[PATCH] add CONFIG_GENERIC_GPIO

Most drivers using GPIOs already know they are running on a system that
supports the generic GPIO calls, because of other platform dependencies.
But the generic GPIO-based LED and input button drivers can't know that.

So this patch adds a Kconfig hook, GENERIC_GPIO, to mark the platforms
where <asm/gpio.h> will do the right thing.  Currently that's a bunch of
ARMs, and AVR32; more are on the way.

It also fixes a dependency bug for the gpio button input driver; it was
wrong to start with, now it covers all platforms with GENERIC_GPIO.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Cc: Arnaud Patard <arnaud.patard@rtp-net.org>
Cc: <raph@8d.com>
Cc: <msvoboda@ra.rockwell.com>
Cc: pHilipp Zabel <philipp.zabel@gmail.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ac2ffdc..e7baca2 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -21,6 +21,10 @@
 config SYS_SUPPORTS_APM_EMULATION
 	bool
 
+config GENERIC_GPIO
+	bool
+	default n
+
 config GENERIC_TIME
 	bool
 	default n
@@ -163,6 +167,7 @@
 
 config ARCH_AT91
 	bool "Atmel AT91"
+	select GENERIC_GPIO
 	help
 	  This enables support for systems based on the Atmel AT91RM9200
 	  and AT91SAM9xxx processors.
@@ -304,6 +309,7 @@
 	bool "PXA2xx-based"
 	depends on MMU
 	select ARCH_MTD_XIP
+	select GENERIC_GPIO
 	select GENERIC_TIME
 	help
 	  Support for Intel's PXA2XX processor line.
@@ -325,11 +331,13 @@
 	select ISA
 	select ARCH_DISCONTIGMEM_ENABLE
 	select ARCH_MTD_XIP
+	select GENERIC_GPIO
 	help
 	  Support for StrongARM 11x0 based boards.
 
 config ARCH_S3C2410
 	bool "Samsung S3C2410, S3C2412, S3C2413, S3C2440, S3C2442, S3C2443"
+	select GENERIC_GPIO
 	help
 	  Samsung S3C2410X CPU based systems, such as the Simtec Electronics
 	  BAST (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or
@@ -354,6 +362,7 @@
 
 config ARCH_OMAP
 	bool "TI OMAP"
+	select GENERIC_GPIO
 	help
 	  Support for TI's OMAP platform (OMAP1 and OMAP2).