dt-bindings: sram: describe option to reserve parts of the memory
From: Heiko Stuebner <heiko@...> Date: Mon, 24 Jun 2013 15:24:52 +0200
Commit-Message
Some SoCs need parts of their sram for special purposes. So while being part of the peripheral, it should not be part of the genpool controlling the sram. Therefore add the option to define reserved regions as subnodes of the sram-node similar to defining reserved global memory regions. Originally Suggested-by: Rob Herring <robherring2@...> Using subnodes for reserved regions Suggested-by: Grant Likely <grant.likely@...> Signed-off-by: Heiko Stuebner <heiko@...> Tested-by: Ulrich Prinz <ulrich.prinz@...>
Patch-Comment
Documentation/devicetree/bindings/misc/sram.txt | 33 +++++++++++++++++++++++++ 1 file changed, 33 insertions(+)
Statistics
- 33 lines added
- 0 lines removed
Changes
--------------- Documentation/devicetree/bindings/misc/sram.txt ----------------
index 4d0a00e..2d83758 100644
@@ -8,9 +8,42 @@ Required properties:
- reg : SRAM iomem address range
+Reserving sram areas:
+---------------------
+
+Each child of the sram node specifies a region of reserved memory. Each
+child node should use a 'reg' property to specify a specific range of
+reserved memory.
+
+Following the generic-names recommended practice, node names should
+reflect the purpose of the node. Unit address (@<address>) should be
+appended to the name.
+
+Required properties in the sram node:
+
+- #address-cells, #size-cells : should use the same values as the root node
+- ranges : standard definition, should be empty
+
+Required properties in the area nodes:
+
+- reg : iomem address range
+
+Optional properties in the area nodes:
+
+- compatible : standard definition
+
Example:
sram: sram@5c000000 {
compatible = "mmio-sram";
reg = <0x5c000000 0x40000>; /* 256 KiB SRAM at address 0x5c000000 */
+
+ #adress-cells = <1>;
+ #size-cells = <1>;
+ ranges;
+
+ smp-sram@5c000100 {
+ compatible = "socvendor,smp-sram";
+ reg = <0x5c000100 0x50>;
+ };
};