Commit | Line | Data |
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4984c6f5 PZ |
1 | Generic on-chip SRAM |
2 | ||
3 | Simple IO memory regions to be managed by the genalloc API. | |
4 | ||
5 | Required properties: | |
6 | ||
7 | - compatible : mmio-sram | |
8 | ||
9 | - reg : SRAM iomem address range | |
10 | ||
96328cda HS |
11 | Reserving sram areas: |
12 | --------------------- | |
13 | ||
14 | Each child of the sram node specifies a region of reserved memory. Each | |
15 | child node should use a 'reg' property to specify a specific range of | |
16 | reserved memory. | |
17 | ||
18 | Following the generic-names recommended practice, node names should | |
19 | reflect the purpose of the node. Unit address (@<address>) should be | |
20 | appended to the name. | |
21 | ||
22 | Required properties in the sram node: | |
23 | ||
24 | - #address-cells, #size-cells : should use the same values as the root node | |
25 | - ranges : standard definition, should translate from local addresses | |
26 | within the sram to bus addresses | |
27 | ||
eb43e023 MW |
28 | Optional properties in the sram node: |
29 | ||
30 | - no-memory-wc : the flag indicating, that SRAM memory region has not to | |
31 | be remapped as write combining. WC is used by default. | |
32 | ||
96328cda HS |
33 | Required properties in the area nodes: |
34 | ||
35 | - reg : iomem address range, relative to the SRAM range | |
36 | ||
37 | Optional properties in the area nodes: | |
38 | ||
39 | - compatible : standard definition, should contain a vendor specific string | |
40 | in the form <vendor>,[<device>-]<usage> | |
b4c3fcb3 VZ |
41 | - pool : indicates that the particular reserved SRAM area is addressable |
42 | and in use by another device or devices | |
43 | - export : indicates that the reserved SRAM area may be accessed outside | |
44 | of the kernel, e.g. by bootloader or userspace | |
45 | - label : the name for the reserved partition, if omitted, the label | |
46 | is taken from the node name excluding the unit address. | |
96328cda | 47 | |
4984c6f5 PZ |
48 | Example: |
49 | ||
50 | sram: sram@5c000000 { | |
51 | compatible = "mmio-sram"; | |
52 | reg = <0x5c000000 0x40000>; /* 256 KiB SRAM at address 0x5c000000 */ | |
96328cda HS |
53 | |
54 | #adress-cells = <1>; | |
55 | #size-cells = <1>; | |
56 | ranges = <0 0x5c000000 0x40000>; | |
57 | ||
58 | smp-sram@100 { | |
59 | compatible = "socvendor,smp-sram"; | |
60 | reg = <0x100 0x50>; | |
61 | }; | |
b4c3fcb3 VZ |
62 | |
63 | device-sram@1000 { | |
64 | reg = <0x1000 0x1000>; | |
65 | pool; | |
66 | }; | |
67 | ||
68 | exported@20000 { | |
69 | reg = <0x20000 0x20000>; | |
70 | export; | |
71 | }; | |
4984c6f5 | 72 | }; |