RE: [PATCH v3 2/3] dt-bindings: fpga: Add binding doc for versal fpga manager

[Nava kishore Manne <navam@xxxxxxxxxx>]

Hi Rob,

	Thanks for providing the review comments.
Please find my response inline.

> -----Original Message-----
> From: Rob Herring <robh@xxxxxxxxxx>
> Sent: Tuesday, March 9, 2021 1:50 AM
> To: Nava kishore Manne <navam@xxxxxxxxxx>
> Cc: mdf@xxxxxxxxxx; trix@xxxxxxxxxx; Michal Simek <michals@xxxxxxxxxx>;
> gregkh@xxxxxxxxxxxxxxxxxxx; Jolly Shah <JOLLYS@xxxxxxxxxx>; Rajan Vaja
> <RAJANV@xxxxxxxxxx>; arnd@xxxxxxxx; Manish Narani
> <MNARANI@xxxxxxxxxx>; Amit Sunil Dhamne <amitsuni@xxxxxxxxxx>; Tejas
> Patel <tejasp@xxxxxxxxxxxxxxx>; linux-fpga@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; chinnikishore369@xxxxxxxxx; Appana Durga
> Kedareswara Rao <appanad@xxxxxxxxxx>
> Subject: Re: [PATCH v3 2/3] dt-bindings: fpga: Add binding doc for versal fpga
> manager
> 
> On Thu, Mar 04, 2021 at 12:32:23PM +0530, Nava kishore Manne wrote:
> > From: Appana Durga Kedareswara rao <appana.durga.rao@xxxxxxxxxx>
> >
> > This patch adds binding doc for versal fpga manager driver.
> 
> Why do you need a DT entry for this? Can't the Versal firmware driver
> instantiate the fpga-mgr device?
> 
This dt entry is need to handle the fpga regions properly for both full and Partial bitstream loading use cases and it cannot be done by Versal firmware driver instantiate.

Complete firmware DT node example is shown below for your reference.
Example for full FPGA configuration:
fpga-region0 {
	compatible = "fpga-region";
	fpga-mgr = <&versal_fpga>;
	#address-cells = <0x1>;
	#size-cells = <0x1>;
};

firmware {
	zynqmp_firmware: zynqmp-firmware {
		compatible = "xlnx,zynqmp-firmware";
		method = "smc";
		versal_fpga: fpga {
			compatible = "xlnx,versal-fpga";
		};
	};
};

Please correct me if my understanding is wrong...

Regards,
Navakishore.