The pmu-sram is used to store resume code, suspend/resume need get the
address of it. Therefore add a binding and documentation for it.

Signed-off-by: Tony Xie <redacted>
Signed-off-by: Chris Zhong <redacted>
Reviewed-by: Doug Anderson <dianders@chromium.org>

---

Changes in v8: None
Changes in v7: None
Changes in v6:
- change pmu_intmem@ff720000 to sram@ff720000

Changes in v5:
- change the size of sram in example

Changes in v4: None
Changes in v3: None
Changes in v2: None

 .../devicetree/bindings/arm/rockchip/pmu-sram.txt        | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/rockchip/pmu-sram.txt

diff --git a/Documentation/devicetree/bindings/arm/rockchip/pmu-sram.txt b/Documentation/devicetree/bindings/arm/rockchip/pmu-sram.txt
new file mode 100644
index 0000000..6b42fda
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/rockchip/pmu-sram.txt

@@ -0,0 +1,16 @@
+Rockchip SRAM for pmu:
+------------------------------
+
+The sram of pmu is used to store the function of resume from maskrom(the 1st
+level loader). This is a common use of the "pmu-sram" because it keeps power
+even in low power states in the system.
+
+Required node properties:
+- compatible : should be "rockchip,rk3288-pmu-sram"
+- reg : physical base address and the size of the registers window
+
+Example:
+	sram@ff720000 {
+		compatible = "rockchip,rk3288-pmu-sram", "mmio-sram";
+		reg = <0xff720000 0x1000>;
+	};

-- 
1.9.1