linux_dsm_epyc7002/Documentation/devicetree/bindings/misc/sram.txt
Heiko Stübner 96328cdae3 dt-bindings: sram: describe option to reserve parts of the memory
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@gmail.com>

Using subnodes for reserved regions
Suggested-by: Grant Likely <grant.likely@linaro.org>

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Ulrich Prinz <ulrich.prinz@googlemail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 15:31:11 -08:00

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Generic on-chip SRAM
Simple IO memory regions to be managed by the genalloc API.
Required properties:
- compatible : mmio-sram
- 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 translate from local addresses
within the sram to bus addresses
Required properties in the area nodes:
- reg : iomem address range, relative to the SRAM range
Optional properties in the area nodes:
- compatible : standard definition, should contain a vendor specific string
in the form <vendor>,[<device>-]<usage>
Example:
sram: sram@5c000000 {
compatible = "mmio-sram";
reg = <0x5c000000 0x40000>; /* 256 KiB SRAM at address 0x5c000000 */
#adress-cells = <1>;
#size-cells = <1>;
ranges = <0 0x5c000000 0x40000>;
smp-sram@100 {
compatible = "socvendor,smp-sram";
reg = <0x100 0x50>;
};
};