On 21/06/2022 21:26, Dmitry Baryshkov wrote:
> On 21/06/2022 21:56, Krzysztof Kozlowski wrote:
>> The top level qcom,msm-id and qcom,board-id properties are utilized by
>> bootloaders on Qualcomm MSM platforms to determine which device tree
>> should be used and passed to the kernel.
>>
>> The commit b32e592d3c28 ("devicetree: bindings: Document qcom board
>> compatible format") from 2015 was a consensus during discussion about
>> upstreaming qcom,msm-id and qcom,board-id fields. There are however still
>> problems with that consensus:
>> 1. It was reached 7 years ago but it turned out its implementation did
>> not reach all possible products.
>>
>> 2. Initially additional tool (dtbTool) was needed for parsing these
>> fields to create a QCDT image consisting of multiple DTBs, later the
>> bootloaders were improved and they use these qcom,msm-id and
>> qcom,board-id properties directly.
>
> I might be mistaken here. I think it was expected that dtbTool would use
> board compat strings to generate qcom,msm-id and qcom,board-id
> properties. It's not that the bootloaders were improved.
Don't ask me, I am new to this.
https://lore.kernel.org/all/02ab0276-b078-fe66-8596-fcec4378722b@xxxxxxxxxxxxxx/
>
>>
>> 3. Extracting relevant information from the board compatible requires
>> this additional tool (dtbTool), which makes the build process more
>> complicated and not easily reproducible (DTBs are modified after the
>> kernel build).
>>
>> 4. Some versions of Qualcomm bootloaders expect these properties even
>> when booting with a single DTB. The community is stuck with these
>> bootloaders thus they require properties in the DTBs.
>>
>> Since several upstreamed Qualcomm SoC-based boards require these
>> properties to properly boot and the properties are reportedly used by
>> bootloaders, document them.
>>
>> Link: https://lore.kernel.org/r/a3c932d1-a102-ce18-deea-18cbbd05ecab@xxxxxxxxxx/
>> Co-developed-by: Kumar Gala <galak@xxxxxxxxxxxxxx>
>> Signed-off-by: Kumar Gala <galak@xxxxxxxxxxxxxx>
>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
>> ---
>> .../devicetree/bindings/arm/qcom.yaml | 123 ++++++++++++++++++
>> include/dt-bindings/arm/qcom,ids.h | 30 +++++
>> 2 files changed, 153 insertions(+)
>> create mode 100644 include/dt-bindings/arm/qcom,ids.h
>>
>> diff --git a/Documentation/devicetree/bindings/arm/qcom.yaml b/Documentation/devicetree/bindings/arm/qcom.yaml
>> index 6c38c1387afd..05b98cde4653 100644
>> --- a/Documentation/devicetree/bindings/arm/qcom.yaml
>> +++ b/Documentation/devicetree/bindings/arm/qcom.yaml
>> @@ -403,6 +403,129 @@ properties:
>> - qcom,sm8450-qrd
>> - const: qcom,sm8450
>>
>> + # Board compatibles go above
>> +
>> + qcom,msm-id:
>> + $ref: /schemas/types.yaml#/definitions/uint32-matrix
>> + minItems: 1
>> + maxItems: 8
>> + items:
>> + items:
>> + - description: |
>> + MSM chipset ID - an exact match value consisting of three bitfields::
>
> two bitfields
Right, thanks.
>
>> + - bits 0-15 - The unique MSM chipset ID
>> + - bits 16-31 - Reserved; should be 0
>> + - description: |
>> + Hardware revision ID - a chipset specific 32-bit ID representing
>> + the version of the chipset. It is best a match value - the
>> + bootloader will look for the closest possible match.
>> + deprecated: true
>> + description:
>> + The MSM chipset and hardware revision use by Qualcomm bootloaders. It
>> + can optionally be an array of these to indicate multiple hardware that
>> + use the same device tree. It is expected that the bootloader will use
>> + this information at boot-up to decide which device tree to use when given
>> + multiple device trees, some of which may not be compatible with the
>> + actual hardware. It is the bootloader's responsibility to pass the
>> + correct device tree to the kernel.
>> + The property is deprecated - it is not expected on newer boards
>> + (starting with SM8350).
>
> Could you please elaborate this?
Second paragraph:
https://lore.kernel.org/all/20220522195138.35943-1-konrad.dybcio@xxxxxxxxxxxxxx/
Plus consensus with Rob:
https://lore.kernel.org/all/CAL_JsqKL-mtAQ8Q9H4vLGM8izVVzDPbUAVWSdS8AmGjN6X6kcA@xxxxxxxxxxxxxx/
> If the AOSP team were to add e.g.
> SM8350-HDK to their single RB3+RB5 images, they would still need the
> qcom,board-id/qcom,msm-id properties to let the bootloader choose proper
> DTB.
If you have any email addresses in mind, please Cc them to invite in
discussions. Otherwise I am afraid it won't be allowed. The feedback I
got before was that SM8350 and newer do not require this property. Feel
free to propose other way to solve comments (see "consensus with Rob"
above).
