linux_dsm_epyc7002/Documentation/devicetree/bindings/sram/sram.txt
Fabio Estevam 11ca58727e dt-bindings: sram: Add 'clocks' as an optional property
Some SoCs (like i.MX53) need to specify the SRAM clock in the
device tree via the clocks property.

Add an entry to the optional property section.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Rob Herring <robh@kernel.org>
2018-07-10 08:08:57 -06:00

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Generic on-chip SRAM
Simple IO memory regions to be managed by the genalloc API.
Required properties:
- compatible : mmio-sram or atmel,sama5d2-securam
- 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
Optional properties in the sram node:
- no-memory-wc : the flag indicating, that SRAM memory region has not to
be remapped as write combining. WC is used by default.
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>
- pool : indicates that the particular reserved SRAM area is addressable
and in use by another device or devices
- export : indicates that the reserved SRAM area may be accessed outside
of the kernel, e.g. by bootloader or userspace
- protect-exec : Same as 'pool' above but with the additional
constraint that code wil be run from the region and
that the memory is maintained as read-only, executable
during code execution. NOTE: This region must be page
aligned on start and end in order to properly allow
manipulation of the page attributes.
- label : the name for the reserved partition, if omitted, the label
is taken from the node name excluding the unit address.
- clocks : a list of phandle and clock specifier pair that controls the
single SRAM clock.
Example:
sram: sram@5c000000 {
compatible = "mmio-sram";
reg = <0x5c000000 0x40000>; /* 256 KiB SRAM at address 0x5c000000 */
#address-cells = <1>;
#size-cells = <1>;
ranges = <0 0x5c000000 0x40000>;
smp-sram@100 {
compatible = "socvendor,smp-sram";
reg = <0x100 0x50>;
};
device-sram@1000 {
reg = <0x1000 0x1000>;
pool;
};
exported@20000 {
reg = <0x20000 0x20000>;
export;
};
};