[linux-yocto] [kernel v5.2/standard/xlnx-soc][PATCH 2/2] arch: arm64: dts: add overlay dts file

[Quanyang Wang]

On 10/15/19 11:27 PM, Bruce Ashfield wrote:
> On Mon, Oct 14, 2019 at 6:19 AM Quanyang Wang
> <quanyang.wang at windriver.com> wrote:
>>
>> On 10/14/19 6:00 PM, Michal Simek wrote:
>>> On 14. 10. 19 11:34, Quanyang Wang wrote:
>>>> On 10/14/19 3:58 PM, Michal Simek wrote:
>>>>> On 14. 10. 19 9:55, Quanyang Wang wrote:
>>>>>> On 10/14/19 2:05 PM, Michal Simek wrote:
>>>>>>> On 13. 10. 19 15:33, quanyang.wang at windriver.com wrote:
>>>>>>>> From: MengLi <meng.li at windriver.com>
>>>>>>>>
>>>>>>>> Add overlay dts file for updating FPGA bitstream file on
>>>>>>>> zynqmp platform.
>>>>>>>>
>>>>>>>> Signed-off-by: Meng Li <Meng.Li at windriver.com>
>>>>>>>> Signed-off-by: Quanyang Wang <quanyang.wang at windriver.com>
>>>>>>>> ---
>>>>>>>>     arch/arm64/boot/dts/xilinx/Makefile            |  1 +
>>>>>>>>     .../dts/xilinx/zynqmp-zcu102-fpga-update.dts   | 18
>>>>>>>> ++++++++++++++++++
>>>>>>>>     2 files changed, 19 insertions(+)
>>>>>>>>     create mode 100644
>>>>>>>> arch/arm64/boot/dts/xilinx/zynqmp-zcu102-fpga-update.dts
>>>>>>>>
>>>>>>>> diff --git a/arch/arm64/boot/dts/xilinx/Makefile
>>>>>>>> b/arch/arm64/boot/dts/xilinx/Makefile
>>>>>>>> index bec4746fe721..d56c449988d0 100644
>>>>>>>> --- a/arch/arm64/boot/dts/xilinx/Makefile
>>>>>>>> +++ b/arch/arm64/boot/dts/xilinx/Makefile
>>>>>>>> @@ -13,6 +13,7 @@ dtb-$(CONFIG_ARCH_ZYNQMP) += zynqmp-zcu100-revC.dtb
>>>>>>>>     dtb-$(CONFIG_ARCH_ZYNQMP) += zynqmp-zcu102-revA.dtb
>>>>>>>>     dtb-$(CONFIG_ARCH_ZYNQMP) += zynqmp-zcu102-revB.dtb
>>>>>>>>     dtb-$(CONFIG_ARCH_ZYNQMP) += zynqmp-zcu102-rev1.0.dtb
>>>>>>>> +dtb-$(CONFIG_ARCH_ZYNQMP) += zynqmp-zcu102-fpga-update.dtb
>>>>>>>>     dtb-$(CONFIG_ARCH_ZYNQMP) += zynqmp-zcu104-revA.dtb
>>>>>>>>     dtb-$(CONFIG_ARCH_ZYNQMP) += zynqmp-zcu104-revC.dtb
>>>>>>>>     dtb-$(CONFIG_ARCH_ZYNQMP) += zynqmp-zcu106-revA.dtb
>>>>>>>> diff --git
>>>>>>>> a/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-fpga-update.dts
>>>>>>>> b/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-fpga-update.dts
>>>>>>>> new file mode 100644
>>>>>>>> index 000000000000..f1e1506b6210
>>>>>>>> --- /dev/null
>>>>>>>> +++ b/arch/arm64/boot/dts/xilinx/zynqmp-zcu102-fpga-update.dts
>>>>>>>> @@ -0,0 +1,18 @@
>>>>>>>> +// overlay dts file.
>>>>>>>> +/dts-v1/;
>>>>>>>> +/plugin/;
>>>>>>>> +
>>>>>>>> +/ {
>>>>>>>> +    fragment at 0 {
>>>>>>>> +        target-path = "/fpga-full";
>>>>>>>> +        #address-cells = <1>;
>>>>>>>> +        #size-cells = <1>;
>>>>>>>> +
>>>>>>>> +        __overlay__ {
>>>>>>>> +            #address-cells = <2>;
>>>>>>>> +            #size-cells = <2>;
>>>>>>>> +
>>>>>>>> +            firmware-name = "system.bit.bin";
>>>>>>>> +        };
>>>>>>>> +    };
>>>>>>>> +};
>>>>>>>>
>>>>>>> I understand what you want to do but not sure why you think that
>>>>>>> this is
>>>>>>> the best way how to do it.
>>>>>> Hi Michal,
>>>>>>
>>>>>> This patch is based on the url:
>>>>>>
>>>>>> https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18841847/Solution+ZynqMP+PL+Programming#x-Programming+the+PL+through+Linux
>>>>>>
>>>>>>
>>>>>> "FPGA programming using Device Tree Overlay (DTO)".
>>>>>>
>>>>>> We will describe how to programming FPGA by using 2 methods in README
>>>>>> for our customer:
>>>>>>
>>>>>> one is FPGA programming using sysfs attributes
>>>>>> <https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18841847/Solution+ZynqMP+PL+Programming#SolutionZynqMPPLProgramming-FPGAprogrammingusingsysfsattributes>
>>>>>>
>>>>>>
>>>>>> And the other is FPGA programming using Device Tree Overlay (DTO)
>>>>>> <https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18841847/Solution+ZynqMP+PL+Programming#SolutionZynqMPPLProgramming-FPGAprogrammingusingDeviceTreeOverlay(DTO)>
>>>>>>
>>>>>>
>>>>>> This patch is used for the second method.
>>>>>>
>>>>>> Is there any better way to do it?
>>>>>>
>>>>> It is not about that using fragments is incorrect. It is about reasons
>>>>> to include this dts file to Linux source code. Because this fragment is
>>>>> just doing programming without anything else. It means it is coupled
>>>>> with also description what it is in DT which is missing here.
>>>>> It means this is just part A (with system.bit.bin generic name - which
>>>>> is not fully accurate) and part B is missing.
>>>>> In part B there should be what you are including with clock/reset and IP
>>>>> part.
>>>>> That's why my question remains if make even sense to merge part A
>>>>> without any details about part B.
>>>> Hi Michal,
>>>>
>>>> The target for this patch is to just simply test the FPGA programming
>>>> function. So it changes nothing.
>>>>
>>>> It seems to be improper to add such a dts file to kernel source.
>>>>
>>>> I will transform the dts file to a text description in README or make it
>>>> to be a more detailed and integral dts file in a V2 patch.
>>> ok. let's see where you want to add this readme. If this targets
>>> "Documentation" folder then not a problem at all.
>> Hi Michal,
>>
>> Sorry for making you confuse. The README which I said about is not in
>> kernel source but in WRLinux project.
>>
>> I mean that maybe I can just describe how to test FPGA programming in
>> some place of our own Product Document
> Just confirming that I'll drop this patch from my pending queue, since
> either this is going to be in documentation or somewhere else in the
> dts.

Hi Bruce,

Yes, please drop this patch.

Thanks,

Quanyang

>
> Cheers,
>
> Bruce
>
>> instead of adding a dts file to kernel source since it's just a simple
>> testcase.
>>
>> Thanks,
>>
>> Quanyang
>>
>>> M
>
>