Enable or disable the power button in Kconfig

Some mainboards need to disable the power button to avoid turning off
right after being turned on, while other boards ship with a jumper over
the power button and should allow the user to configure the behavior.

This adds infrastructure in the form of four mutually exclusive options
which can be selected in a mainboard Kconfig (power button forced on/off,
and user-controllable with default on/off) and one result bool which
source code can test. (Enable the button or not.)

The options have been implemented in CS5536 code and for all mainboards
which select SOUTHBRIDGE_AMD_CS5536, but should be used also by other
chipsets where applicable. Note that if chipset code uses the result
bool ENABLE_POWER_BUTTON, then every board using that chipset must
select one out of the four control options in order to build.

All touched boards should have unchanged behavior, except
pcengines/alix1c, traverse/geos and lippert/hurricane-lx where the
power button can now be configured by the user.

Build tested for alix1c, alix2d, hurricane-lx and wyse-s50. Confirmed
to work as advertised on alix1c both with button enabled and disabled.

Includes additional traverse/geos changes from Nathan and
lippert/hurricane-lx changes from Jens to correctly use the new
feature on those boards.

Signed-off-by: Peter Stuge <peter@stuge.se>
Acked-by: Aurelien Guillaume <aurelien@iwi.me>
Acked-by: Nils Jacobs <njacobs8@hetnet.nl>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5948 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
diff --git a/src/Kconfig b/src/Kconfig
index 690a1d4..a61efe1 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -736,4 +736,43 @@
 	hex
 	default 0x10
 
+# The four POWER_BUTTON_DEFAULT_ENABLE, POWER_BUTTON_DEFAULT_DISABLE,
+# POWER_BUTTON_FORCE_ENABLE and POWER_BUTTON_FORCE_DISABLE options are
+# mutually exclusive. One of these options must be selected in the
+# mainboard Kconfig if the chipset supports enabling and disabling of
+# the power button. Chipset code uses the ENABLE_POWER_BUTTON option set
+# in mainboard/Kconfig to know if the button should be enabled or not.
+
+config POWER_BUTTON_DEFAULT_ENABLE
+	def_bool n
+	help
+	  Select when the board has a power button which can optionally be
+	  disabled by the user.
+
+config POWER_BUTTON_DEFAULT_DISABLE
+	def_bool n
+	help
+	  Select when the board has a power button which can optionally be
+	  enabled by the user, e.g. when the board ships with a jumper over
+	  the power switch contacts.
+
+config POWER_BUTTON_FORCE_ENABLE
+	def_bool n
+	help
+	  Select when the board requires that the power button is always
+	  enabled.
+
+config POWER_BUTTON_FORCE_DISABLE
+	def_bool n
+	help
+	  Select when the board requires that the power button is always
+	  disabled, e.g. when it has been hardwired to ground.
+
+config POWER_BUTTON_IS_OPTIONAL
+	bool
+	default y if POWER_BUTTON_DEFAULT_ENABLE || POWER_BUTTON_DEFAULT_DISABLE
+	default n if !(POWER_BUTTON_DEFAULT_ENABLE || POWER_BUTTON_DEFAULT_DISABLE)
+	help
+	  Internal option that controls ENABLE_POWER_BUTTON visibility.
+
 source src/Kconfig.deprecated_options