Hello,

Xilinx Alveo PCIe accelerator cards use flattened device tree to describe
HW subsystems or endpoints. Each device tree node represents a hardware
endpoint and each endpoint is an hardware unit which requires a driver.
The product detail: 
    https://www.xilinx.com/products/boards-and-kits/alveo.html

The feedback from the previous patches was to create a base tree if there
is not one and apply the unflattened device nodes by existing Linux
platform device and OF infrastructure. Please refer to previous discussion
with device tree and fpga maintainers.
    https://lore.kernel.org/lkml/CAL_JsqJfyRymB=VxLuQqLpep+Q1Eie48dobv9sC5OizDz0d2DQ@mail.gmail.com/
    https://lore.kernel.org/lkml/20220105225013.1567871-1-lizhi.hou@xilinx.com/

This patch adds OF_EMPTY_ROOT config. When it is selected and there is not
a device tree, create an empty device tree root node.

Lizhi Hou (1):
  of: create empty of root

 drivers/of/Kconfig         |  3 +++
 drivers/of/Makefile        |  1 +
 drivers/of/of_empty_root.c | 51 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 55 insertions(+)
 create mode 100644 drivers/of/of_empty_root.c

-- 
2.27.0

Hi Rob,


We are still waiting for your feedback and guidance on this. Could you 
take a look?


Thanks,

Lizhi

On 1/25/22 9:48 PM, Lizhi Hou wrote:
> Hello,
>
> Xilinx Alveo PCIe accelerator cards use flattened device tree to describe
> HW subsystems or endpoints. Each device tree node represents a hardware
> endpoint and each endpoint is an hardware unit which requires a driver.
> The product detail:
>      https://www.xilinx.com/products/boards-and-kits/alveo.html
>
> The feedback from the previous patches was to create a base tree if there
> is not one and apply the unflattened device nodes by existing Linux
> platform device and OF infrastructure. Please refer to previous discussion
> with device tree and fpga maintainers.
>      https://lore.kernel.org/lkml/CAL_JsqJfyRymB=VxLuQqLpep+Q1Eie48dobv9sC5OizDz0d2DQ@mail.gmail.com/
>      https://lore.kernel.org/lkml/20220105225013.1567871-1-lizhi.hou@xilinx.com/
>
> This patch adds OF_EMPTY_ROOT config. When it is selected and there is not
> a device tree, create an empty device tree root node.
>
> Lizhi Hou (1):
>    of: create empty of root
>
>   drivers/of/Kconfig         |  3 +++
>   drivers/of/Makefile        |  1 +
>   drivers/of/of_empty_root.c | 51 ++++++++++++++++++++++++++++++++++++++
>   3 files changed, 55 insertions(+)
>   create mode 100644 drivers/of/of_empty_root.c
>

Hi all,

Gentle ping. Are we okay with this series?

Will appreciate feedback as our next set of patches for Alveo is based on this feature.

Thanks,
-Sonal

> -----Original Message-----
> From: Lizhi Hou <lizhi.hou@xilinx.com>
> Sent: Monday, January 31, 2022 4:50 PM
> To: Lizhi Hou <lizhih@xilinx.com>; devicetree@vger.kernel.org;
> robh@kernel.org
> Cc: linux-kernel@vger.kernel.org; yilun.xu@intel.com; Max Zhen
> <maxz@xilinx.com>; Sonal Santan <sonals@xilinx.com>; Yu Liu
> <yliu@xilinx.com>; Michal Simek <michals@xilinx.com>; Stefano Stabellini
> <stefanos@xilinx.com>; trix@redhat.com; mdf@kernel.org;
> dwmw2@infradead.org
> Subject: Re: [PATCH V1 Create empty OF root 0/1] XRT Alveo driver
> infrastructure overview
> 
> Hi Rob,
> 
> 
> We are still waiting for your feedback and guidance on this. Could you take a
> look?
> 
> 
> Thanks,
> 
> Lizhi
> 
> On 1/25/22 9:48 PM, Lizhi Hou wrote:
> > Hello,
> >
> > Xilinx Alveo PCIe accelerator cards use flattened device tree to describe
> > HW subsystems or endpoints. Each device tree node represents a hardware
> > endpoint and each endpoint is an hardware unit which requires a driver.
> > The product detail:
> >      https://www.xilinx.com/products/boards-and-kits/alveo.html
> >
> > The feedback from the previous patches was to create a base tree if there
> > is not one and apply the unflattened device nodes by existing Linux
> > platform device and OF infrastructure. Please refer to previous discussion
> > with device tree and fpga maintainers.
> >
> https://lore.kernel.org/lkml/CAL_JsqJfyRymB=VxLuQqLpep+Q1Eie48dobv9sC5Oi
> zDz0d2DQ@mail.gmail.com/
> >      https://lore.kernel.org/lkml/20220105225013.1567871-1-
> lizhi.hou@xilinx.com/
> >
> > This patch adds OF_EMPTY_ROOT config. When it is selected and there is not
> > a device tree, create an empty device tree root node.
> >
> > Lizhi Hou (1):
> >    of: create empty of root
> >
> >   drivers/of/Kconfig         |  3 +++
> >   drivers/of/Makefile        |  1 +
> >   drivers/of/of_empty_root.c | 51
> ++++++++++++++++++++++++++++++++++++++
> >   3 files changed, 55 insertions(+)
> >   create mode 100644 drivers/of/of_empty_root.c
> >