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gpio: Increase ARCH_NR_GPIOs to 512

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Some newer Intel SoCs, like Braswell already have more than 256 GPIOs
available so the default limit is exceeded. Instead of adding more
architecture specific gpio.h files with custom ARCH_NR_GPIOs we increase
the gpiolib default limit to be twice the current.

Current generic ARCH_NR_GPIOS limit is 256 which starts to be too small
for newer Intel SoCs like Braswell. In order to support GPIO controllers
on these SoCs we increase ARCH_NR_GPIOS to be 512 which should be
sufficient for now.

The kernel size increases a bit with this change. Below is an example of
x86_64 kernel image.

ARCH_NR_GPIOS=256
 text     data    bss     dec      hex    filename
 11476173 1971328 1265664 14713165 e0814d vmlinux

ARCH_NR_GPIOS=512
 text     data    bss     dec      hex    filename
 11476173 1971328 1269760 14717261 e0914d vmlinux

So the BSS size and this the kernel image size increases by 4k.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Mika Westerberg 2014-09-15 17:09:44 +03:00 committed by Linus Walleij
parent 56b427678c
commit 7ca267faba
1 changed files with 1 additions and 1 deletions
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2
include/asm-generic/gpio.h
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@ -27,7 +27,7 @@
*/
#ifndef ARCH_NR_GPIOS
#define ARCH_NR_GPIOS 256
#define ARCH_NR_GPIOS 512
#endif
/*