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path: root/drivers/thermal/imx_thermal.c
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Diffstat (limited to 'drivers/thermal/imx_thermal.c')
-rw-r--r--drivers/thermal/imx_thermal.c54
1 files changed, 39 insertions, 15 deletions
diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
index 1d6c801c1eb9..45af765a3198 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,
@@ -284,7 +286,7 @@ static int imx_unbind(struct thermal_zone_device *tz,
return 0;
}
-static const struct thermal_zone_device_ops imx_tz_ops = {
+static struct thermal_zone_device_ops imx_tz_ops = {
.bind = imx_bind,
.unbind = imx_unbind,
.get_temp = imx_get_temp,
@@ -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);
@@ -490,27 +510,30 @@ static int imx_thermal_suspend(struct device *dev)
{
struct imx_thermal_data *data = dev_get_drvdata(dev);
struct regmap *map = data->tempmon;
- u32 val;
- regmap_read(map, TEMPSENSE0, &val);
- if ((val & TEMPSENSE0_POWER_DOWN) == 0) {
- /*
- * If a measurement is taking place, wait for a long enough
- * time for it to finish, and then check again. If it still
- * does not finish, something must go wrong.
- */
- udelay(50);
- regmap_read(map, TEMPSENSE0, &val);
- if ((val & TEMPSENSE0_POWER_DOWN) == 0)
- return -ETIMEDOUT;
- }
+ /*
+ * Need to disable thermal sensor, otherwise, when thermal core
+ * try to get temperature before thermal sensor resume, a wrong
+ * temperature will be read as the thermal sensor is powered
+ * down.
+ */
+ regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
+ regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
+ data->mode = THERMAL_DEVICE_DISABLED;
return 0;
}
static int imx_thermal_resume(struct device *dev)
{
- /* Nothing to do for now */
+ struct imx_thermal_data *data = dev_get_drvdata(dev);
+ struct regmap *map = data->tempmon;
+
+ /* Enabled thermal sensor after resume */
+ regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
+ regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
+ data->mode = THERMAL_DEVICE_ENABLED;
+
return 0;
}
#endif
@@ -522,6 +545,7 @@ static const struct of_device_id of_imx_thermal_match[] = {
{ .compatible = "fsl,imx6q-tempmon", },
{ /* end */ }
};
+MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
static struct platform_driver imx_thermal = {
.driver = {