ACPI: add support for Smart Battery

Most batteries today are ACPI "Control Method" batteries,
but some models ship with the older "Smart Battery"
that requires this code.

Rich Townsend and Bruno Ducrot were the original authors.
Vladimir Lebedev updated to run on latest kernel.

http://bugzilla.kernel.org/show_bug.cgi?id=3734

Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index bc2652d..fef7bab 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -352,6 +352,18 @@
 	  If one selects "m," this driver can be loaded using the following
 	  command: 
 		$>modprobe acpi_memhotplug 
+
+config ACPI_SBS
+	tristate "Smart Battery System (EXPERIMENTAL)"
+	depends on X86 && I2C
+	depends on EXPERIMENTAL
+	default y
+	help
+	  This driver adds support for the Smart Battery System.
+	  Depends on I2C (Device Drivers ---> I2C support)
+	  A "Smart Battery" is quite old and quite rare compared
+	  to today's ACPI "Control Method" battery.
+
 endif	# ACPI
 
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