Re: [PATCH v2 1/4] dt-bindings: bluetooth: add 'qcom,product-variant'

[Cheng Jiang (IOE)]

Hi Dmitry,

On 12/2/2024 11:14 PM, Dmitry Baryshkov wrote:
> On Mon, 2 Dec 2024 at 16:25, Cheng Jiang (IOE)
> <quic_chejiang@xxxxxxxxxxx> 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@xxxxxxxxxxx> 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@xxxxxxxxxxx> 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@xxxxxxxxxxx>
>>>>>>>>>> ---
>>>>>>>>>>  .../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?
> 
WCN3990 supports reading board id. However, the board ID is only associated with
the connectivity board, not the chipset itself. From a Bluetooth perspective,
all WCN3990 connectivity boards use the same NVM file.

>>
>> 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
>>>>
>>>
>>
> 
>