[PATCH 1/1] ARM: EXYNOS: Update CONFIG_ARCH_NR_GPIO for Exynos

[Tomasz Figa]

On Monday 22 of July 2013 12:37:52 Kukjin Kim wrote:
> Sachin Kamat wrote:
> > On 22 July 2013 07:18, Kukjin Kim <kgene.kim at samsung.com> wrote:
> > > Sachin Kamat wrote:
> > >> With the recent cleanup in Exynos platform code notably commits
> > >> 17859bec ("ARM: EXYNOS: Do not select legacy Kconfig symbols any
> > >> more") and b9222210 ("ARM: EXYNOS: Remove mach/gpio.h"), the
> > >> definition
> > >> of ARCH_NR_GPIOS got removed. This started causing problems on SoCs
> > 
> > like
> > 
> > >> Exynos4412 which have more (285) than the default number of GPIOs
> 
> (255).
> 
> > >> Thus define this number in Kconfig file. Without this patch we get
> > >> the
> > >> following errors during boot:
> > >> 
> > >> gpiochip_add: gpios 251..258 (gpv0) failed to register
> > >> samsung-pinctrl 106e0000.pinctrl: failed to register gpio_chip gpv0,
> > >> error code: -22
> > >> samsung-pinctrl: probe of 106e0000.pinctrl failed with error -22
> > >> 
> > >> Signed-off-by: Sachin Kamat <sachin.kamat at linaro.org>
> > >> Cc: Tomasz Figa <t.figa at samsung.com>
> > >> ---
> > >> Based on Kukjin's for-next tree.
> > >> ---
> > >> 
> > >>  arch/arm/Kconfig |    1 +
> > >>  1 file changed, 1 insertion(+)
> > >> 
> > >> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> > >> index ddf2667..380a53b 100644
> > >> --- a/arch/arm/Kconfig
> > >> +++ b/arch/arm/Kconfig
> > >> @@ -1578,6 +1578,7 @@ config ARCH_NR_GPIO
> > >> 
> > >>       default 512 if SOC_OMAP5
> > >>       default 392 if ARCH_U8500
> > >>       default 352 if ARCH_VT8500
> > >> 
> > >> +     default 288 if ARCH_EXYNOS
> > >> 
> > >>       default 288 if ARCH_SUNXI
> > >>       default 264 if MACH_H4700
> > >>       default 0
> > >> 
> > >> --
> > >> 1.7.9.5
> > > 
> > > Hmm, BTW, I'm wondering why it is 288 not 285 or other specific
> 
> number...
> 
> > I wasn't really sure if we can have any number there. I chose the
> > closest one (288) which was already used by other platform.
> > If there is no problem to use 285 itself then I can resend with that
> > number. Please let me know.
> 
> If there is no reason, please don't use bigger value than necessary one.

Hmm, what about some GPIO expanders that would require bigger GPIO address 
space? I would reserve some space just in case, i.e. define this value to be 
the highest number of GPIOs on all Exynos SoCs + some extra, like 32 or 64.

Best regards,
Tomasz