linux-kernel - Re: [PATCH v6 0/4] Exynos Thermal code improvement

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Message-ID: <92c2949e-2fc1-40e9-9dea-e3d9f7aa571d@linaro.org>
Date: Thu, 15 May 2025 15:28:55 +0200
From: Daniel Lezcano <daniel.lezcano@...aro.org>
To: Anand Moon <linux.amoon@...il.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@...il.com>,
 Krzysztof Kozlowski <krzk@...nel.org>, "Rafael J. Wysocki"
 <rafael@...nel.org>, Zhang Rui <rui.zhang@...el.com>,
 Lukasz Luba <lukasz.luba@....com>, Alim Akhtar <alim.akhtar@...sung.com>,
 Nathan Chancellor <nathan@...nel.org>,
 Nick Desaulniers <nick.desaulniers+lkml@...il.com>,
 Bill Wendling <morbo@...gle.com>, Justin Stitt <justinstitt@...gle.com>,
 "open list:SAMSUNG THERMAL DRIVER" <linux-pm@...r.kernel.org>,
 "open list:SAMSUNG THERMAL DRIVER" <linux-samsung-soc@...r.kernel.org>,
 "moderated list:ARM/SAMSUNG S3C, S5P AND EXYNOS ARM ARCHITECTURES"
 <linux-arm-kernel@...ts.infradead.org>,
 open list <linux-kernel@...r.kernel.org>,
 "open list:CLANG/LLVM BUILD SUPPORT:Keyword:b(?i:clang|llvm)b"
 <llvm@...ts.linux.dev>
Subject: Re: [PATCH v6 0/4] Exynos Thermal code improvement

On 5/15/25 13:10, Anand Moon wrote:
> Hi Daniel,
> 
> On Wed, 14 May 2025 at 16:53, Daniel Lezcano <daniel.lezcano@...aro.org> wrote:
>>
>> On Wed, Apr 30, 2025 at 06:02:56PM +0530, Anand Moon wrote:
>>> Hi All,
>>
>> Hi Anand,
>>
>> if the goal of the changes is to do cleanups, I recommend to rework
>> how the code is organized. Instead of having the data->soc check all
>> around the functions, write per platform functions and store them in
>> struct of_device_id data field instead of the soc version.
>>
>> Basically get rid of exynos_map_dt_data by settings the different ops
>> in a per platform structure.
>>
>> Then the initialization routine would be simpler to clean.
>>
> 
> Thanks, I had previously attempted this approach.
> The goal is to split the exynos_tmu_data structure to accommodate
> SoC-specific callbacks for initialization and configuration.
> 
> In my earlier attempt, I tried to refactor the code to achieve this.
> However, the main challenge I encountered was that the
> exynos_sensor_ops weren’t being correctly mapped for each SoC.
> 
> Some SoC have multiple sensor
> exynos4x12
>                      tmu: tmu@...c0000
> exynos5420
>                  tmu_cpu0: tmu@...60000
>                  tmu_cpu1: tmu@...64000
>                  tmu_cpu2: tmu@...68000
>                  tmu_cpu3: tmu@...6c000
>                  tmu_gpu: tmu@...a0000
>   exynos5433
>                  tmu_atlas0: tmu@...60000
>                  tmu_atlas1: tmu@...68000
>                  tmu_g3d: tmu@...70000
> exynos7
>                  tmu@...60000
> 
> It could be a design issue of the structure.or some DTS issue.
> So what I found in debugging it is not working correctly.
> 
> static const struct thermal_zone_device_ops exynos_sensor_ops = {
>          .get_temp = exynos_get_temp,
>          .set_emul_temp = exynos_tmu_set_emulation,
>          .set_trips = exynos_set_trips,
> };
> 
> The sensor callback will not return a valid pointer and soc id for the get_temp.
> 
> Here is my earlier version of local changes.
> [1] https://pastebin.com/bbEP04Zh exynos_tmu.c
> [2] https://pastebin.com/PzNz5yve Odroid U3 dmesg.log
> [3] https://pastebin.com/4Yjt2d2u    Odroid Xu4 dmesg.log
> 
> I want to re-model the structure to improve the code.
> Once Its working condition I will send this for review.
> 
> If you have some suggestions please let me know.

I suggest to do the conversion step by step beginning by 
exynos4210_tmu_clear_irqs, then by exynos_map_dt_data as the first 
cleanup iteration


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