[PATCH v1 1/3] dt-bindings: interconnect: Add Qualcomm CAMNOC ICC binding

[Atanas Filipov]

Add a device tree binding for the Qualcomm Camera Network-on-Chip
(CAMNOC) interconnect provider. CAMNOC is the internal AXI
interconnect within the camera subsystem that arbitrates bandwidth
between camera sub-devices and the external memory interconnect.

The CAMNOC ICC provider aggregates bandwidth requests from multiple
independent consumers and scales the CAMNOC AXI clock accordingly,
avoiding the race conditions that arise when each consumer calls
clk_set_rate() directly on the shared clock.

Signed-off-by: Atanas Filipov <atanas.filipov@xxxxxxxxxxxxxxxx>
---
 .../bindings/interconnect/qcom,camnoc.yaml    | 98 +++++++++++++++++++
 .../dt-bindings/interconnect/qcom,camnoc.h    | 12 +++
 2 files changed, 110 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interconnect/qcom,camnoc.yaml
 create mode 100644 include/dt-bindings/interconnect/qcom,camnoc.h

diff --git a/Documentation/devicetree/bindings/interconnect/qcom,camnoc.yaml b/Documentation/devicetree/bindings/interconnect/qcom,camnoc.yaml
new file mode 100644
index 000000000000..b2f5c140ff80
--- /dev/null
+++ b/Documentation/devicetree/bindings/interconnect/qcom,camnoc.yaml
@@ -0,0 +1,98 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interconnect/qcom,camnoc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Camera NOC (CAMNOC) Interconnect Provider
+
+maintainers:
+  - Aleksandar Filipov <quic_afilipov@xxxxxxxxxxx>
+
+description:
+  The Camera Network-on-Chip (CAMNOC) is the internal AXI interconnect
+  within the Qualcomm camera subsystem. It arbitrates AXI bandwidth
+  between camera sub-devices (IFE, JPEG, BPS, etc.) and the external
+  memory interconnect. Multiple consumers may independently request
+  bandwidth; the CAMNOC ICC provider aggregates these requests and
+  scales CAM_CC_CAMNOC_AXI_CLK accordingly.
+
+properties:
+  compatible:
+    enum:
+      - qcom,sm8250-cam-virt
+
+  clocks:
+    items:
+      - description: CAMNOC AXI clock
+
+  clock-names:
+    items:
+      - const: camnoc_axi
+
+  '#interconnect-cells':
+    const: 1
+
+required:
+  - compatible
+  - clocks
+  - clock-names
+  - '#interconnect-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/qcom,camcc-sm8250.h>
+    #include <dt-bindings/interconnect/qcom,camnoc.h>
+
+    camnoc_icc: interconnect {
+        compatible = "qcom,sm8250-cam-virt";
+        clocks = <&camcc CAM_CC_CAMNOC_AXI_CLK>;
+        clock-names = "camnoc_axi";
+        #interconnect-cells = <1>;
+    };
+
+    /* Example camera sub-device consuming the CAMNOC provider above */
+    camera-subsystem@ac53000 {
+        reg = <0x0ac53000 0x1000>;
+
+        interconnects = <&camnoc_icc MASTER_CAMNOC_JPEG
+                         &camnoc_icc SLAVE_CAMNOC_AXI>;
+        interconnect-names = "camnoc";
+
+        /*
+         * Optional: an operating-points-v2 table lets the consumer
+         * drive its CAMNOC bandwidth vote from the same OPP that
+         * selects its core clock rate and RPMh performance state.
+         */
+        operating-points-v2 = <&camera_opp_table>;
+
+        camera_opp_table: opp-table {
+            compatible = "operating-points-v2";
+
+            opp-100000000 {
+                opp-hz = /bits/ 64 <100000000>;
+                opp-peak-kBps = <22246>;
+                required-opps = <&rpmhpd_opp_min_svs>;
+            };
+
+            opp-200000000 {
+                opp-hz = /bits/ 64 <200000000>;
+                opp-peak-kBps = <44492>;
+                required-opps = <&rpmhpd_opp_low_svs>;
+            };
+
+            opp-400000000 {
+                opp-hz = /bits/ 64 <400000000>;
+                opp-peak-kBps = <88983>;
+                required-opps = <&rpmhpd_opp_svs>;
+            };
+
+            opp-480000000 {
+                opp-hz = /bits/ 64 <480000000>;
+                opp-peak-kBps = <106780>;
+                required-opps = <&rpmhpd_opp_svs_l1>;
+            };
+        };
+    };
diff --git a/include/dt-bindings/interconnect/qcom,camnoc.h b/include/dt-bindings/interconnect/qcom,camnoc.h
new file mode 100644
index 000000000000..a03f5e3f6446
--- /dev/null
+++ b/include/dt-bindings/interconnect/qcom,camnoc.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause */
+/*
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#ifndef __DT_BINDINGS_INTERCONNECT_QCOM_CAMNOC_H
+#define __DT_BINDINGS_INTERCONNECT_QCOM_CAMNOC_H
+
+#define MASTER_CAMNOC_JPEG	0
+#define SLAVE_CAMNOC_AXI	1
+
+#endif /* __DT_BINDINGS_INTERCONNECT_QCOM_CAMNOC_H */
-- 
2.34.1