On Fri, 11 Sep 2015, Peter Griffin wrote:
> On Fri, 11 Sep 2015, Lee Jones wrote:
> > On Fri, 11 Sep 2015, Peter Griffin wrote:
> >
> > > These nodes are required to get the fdma driver working
> > > on STiH407 based silicon.
> > >
> > > Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
> > > ---
> > > arch/arm/boot/dts/stih407-family.dtsi | 51 +++++++++++++++++++++++++++++++++++
> > > 1 file changed, 51 insertions(+)
> > >
> > > diff --git a/arch/arm/boot/dts/stih407-family.dtsi b/arch/arm/boot/dts/stih407-family.dtsi
> > > index 838b812..da07474b 100644
> > > --- a/arch/arm/boot/dts/stih407-family.dtsi
> > > +++ b/arch/arm/boot/dts/stih407-family.dtsi
> > > @@ -565,5 +565,56 @@
> > > <&phy_port2 PHY_TYPE_USB3>;
> > > };
> > > };
> > > +
> > > + fdma0: fdma0-audio@8e20000 {
> >
> > I'm not familiar with the FDMA driver, so can't comment knowledgeably,
> > but the <dev> part of <dev>@<base_address> should only describe the
> > type of hardware. I believe in this case it should just be
> > dma@08e20000. Also notice the leading zero in the address, which I
> > believe mitigates possible confusion. Then you be more specific with
> > the label, so something like 'fdma-audio' seems appropriate here.
>
> Ok, can change to that format in v3.
>
> >
> > > + compatible = "st,stih407-fdma-mpe31";
> > > + reg = <0x8e20000 0x20000>;
> >
> > I personally find padding up to 32bits helpful in the addresses.
>
> None of the stih407-family nodes I can see have this padding, including
> the ones merged by you.
Nither of these two facts mean it's correct.
I'm happy to write a patch to correct them all.
Bear in mind that this isn't a hard and fast rule. Both work and are
legal. I just think the padding is more consistent.
> > > + interrupts = <GIC_SPI 5 IRQ_TYPE_NONE>;
> > > + dma-channels = <16>;
> > > + #dma-cells = <3>;
> > > + st,fdma-id = <0>;
> >
> > We usually shy away from ID properties. What is it required for in
> > this case?
>
> Yes Rob did already mention that over here, see my reply at the bottom
> http://www.spinics.net/lists/devicetree/msg92529.html.
>
> However I can't think of any other useful properties we could add
> to derive this information. The fdma controller number is used
> by the driver to generate a unique firmware filename.
Who chooses the naming scheme of the firmware binary?
Is there any reason they can't be:
fdma_STiH407_audio.elf
fdma_STiH407_app.elf
fdma_STiH407_free_running.elf
Then you can have a different compatible for each.
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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