RE: [PATCH v6 1/2] mtd: arasan: Add device tree binding documentation

[Punnaiah Choudary Kalluri]

Hi Marek,

 Thanks for the review.

> -----Original Message-----
> From: Marek Vasut [mailto:marek.vasut@xxxxxxxxx]
> Sent: Monday, December 05, 2016 9:56 AM
> To: Punnaiah Choudary Kalluri <punnaia@xxxxxxxxxx>;
> dwmw2@xxxxxxxxxxxxx; computersforpeace@xxxxxxxxx;
> boris.brezillon@xxxxxxxxxxxxxxxxxx; richard@xxxxxx;
> cyrille.pitchen@xxxxxxxxx; robh+dt@xxxxxxxxxx; mark.rutland@xxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-mtd@xxxxxxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; Michal Simek <michals@xxxxxxxxxx>;
> kalluripunnaiahchoudary@xxxxxxxxx; kpc528@xxxxxxxxx; Punnaiah
> Choudary Kalluri <punnaia@xxxxxxxxxx>
> Subject: Re: [PATCH v6 1/2] mtd: arasan: Add device tree binding
> documentation
> 
> On 12/05/2016 05:11 AM, Punnaiah Choudary Kalluri wrote:
> > This patch adds the dts binding document for arasan nand flash
> > controller.
> >
> > Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xxxxxxxxxx>
> > Acked-by: Rob Herring <robh@xxxxxxxxxx>
> > ---
> > 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..dcbe7ad
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mtd/arasan_nfc.txt
> > @@ -0,0 +1,38 @@
> > +Arasan Nand Flash Controller with ONFI 3.1 support
> 
> Arasan NAND Flash ...
> 
> > +Required properties:
> > +- compatible: Should be "arasan,nfc-v3p10"
> 
> This v3p10 looks like version 3 patchlevel 10, but shouldn't we have
> some fallback option which doesn't encode IP version in the compat
> string ?
> 

This is a third-party IP and v3p10 is the version that we are using in our SOC.
Also this IP doesnât have the IP version information in the register space to
read dynamically and having generic compatible name. So, any new versions
can be added through  of_match_table with config data inside the driver.

> Also, shouldn't quirks be handled by DT props instead of effectively
> encoding them into the compatible string ?
>
I feel the above mentioned method will be more appropriate rather than defining
the quirks through DT properties.

I will fix all other comments

Regards,
Punnaiah
> > +- 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"
> > +	      (See clock bindings for details)
> > +- clocks: Clock phandles (see clock bindings for details)
> > +
> > +Optional properties:
> > +- arasan,has-mdma: Enables Dma support
> 
> 'Enables DMA support' , with DMA in caps.
> 
> > +for nand partition information please refer the below file
> 
> For NAND ...
> 
> > +Documentation/devicetree/bindings/mtd/partition.txt
> > +
> > +Example:
> > +	nand0: nand@ff100000 {
> > +		compatible = "arasan,nfc-v3p10"
> > +		reg = <0x0 0xff100000 0x1000>;
> > +		clock-name = "clk_sys", "clk_flash"
> > +		clocks = <&misc_clk &misc_clk>;
> > +		interrupt-parent = <&gic>;
> > +		interrupts = <0 14 4>;
> > +		arasan,has-mdma;
> > +		#address-cells = <1>;
> > +		#size-cells = <0>
> > +
> > +		nand@0 {
> > +			reg = <0>
> > +			partition@0 {
> > +				label = "filesystem";
> > +				reg = <0x0 0x0 0x1000000>;
> > +			};
> > +			(...)
> > +		};
> > +	};
> >
> 
> 
> --
> Best regards,
> Marek Vasut