powerpc: Implement GPIO driver for simple memory-mapped banks

The driver supports very simple GPIO controllers, that is, when a
controller provides just a 'data' register. Such controllers may be
found in various BCSRs (Board's FPGAs used to control board's
switches, LEDs, chip-selects, Ethernet/USB PHY power, etc).

So far we support only 1-byte GPIO banks. Support for other widths may
be implemented when/if needed.

p.s.
To avoid "made up" compatible entries (like compatible = "simple-gpio"),
boards must call simple_gpiochip_init() to pass the compatible string.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 47e956c871fe..47fe2bea9865 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -312,4 +312,15 @@ config MPC8xxx_GPIO
 	  Say Y here if you're going to use hardware that connects to the
 	  MPC831x/834x/837x/8572/8610 GPIOs.
 
+config SIMPLE_GPIO
+	bool "Support for simple, memory-mapped GPIO controllers"
+	depends on PPC
+	select GENERIC_GPIO
+	select ARCH_REQUIRE_GPIOLIB
+	help
+	  Say Y here to support simple, memory-mapped GPIO controllers.
+	  These are usually BCSRs used to control board's switches, LEDs,
+	  chip-selects, Ethernet/USB PHY's power and various other small
+	  on-board peripherals.
+
 endmenu