linux-kernel - Re: [RRC v1 1/3] thermal/drivers/exynos: Remove unused base

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Message-ID: <20250625143816.1146123-1-m.majewski2@samsung.com>
Date: Wed, 25 Jun 2025 16:38:16 +0200
From: Mateusz Majewski <m.majewski2@...sung.com>
To: linux.amoon@...il.com
Cc: alim.akhtar@...sung.com, bzolnier@...il.com, daniel.lezcano@...aro.org,
	krzk@...nel.org, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
	linux-samsung-soc@...r.kernel.org, lukasz.luba@....com,
	m.majewski2@...sung.com, rafael@...nel.org, rui.zhang@...el.com
Subject: Re: [RRC v1 1/3] thermal/drivers/exynos: Remove unused base_second
 mapping and references

> Can you check with with following changes
> 
> diff --git a/drivers/thermal/samsung/exynos_tmu.c
> b/drivers/thermal/samsung/exynos_tmu.c
> index 9fc085f4ea1a..0776801fafea 100644
> --- a/drivers/thermal/samsung/exynos_tmu.c
> +++ b/drivers/thermal/samsung/exynos_tmu.c
> @@ -469,14 +469,11 @@ static void exynos4412_tmu_initialize(struct
> platform_device *pdev)
>         ctrl = readl(data->base + EXYNOS_TMU_TRIMINFO_CON2);
>         ctrl = EXYNOS_TRIMINFO_RELOAD_ENABLE;
>         writel(ctrl, data->base + EXYNOS_TMU_TRIMINFO_CON2);
> +       return;
>     }
> 
> -   /* On exynos5420 the triminfo register is in the shared space */
> -   if (data->soc == SOC_ARCH_EXYNOS5420
> -           data->soc == SOC_ARCH_EXYNOS5420_TRIMINFO) {
> -       trim_info = readl(data->base + EXYNOS_TMU_REG_TRIMINFO);
> -       sanitize_temp_error(data, trim_info);
> -   }
> +   trim_info = readl(data->base + EXYNOS_TMU_REG_TRIMINFO);
> +   sanitize_temp_error(data, trim_info);
> }

This does seem to work (tested on 3250 and on 5420) in the sense that I
can read the temperatures, when they increase the state of the cooling
device gets increased, and the values look reasonable and stay in a
reasonable range. Hard to say if the trim and the temperature values are
correct, though.

(FYI I will probably have a harder time regarding the drivers from
GitHub you linked in 2/3, so no promises on testing them.)

> As per my Exynos5422 user manual and DTS mapping
> thermal-sensor tmu@...60000 is mapped to CPU0 with tmu_apbif clock
> thermal-sensor tmu@...64000 is mapped to CPU1 with tmu_apbif clock
> thermal-sensor tmu@...68000 is mapped to CPU2 with tmu_apbif clock
> thermal-sensor tmu@...6c000 is mapped to CPU3 with tmu_apbif clock
> thermal-sensor tmu@...a0000 is mapped to GPU with tmu_triminfo_apbif clock.

Hmm, I might be missing something, but I think the DTS does link to two
adresses and two clocks, for instance for GPU (in
arch/arm/boot/dts/samsung/exynos5420.dtsi):

		tmu_gpu: tmu@...a0000 {
			compatible = "samsung,exynos5420-tmu-ext-triminfo";
			reg = <0x100a0000 0x100>, <0x10068000 0x4>;
			interrupts = <GIC_SPI 215 IRQ_TYPE_LEVEL_HIGH>;
			clocks = <&clock CLK_TMU_GPU>, <&clock CLK_TMU>;
			clock-names = "tmu_apbif", "tmu_triminfo_apbif";
			#thermal-sensor-cells = <0>;
		};

The manual does indeed not say anything about this, but I feel like the
current code in essence states that the manual is not correct. We
probably should have some evidence that the current code is wrong and
the manual was correct all along?

Thank you,
Mateusz Majewski