PM / OPP: Hide OPP configuration when SoCs do not provide an implementation

Since the OPP API is only useful with an appropraite SoC-specific
implementation there is no point in offering the ability to enable
the API on general systems. Provide an ARCH_HAS OPP Kconfig symbol
which masks out the option unless selected by an implementation.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Nishanth Menon <nm@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

diff --git a/Documentation/power/opp.txt b/Documentation/power/opp.txt
index 44d87ad..cd44558 100644 (file)
--- a/Documentation/power/opp.txt
+++ b/Documentation/power/opp.txt
@@ -37,6 +37,9 @@ Typical usage of the OPP library is as follows:
 SoC framework  -> modifies on required cases certain OPPs      -> OPP layer
                -> queries to search/retrieve information       ->
 
+Architectures that provide a SoC framework for OPP should select ARCH_HAS_OPP
+to make the OPP layer available.
+
 OPP layer expects each domain to be represented by a unique device pointer. SoC
 framework registers a set of initial OPPs per device with the OPP layer. This
 list is expected to be an optimally small number typically around 5 per device.

diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 29bff61..a5aff3e 100644 (file)
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -246,9 +246,13 @@ config PM_OPS
        depends on PM_SLEEP || PM_RUNTIME
        default y
 
+config ARCH_HAS_OPP
+       bool
+
 config PM_OPP
        bool "Operating Performance Point (OPP) Layer library"
        depends on PM
+       depends on ARCH_HAS_OPP
        ---help---
          SOCs have a standard set of tuples consisting of frequency and
          voltage pairs that the device will support per voltage domain. This