imx: thermal: imx_get_temp might be called before sensor clock is prepared
imx_get_temp might be called before the sensor clock is prepared
thus resulting in a timeout of the first attempt to read temp:
thermal thermal_zone0: failed to read out thermal zone 0
Happened to me on a Utilite Standard with IMX6 Dual SoC.
Reason is that in imx_thermal_probe thermal_zone_device_register
is called before the sensor clock is prepared.
thermal_zone_device_register however calls
thermal_zone_device_update which eventually calls imx_get_temp.
Fix this by preparing the clock before calling
thermal_zone_device_register.
Signed-off-by: Heiner Kallweit <heiner.kallweit@web.de>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
index 0e35999..5a1f107 100644
--- a/drivers/thermal/imx_thermal.c
+++ b/drivers/thermal/imx_thermal.c
@@ -525,6 +525,30 @@
return ret;
}
+ data->thermal_clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(data->thermal_clk)) {
+ ret = PTR_ERR(data->thermal_clk);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev,
+ "failed to get thermal clk: %d\n", ret);
+ cpufreq_cooling_unregister(data->cdev);
+ return ret;
+ }
+
+ /*
+ * Thermal sensor needs clk on to get correct value, normally
+ * we should enable its clk before taking measurement and disable
+ * clk after measurement is done, but if alarm function is enabled,
+ * hardware will auto measure the temperature periodically, so we
+ * need to keep the clk always on for alarm function.
+ */
+ ret = clk_prepare_enable(data->thermal_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
+ cpufreq_cooling_unregister(data->cdev);
+ return ret;
+ }
+
data->tz = thermal_zone_device_register("imx_thermal_zone",
IMX_TRIP_NUM,
BIT(IMX_TRIP_PASSIVE), data,
@@ -535,26 +559,11 @@
ret = PTR_ERR(data->tz);
dev_err(&pdev->dev,
"failed to register thermal zone device %d\n", ret);
+ clk_disable_unprepare(data->thermal_clk);
cpufreq_cooling_unregister(data->cdev);
return ret;
}
- data->thermal_clk = devm_clk_get(&pdev->dev, NULL);
- if (IS_ERR(data->thermal_clk)) {
- dev_warn(&pdev->dev, "failed to get thermal clk!\n");
- } else {
- /*
- * Thermal sensor needs clk on to get correct value, normally
- * we should enable its clk before taking measurement and disable
- * clk after measurement is done, but if alarm function is enabled,
- * hardware will auto measure the temperature periodically, so we
- * need to keep the clk always on for alarm function.
- */
- ret = clk_prepare_enable(data->thermal_clk);
- if (ret)
- dev_warn(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
- }
-
/* Enable measurements at ~ 10 Hz */
regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
measure_freq = DIV_ROUND_UP(32768, 10); /* 10 Hz */