dmaengine: add device tree binding documentation for the nbpfaxi driver

The nbpfaxi dmaengine driver doesn't define any new bindings, it only
uses standard dmaengine bindings and defines 3 flags for the 3rd parameter
of the "dmas" property.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/Documentation/devicetree/bindings/dma/nbpfaxi.txt b/Documentation/devicetree/bindings/dma/nbpfaxi.txt
new file mode 100644 (file)
index 0000000..d5e2522
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/nbpfaxi.txt
@@ -0,0 +1,61 @@
+* Renesas "Type-AXI" NBPFAXI* DMA controllers
+
+* DMA controller
+
+Required properties
+
+- compatible:  must be one of
+               "renesas,nbpfaxi64dmac1b4"
+               "renesas,nbpfaxi64dmac1b8"
+               "renesas,nbpfaxi64dmac1b16"
+               "renesas,nbpfaxi64dmac4b4"
+               "renesas,nbpfaxi64dmac4b8"
+               "renesas,nbpfaxi64dmac4b16"
+               "renesas,nbpfaxi64dmac8b4"
+               "renesas,nbpfaxi64dmac8b8"
+               "renesas,nbpfaxi64dmac8b16"
+- #dma-cells:  must be 2: the first integer is a terminal number, to which this
+               slave is connected, the second one is flags. Flags is a bitmask
+               with the following bits defined:
+
+#define NBPF_SLAVE_RQ_HIGH     1
+#define NBPF_SLAVE_RQ_LOW      2
+#define NBPF_SLAVE_RQ_LEVEL    4
+
+Optional properties:
+
+You can use dma-channels and dma-requests as described in dma.txt, although they
+won't be used, this information is derived from the compatibility string.
+
+Example:
+
+       dma: dma-controller@48000000 {
+               compatible = "renesas,nbpfaxi64dmac8b4";
+               reg = <0x48000000 0x400>;
+               interrupts = <0 12 0x4
+                             0 13 0x4
+                             0 14 0x4
+                             0 15 0x4
+                             0 16 0x4
+                             0 17 0x4
+                             0 18 0x4
+                             0 19 0x4>;
+               #dma-cells = <2>;
+               dma-channels = <8>;
+               dma-requests = <8>;
+       };
+
+* DMA client
+
+Required properties:
+
+dmas and dma-names are required, as described in dma.txt.
+
+Example:
+
+#include <dt-bindings/dma/nbpfaxi.h>
+
+...
+               dmas = <&dma 0 (NBPF_SLAVE_RQ_HIGH | NBPF_SLAVE_RQ_LEVEL)
+                       &dma 1 (NBPF_SLAVE_RQ_HIGH | NBPF_SLAVE_RQ_LEVEL)>;
+               dma-names = "rx", "tx";

diff --git a/include/dt-bindings/dma/nbpfaxi.h b/include/dt-bindings/dma/nbpfaxi.h
new file mode 100644 (file)
index 0000000..c1a5b9e
--- /dev/null
+++ b/include/dt-bindings/dma/nbpfaxi.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2013-2014 Renesas Electronics Europe Ltd.
+ * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef DT_BINDINGS_NBPFAXI_H
+#define DT_BINDINGS_NBPFAXI_H
+
+/**
+ * Use "#dma-cells = <2>;" with the second integer defining slave DMA flags:
+ */
+#define NBPF_SLAVE_RQ_HIGH     1
+#define NBPF_SLAVE_RQ_LOW      2
+#define NBPF_SLAVE_RQ_LEVEL    4
+
+#endif