Re: [PATCH 2/4] dt/bindings: Introduce the FSL QorIQ DPAA BMan portal(s)
From: Mark Rutland <mark.rutland@arm.com>
Date: 2014-10-22 14:29:31
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linuxppc-dev
On Wed, Oct 22, 2014 at 03:09:30PM +0100, Emil Medve wrote:
Portals are used by software running on processor cores, accelerators and network interfaces to communicate with the BMan
What exactly is a portal? Is it a region of shared memory? A device? I only received emails 2 and 3 of this series, so I'm lacking the context necessary to understand the bindings.
quoted hunk ↗ jump to hunk
Signed-off-by: Emil Medve <redacted> Change-Id: I6d245ffc14ba3d0e91d403ac7c3b91b75a9e6a95 --- .../bindings/powerpc/fsl/bman-portals.txt | 50 ++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 Documentation/devicetree/bindings/powerpc/fsl/bman-portals.txtdiff --git a/Documentation/devicetree/bindings/powerpc/fsl/bman-portals.txt b/Documentation/devicetree/bindings/powerpc/fsl/bman-portals.txt new file mode 100644 index 0000000..40e607e --- /dev/null +++ b/Documentation/devicetree/bindings/powerpc/fsl/bman-portals.txt@@ -0,0 +1,50 @@ +QorIQ DPAA Buffer Manager Portals Device Tree Binding + +Copyright (C) 2008 - 2014 Freescale Semiconductor Inc. + +CONTENTS + + - BMan Portal + - Example + +NOTE: The bindings described in this document are preliminary and subject to + change
While we've tried that elsewhere, unstable DT bindings have been shown to be a major source of pain. I'd feel rather uncomfortable accepting a binding that we already believe to be insufficient to describe the hardware. What do you expect to change?
+ +BMan Portal Node + +PROPERTIES + +- compatible + Usage: Required + Value type: <stringlist> + Definition: Must include "fsl,bman-portal-<hardware revision>" + May include "fsl,<SoC>-bman-portal" or "fsl,bman-portal" + +- reg + Usage: Required + Value type: <prop-encoded-array> + Definition: Two regions. The first is the cache-enabled region of + the portal. The second is the cache-inhibited region of + the portal + +EXAMPLE + +The example below shows a (P4080) BMan portals container/bus node with two portals
Is there any particular reason to place these under a simple-bus?
+
+ bman-portals@ff4000000 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "simple-bus";
+ ranges = <0 0xf 0xf4000000 0x200000>;
+
+ bman-portal@0 {
+ compatible = "fsl,bman-portal-1.0.0", "fsl,bman-portal";
+ reg = <0x0 0x4000 0x100000 0x1000>;It would be easier to read is each entry had its own set of brackets. Initially this looked to me like a single 64-bit address/size pair.
+ interrupts = <105 2 0 0>; + };
Given the description above, surely you need to know what the portal is used for? Or is that queried from the portal? Thanks, Mark.
+ bman-portal@4000 {
+ compatible = "fsl,bman-portal-1.0.0", "fsl,bman-portal";
+ reg = <0x4000 0x4000 0x101000 0x1000>;
+ interrupts = <107 2 0 0>;
+ };
+ };
--
2.1.2