dt-bindings: Consolidate SRAM bindings from all vendors

SRAM bindings for various SoCs, using the mmio-sram genalloc
API, are spread over different places - per SoC vendor. Since all of
these are quite similar (they depend on mmio-sram) move them to a common
place.

Suggested-by: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Kukjin Kim <kgene@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Rob Herring <robh@kernel.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/sram/rockchip-pmu-sram.txt b/Documentation/devicetree/bindings/sram/rockchip-pmu-sram.txt
new file mode 100644
index 000000000000..6b42fda306ff
--- /dev/null
+++ b/Documentation/devicetree/bindings/sram/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>;
+	};