[PATCH v2 2/2] dt-bindings: qcom: Update DT bindings for multiple DT

[Amrit Anand]

Qualcomm produces a lot of "unique" boards with slight differences in
SoC's and board's configuration. For eg, there can be SM8150v1 on MTPv1,
SM8150v1 on MTPv2, SM8150v2 on MTPv2, SM8150v2 on MTPv2 with a different
PMIC, SM8150v2 with no modem support and so on. For instance, suppose we
have 3 SoC, each with 4 boards supported, along with 2 PMIC support for
each case which would lead to total of 24 DTB files. Along with these
configurations, OEMs may also add certain additional board variants. Thus
a mechanism is required to pick the correct DTB for the corresponding board.

Introduce mechanism to select required DTB using newly introduced device
tree properties "board-id" and "board-id-type". "board-id" will contain
the list of values of "qcom,soc-id", "qcom,board-id", "qcom,pmic-id" or
"qcom,oem-id". "board-id-types" contains the type of parameter which is
entered. It can be either "qcom,soc-id", "qcom,board-id", "qcom,pmic-id"
or "qcom,oem-id".

Qualcomm based bootloader will use these properties to pick the best
matched DTB to boot the device with.

Signed-off-by: Amrit Anand <quic_amrianan at quicinc.com>
---
 Documentation/devicetree/bindings/arm/qcom.yaml | 90 +++++++++++++++++++++++++
 1 file changed, 90 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/qcom.yaml b/Documentation/devicetree/bindings/arm/qcom.yaml
index 7f80f48..dc66ae9 100644
--- a/Documentation/devicetree/bindings/arm/qcom.yaml
+++ b/Documentation/devicetree/bindings/arm/qcom.yaml
@@ -1100,6 +1100,76 @@ properties:
       kernel
       The property is deprecated.
 
+  board-id:
+    $ref: /schemas/types.yaml#/definitions/uint32-matrix
+    minItems: 2
+    description: |
+      Qualcomm specific bootloader uses multiple different identifiers
+      (qcom,soc-id, qcom,board-id, qcom,pmic-id, qcom,oem-id) to select
+      single Devicetree among list of Devicetrees. For different identifiers,
+      the selection can be done either based on exact match (where the
+      identifiers information coming from firmware should exactly match
+      the ones described in devicetree) or best match (firmware provided
+      identifier information closely matches with the one of the Devicetree).
+      Below table describes matching criteria for each identifier::
+      |----------------------------------------------------------------------|
+      |  DT property  |  Individual fields   |   Exact  |  Best  |  Default  |
+      |----------------------------------------------------------------------|
+      | qcom,soc-id   |                                                      |
+      |               |  Chipset Id          |     Y    |    N   |     -     |
+      |               |  SoC Revision        |     N    |    Y   |     -     |
+      | qcom,board-id |                                                      |
+      |               |  Board Id            |     Y    |    N   |     -     |
+      |               |  Board Major         |     N    |    Y   |     -     |
+      |               |  Board Minor         |     N    |    Y   |     -     |
+      |               |  Subtype             |     Y    |    N   |     0     |
+      |               |  DDRtype             |     Y    |    N   |     0     |
+      |               |  BootDevice Type     |     Y    |    N   |     0     |
+      | qcom,pmic-id  |                                                      |
+      |               |  Slave Id            |     Y    |    N   |     0     |
+      |               |  PMIC Id             |     Y    |    N   |     0     |
+      |               |  PMIC Major          |     N    |    Y   |     0     |
+      |               |  PMIC Minor          |     N    |    Y   |     0     |
+      | qcom,oem-id   |                                                      |
+      |               |  OEM Id              |     Y    |    N   |     0     |
+      |----------------------------------------------------------------------|
+      For best match, identifiers are matched based on following priority order::
+      SoC Revision > Board Major > Board Minor > PMIC Major > PMIC Minor
+
+  board-id-types:
+    $ref: /schemas/types.yaml#/definitions/non-unique-string-array
+    description:
+       Each field and helper macros are defined at include/dt-bindings/arm/qcom,ids.
+    minItems: 2
+    items:
+       oneOf:
+         - const: qcom,soc-id
+           description:
+              Matches Qualcomm Technologies, Inc. boards with the specified SoC.
+              2 integers are needed to describe a soc-id. The first integer is the
+              SoC ID and the second integer is the SoC revision.
+              qcom,soc-id = <soc-id  soc-revision>
+         - const: qcom,board-id
+           description: |
+              Matches Qualcomm Technologies, Inc. boards with the specified board.
+              2 integers are needed to describe a board-id. The first integer is the
+              board ID. The second integer is the board-subtype.
+              qcom,board-id = <board-id  board-subtype>
+         - const: qcom,pmic-id
+           description: |
+              Qualcomm boards can be attached to multiple PMICs where slave-id (SID)
+              indicates the address of the bus on which the PMIC is attached. It can be
+              any number. The model for a PMIC indicates the PMIC name attached to bus
+              described by SID along with  major and minor version. 2 integers are needed
+              to describe qcom,pmic-id. The first integer is the slave-id and the second integer
+              is the pmic model.
+              qcom,pmic-id = <pmic-sid pmic-model>
+         - const: qcom,oem-id
+           description: |
+              Matches Qualcomm Technologies, Inc. boards with the specified OEM ID.
+              1 integer is needed to describe the oem-id.
+              qcom,oem-id = <oem-id>
+
 allOf:
   # Explicit allow-list for older SoCs. The legacy properties are not allowed
   # on newer SoCs.
@@ -1167,4 +1237,24 @@ allOf:
 
 additionalProperties: true
 
+examples:
+  - |
+    #include <dt-bindings/arm/qcom,ids.h>
+    / {
+         model = "Qualcomm Technologies, Inc. sc7280 IDP SKU1 platform";
+         compatible = "qcom,sc7280-idp", "google,senor", "qcom,sc7280";
+
+         #board-id-cells = <2>;
+         board-id = <QCOM_SOC_ID(SC7280) QCOM_SOC_REVISION(1)>,
+                    <QCOM_SOC_ID(SC7280) QCOM_SOC_REVISION(2)>,
+                    <QCOM_BOARD_ID(IDP, 1, 0) QCOM_BOARD_SUBTYPE(UFS, ANY, 1)>;
+         board-id-types = "qcom,soc-id",
+                          "qcom,soc-id",
+                          "qcom,board-id";
+
+         #address-cells = <2>;
+         #size-cells = <2>;
+    };
+
+
 ...
-- 
2.7.4