Re: [PATCH] gpio: dwapb: enable for ARC

[Alexey Brodkin <Alexey.Brodkin@synopsys.com>]

On Wed, 2015-04-08 at 17:03 +0200, Linus Walleij wrote:
> On Tue, Mar 31, 2015 at 10:30 AM, Alexey Brodkin
> <Alexey.Brodkin@synopsys.com> wrote:
> 
> > From: Vineet Gupta <vgupta@synopsys.com>
> >
> > Synopsys SDP platform uses DW GPIO controller in design with
> > ARC cores. So adding ARC to architectures that may select this
> > GPIO controller.
> >
> > Even though support for Synopsys SDP is yet to be submitted we'll need
> > this tiny option enabled at least for properly working interrupts (DW
> > GPIO controller is used as interrupt controller).
> >
> > Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
> > Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> > Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > Cc: Linus Walleij <linus.walleij@linaro.org>
> 
> Patch applied.
> 
> But ...
> 
> > -       depends on ((ARM || ARM64) && OF_GPIO) || X86_INTEL_QUARK
> > +       depends on ((ARC || ARM || ARM64) && OF_GPIO) || X86_INTEL_QUARK
> 
> This is getting a bit silly. What stops us from actually just enabling
> it for any architecture?

Agree. That looks like nonsense now.
Origin of arch-limitation is
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/gpio/Kconfig?id=1972c97db5b0c125918f662cd084c7d5370674c0

--->8---
gpio: dwapb: fix compile errors
Whereas the DWAPB driver does not really depend on the ARM
architecture, it uses [readl|writel]_relaxed() not found on
arch such as Blackfin, so restrict this to ARM until there is
another architecture that can make use of it.

It is also using the of_node of the gpiochip, so fix this
too by requiring OF_GPIO.

All error/warnings:

make.cross ARCH=blackfin
drivers/gpio/gpio-dwapb.c: In function 'dwapb_irq_handler':
drivers/gpio/gpio-dwapb.c:91:2: error: implicit declaration of function
'readl_relaxed' [-Werror=implicit-function-declaration]
drivers/gpio/gpio-dwapb.c: In function 'dwapb_configure_irqs':
drivers/gpio/gpio-dwapb.c:212:32: error: 'struct gpio_chip' has no
member named 'of_node'
drivers/gpio/gpio-dwapb.c:221:16: error: 'struct gpio_chip' has no
member named 'of_node'
drivers/gpio/gpio-dwapb.c: In function 'dwapb_gpio_add_port':
drivers/gpio/gpio-dwapb.c:331:14: error: 'struct gpio_chip' has no
member named 'of_node'
cc1: some warnings being treated as errors
--->8---

Probably better fix is to make dwgpio depend on !BLACKFIN because we
know it won't be built for it. If there're other arches that don't
define [readl|writel]_relaxed() we may add them as well.

-Alexey