[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <1394848790.1570451.1709735361852.JavaMail.zimbra@savoirfairelinux.com>
Date: Wed, 6 Mar 2024 09:29:21 -0500 (EST)
From: Charles Perry <charles.perry@...oirfairelinux.com>
To: Xu Yilun <yilun.xu@...ux.intel.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
yilun xu <yilun.xu@...el.com>, Rob Herring <robh+dt@...nel.org>,
mdf <mdf@...nel.org>, Allen VANDIVER <avandiver@...kem-imaje.com>,
Brian CODY <bcody@...kem-imaje.com>, hao wu <hao.wu@...el.com>,
Tom Rix <trix@...hat.com>,
krzysztof kozlowski+dt <krzysztof.kozlowski+dt@...aro.org>,
Conor Dooley <conor+dt@...nel.org>,
Michal Simek <michal.simek@....com>,
linux-fpga <linux-fpga@...r.kernel.org>,
devicetree <devicetree@...r.kernel.org>,
linux-kernel <linux-kernel@...r.kernel.org>,
linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v4 2/3] dt-bindings: fpga: xlnx,fpga-selectmap: add DT
schema
----- On Mar 6, 2024, at 12:10 AM, Xu Yilun yilun.xu@...ux.intel.com wrote:
> On Mon, Mar 04, 2024 at 09:27:04PM -0500, Charles Perry wrote:
>>
>>
>> On Mar 4, 2024, at 12:31 AM, Krzysztof Kozlowski krzysztof.kozlowski@...aro.org
>> wrote:
>>
>> > On 04/03/2024 08:30, Krzysztof Kozlowski wrote:
>> >> On 03/03/2024 18:21, Charles Perry wrote:
>> >>> On Feb 27, 2024, at 3:10 AM, Krzysztof Kozlowski krzysztof.kozlowski@...aro.org
>> >>> wrote:
>> >>>
>> >>>> On 21/02/2024 20:50, Charles Perry wrote:
>> >>>>> Document the SelectMAP interface of Xilinx 7 series FPGA.
>> >>>>>
>> >>>>> Signed-off-by: Charles Perry <charles.perry@...oirfairelinux.com>
>> >>>>> ---
>> >>>>> .../bindings/fpga/xlnx,fpga-selectmap.yaml | 86 +++++++++++++++++++
>> >>>>> 1 file changed, 86 insertions(+)
>> >>>>> create mode 100644
>> >>>>> Documentation/devicetree/bindings/fpga/xlnx,fpga-selectmap.yaml
>> >>>>>
>> >>>>> diff --git a/Documentation/devicetree/bindings/fpga/xlnx,fpga-selectmap.yaml
>> >>>>> b/Documentation/devicetree/bindings/fpga/xlnx,fpga-selectmap.yaml
>> >>>>> new file mode 100644
>> >>>>> index 0000000000000..08a5e92781657
>> >>>>> --- /dev/null
>> >>>>> +++ b/Documentation/devicetree/bindings/fpga/xlnx,fpga-selectmap.yaml
>> >>>>> @@ -0,0 +1,86 @@
>> >>>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> >>>>> +%YAML 1.2
>> >>>>> +---
>> >>>>> +$id: http://devicetree.org/schemas/fpga/xlnx,fpga-selectmap.yaml#
>> >>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> >>>>> +
>> >>>>> +title: Xilinx SelectMAP FPGA interface
>> >>>>> +
>> >>>>> +maintainers:
>> >>>>> + - Charles Perry <charles.perry@...oirfairelinux.com>
>> >>>>> +
>> >>>>> +description: |
>> >>>>> + Xilinx 7 Series FPGAs support a method of loading the bitstream over a
>> >>>>> + parallel port named the SelectMAP interface in the documentation. Only
>> >>>>> + the x8 mode is supported where data is loaded at one byte per rising edge of
>> >>>>> + the clock, with the MSB of each byte presented to the D0 pin.
