_sleep = true for now, see [1]. >> >> >> >> Unfortunately, there is no easy way to ask the regmap >> >> >> >> if its mmio/fastio. >> >> >> > >> >> >> > I don't see how it is an impediment. >> >> >> >> >> >> You'd have to use the *_cansleep() variants with the gpios, >> >> >> which cannot be used everywhere, no? >> >> > >> >> > *can* sleep means that it requires a sleeping context to run, if your >> >> > controller is fine with that, there are no worries. OTOH if you want >> >> > to run this in an atomic context, then consumers can't do with that >> >> > kind of controller. >> >> >> >> Ok, then we are on the same track. >> >> >> >> > What I meant above (and you stripped it here) is >> >> > to add a patch that will fix that and set it based on >> >> > gpio_regmap_config. >> >> >> >> Yes, but ideally, it would ask the regmap. Otherwise that >> >> information is redundant and might mismatch, i.e. gpio_regmap_config >> >> tell can_sleep=false but the regmap is an I2C type for example. Also >> >> if a driver wants to support both regmap types, we are no step >> >> further. >> > >> > Yeah, I agree that is a band aid, but you are free to fix it actually >> > on regmap level. >> > I don't think it will require an enormous amount of work there. >> >> I'd love to fix that, but Mark was against exposing that property >> outside of regmap. So it it what it is for now ;) Maybe he'll change >> his mind or someone has another idea. > > Then let's go to ugly variant with duplicating it in gpio-regmap > config. with a FIXME note or so. I don't think we should allow new > drivers be based on bgpio_init().
Agreed, given that a possible fix should be easy enough later.
-michael
| |