Thread (20 messages) 20 messages, 7 authors, 2021-07-29
STALE1770d
Revisions (2)
  1. rfc current
  2. v2 [diff vs current]

[RFC PATCH net-next 3/4] dt-bindings: net: Add schema for Qualcomm BAM-DMUX

From: Stephan Gerhold <stephan@gerhold.net>
Date: 2021-07-19 15:02:57
Also in: dmaengine, linux-arm-msm, linux-devicetree, lkml, phone-devel
Subsystem: arm/qualcomm mailing list, networking drivers, open firmware and flattened device tree bindings, qualcomm bam-dmux wwan network driver, the rest · Maintainers: Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Stephan Gerhold, Linus Torvalds

The BAM Data Multiplexer provides access to the network data channels of
modems integrated into many older Qualcomm SoCs, e.g. Qualcomm MSM8916 or
MSM8974. It is built using a simple protocol layer on top of a DMA engine
(Qualcomm BAM) and bidirectional interrupts to coordinate power control.

The device tree node combines the incoming interrupt with the outgoing
interrupts (smem-states) as well as the two DMA channels, which allows
the BAM-DMUX driver to request all necessary resources.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
---
 .../bindings/net/qcom,bam-dmux.yaml           | 87 +++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml
diff --git a/Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml b/Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml
new file mode 100644
index 000000000000..33e125e70cb4
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml
@@ -0,0 +1,87 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/qcom,bam-dmux.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm BAM Data Multiplexer
+
+maintainers:
+  - Stephan Gerhold <stephan@gerhold.net>
+
+description: |
+  The BAM Data Multiplexer provides access to the network data channels
+  of modems integrated into many older Qualcomm SoCs, e.g. Qualcomm MSM8916
+  or MSM8974. It is built using a simple protocol layer on top of a DMA engine
+  (Qualcomm BAM DMA) and bidirectional interrupts to coordinate power control.
+
+properties:
+  compatible:
+    const: qcom,bam-dmux
+
+  interrupts:
+    description:
+      Interrupts used by the modem to signal the AP.
+      Both interrupts must be declared as IRQ_TYPE_EDGE_BOTH.
+    items:
+      - description: Power control
+      - description: Power control acknowledgment
+
+  interrupt-names:
+    items:
+      - const: pc
+      - const: pc-ack
+
+  qcom,smem-states:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    description: State bits used by the AP to signal the modem.
+    items:
+      - description: Power control
+      - description: Power control acknowledgment
+
+  qcom,smem-state-names:
+    description: Names for the state bits used by the AP to signal the modem.
+    items:
+      - const: pc
+      - const: pc-ack
+
+  dmas:
+    items:
+      - description: TX DMA channel phandle
+      - description: RX DMA channel phandle
+
+  dma-names:
+    items:
+      - const: tx
+      - const: rx
+
+required:
+  - compatible
+  - interrupts
+  - interrupt-names
+  - qcom,smem-states
+  - qcom,smem-state-names
+  - dmas
+  - dma-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    mpss: remoteproc {
+        bam-dmux {
+            compatible = "qcom,bam-dmux";
+
+            interrupt-parent = <&modem_smsm>;
+            interrupts = <1 IRQ_TYPE_EDGE_BOTH>, <11 IRQ_TYPE_EDGE_BOTH>;
+            interrupt-names = "pc", "pc-ack";
+
+            qcom,smem-states = <&apps_smsm 1>, <&apps_smsm 11>;
+            qcom,smem-state-names = "pc", "pc-ack";
+
+            dmas = <&bam_dmux_dma 4>, <&bam_dmux_dma 5>;
+            dma-names = "tx", "rx";
+        };
+    };
-- 
2.32.0
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