On Tue, Jul 26, 2011 at 11:32:22AM -0700, Colin Cross wrote:

On Tue, Jul 26, 2011 at 3:46 AM, Russell King - ARM Linux
[off-list ref] wrote:

quoted

On Tue, Jul 26, 2011 at 11:09:28AM +0100, Russell King - ARM Linux wrote:

quoted

Hmm, yet another trivial gpio implementation. ?We have 24 others just like
this. ?Well, mainline does... I have just one. ?Patches after the merge
window closes.

As an additional note to this: we _really_ need to get on top of the
includes of mach/gpio.h rather than linux/gpio.h - there are around 139
files in mainline (this morning) which include mach/gpio.h directly.

There's one which includes both asm/gpio.h and mach/gpio.h, which is
silly when you look at what asm/gpio.h contains - maybe one attempt
to include mach/gpio.h wasn't enough!

These includes get in the way of consolidating stuff out of mach/gpio.h
into asm/gpio.h - moving stuff out of mach/gpio.h could take it out of
view of these files, thereby causing build errors.

What is even less clear is whether changing these mach/gpio.h includes
to linux/gpio.h is correct or not.

So, what I'd like all platform and all soc maintainers to do is to:

? ? ? ?grep -rl '<mach/gpio.h>' arch/arm drivers

and investigate their files from that list which they're responsible for,
and submit patches to _me_ to fix these includes up (preferably to use
linux/gpio.h). ?I'd also like them to do a better job at spotting these
while reviewing patches on the list to help reduce new occurances of
this.

Thanks.

Tegra has four uses of mach/gpio.h:
arch/arm/mach-tegra/board-trimslice-pinmux.c
arch/arm/mach-tegra/board-paz00.c
arch/arm/mach-tegra/board-trimslice.c
drivers/mmc/host/sdhci-tegra.c

Each of these files calls tegra_gpio_enable/tegra_gpio_disable, which
flip the pin in/out of gpio mode.  Including linux/gpio.h and
mach/gpio.h was deliberate, so that when linux/gpio.h stops causing
mach/gpio.h to be included, the tegra gpio apis are still available.
Should I move the tegra gpio apis to a separate include and drop
mach/gpio.h?

I don't think there's any plans to break the:

linux/gpio.h -> asm/gpio.h -> mach/gpio.h

include path at the moment, as platforms do define ARCH_NR_GPIO,
which has to be done before asm-generic/gpiolib.h is included.

The problem which is there at the moment is that moving stuff out of
mach/gpio.h is *dangerous* because soo much stuff includes mach/gpio.h,
it's impossible to tell whether moving stuff like gpio_set_value,
gpio_get_value, etc into asm/gpio.h is going to break anything - and
there's no way I can get sufficient coverage to check that.

So, the only way I can think of sorting this out is to forcefully
change all mach/gpio.h to be linux/gpio.h first, before starting
to migrate stuff out of mach/gpio.h.

What we may do later is make the include of mach/gpio.h conditional,
and those platforms with their own specific stuff would continue to
include that.  Those which don't need mach/gpio.h can then live on
without it.