Thread (40 messages) 40 messages, 3 authors, 2020-11-09
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[PATCH 09/18] dt-bindings: dma: ti: Add document for K3 BCDMA

From: Peter Ujfalusi <hidden>
Date: 2020-09-30 09:15:24
Also in: dmaengine, linux-devicetree, lkml
Subsystem: dma generic offload engine subsystem, open firmware and flattened device tree bindings, texas instruments dma drivers, the rest · Maintainers: Vinod Koul, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Vignesh Raghavendra, Linus Torvalds

New binding document for
Texas Instruments K3 Block Copy DMA (BCDMA).

BCDMA is introduced as part of AM64.

Signed-off-by: Peter Ujfalusi <redacted>
---
 .../devicetree/bindings/dma/ti/k3-bcdma.yaml  | 183 ++++++++++++++++++
 1 file changed, 183 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
diff --git a/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml b/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
new file mode 100644
index 000000000000..c84fb641738f
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
@@ -0,0 +1,183 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dma/ti/k3-bcdma.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Texas Instruments K3 DMSS BCDMA Device Tree Bindings
+
+maintainers:
+  - Peter Ujfalusi <peter.ujfalusi@ti.com>
+
+description: |
+  The Block Copy DMA (BCDMA) is intended to perform similar functions as the TR
+  mode channels of K3 UDMA-P.
+  BCDMA includes block copy channels and Split channels.
+
+  Block copy channels mainly used for memory to memory transfers, but with
+  optional triggers a block copy channel can service peripherals by accessing
+  directly to memory mapped registers or area.
+
+  Split channels can be used to service PSI-L based peripherals.
+  The peripherals can be PSI-L native or legacy, non PSI-L native peripherals
+  with PDMAs. PDMA is tasked to act as a bridge between the PSI-L fabric and the
+  legacy peripheral.
+
+  PDMAs can be configured via BCDMA split channel's peer registers to match with
+  the configuration of the legacy peripheral.
+
+allOf:
+  - $ref: /schemas/dma/dma-controller.yaml#
+
+properties:
+  "#dma-cells":
+    const: 3
+    description: |
+      cell 1: type of the BCDMA channel to be used to service the peripheral:
+        0 - split channel
+        1 - block copy channel using global trigger 1
+        2 - block copy channel using global trigger 2
+        3 - block copy channel using local trigger
+
+      cell 2: parameter for the channel:
+        if cell 1 is 0 (split channel):
+          PSI-L thread ID of the remote (to BCDMA) end.
+          Valid ranges for thread ID depends on the data movement direction:
+          for source thread IDs (rx): 0 - 0x7fff
+          for destination thread IDs (tx): 0x8000 - 0xffff
+
+          Please refer to the device documentation for the PSI-L thread map and
+          also the PSI-L peripheral chapter for the correct thread ID.
+        if cell 1 is 1 or 2 (block copy channel using global trigger):
+          Unused, ignored
+
+          The trigger must be configured for the channel externally to BCDMA,
+          channels using global triggers should not be requested directly, but
+          via DMA event router.
+        if cell 1 is 3 (block copy channel using local trigger):
+          bchan number of the locally triggered channel
+
+      cell 3: ASEL value for the channel
+
+  compatible:
+    enum:
+      - ti,am64-dmss-bcdma
+
+  "#address-cells":
+    const: 2
+
+  "#size-cells":
+    const: 2
+
+  reg:
+    maxItems: 5
+
+  reg-names:
+   items:
+     - const: gcfg
+     - const: bchanrt
+     - const: rchanrt
+     - const: tchanrt
+     - const: ringrt
+
+  msi-parent: true
+
+  ti,sci:
+    description: phandle to TI-SCI compatible System controller node
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/phandle
+
+  ti,sci-dev-id:
+    description: TI-SCI device id of BCDMA
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+
+  ti,asel:
+    description: ASEL value for non slave channels
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+
+  ti,sci-rm-range-bchan:
+    description: |
+      Array of BCDMA block-copy channel resource subtypes for resource
+      allocation for this host
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 1
+    # Should be enough
+    maxItems: 255
+
+  ti,sci-rm-range-tchan:
+    description: |
+      Array of BCDMA split tx channel resource subtypes for resource allocation
+      for this host
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 1
+    # Should be enough
+    maxItems: 255
+
+  ti,sci-rm-range-rchan:
+    description: |
+      Array of BCDMA split rx channel resource subtypes for resource allocation
+      for this host
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 1
+    # Should be enough
+    maxItems: 255
+
+required:
+  - compatible
+  - "#address-cells"
+  - "#size-cells"
+  - "#dma-cells"
+  - reg
+  - reg-names
+  - msi-parent
+  - ti,sci
+  - ti,sci-dev-id
+  - ti,sci-rm-range-bchan
+  - ti,sci-rm-range-tchan
+  - ti,sci-rm-range-rchan
+
+additionalProperties: false
+
+examples:
+  - |+
+    cbass_main {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        main_dmss {
+            compatible = "simple-mfd";
+            #address-cells = <2>;
+            #size-cells = <2>;
+            dma-ranges;
+            ranges;
+
+            ti,sci-dev-id = <25>;
+
+            main_bcdma: dma-controller@485c0100 {
+                compatible = "ti,am64-dmss-bcdma";
+                #address-cells = <2>;
+                #size-cells = <2>;
+
+                reg = <0x0 0x485c0100 0x0 0x100>,
+                      <0x0 0x4c000000 0x0 0x20000>,
+                      <0x0 0x4a820000 0x0 0x20000>,
+                      <0x0 0x4aa40000 0x0 0x20000>,
+                      <0x0 0x4bc00000 0x0 0x100000>;
+                reg-names = "gcfg", "bchanrt", "rchanrt", "tchanrt", "ringrt";
+                msi-parent = <&inta_main_dmss>;
+                #dma-cells = <3>;
+
+                ti,sci = <&dmsc>;
+                ti,sci-dev-id = <26>;
+
+                ti,sci-rm-range-bchan = <0x20>; /* BLOCK_COPY_CHAN */
+                ti,sci-rm-range-rchan = <0x21>; /* SPLIT_TR_RX_CHAN */
+                ti,sci-rm-range-tchan = <0x22>; /* SPLIT_TR_TX_CHAN */
+            };
+        };
+    };
-- 
Peter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki


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