dt-bindings: dmaengine: Introduce RZN1 dmamux bindings

The Renesas RZN1 DMA IP is based on a DW core, with eg. an additional
dmamux register located in the system control area which can take up to
32 requests (16 per DMA controller). Each DMA channel can be wired to
two different peripherals.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20220427095653.91804-2-miquel.raynal@bootlin.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/Documentation/devicetree/bindings/dma/renesas,rzn1-dmamux.yaml b/Documentation/devicetree/bindings/dma/renesas,rzn1-dmamux.yaml
new file mode 100644 (file)
index 0000000..d83013b
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/renesas,rzn1-dmamux.yaml
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dma/renesas,rzn1-dmamux.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas RZ/N1 DMA mux
+
+maintainers:
+  - Miquel Raynal <miquel.raynal@bootlin.com>
+
+allOf:
+  - $ref: "dma-router.yaml#"
+
+properties:
+  compatible:
+    const: renesas,rzn1-dmamux
+
+  reg:
+    maxItems: 1
+    description: DMA mux first register offset within the system control parent.
+
+  '#dma-cells':
+    const: 6
+    description:
+      The first four cells are dedicated to the master DMA controller. The fifth
+      cell gives the DMA mux bit index that must be set starting from 0. The
+      sixth cell gives the binary value that must be written there, ie. 0 or 1.
+
+  dma-masters:
+    minItems: 1
+    maxItems: 2
+
+  dma-requests:
+    const: 32
+
+required:
+  - reg
+  - dma-requests
+
+additionalProperties: false
+
+examples:
+  - |
+    dma-router@a0 {
+      compatible = "renesas,rzn1-dmamux";
+      reg = <0xa0 4>;
+      #dma-cells = <6>;
+      dma-masters = <&dma0 &dma1>;
+      dma-requests = <32>;
+    };

diff --git a/MAINTAINERS b/MAINTAINERS
index 2cdb36a..e7c0b08 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19040,6 +19040,7 @@ SYNOPSYS DESIGNWARE DMAC DRIVER
 M:     Viresh Kumar <vireshk@kernel.org>
 R:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
 S:     Maintained
+F:     Documentation/devicetree/bindings/dma/renesas,rzn1-dmamux.yaml
 F:     Documentation/devicetree/bindings/dma/snps,dma-spear1340.yaml
 F:     drivers/dma/dw/
 F:     include/dt-bindings/dma/dw-dmac.h