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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;
- };
- };
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