Add a power domain framework/uclass

Many SoCs allow power to be applied to or removed from portions of the SoC
(power domains). This may be used to save power. This API provides the
means to control such power management hardware.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/power/domain/Kconfig b/drivers/power/domain/Kconfig
new file mode 100644
index 0000000..b904097
--- /dev/null
+++ b/drivers/power/domain/Kconfig
@@ -0,0 +1,20 @@
+menu "Power Domain Support"
+
+config POWER_DOMAIN
+	bool "Enable power domain support using Driver Model"
+	depends on DM && OF_CONTROL
+	help
+	  Enable support for the power domain driver class. Many SoCs allow
+	  power to be applied to or removed from portions of the SoC (power
+	  domains). This may be used to save power. This API provides the
+	  means to control such power management hardware.
+
+config SANDBOX_POWER_DOMAIN
+	bool "Enable the sandbox power domain test driver"
+	depends on POWER_DOMAIN && SANDBOX
+	help
+	  Enable support for a test power domain driver implementation, which
+	  simply accepts requests to power on/off various HW modules without
+	  actually doing anything beyond a little error checking.
+
+endmenu