>
>> +
>> + qcom,board-id:
>> + $ref: /schemas/types.yaml#/definitions/uint32-matrix
>> + minItems: 1
>> + maxItems: 8
>> + items:
>> + oneOf:
>> + - maxItems: 2
>> + items:
>> + - description: |
>> + Board ID consisting of three bitfields::
>> + - bits 31-24 - Unused
>> + - bits 23-16 - Platform Version Major
>> + - bits 15-8 - Platform Version Minor
>> + - bits 7-0 - Platform Type
>> + Platform Type field is an exact match value. The
>> + Platform Major/Minor field is a best match. The bootloader will
>> + look for the closest possible match.
>> + - description: |
>> + Subtype ID unique to a Platform Type/Chipset ID. For a given
>> + Platform Type, there will typically only be a single board and the
>> + subtype_id will be 0. However in some cases board variants may
>> + need to be distinguished by different subtype_id values.
>> + # OnePlus uses a variant of board-id with four elements:
>> + - minItems: 4
>> + items:
>> + - const: 8
>> + - const: 0
>> + - description: OnePlus board ID
>> + - description: OnePlus subtype ID
>> + deprecated: true
>> + description:
>> + The board type and revision information. It can optionally be an array
>> + of these to indicate multiple boards that use the same device tree. It
>> + is expected that the bootloader will use this information at boot-up to
>> + decide which device tree to use when given multiple device trees, some of
>> + which may not be compatible with the actual hardware. It is the
>> + bootloader's responsibility to pass the correct device tree to the
>> + kernel
>> + The property is deprecated - it is not expected on newer boards
>> + (starting with SM8350).
>> +
>> +allOf:
>> + # Explicit allow-list for older SoCs. The legacy properties are not allowed
>> + # on newer SoCs.
>> + - if:
>> + properties:
>> + compatible:
>> + contains:
>> + enum:
>> + - qcom,apq8026
>> + - qcom,apq8094
>> + - qcom,apq8096
>> + - qcom,msm8992
>> + - qcom,msm8994
>> + - qcom,msm8996
>> + - qcom,msm8998
>> + - qcom,sdm630
>> + - qcom,sdm632
>> + - qcom,sdm845
>> + - qcom,sdx55
>> + - qcom,sdx65
>> + - qcom,sm6125
>> + - qcom,sm6350
>> + - qcom,sm7225
>> + - qcom,sm8150
>> + - qcom,sm8250
>> + then:
>> + properties:
>> + qcom,board-id: true
>> + qcom,msm-id: true
>> + else:
>> + properties:
>> + qcom,board-id: false
>> + qcom,msm-id: false
>> +
>> + - if:
>> + properties:
>> + compatible:
>> + contains:
>> + enum:
>> + - oneplus,cheeseburger
>> + - oneplus,dumpling
>> + - oneplus,enchilada
>> + - oneplus,fajita
>> + then:
>> + properties:
>> + qcom,board-id:
>> + items:
>> + minItems: 4
>> + else:
>> + properties:
>> + qcom,board-id:
>> + items:
>> + maxItems: 2
>> +
>> additionalProperties: true
>>
>> ...
>> diff --git a/include/dt-bindings/arm/qcom,ids.h b/include/dt-bindings/arm/qcom,ids.h
>> new file mode 100644
>> index 000000000000..eaf86c18650f
>> --- /dev/null
>> +++ b/include/dt-bindings/arm/qcom,ids.h
>> @@ -0,0 +1,30 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (c) 2015, The Linux Foundation. All rights reserved.
>> + * Copyright (c) 2022 Linaro Ltd
>> + * Author: Krzysztof Kozlowski <krzk@xxxxxxxxxx> based on previous work of Kumar Gala.
>> + */
>> +#ifndef _DT_BINDINGS_ARM_QCOM_IDS_H
>> +#define _DT_BINDINGS_ARM_QCOM_IDS_H
>> +
>> +/* qcom,msm-id */
>> +#define QCOM_ID_APQ8026 199
>> +#define QCOM_ID_MSM8916 206
>> +#define QCOM_ID_MSM8994 207
>> +#define QCOM_ID_MSM8996_3_0 246
>
> 2_0 too.
> And then (according to 3.18):
> 8996-pro 305
> 8996-pro-auto 315
> 8996-auto 310
Sure, I can add these.
>
>> +#define QCOM_ID_APQ8016 247
>> +#define QCOM_ID_MSM8216 248
>> +#define QCOM_ID_MSM8116 249
>> +#define QCOM_ID_MSM8616 250
>> +#define QCOM_ID_MSM8998 292
>> +#define QCOM_ID_SDM845 321
>
> sdm845-v2.1-rb3.dts: qcom,msm-id = <341 0x20001>;
> But this might be a typo
Yeah, that's an interesting one. I did not fill the list to all possible
options, rather to some subset of more reasonable sources.
>
>> +
>> +/* qcom,board-id */
>> +#define QCOM_BOARD_ID(a, major, minor) \
>> + (((major & 0xff) << 16) | ((minor & 0xff) << 8) | QCOM_BOARD_ID_##a)
>> +
>> +#define QCOM_BOARD_ID_MTP 8
>> +#define QCOM_BOARD_ID_DRAGONBOARD 10
>> +#define QCOM_BOARD_ID_SBC 24
>> +
>> +#endif /* _DT_BINDINGS_ARM_QCOM_IDS_H */
>
>
Best regards,
Krzysztof
