Re: [PATCH v7 1/2] mtd: arasan: Add device tree binding documentation

[Boris Brezillon <boris.brezillon@free-electrons.com>]

Hi Punnaiah,

On Tue, 10 Jan 2017 06:03:25 +0000
Punnaiah Choudary Kalluri <punnaiah.choudary.kalluri@xilinx.com> wrote:

> Hi Rob,
>     
>    Thanks for the review.
> 
> > -----Original Message-----
> > From: Rob Herring [mailto:robh@kernel.org]
> > Sent: Tuesday, January 10, 2017 11:06 AM
> > To: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
> > Cc: dwmw2@infradead.org; computersforpeace@gmail.com;
> > boris.brezillon@free-electrons.com; marek.vasut@gmail.com;
> > richard@nod.at; cyrille.pitchen@atmel.com; mark.rutland@arm.com; linux-
> > kernel@vger.kernel.org; linux-mtd@lists.infradead.org;
> > devicetree@vger.kernel.org; Michal Simek <michals@xilinx.com>;
> > kalluripunnaiahchoudary@gmail.com; kpc528@gmail.com; Punnaiah
> > Choudary Kalluri <punnaia@xilinx.com>
> > Subject: Re: [PATCH v7 1/2] mtd: arasan: Add device tree binding
> > documentation
> > 
> > On Mon, Jan 09, 2017 at 08:28:53AM +0530, Punnaiah Choudary Kalluri wrote:  
> > > This patch adds the dts binding document for arasan nand flash
> > > controller.
> > >
> > > Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
> > > ---
> > > Changes in v7:
> > > - Corrected the acronyms those should be in caps
> > > changes in v6:
> > > - Removed num-cs property
> > > - Separated nandchip from nand controller
> > > changes in v5:
> > > - None
> > > Changes in v4:
> > > - Added num-cs property
> > > - Added clock support
> > > Changes in v3:
> > > - None
> > > Changes in v2:
> > > - None
> > > ---
> > >  .../devicetree/bindings/mtd/arasan_nfc.txt         | 38  
> > ++++++++++++++++++++++  
> > >  1 file changed, 38 insertions(+)
> > >  create mode 100644  
> > Documentation/devicetree/bindings/mtd/arasan_nfc.txt  
> > >
> > > diff --git a/Documentation/devicetree/bindings/mtd/arasan_nfc.txt  
> > b/Documentation/devicetree/bindings/mtd/arasan_nfc.txt  
> > > new file mode 100644
> > > index 0000000..f20adfc
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/mtd/arasan_nfc.txt
> > > @@ -0,0 +1,38 @@
> > > +Arasan NAND Flash Controller with ONFI 3.1 support
> > > +
> > > +Required properties:
> > > +- compatible: Should be "arasan,nfc-v3p10"  
> > 
> > Needs a note that it must also have an SoC specific compatible string.
> >   
>   Sorry, I couldn't understand this comment. Could you elaborate it?

Arasan is an IP vendor, and those IPs are usually embedded in specific
SoCs. I guess Rob was suggesting to define something like:

  compatible = "<soc-vendor>,<ip-revision>", "arasan,<ip-revision>";

This way you can differentiate minor changes/tweaks between each SoC
(each SoC vendor usually enable/disable specific features based on
their needs).

> 
> > > +- reg: Memory map for module access
> > > +- interrupt-parent: Interrupt controller the interrupt is routed through
> > > +- interrupts: Should contain the interrupt for the device
> > > +- clock-name: List of input clocks - "clk_sys", "clk_flash"  
> > 
> > clk_ is redundant.
> >   
>   
>  I have defined these clock names as per the controller data sheet.
>  So, I feel it is fine to have them in sync with the datasheet.
>   Please let me know if you still want me to change this.

We already know this is a clock, hence the unneeded clk_ prefix. Please
drop it.

Thanks,

Boris