Re: [PATCH 22/22] arm64: dts: qcom: Add reduced functional DT for SA8255p Ride platform

[Nikunj Kela <quic_nkela@xxxxxxxxxxx>]

On 8/30/2024 2:51 AM, Krzysztof Kozlowski wrote:
> On 29/08/2024 21:06, Nikunj Kela wrote:
>> On 8/29/2024 12:49 AM, Krzysztof Kozlowski wrote:
>>> On 28/08/2024 22:37, Nikunj Kela wrote:
>>>> SA8255p Ride platform is an automotive virtual platform. This platform
>>>> abstracts resources such as clocks, regulators etc. in the firmware VM.
>>>> The device drivers request resources operations over SCMI using power,
>>>> performance, reset and sensor protocols.
>>>>
>>>> Multiple virtual SCMI instances are being employed for greater parallelism.
>>>> These instances are tied to devices such that devices can have dedicated
>>>> SCMI channel. Firmware VM (runs SCMI platform stack) is SMP enabled and
>>>> can process requests from agents in parallel. Qualcomm smc transport is
>>>> used for communication between SCMI agent and platform.
>>>>
>>>> Let's add the reduced functional support for SA8255p Ride board.
>>>> Subsequently, the support for PCIe, USB, UFS, Ethernet will be added.
>>>>
>>>> Co-developed-by: Shazad Hussain <quic_shazhuss@xxxxxxxxxxx>
>>>> Signed-off-by: Shazad Hussain <quic_shazhuss@xxxxxxxxxxx>
>>>> Signed-off-by: Nikunj Kela <quic_nkela@xxxxxxxxxxx>
>>>> ---
>>>>  arch/arm64/boot/dts/qcom/Makefile           |    1 +
>>>>  arch/arm64/boot/dts/qcom/sa8255p-pmics.dtsi |   80 +
>>>>  arch/arm64/boot/dts/qcom/sa8255p-ride.dts   |  149 ++
>>>>  arch/arm64/boot/dts/qcom/sa8255p-scmi.dtsi  | 2312 ++++++++++++++++++
>>>>  arch/arm64/boot/dts/qcom/sa8255p.dtsi       | 2405 +++++++++++++++++++
>>>>  5 files changed, 4947 insertions(+)
>>>>  create mode 100644 arch/arm64/boot/dts/qcom/sa8255p-pmics.dtsi
>>>>  create mode 100644 arch/arm64/boot/dts/qcom/sa8255p-ride.dts
>>>>  create mode 100644 arch/arm64/boot/dts/qcom/sa8255p-scmi.dtsi
>>>>  create mode 100644 arch/arm64/boot/dts/qcom/sa8255p.dtsi
>>>>
>>> ...
>>>
>>>> diff --git a/arch/arm64/boot/dts/qcom/sa8255p-ride.dts b/arch/arm64/boot/dts/qcom/sa8255p-ride.dts
>>>> new file mode 100644
>>>> index 000000000000..1dc03051ad92
>>>> --- /dev/null
>>>> +++ b/arch/arm64/boot/dts/qcom/sa8255p-ride.dts
>>>> @@ -0,0 +1,149 @@
>>>> +// SPDX-License-Identifier: BSD-3-Clause
>>>> +/*
>>>> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
>>>> + */
>>>> +
>>>> +/dts-v1/;
>>>> +
>>>> +#include <dt-bindings/gpio/gpio.h>
>>>> +
>>>> +#include "sa8255p.dtsi"
>>>> +#include "sa8255p-pmics.dtsi"
>>>> +#include "sa8255p-scmi.dtsi"
>>>> +
>>>> +/ {
>>>> +	model = "Qualcomm Technologies, Inc. SA8255P Ride";
>>>> +	compatible = "qcom,sa8255p-ride", "qcom,sa8255p";
>>>> +
>>>> +	aliases {
>>>> +		i2c11 = &i2c11;
>>>> +		i2c18 = &i2c18;
>>>> +		serial0 = &uart10;
>>>> +		serial1 = &uart4;
>>>> +		spi16 = &spi16;
>>>> +		scmichannels = &scmichannels;
>>> Nothing parses this.
>>>
>> We are using this alias in bootloader to speed up the parsing. Since we
> Then please provide link to the bindings in this open-source upstream
> bootloader.
>
> Otherwise it is a clear no-go for me. We don't add properties because
> some downstream wants them. Imagine what would happen if we opened that
> can of worms...

Point taken! I will remove this alias and label from DT in next version.
We can add it back if/once the bootloader changes are upstreamed. Thanks!


>> are using 64 SCMI instances and SCMI smc transport driver for
>> Qualcomm(drivers/firmware/arm_scmi/transports/smc.c) expects
>> cap-id(created by hypervisor at boot time), our bootloader gets those
>> cap-id for each channel and populate them. This alias is an optimization
>> to save boottime as in automotive, boot KPIs are critical.
> I will refrain about commenting on KPIs...
>
>
>
> Best regards,
> Krzysztof
>