diff mbox series

[v2,2/4] dt-bindings: memory: tegra20: emc: Document new LPDDR2 sub-node

Message ID 20211003003509.28241-3-digetx@gmail.com
State Superseded, archived
Headers show
Series tegra20-emc: Identify memory chip by LPDDR configuration | expand

Checks

Context Check Description
robh/checkpatch success
robh/dt-meta-schema fail build log

Commit Message

Dmitry Osipenko Oct. 3, 2021, 12:35 a.m. UTC
Some Tegra20 boards don't have RAM code stored in NVMEM, which is used for
the memory chip identification and the identity information should be read
out from LPDDR2 chip in this case. Document new sub-node containing generic
LPDDR2 properties that will be used for the memory chip identification if
RAM code isn't available. The identification is done by reading out memory
configuration values from generic LPDDR2 mode registers of SDRAM chip and
comparing them with the values of device-tree sub-node's.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../memory-controllers/nvidia,tegra20-emc.yaml  | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

Comments

Dmitry Osipenko Oct. 3, 2021, 1:28 a.m. UTC | #1
03.10.2021 03:35, Dmitry Osipenko пишет:
> +      lpddr2-configuration:
> +        $ref: "jedec,lpddr2.yaml#"
> +        type: object
...
> +
> +            lpddr2-config {
> +                jedec,lpddr2-manufacturer-id = <LPDDR2_MANID_ELPIDA>;
> +                jedec,lpddr2-revision-id1 = <1>;
> +                jedec,lpddr2-density-mbits = <2048>;
> +                jedec,lpddr2-io-width-bits = <16>;
> +                jedec,lpddr2-type = <LPDDR2_TYPE_S4>;
> +            };

I just noticed that this is a wrong node name and I missed to run
dt_binding_check after the last edit. I'll send v3 with the corrected
name shortly.
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.yaml b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.yaml
index cac6842dc8f1..2741333591bf 100644
--- a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.yaml
@@ -164,13 +164,14 @@  patternProperties:
       "#size-cells":
         const: 0
 
+      lpddr2-configuration:
+        $ref: "jedec,lpddr2.yaml#"
+        type: object
+
     patternProperties:
       "^emc-table@[0-9]+$":
         $ref: "#/$defs/emc-table"
 
-    required:
-      - nvidia,ram-code
-
     additionalProperties: false
 
 required:
@@ -186,6 +187,8 @@  additionalProperties: false
 
 examples:
   - |
+    #include <dt-bindings/memory/lpddr2.h>
+
     external-memory-controller@7000f400 {
         compatible = "nvidia,tegra20-emc";
         reg = <0x7000f400 0x400>;
@@ -226,5 +229,13 @@  examples:
                         0x007fe010 0x00001414 0x00000000 0x00000000
                         0x00000000 0x00000000 0x00000000 0x00000000>;
             };
+
+            lpddr2-config {
+                jedec,lpddr2-manufacturer-id = <LPDDR2_MANID_ELPIDA>;
+                jedec,lpddr2-revision-id1 = <1>;
+                jedec,lpddr2-density-mbits = <2048>;
+                jedec,lpddr2-io-width-bits = <16>;
+                jedec,lpddr2-type = <LPDDR2_TYPE_S4>;
+            };
         };
     };