linux-kernel - [PATCH 04/11] thermal: exynos: remove fine-grained clk management

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Message-ID: <20230829091853.626011-5-m.majewski2@samsung.com>
Date:   Tue, 29 Aug 2023 11:18:42 +0200
From:   Mateusz Majewski <m.majewski2@...sung.com>
To:     devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-pm@...r.kernel.org
Cc:     Mateusz Majewski <m.majewski2@...sung.com>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Alim Akhtar <alim.akhtar@...sung.com>,
        Bartlomiej Zolnierkiewicz <bzolnier@...il.com>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Amit Kucheria <amitk@...nel.org>,
        Zhang Rui <rui.zhang@...el.com>,
        Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>,
        Marek Szyprowski <m.szyprowski@...sung.com>
Subject: [PATCH 04/11] thermal: exynos: remove fine-grained clk management

This clock only controls the register operations. The gain in power
efficiency is therefore quite dubious, while there is price of added
complexity that is important to get right (as a register operation might
outright hang the CPU if the clock is not enabled).

Signed-off-by: Mateusz Majewski <m.majewski2@...sung.com>
---
 drivers/thermal/samsung/exynos_tmu.c | 25 +++----------------------
 1 file changed, 3 insertions(+), 22 deletions(-)

diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
index 35b0a55017ad..2c5501704911 100644
--- a/drivers/thermal/samsung/exynos_tmu.c
+++ b/drivers/thermal/samsung/exynos_tmu.c
@@ -275,7 +275,6 @@ static int exynos_tmu_initialize(struct platform_device *pdev)
 	}
 
 	mutex_lock(&data->lock);
-	clk_enable(data->clk);
 	if (!IS_ERR(data->clk_sec))
 		clk_enable(data->clk_sec);
 
@@ -305,7 +304,6 @@ static int exynos_tmu_initialize(struct platform_device *pdev)
 		data->tmu_clear_irqs(data);
 	}
 err:
-	clk_disable(data->clk);
 	mutex_unlock(&data->lock);
 	if (!IS_ERR(data->clk_sec))
 		clk_disable(data->clk_sec);
@@ -336,10 +334,8 @@ static void exynos_tmu_control(struct platform_device *pdev, bool on)
 	struct exynos_tmu_data *data = platform_get_drvdata(pdev);
 
 	mutex_lock(&data->lock);
-	clk_enable(data->clk);
 	data->tmu_control(pdev, on);
 	data->enabled = on;
-	clk_disable(data->clk);
 	mutex_unlock(&data->lock);
 }
 
@@ -654,7 +650,6 @@ static int exynos_get_temp(struct thermal_zone_device *tz, int *temp)
 		return -EAGAIN;
 
 	mutex_lock(&data->lock);
-	clk_enable(data->clk);
 
 	value = data->tmu_read(data);
 	if (value < 0)
@@ -662,7 +657,6 @@ static int exynos_get_temp(struct thermal_zone_device *tz, int *temp)
 	else
 		*temp = code_to_temp(data, value) * MCELSIUS;
 
-	clk_disable(data->clk);
 	mutex_unlock(&data->lock);
 
 	return ret;
@@ -729,9 +723,7 @@ static int exynos_tmu_set_emulation(struct thermal_zone_device *tz, int temp)
 		goto out;
 
 	mutex_lock(&data->lock);
-	clk_enable(data->clk);
 	data->tmu_set_emulation(data, temp);
-	clk_disable(data->clk);
 	mutex_unlock(&data->lock);
 	return 0;
 out:
@@ -769,12 +761,10 @@ static irqreturn_t exynos_tmu_threaded_irq(int irq, void *id)
 	thermal_zone_device_update(data->tzd, THERMAL_EVENT_UNSPECIFIED);
 
 	mutex_lock(&data->lock);
-	clk_enable(data->clk);
 
 	/* TODO: take action based on particular interrupt */
 	data->tmu_clear_irqs(data);
 
-	clk_disable(data->clk);
 	mutex_unlock(&data->lock);
 
 	return IRQ_HANDLED;
@@ -1012,7 +1002,7 @@ static int exynos_tmu_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_sensor;
 
-	data->clk = devm_clk_get(&pdev->dev, "tmu_apbif");
+	data->clk = devm_clk_get_enabled(&pdev->dev, "tmu_apbif");
 	if (IS_ERR(data->clk)) {
 		dev_err(&pdev->dev, "Failed to get clock\n");
 		ret = PTR_ERR(data->clk);
@@ -1034,12 +1024,6 @@ static int exynos_tmu_probe(struct platform_device *pdev)
 		}
 	}
 
-	ret = clk_prepare(data->clk);
-	if (ret) {
-		dev_err(&pdev->dev, "Failed to get clock\n");
-		goto err_clk_sec;
-	}
-
 	switch (data->soc) {
 	case SOC_ARCH_EXYNOS5433:
 	case SOC_ARCH_EXYNOS7:
@@ -1047,12 +1031,12 @@ static int exynos_tmu_probe(struct platform_device *pdev)
 		if (IS_ERR(data->sclk)) {
 			dev_err(&pdev->dev, "Failed to get sclk\n");
 			ret = PTR_ERR(data->sclk);
-			goto err_clk;
+			goto err_clk_sec;
 		} else {
 			ret = clk_prepare_enable(data->sclk);
 			if (ret) {
 				dev_err(&pdev->dev, "Failed to enable sclk\n");
-				goto err_clk;
+				goto err_clk_sec;
 			}
 		}
 		break;
@@ -1094,8 +1078,6 @@ static int exynos_tmu_probe(struct platform_device *pdev)
 
 err_sclk:
 	clk_disable_unprepare(data->sclk);
-err_clk:
-	clk_unprepare(data->clk);
 err_clk_sec:
 	if (!IS_ERR(data->clk_sec))
 		clk_unprepare(data->clk_sec);
@@ -1113,7 +1095,6 @@ static int exynos_tmu_remove(struct platform_device *pdev)
 	exynos_tmu_control(pdev, false);
 
 	clk_disable_unprepare(data->sclk);
-	clk_unprepare(data->clk);
 	if (!IS_ERR(data->clk_sec))
 		clk_unprepare(data->clk_sec);
 
-- 
2.41.0