On 08/26/2014 03:12 AM, Chanwoo Choi wrote:
Hi Jonghwa,
On 08/26/2014 02:33 PM, Jonghwa Lee wrote:
To get more comprehensive and integrated thermal management, it adds ntc
thermistor to thermal framework as a thermal sensor. It's governed thermal
susbsystem only if it is described in DT node. Otherwise, it just notifies
temperature to userspace via sysfs as it used to be.
Signed-off-by: Jonghwa Lee <jonghwa3....@samsung.com>
---
.../devicetree/bindings/hwmon/ntc_thermistor.txt | 3 +++
drivers/hwmon/ntc_thermistor.c | 26 ++++++++++++++++++++
2 files changed, 29 insertions(+)
diff --git a/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
b/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
index 2391e5c..fcca8e7 100644
--- a/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
+++ b/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
@@ -25,6 +25,9 @@ Requires node properties:
- "io-channels" Channel node of ADC to be used for
conversion.
+Optional node properties:
+- "#thermal-sensor-cells" Used to expose itself to thermal fw.
+
Read more about iio bindings at
Documentation/devicetree/bindings/iio/iio-bindings.txt
diff --git a/drivers/hwmon/ntc_thermistor.c b/drivers/hwmon/ntc_thermistor.c
index bd41072..369dc8c 100644
--- a/drivers/hwmon/ntc_thermistor.c
+++ b/drivers/hwmon/ntc_thermistor.c
@@ -38,6 +38,7 @@
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
+#include <linux/thermal.h>
struct ntc_compensation {
int temp_c;
@@ -182,6 +183,7 @@ struct ntc_data {
struct device *dev;
int n_comp;
char name[PLATFORM_NAME_SIZE];
+ struct thermal_zone_device *tz;
};
#if defined(CONFIG_OF) && IS_ENABLED(CONFIG_IIO)
@@ -428,6 +430,20 @@ static int ntc_thermistor_get_ohm(struct ntc_data *data)
return -EINVAL;
}
+static int ntc_read_temp(void *dev, long *temp)
+{
+ struct ntc_data *data = dev_get_drvdata(dev);
+ int ohm;
+
+ ohm = ntc_thermistor_get_ohm(data);
+ if (ohm < 0)
+ return ohm;
+
+ *temp = get_temp_mc(data, ohm);
+
+ return 0;
+}
+
static ssize_t ntc_show_name(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -562,6 +578,13 @@ static int ntc_thermistor_probe(struct platform_device
*pdev)
dev_info(&pdev->dev, "Thermistor type: %s successfully probed.\n",
pdev_id->name);
+ data->tz = thermal_zone_of_sensor_register(data->dev, 0, data->dev,
+ ntc_read_temp, NULL);
+ if (IS_ERR(data->tz)) {
+ dev_dbg(&pdev->dev, "Failed to register to thermal fw.\n");
+ data->tz = NULL;
+ }
+
return 0;
err_after_sysfs:
sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
@@ -578,6 +601,9 @@ static int ntc_thermistor_remove(struct platform_device
*pdev)
sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
ntc_iio_channel_release(pdata);
+ if (data->tz)
+ thermal_zone_of_sensor_unregister(data->dev, data->tz);
thermal_zone_of_sensor_unregister just return without operation if data->tz is
NULL.
So, don't need to check the value of data->tz with if statement.
On a side note, devm_thermal_zone_of_sensor_register would be quite useful to
have.
Guenter
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
