thermal/drivers/exynos: Split initialization of TMU and the thermal zone

This will be needed in the future, as the thermal zone subsystem might
call our callbacks right after devm_thermal_of_zone_register. Currently
we just make get_temp return EAGAIN in such case, but this will not be
possible with state-modifying callbacks, for instance set_trips.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Mateusz Majewski <m.majewski2@samsung.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20231201095625.301884-8-m.majewski2@samsung.com

drivers/thermal/samsung/exynos_tmu.c

@@ -251,18 +251,47 @@ static void sanitize_temp_error(struct exynos_tmu_data *data, u32 trim_info)
 static int exynos_tmu_initialize(struct platform_device *pdev)
 {
 	struct exynos_tmu_data *data = platform_get_drvdata(pdev);
-	struct thermal_zone_device *tzd = data->tzd;
-	int num_trips = thermal_zone_get_num_trips(tzd);
 	unsigned int status;
+	int ret = 0;
+
+	mutex_lock(&data->lock);
+	clk_enable(data->clk);
+	if (!IS_ERR(data->clk_sec))
+		clk_enable(data->clk_sec);
+
+	status = readb(data->base + EXYNOS_TMU_REG_STATUS);
+	if (!status) {
+		ret = -EBUSY;
+	} else {
+		data->tmu_initialize(pdev);
+		data->tmu_clear_irqs(data);
+	}
+
+	if (!IS_ERR(data->clk_sec))
+		clk_disable(data->clk_sec);
+	clk_disable(data->clk);
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int exynos_thermal_zone_configure(struct platform_device *pdev)
+{
+	struct exynos_tmu_data *data = platform_get_drvdata(pdev);
+	struct thermal_zone_device *tzd = data->tzd;
+	int i, num_trips = thermal_zone_get_num_trips(tzd);
 	int ret = 0, temp;
 
 	ret = thermal_zone_get_crit_temp(tzd, &temp);
+
 	if (ret && data->soc != SOC_ARCH_EXYNOS5433) { /* FIXME */
 		dev_err(&pdev->dev,
 			"No CRITICAL trip point defined in device tree!\n");
 		goto out;
 	}
 
+	mutex_lock(&data->lock);
+
 	if (num_trips > data->ntrip) {
 		dev_info(&pdev->dev,
 			 "More trip points than supported by this TMU.\n");
@@ -271,41 +300,26 @@ static int exynos_tmu_initialize(struct platform_device *pdev)
 			 num_trips - data->ntrip);
 	}
 
-	mutex_lock(&data->lock);
 	clk_enable(data->clk);
-	if (!IS_ERR(data->clk_sec))
-		clk_enable(data->clk_sec);
-
-	status = readb(data->base + EXYNOS_TMU_REG_STATUS);
-	if (!status) {
-		ret = -EBUSY;
-	} else {
-		int i, ntrips =
-			min_t(int, num_trips, data->ntrip);
-
-		data->tmu_initialize(pdev);
 
-		/* Write temperature code for rising and falling threshold */
-		for (i = 0; i < ntrips; i++) {
+	num_trips = min_t(int, num_trips, data->ntrip);
 
-			struct thermal_trip trip;
+	/* Write temperature code for rising and falling threshold */
+	for (i = 0; i < num_trips; i++) {
+		struct thermal_trip trip;
 
-			ret = thermal_zone_get_trip(tzd, i, &trip);
-			if (ret)
-				goto err;
+		ret = thermal_zone_get_trip(tzd, i, &trip);
+		if (ret)
+			goto err;
 
-			data->tmu_set_trip_temp(data, i, trip.temperature / MCELSIUS);
-			data->tmu_set_trip_hyst(data, i, trip.temperature / MCELSIUS,
-						trip.hysteresis / MCELSIUS);
-		}
-
-		data->tmu_clear_irqs(data);
+		data->tmu_set_trip_temp(data, i, trip.temperature / MCELSIUS);
+		data->tmu_set_trip_hyst(data, i, trip.temperature / MCELSIUS,
+					trip.hysteresis / MCELSIUS);
 	}
+
 err:
 	clk_disable(data->clk);
 	mutex_unlock(&data->lock);
-	if (!IS_ERR(data->clk_sec))
-		clk_disable(data->clk_sec);
 out:
 	return ret;
 }
@@ -1044,10 +1058,12 @@ static int exynos_tmu_probe(struct platform_device *pdev)
 		break;
 	}
 
-	/*
-	 * data->tzd must be registered before calling exynos_tmu_initialize(),
-	 * requesting irq and calling exynos_tmu_control().
-	 */
+	ret = exynos_tmu_initialize(pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to initialize TMU\n");
+		goto err_sclk;
+	}
+
 	data->tzd = devm_thermal_of_zone_register(&pdev->dev, 0, data,
 						  &exynos_sensor_ops);
 	if (IS_ERR(data->tzd)) {
@@ -1058,9 +1074,9 @@ static int exynos_tmu_probe(struct platform_device *pdev)
 		goto err_sclk;
 	}
 
-	ret = exynos_tmu_initialize(pdev);
+	ret = exynos_thermal_zone_configure(pdev);
 	if (ret) {
-		dev_err(&pdev->dev, "Failed to initialize TMU\n");
+		dev_err(&pdev->dev, "Failed to configure the thermal zone\n");
 		goto err_sclk;
 	}