1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
XSCOM Bindings
==============
XSCOM regions
-------------
The top-level xscom nodes specify the mapping range from the 64-bit address
space into the PCB address space.
There's one mapping range per chip xscom, therefore one node per mapping range.
::
/
/xscom@<chip-base-address-0>/
/xscom@<chip-base-address-1>/
…
/xscom@<chip-base-address-n>/
* where <chip-base-address-n> is the xscom base address with the gcid-specific
bits (for chip n) OR-ed in.
Each xscom node has the following properties:
* #address-cells = 1
* #size-cells = 1
* reg = <base-address[#parent-address-cells] size[#parent-size-cells]>
* ibm,chip-id = gcid
* compatible = "ibm,xscom", "ibm,power8-scom" / "ibm,power7-xscom"
* ecid = <Electronic Chip ID, applicable for POWER9 onwards>
* wafer-id = <wafer ID, applicable for POWER9 onwards>
* wafer-location = <wafer location, applicable for POWER9 onwards>
ECID
----
Electronic Chip ID (ECID) is a process by which the wafer number, chip location
(i.e. X,Y) and other optional data items are electrically encoded directly on
the chip. wafer-id property represents wafer number and wafer-location property
represents chip location (both X and Y location).
Chiplet endpoints
-----------------
One sub-node per endpoint. Endpoints are defined by their (port,
endpoint-address) data on the PCB, and are named according to their endpoint
types:
::
/xscom@<chip-base-address>/
/xscom@<chip-base-address>/chiptod@<endpoint-addr>
/xscom@<chip-base-address>/lpc@<endpoint-addr>
* where the <endpoint-addr> is a single address (as distinct from the current
(gcid,base) format), consisting of the SCOM port and SCOM endpoint bits in
their 31-bit address format.
Each endpoint node has the following properties:
* reg = <endpoint-address[#parent-address-cells] size[#parent-size-cells]>
* compatible - depends on endpoint type, eg "ibm,power8-chiptod"
The endpoint address specifies the address on the PCB. So, to calculate the
MMIO address for a PCB register:
::
mmio_addr = <xscom-base-addr> | (pcb_addr[1:27] << 4)
| (pcb_addr[28:31] << 3)
Where:
* xscom-base-addr is the address from the first two cells of the parent
node's reg property
* pcb_addr is the first cell of the endpoint's reg property
|