>> >>>>> +
>> >>>>> + Datasheets:
>> >>>>> +
>> >>>>> https://www.xilinx.com/support/documentation/user_guides/ug470_7Series_Config.pdf
>> >>>>> +
>> >>>>> +allOf:
>> >>>>> + - $ref: /schemas/memory-controllers/mc-peripheral-props.yaml#
>> >>>>> +
>> >>>>> +properties:
>> >>>>> + compatible:
>> >>>>> + enum:
>> >>>>> + - xlnx,fpga-xc7s-selectmap
>> >>>>> + - xlnx,fpga-xc7a-selectmap
>> >>>>> + - xlnx,fpga-xc7k-selectmap
>> >>>>> + - xlnx,fpga-xc7v-selectmap
>> >>>>> +
>> >>>>> + reg:
>> >>>>> + description:
>> >>>>> + At least 1 byte of memory mapped IO
>> >>>>> + maxItems: 1
>> >>>>> +
>> >>>>> + prog_b-gpios:
>> >>>>
>> >>>> I commented on this and still see underscore. Nothing in commit msg
>> >>>> explains why this should have underscore. Changelog is also vague -
>> >>>> describes that you brought back underscores, instead of explaining why
>> >>>> you did it.
>> >>>>
>> >>>> So the same comments as usual:
>> >>>>
>> >>>> No underscores in names.
>> >>>>
>> >>>> Best regards,
>> >>>> Krzysztof
>> >>>
>> >>> Hello Krzysztof,
>> >>>
>> >>> Yes, I've gone full circle on that issue. Here's what I tried so far:
>> >>
>> >> And what part of the commit description allows me to understand this?
>> >>
>>
>> I have a changelog in the cover letter:
>> https://lore.kernel.org/all/20240221195058.1281973-1-charles.perry@savoirfairelinux.com/
>>
>> >>>
>> >>> 1) Reuse the same gpio names: Duplicates errors of the past, Krzysztof
>> >>> doesn't like it.
>> >>> 2) Different gpio names for new driver only: Makes the driver code
>> >>> overly complicated, Yilun doesn't like it.
>> >>
>> >> That's a new driver, right? So what is complicated here? You have new
>> >> code and you take prog-b or prog_b?
>> >>
>> >>> 3) Change gpio names for both drivers, deprecate the old names: Makes
>> >>> the DT binding and the driver code overly complicated, Rob doesn't
>> >>> like it.
>> >>
>> >> I don't think I proposed changing existing bindings.
>> >>
>> >>>
>> >>> I think that while the driver code shouldn't be the driving force for
>> >>> the DT spec, it can be a good indication that the spec is unpractical to
>> >>> implement.
>> >>
>> >> What is impractical in implementing this? You just pass either A or B to
>> >> function requesting GPIO. Just choose proper name.
>> >>
>>
>> It's not complicated but it requires more code than if "prog_b" had been
>> used.
>>
>> >>>
>> >>> In this case, there are two interfaces on a chip that uses the same GPIO
>> >>> protocol, it would only make sense that they use the same names, this
>> >>> discards solution #2.
>> >>
>> >> I don't understand this. You have devm_gpiod_get() in your new code. Why
>> >> is it difficult to use different name?
>>
>> Yilun asked to avoid changing the names between the two drivers.
>> First comment in this mail:
>> https://lore.kernel.org/all/Zb9GkY6cMtR+4xOX@yilunxu-OptiPlex-7050/
>>
>> Yilun, let me know if this is something you'd accept as this is a concern
>> for the device tree maintainers.
>
> I agree that deprecated names should not be used for new DT bindings, while
> keeping backward compatibility to exsiting ones, unless there is other
> DT side concern.
>
> I'm also good that the driver adapts to the DT binding change.
>
> What I'm concerned is the driver API:
>
> int xilinx_core_probe(struct xilinx_fpga_core *core, struct device *dev,
> xilinx_write_func write,
> - xilinx_write_one_dummy_byte_func write_one_dummy_byte)
> + xilinx_write_one_dummy_byte_func write_one_dummy_byte,
> + const char *prog_con_id, const char *init_con_id)
>
> You don't have to make every bus driver input the gpio names. The core
> falls back to use old gpio names only for existing devices
> (.compatible = "xlnx,fpga-slave-serial"). Then the issue could be
> solved?
>
> Thanks,
> Yilun
>
Ok, thank you for the guidance.
Regards,
Charles
>>
>> >
>> > And I forgot to emphasize: none of these is mentioned in commit msg, so
>> > for v5 you will get exactly the same complains. And for every other
>> > patch which repeats the same and does not clarify caveats or exceptions.
>> >
>> > Best regards,
>> > Krzysztof
>>
>> Should I keep my changelog in the individual commits? I thought the norm
>> was to put this the cover letter.
>>
>> Regards,
>> Charles
Powered by blists - more mailing lists