ARM: socfpga: support suspend to ram

Add code that requests that the sdr controller go into
self-refresh mode.  This code is run from ocram.

Suspend-to-RAM and EDAC support are mutually exclusive on
SOCFPGA.  If the EDAC is enabled, it will prevent the
platform from going into suspend.

Example of how to request to suspend to ram:
 $ echo enabled > \
/sys/devices/soc/ffc02000.serial0/tty/ttyS0/power/wakeup

 $ echo -n mem > /sys/power/state

Signed-off-by: Alan Tull <atull@opensource.altera.com>
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>

1 files changed, 9 insertions, 1 deletions

diff --git a/arch/arm/mach-socfpga/Kconfig b/arch/arm/mach-socfpga/Kconfig
index f420a1b200c2..90efdeb56be5 100644
--- a/arch/arm/mach-socfpga/Kconfig
+++ b/arch/arm/mach-socfpga/Kconfig
@@ -1,4 +1,4 @@
-config ARCH_SOCFPGA
+menuconfig ARCH_SOCFPGA
         bool "Altera SOCFPGA family" if ARCH_MULTI_V7
         select ARCH_SUPPORTS_BIG_ENDIAN
         select ARM_AMBA
@@ -9,3 +9,11 @@ config ARCH_SOCFPGA
         select HAVE_ARM_SCU
         select HAVE_ARM_TWD if SMP
         select MFD_SYSCON
+
+if ARCH_SOCFPGA
+config SOCFPGA_SUSPEND
+        bool "Suspend to RAM on SOCFPGA"
+        help
+          Select this if you want to enable Suspend-to-RAM on SOCFPGA
+          platforms.
+endif