| 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; |
| }; |
| }; |