bindings: soc: qcom: add Glink PMIC debug controller binding documentation

Add binding documentation for the Qualcomm Technologies, Inc.
Glink PMIC debug controller device.  This device provides an
interface to read and write PMIC registers over PMIC Glink using
a remote subsytem (e.g. DSP).  This allows for debugging PMIC
peripherals that would typically only be accessible to the
charger and fuel gauging firmware running on the remote
subsystem.  The PMICs may be physically connected using either
SPMI or I2C.

This is a snapshot of qcom,pmic-glink-debug.txt taken as of qcom-6.1
commit 5c116d156aae ("bindings: pmic-glink-debug: Add SPMI bridge bus
support") which was then converted to yaml format.

Change-Id: Ie4b3e188feea28b9c80413b0397eb1658e03835f
Signed-off-by: David Collins <quic_collinsd@quicinc.com>

bindings/soc/qcom/qcom,pmic-glink-debug.yaml

@@ -0,0 +1,132 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/qcom/qcom,pmic-glink-debug.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Technologies, Inc. Glink PMIC Debug Controller
+
+maintainers:
+  - David Collins <quic_collinsd@quicinc.com>
+
+description: |
+  The Qualcomm Technologies, Inc. Glink PMIC debug controller device provides an
+  interface to read and write PMIC registers over PMIC Glink using a remote
+  subsytem (e.g. DSP).  This allows for debugging PMIC peripherals on either
+  SPMI bus or I2C bus that would typically only be accessible to the charger
+  and fuel gauging firmware running on the remote subsystem.
+
+  The Glink PMIC debug controller node must contain at least one child node.
+  Each child node corresponds to either an SPMI bus or I2C bus accessible from
+  the remote subsystem.
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - qcom,pmic-glink-debug
+          - qcom,spmi-glink-debug
+          - qcom,i2c-glink-debug
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+patternProperties:
+  "spmi@[0-9a-f]+$":
+    description: SPMI bus node
+    $ref: /schemas/spmi/spmi.yaml#
+    type: object
+
+    properties:
+      qcom,bus-type:
+        description: |
+          Specifies the bus type on the remote subsystem to access the PMIC
+          devices defined in the child nodes.
+        $ref: /schemas/types.yaml#/definitions/string
+        const: spmi
+        default: spmi
+
+      reg:
+        description: |
+          The bus ID used by firmware.
+
+          For a directly connected SPMI bus, this is the physical SPMI bus ID in
+          the system.
+
+          For an SPMI-bridge bus which relies on the brain PMIC for the real
+          SPMI bus transaction, the bus ID is specified with an offset of 0x200.
+        items:
+          items:
+            - oneOf:
+                - minimum: 0x0
+                  maximum: 0x7
+                - minimum: 0x200
+                  maximum: 0x207
+
+    required:
+      - reg
+
+  "i2c@[0-9a-f]+$":
+    description: I2C bus node
+    $ref: /schemas/i2c/i2c-controller.yaml#
+    type: object
+
+    properties:
+      qcom,bus-type:
+        description: |
+          Specifies the bus type on the remote subsystem to access the PMIC
+          devices defined in the child nodes.
+        $ref: /schemas/types.yaml#/definitions/string
+        const: i2c
+
+      reg:
+        description: |
+          The bus ID used by firmware.
+
+          This is the I2C bus instance ID (indexed from 1) in the remote
+          subsystem along with an added offset of 0x100.
+        minimum: 0x101
+        maximum: 0x1ff
+
+    required:
+      - reg
+      - qcom,bus-type
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    pmic_glink_log {
+        spmi_glink_debug {
+            compatible = "qcom,spmi-glink-debug";
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            spmi@0 {
+                reg = <0>;
+            };
+
+            spmi@1 {
+                reg = <1>;
+                qcom,bus-type = "spmi";
+            };
+
+            /* I2C bus with instance ID 7 in ADSP for SE6 */
+            i2c@107 {
+                reg = <0x107>;
+                qcom,bus-type = "i2c";
+            };
+
+            /* SPMI-bridge bus 0 */
+            spmi@200 {
+                reg = <0x200>;
+                qcom,bus-type = "spmi";
+            };
+        };
+    };