Message-ID: <CAA8EJprgYM1zqzoJvvUAFbauMLQR0zpvQ93eVY6wzxU5YGvhiw@mail.gmail.com>
Date: Mon, 2 Dec 2024 17:14:42 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: "Cheng Jiang (IOE)" <quic_chejiang@...cinc.com>
Cc: Marcel Holtmann <marcel@...tmann.org>, Luiz Augusto von Dentz <luiz.dentz@...il.com>, 
	Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Bjorn Andersson <andersson@...nel.org>, Konrad Dybcio <konradybcio@...nel.org>, 
	Balakrishna Godavarthi <quic_bgodavar@...cinc.com>, Rocky Liao <quic_rjliao@...cinc.com>, 
	quic_zijuhu@...cinc.com, linux-bluetooth@...r.kernel.org, 
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, 
	linux-arm-msm@...r.kernel.org, quic_mohamull@...cinc.com
Subject: Re: [PATCH v2 1/4] dt-bindings: bluetooth: add 'qcom,product-variant'

On Mon, 2 Dec 2024 at 16:25, Cheng Jiang (IOE)
<quic_chejiang@...cinc.com> wrote:
>
>
>
> On 12/2/2024 7:38 PM, Dmitry Baryshkov wrote:
> > On Mon, Dec 02, 2024 at 10:22:52AM +0800, Cheng Jiang (IOE) wrote:
> >> Hi Dmitry,
> >>
> >> On 11/30/2024 4:24 PM, Dmitry Baryshkov wrote:
> >>> On Sat, 30 Nov 2024 at 05:48, Cheng Jiang (IOE)
> >>> <quic_chejiang@...cinc.com> wrote:
> >>>>
> >>>> Hi Dmitry,
> >>>>
> >>>> On 11/21/2024 12:38 PM, Dmitry Baryshkov wrote:
> >>>>> On Thu, 21 Nov 2024 at 06:02, Cheng Jiang <quic_chejiang@...cinc.com> wrote:
> >>>>>>
> >>>>>> Hi Dmitry,
> >>>>>>
> >>>>>> On 11/20/2024 6:43 PM, Dmitry Baryshkov wrote:
> >>>>>>> On Wed, Nov 20, 2024 at 05:54:25PM +0800, Cheng Jiang wrote:
> >>>>>>>> Several Qualcomm projects will use the same Bluetooth chip, each
> >>>>>>>> focusing on different features. For instance, consumer projects
> >>>>>>>> prioritize the A2DP SRC feature, while IoT projects focus on the A2DP
> >>>>>>>> SINK feature, which may have more optimizations for coexistence when
> >>>>>>>> acting as a SINK. Due to the patch size, it is not feasible to include
> >>>>>>>> all features in a single firmware.
> >>>>>>>>
> >>>>>>>> Therefore, the 'product-variant' devicetree property is used to provide
> >>>>>>>> product information for the Bluetooth driver to load the appropriate
> >>>>>>>> firmware.
> >>>>>>>>
> >>>>>>>> If this property is not defined, the default firmware will be loaded,
> >>>>>>>> ensuring there are no backward compatibility issues with older
> >>>>>>>> devicetrees.
> >>>>>>>>
> >>>>>>>> The product-variant defines like this:
> >>>>>>>>   0 - 15 (16 bits) are product line specific definitions
> >>>>>>>>   16 - 23 (8 bits) are for the product line.
> >>>>>>>>   24 - 31 (8 bits) are reserved for future use, 0 currently
> >>>>>>>
> >>>>>>> Please use text strings instead of encoding this information into random
> >>>>>>> integers and then using just 3 bits out of 32.
> >>>>>> Ack. Originally intended to make it more flexible for future use. It can be
> >>>>>> text strings for current requirement.
> >>>>>
> >>>>> No, fixed-format data isn't flexible. Fine-grained properties are.
> >>>>> Please define exactly what is necessary rather than leaving empty
> >>>>> holes "for future expansion".=
> >>>>>
> >>>>>>>
> >>>>>>>>
> >>>>>>>> |---------------------------------------------------------------------|
> >>>>>>>> |                       32 Bits                                       |
> >>>>>>>> |---------------------------------------------------------------------|
> >>>>>>>> |  31 - 24 (bits)   |    23 - 16 (bits)   | 15 - 0 (16 bits)          |
> >>>>>>>> |---------------------------------------------------------------------|
> >>>>>>>> |   Reserved        |    0: default       | 0: default                |
> >>>>>>>> |                   |    1: CE            |                           |
> >>>>>>>> |                   |    2: IoT           |                           |
> >>>>>>>> |                   |    3: Auto          |                           |
> >>>>>>>> |                   |    4: Reserved      |                           |
> >>>>>>>> |---------------------------------------------------------------------|
> >>>>>>>>
> >>>>>>>> Signed-off-by: Cheng Jiang <quic_chejiang@...cinc.com>
> >>>>>>>> ---
> >>>>>>>>  .../bindings/net/bluetooth/qualcomm-bluetooth.yaml          | 6 ++++++
> >>>>>>>>  1 file changed, 6 insertions(+)
> >>>>>>>>
> >>>>>>>> diff --git a/Documentation/devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml b/Documentation/devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml
> >>>>>>>> index 7bb68311c609..9019fe7bcdc6 100644
> >>>>>>>> --- a/Documentation/devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml
> >>>>>>>> +++ b/Documentation/devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml
> >>>>>>>> @@ -110,6 +110,12 @@ properties:
> >>>>>>>>      description:
> >>>>>>>>        boot firmware is incorrectly passing the address in big-endian order
> >>>>>>>>
> >>>>>>>> +  qcom,product-variant:
> >>>>>>>> +    $ref: /schemas/types.yaml#/definitions/uint32
> >>>>>>>> +    description:
> >>>>>>>> +      specify the product information for driver to load the appropriate firmware
> >>>>>>>
> >>>>>>> DT describes hardware. Is this a hardware property?
> >>>>>>
> >>>>>> It has been added to identify the firmware image for the platform. The driver
> >>>>>> parses it, and then the rampatch is selected from a specify directory. Currently,
> >>>>>> there is a 'firmware-name' parameter, but it is only used to specify the NVM
> >>>>>> (config) file. We also need to specify the rampatch (TLV file).
> >>>>>>
> >>>>>>
> >>>>>> Can we re-use the "firmware-name"? add two segments like the following?
> >>>>>> firmware-name = "rampatch_xx.tlv",  "nvm_xx.bin";
> >>>>>
> >>>>> I think this is the better solution
> >>>>>
> >>>> How about the following logic for handling 'firmware-name' property:
> >>>> 1. If there is only one string in firmware-name, it must be the NVM file, which is used
> >>>>    for backward compatibility.
> >>>>
> >>>> 2. If there are two strings in firmware-name, the first string is for the rampatch, and
> >>>>    the second string is for the NVM.
> >>>
> >>> I'd say, other way around: the first one is always NVM, the second one
> >>> is rampatch and it is optional.
> >>>
> >> OK, Got it.
> >>>>
> >>>> 3. Due to variations in RF performance of chips from different foundries, different NVM
> >>>>    configurations are used based on the board ID. If the second string ends with boardid,
> >>>>    the NVM file will be selected according to the board ID.
> >>>
> >>> Is there a reason why you can not use the exact firmware name? The
> >>> firmware name is a part of the board DT file. I assume you know the
> >>> board ID that has been used for the board.
> >>>
> >> The boardid is the connectivity board's id. NVM is a board specific configuration file,
> >> it's related to the connectivity board. We may attach different connectivity board on the
> >> same platform. For example, we have connectivity boards based on the QCA6698 chipset that
> >> can support either a two-antenna or three-antenna solution. Both boards work fine on the
> >> sa8775p-ride platform.
> >
> > Please add such an info to the commit messages (plural for it being a
> > generic feedback: please describe the reasons for your design
> > decisions),
> >
> Ack.
> > I really don't like the .boardid template. What if we change property
> > behaviour in the following way: if there is no file extension then .bNN
> > will be probed, falling back to .bin. This will require reading board ID
> > for all the platforms that support it (do wcn3990 have board ID?)
> >
> Ack, this proposal is great.
> Yes, We have board ID for each connectivity card. An NVM file maps to it
> if necessary.

