hdata: Parse SPD data

Parse SPD data and populate device tree.

list of properites parsing from SPD:
-----------------------------------
[root@ltc-wspoon dimm@d00f]# lsprop .
memory-id        0000000c (12)      <-- DIMM type
product-version  00000032 (50)	    <-- Module Revision Code
device_type      "memory-dimm-ddr4"
serial-number    15d9acb6 (366587062)
status           "okay"
size             00004000 (16384)
phandle          000000bd (189)
ibm,loc-code     "UOPWR.0000000-Node0-DIMM7"
part-number      "36ASF2G72PZ-2G6B2   "
reg              0000d007 (53255)
name             "dimm"
manufacturer-id  0000802c (32812)    <-- Vendor ID, we can get vendor name from this ID

Also update documentation.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/doc/device-tree/memory-hierarchy.rst b/doc/device-tree/memory-hierarchy.rst
new file mode 100644
index 00000000..1da0c54d
--- /dev/null
+++ b/doc/device-tree/memory-hierarchy.rst
@@ -0,0 +1,24 @@
+P9 memory hierarchy
+-------------------
+P9 Nimbus supports direct attached DDR memory through 4 DDR ports per side
+of the processor. Device tree contains memory hierarchy so that one can
+traverse from chip to DIMM like below:
+
+  xscom@<addr>/mcbist@<mcbist_id>/mcs@<mcs_id>/mca@<mca_id>/dimm@<resource_id>
+
+Example of dimm node:
+.. code-block:: dts
+
+  dimm@d00e {
+          memory-id = <0xc>; /* DRAM Device Type. 0xc = DDR4 */
+          product-version = <0x32>; /* Module Revision Code */
+          device_type = "memory-dimm-ddr4";
+          serial-number = <0x15d9ad1c>;
+          status = "okay";
+          size = <0x4000>;
+          phandle = <0xd2>;
+          ibm,loc-code = "UOPWR.0000000-Node0-DIMM14";
+          part-number = "36ASF2G72PZ-2G6B2   ";
+          reg = <0xd00e>;
+          manufacturer-id = <0x802c>; /* Vendor ID, we can get vendor name from this ID */
+  };