Re: [PATCH v8 2/3] DMA: Freescale: Add new 8-channel DMA engine devicetree nodes

From: Hongbo Zhang
Date: Wed Aug 28 2013 - 02:54:20 EST


On 08/27/2013 07:35 PM, Mark Rutland wrote:
On Tue, Aug 27, 2013 at 11:42:02AM +0100, hongbo.zhang@xxxxxxxxxxxxx wrote:
From: Hongbo Zhang <hongbo.zhang@xxxxxxxxxxxxx>

Freescale QorIQ T4 and B4 introduce new 8-channel DMA engines, this patch adds
the device tree nodes for them.

Signed-off-by: Hongbo Zhang <hongbo.zhang@xxxxxxxxxxxxx>
---
.../devicetree/bindings/powerpc/fsl/dma.txt | 66 ++++++++++++++++
arch/powerpc/boot/dts/fsl/b4si-post.dtsi | 4 +-
arch/powerpc/boot/dts/fsl/elo3-dma-0.dtsi | 81 ++++++++++++++++++++
arch/powerpc/boot/dts/fsl/elo3-dma-1.dtsi | 81 ++++++++++++++++++++
arch/powerpc/boot/dts/fsl/t4240si-post.dtsi | 4 +-
5 files changed, 232 insertions(+), 4 deletions(-)
create mode 100644 arch/powerpc/boot/dts/fsl/elo3-dma-0.dtsi
create mode 100644 arch/powerpc/boot/dts/fsl/elo3-dma-1.dtsi

diff --git a/Documentation/devicetree/bindings/powerpc/fsl/dma.txt b/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
index ddf17af..10fd031 100644
--- a/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
+++ b/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
@@ -126,6 +126,72 @@ Example:
};
};

+** Freescale Elo3 DMA Controller
+ This is EloPlus controller with 8 channels, used in Freescale Txxx and Bxxx
+ series chips, such as t1040, t4240, b4860.
+
+Required properties:
+
+- compatible : must include "fsl,elo3-dma"
+- reg : <registers specifier for DMA general status reg>
+- ranges : describes the mapping between the address space of the
+ DMA channels and the address space of the DMA controller
+
+- DMA channel nodes:
+ - compatible : must include "fsl,eloplus-dma-channel"
+ - reg : <registers specifier for channel>
+ - interrupts : <interrupt specifier for DMA channel IRQ>
+ - interrupt-parent : optional, if needed for interrupt mapping
+
+Example:
+dma@100300 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "fsl,elo3-dma";
+ reg = <0x100300 0x4 0x100600 0x4>;
Is that one reg entry where #size-cells=2 and #address-cells=2?

That's what the binding implies (given it only describes a single reg
entry).

if it's two entries, we should make that explicit (both in the binding
and example):

reg = <0x100300 0x4>,
<0x100600 0x4>;
Yes they are two entries, I will change it this way.
+ ranges = <0x0 0x100100 0x500>;
If it is one reg entry then the example ranges property isn't big enough
to contain the parent-bus-address.
They are two reg entries, so the range is big enough.

+ dma-channel@0 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x0 0x80>;
+ interrupts = <28 2 0 0>;
+ };
+ dma-channel@80 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x80 0x80>;
+ interrupts = <29 2 0 0>;
+ };
+ dma-channel@100 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x100 0x80>;
+ interrupts = <30 2 0 0>;
+ };
+ dma-channel@180 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x180 0x80>;
+ interrupts = <31 2 0 0>;
+ };
+ dma-channel@300 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x300 0x80>;
+ interrupts = <76 2 0 0>;
+ };
+ dma-channel@380 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x380 0x80>;
+ interrupts = <77 2 0 0>;
+ };
+ dma-channel@400 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x400 0x80>;
+ interrupts = <78 2 0 0>;
+ };
+ dma-channel@480 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x480 0x80>;
+ interrupts = <79 2 0 0>;
+ };
+};
+
Note on DMA channel compatible properties: The compatible property must say
"fsl,elo-dma-channel" or "fsl,eloplus-dma-channel" to be used by the Elo DMA
driver (fsldma). Any DMA channel used by fsldma cannot be used by another
diff --git a/arch/powerpc/boot/dts/fsl/b4si-post.dtsi b/arch/powerpc/boot/dts/fsl/b4si-post.dtsi
index 7399154..ea53ea1 100644
--- a/arch/powerpc/boot/dts/fsl/b4si-post.dtsi
+++ b/arch/powerpc/boot/dts/fsl/b4si-post.dtsi
@@ -223,13 +223,13 @@
reg = <0xe2000 0x1000>;
};

-/include/ "qoriq-dma-0.dtsi"
+/include/ "elo3-dma-0.dtsi"
dma@100300 {
fsl,iommu-parent = <&pamu0>;
fsl,liodn-reg = <&guts 0x580>; /* DMA1LIODNR */
};

-/include/ "qoriq-dma-1.dtsi"
+/include/ "elo3-dma-1.dtsi"
dma@101300 {
fsl,iommu-parent = <&pamu0>;
fsl,liodn-reg = <&guts 0x584>; /* DMA2LIODNR */
diff --git a/arch/powerpc/boot/dts/fsl/elo3-dma-0.dtsi b/arch/powerpc/boot/dts/fsl/elo3-dma-0.dtsi
new file mode 100644
index 0000000..69a3277
--- /dev/null
+++ b/arch/powerpc/boot/dts/fsl/elo3-dma-0.dtsi
@@ -0,0 +1,81 @@
+/*
+ * QorIQ DMA device tree stub [ controller @ offset 0x100000 ]
Copy-pasted?

Presumably should be "Elo3 DMA devicetree stub", or similar?

Similarly for elo3-dma-1.dtsi.
Yes copy-pasted, but QorIQ isn't wrong, it is name of Freescale series chips.
To be more specific, I'd like to use "QorIQ Elo3 DMA devicetree stub"
Thanks,
Mark.




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