Re: [PATCH v2 2/6] dt-bindings: mediatek: Add smi dts binding

From: Yong Wu
Date: Wed May 27 2015 - 03:36:19 EST


Hi Tomasz,

On Mon, 2015-05-25 at 15:48 +0900, Tomasz Figa wrote:
> Hi,
>
> Please see my comments inline.
>
> On Fri, May 15, 2015 at 6:43 PM, Yong Wu <yong.wu@xxxxxxxxxxxx> wrote:
> > This patch add smi binding document.
> >
> > Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> > ---
> > .../bindings/soc/mediatek/mediatek,smi-larb.txt | 24 ++++++++++++++++++++++
> > .../bindings/soc/mediatek/mediatek,smi.txt | 22 ++++++++++++++++++++
> > 2 files changed, 46 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/soc/mediatek/mediatek,smi-larb.txt
> > create mode 100644 Documentation/devicetree/bindings/soc/mediatek/mediatek,smi.txt
> >
> > diff --git a/Documentation/devicetree/bindings/soc/mediatek/mediatek,smi-larb.txt b/Documentation/devicetree/bindings/soc/mediatek/mediatek,smi-larb.txt
> > new file mode 100644
> > index 0000000..c06c5b6
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/soc/mediatek/mediatek,smi-larb.txt
> > @@ -0,0 +1,24 @@
> > +SMI(Smart Multimedia Interface) Local Arbiter
> > +
> > +The hardware block diagram please check bindings/iommu/mediatek,iommu.txt
> > +
> > +Required properties:
> > +- compatible : must be "mediatek,mt8173-smi-larb"
> > +- reg : the register and size of each local arbiter.
>
> Shouldn't it be "of this local arbiter"?
>
> > +- smi : must be "&smi_common". Refer to bindings/soc/mediatek,smi.txt.
>
> This is incorrect. Device tree source authors are free to use any
> labels for their nodes and documentation should not rely on the fact
> that there is some node with some particular label. This should be
> something like:
>
> - smi : a phandle to node of XYZ
>
> with proper description of that node in place of XYZ.
Thanks. how about this?
smi : a phandle to the smi_common node
>
> > +- clocks : must contain one entry for each clock-names.
> > + There are 2 clockes:
> > + APB clock : Advanced Peripheral Bus clock, It's the clock for setting
> > + the register.
> > + SMI clock : It's the clock for transfer data and command.
>
> The description of each clock should go to "clock-names" property.
> Please use some of already existing bindings as an example.
>
> > +- clock-name: must be "apb" and "smi".
>
> typo: Should be "clock-names".
>
> I'd recommend describing this property as below:
>
> - clock-names: must contain 2 entries, as follows:
> - "apb" : <here comes the description of APB clock>,
> - "smi" : <here comes the description of SMI clock>.
Thanks. I will follow this.

> > +
> > +Example:
> > + larb0:larb@14021000 {
> > + compatible = "mediatek,mt8173-smi-larb";
> > + reg = <0 0x14021000 0 0x1000>;
> > + smi = <&smi_common>;
> > + clocks = <&mmsys MM_SMI_LARB0>,
> > + <&mmsys MM_SMI_LARB0>;
> > + clock-names = "apb", "smi";
And another question,
Could I add a item(port-count) in larb node. like:
port-count = M4U_PORT_LARB0_NR;
This item will only check the portid in client dsti is right or not?
iommu = <&iommu larbid portid>

Then, the port-count is necessary to add? or we could assume all the
input is correct.

> > + };
> > diff --git a/Documentation/devicetree/bindings/soc/mediatek/mediatek,smi.txt b/Documentation/devicetree/bindings/soc/mediatek/mediatek,smi.txt
> > new file mode 100644
> > index 0000000..c2389b4
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/soc/mediatek/mediatek,smi.txt
> > @@ -0,0 +1,22 @@
> > +SMI(Smart Multimedia Interface)
> > +
> > +The hardware block diagram please check bindings/iommu/mediatek,iommu.txt
> > +
> > +Required properties:
> > +- compatible : must be "mediatek,mt8173-smi"
> > +- reg : the register and size of the smi.
>
> nit: s/smi/SMI block/
>
> > +- clocks : must contain one entry for each clock-names.
> > + There are 2 clockes:
> > + APB clock : Advanced Peripheral Bus clock, It's the clock for setting
> > + the register.
> > + SMI clock : It's the clock for transfer data and command.
> > +- clock-name: must be "apb" and "smi".
>
> See my comment for those properties in the first binding.
>
> Best regards,
> Tomasz


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