thermal: exynos: Fix first temperature read after registering sensor

Thermal core could not read the temperature after registering the
thermal sensor with thermal_zone_of_sensor_register() because the driver
was not yet initialized.

The call trace looked like:
    exynos_tmu_probe()
        thermal_zone_of_sensor_register()
            of_thermal_set_mode()
                thermal_zone_device_update()
                    exynos_get_temp()
                        if (!data->tmu_read) return -EINVAL;
        exynos_map_dt_data()
            data->tmu_read = ...

This produced an error in dmesg:
thermal thermal_zone0: failed to read out thermal zone (-22)

Register the thermal_zone_device later, after parsing Device Tree and
enabling necessary clocks, but before calling exynos_tmu_initialize()
which uses the registered thermal_zone_device.

Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Fixes: 3b6a1a805f34 ("thermal: samsung: core: Exynos TMU rework to use device tree for configuration")
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

1 files changed, 17 insertions, 10 deletions

diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
index 23f4320f8ef7..bc71a61f0c4a 100644
--- a/drivers/thermal/samsung/exynos_tmu.c
+++ b/drivers/thermal/samsung/exynos_tmu.c
@@ -1289,13 +1289,6 @@ static int exynos_tmu_probe(struct platform_device *pdev)
         platform_set_drvdata(pdev, data);
         mutex_init(&data->lock);
 
-        data->tzd = thermal_zone_of_sensor_register(&pdev->dev, 0, data,
-                                                    &exynos_sensor_ops);
-        if (IS_ERR(data->tzd)) {
-                pr_err("thermal: tz: %p ERROR\n", data->tzd);
-                return PTR_ERR(data->tzd);
-        }
-
         /*
          * Try enabling the regulator if found
          * TODO: Add regulator as an SOC feature, so that regulator enable
@@ -1365,21 +1358,36 @@ 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().
+         */
+        data->tzd = thermal_zone_of_sensor_register(&pdev->dev, 0, data,
+                                                    &exynos_sensor_ops);
+        if (IS_ERR(data->tzd)) {
+                ret = PTR_ERR(data->tzd);
+                dev_err(&pdev->dev, "Failed to register sensor: %d\n", ret);
+                goto err_sclk;
+        }
+
         ret = exynos_tmu_initialize(pdev);
         if (ret) {
                 dev_err(&pdev->dev, "Failed to initialize TMU\n");
-                goto err_sclk;
+                goto err_thermal;
         }
 
         ret = devm_request_irq(&pdev->dev, data->irq, exynos_tmu_irq,
                 IRQF_TRIGGER_RISING | IRQF_SHARED, dev_name(&pdev->dev), data);
         if (ret) {
                 dev_err(&pdev->dev, "Failed to request irq: %d\n", data->irq);
-                goto err_sclk;
+                goto err_thermal;
         }
 
         exynos_tmu_control(pdev, true);
         return 0;
+
+err_thermal:
+        thermal_zone_of_sensor_unregister(&pdev->dev, data->tzd);
 err_sclk:
         clk_disable_unprepare(data->sclk);
 err_clk:
@@ -1390,7 +1398,6 @@ err_clk_sec:
 err_sensor:
         if (!IS_ERR_OR_NULL(data->regulator))
                 regulator_disable(data->regulator);
-        thermal_zone_of_sensor_unregister(&pdev->dev, data->tzd);
 
         return ret;
 }