The question was about the WiFI generations, not about the NVM cards.
Do wcn3990 also support reading board ID?

>
> Let me provide a new patchset based on this solution. Thank you very much for
> the valuable comments.

:-)

> >>>>
> >>>>
> >>>> Here are two examples:
> >>>>
> >>>>  firmware-name = "qca/QCA6698/hpbtfw21.tlv",  "qca/QCA6698/hpnv21.bin";
> >>>> In this configuration, the driver will use the two files directly.
> >>>>
> >>>>
> >>>>  firmware-name = "qca/QCA6698/hpbtfw21.tlv",  "qca/QCA6698/hpnv21.boardid";
> >>>> In this configuration, the driver will replace boardid with the actual board information.
> >>>> If the board id is 0x0206, the nvm file name will be qca/QCA6698/hpnv21.b0206
> >>>>
> >>>>>>
> >>>>>> Or add a new property to specify the rampatch file?
> >>>>>> rampatch-name = "rampatch_xx.tlv";
> >>>>>>
> >>>>>>>
> >>>>>>>> +
> >>>>>>>> +
> >>>>>>>>  required:
> >>>>>>>>    - compatible
> >>>>>>>>
> >>>>>>>> --
> >>>>>>>> 2.25.1
> >>>>>>>>
> >>>>>>>
> >>>>>>
> >>>>>
> >>>>>
> >>>>
> >>>
> >>> --
> >>> With best wishes
> >>> Dmitry
> >>
> >
>


-- 
With best wishes
Dmitry

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