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-rw-r--r--Documentation/devicetree/bindings/thermal/imx-thermal.txt4
-rw-r--r--drivers/thermal/imx_thermal.c20
2 files changed, 24 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/thermal/imx-thermal.txt b/Documentation/devicetree/bindings/thermal/imx-thermal.txt
index 541c25e49abf..1f0f67234a91 100644
--- a/Documentation/devicetree/bindings/thermal/imx-thermal.txt
+++ b/Documentation/devicetree/bindings/thermal/imx-thermal.txt
@@ -8,10 +8,14 @@ Required properties:
calibration data, e.g. OCOTP on imx6q. The details about calibration data
can be found in SoC Reference Manual.
+Optional properties:
+- clocks : thermal sensor's clock source.
+
Example:
tempmon {
compatible = "fsl,imx6q-tempmon";
fsl,tempmon = <&anatop>;
fsl,tempmon-data = <&ocotp>;
+ clocks = <&clks 172>;
};
diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
index 77a962f1837b..deab7baeeb72 100644
--- a/drivers/thermal/imx_thermal.c
+++ b/drivers/thermal/imx_thermal.c
@@ -7,6 +7,7 @@
*
*/
+#include <linux/clk.h>
#include <linux/cpu_cooling.h>
#include <linux/cpufreq.h>
#include <linux/delay.h>
@@ -73,6 +74,7 @@ struct imx_thermal_data {
unsigned long last_temp;
bool irq_enabled;
int irq;
+ struct clk *thermal_clk;
};
static void imx_set_alarm_temp(struct imx_thermal_data *data,
@@ -457,6 +459,22 @@ static int imx_thermal_probe(struct platform_device *pdev)
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 */
@@ -478,6 +496,8 @@ static int imx_thermal_remove(struct platform_device *pdev)
/* Disable measurements */
regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
+ if (!IS_ERR(data->thermal_clk))
+ clk_disable_unprepare(data->thermal_clk);
thermal_zone_device_unregister(data->tz);
cpufreq_cooling_unregister(data->cdev);

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