On Wednesday 08 January 2014, Linus Walleij wrote: > On Tue, Jan 7, 2014 at 8:52 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > What is actually the bigger worry here is that the contents > > of the new file, while correctly moved out of mach/gpio.h also > > don't belong into include/linux/platform_data, because they don't > > define a pdata structure but rather the contents that are supposed > > to be passed from the platform code. I would much prefer if you could > > move the file back into mach-s3c24xx/ under a new name and keep it out of > > platform_data. > > Unfortunately it cannot live right under mach-s3c24xx because there > are drivers here and there referring directly to the contents of this > file. I think they only reference a small portion of the total contents. The idea was to make whatever is really needed by drivers visible in a header and keep everything else in the mach directory. > The only quick-fix option would be to move it back to > <mach/gpio-samsung-s3c24xx.h> > but the real solution is of course to augment all drivers to use > gpio descriptors and add descriptor tables to the boardfiles. Right. I would use <mach/gpio-samsung.h> though, so you don't have to #ifdef it on the platform as you currently do in the gpio driver. > I'm a bit reluctant to do that as I'd prefer to be able to test > such modifications on HW ... plus time may be better invested > in DT migration (as I think is the conclusion of this thread > eventually). Doing the full DT migration would of course be best, but I would suspect that to take quite a while still. > > I suspect that the only thing actually needed by the > > gpio driver is the number of GPIO lines per platform, and we can > > find another way to communicate that. > > A bit more: if you look in drivers/gpio/gpio-samsung.c you see > bank base GPIO offset for each bank into the global scope > *and* the number of GPIOs for each bank propagated from > machine headers instead of using platform data. > > Again the proper solution (if the boardfiles are kept) is to switch > to using a GPIO descriptor table. Or using DT. Ok. > > Most of the contents should > > be private to the mach-s3c code and not be visible to either the > > gpio driver or any drivers using the plat/gpio-cfg.h interface. > > Samsungs <plat/gpio-cfg.h> is basically a custom legacy pin > control implementation. > > The real solution to getting rid of that file is to switch over > to using pinctrl-[samsung|s3c24xx] which as Heiko describes > mandates also using DT, and thus blocks attempts > at using this path for fixing the legacy boardfiles. > > It's one of these situations where we end up with an > all-or-nothing conversion path: either you change everything > over to device tree or everything stays in two copies ... > I'm trying to refactor the existing board files here maybe > that is in vain :-/ as GPIO maintainer I want to get rid of > <mach/gpio.h>. Well, we can't do it all at once, and we have to start untangling this somewhere. Getting rid of mach/gpio.h sounds as good to me as any other part of the puzzle, as long as we don't do something bad along the lines that comes back to bite us later. > >> > Note that on Exynos, the solution for the gpio driver dependencies > >> > was to scrap the driver and use pinctrl-exynos instead. > >> > >> I think the S3C driver is a different piece of hardware unfortunately. > > > > But exynos was using this driver before it moved to the new pinctrl > > driver. > > I was wrong about this, too much in my head. As Tomasz says, > pinctrl-samsung can be used, but mandates that everything is > moved over to device tree. > > Probably the best thing now that I have one problem less is to > leave it to the S3C maintainers to complete their DT migration? Let me have another look first, maybe I can find an intermediate step that helps you on your conquest to kill mach/gpio.h. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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