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

From: Hongbo Zhang <[email-masked]>
Date: Wed, 28 Aug 2013 14:54:01 +0800

On 08/27/2013 07:35 PM, Mark Rutland wrote:
> On Tue, Aug 27, 2013 at 11:42:02AM +0100, [email-masked] wrote:
>> From: Hongbo Zhang <[email-masked]>
>>
>> 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 <[email-masked]>
>> ---
>>   .../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.