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authorJonghwa Lee <jonghwa3.lee@samsung.com>2014-08-20 09:28:13 +0900
committerJonghwa Lee <jonghwa3.lee@samsung.com>2014-10-08 11:16:15 +0900
commita5ec87b1da6c588438516a2f3c1ec076c074b270 (patch)
tree7a8b1f9420f895c0feb5b7002aeeb1ecfc76927f
parent2c1935a7defd9afaaa4f7764c5c206d043d5a850 (diff)
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hwmon: ntc_thermistor: Add ntc thermistor to thermal subsystem as a sensor.
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. Change-Id: Ie5b8948ca0cb567854905e0e9ea903ff7cdc1f4c Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
-rw-r--r--Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt3
-rw-r--r--drivers/hwmon/Kconfig1
-rw-r--r--drivers/hwmon/ntc_thermistor.c25
3 files changed, 29 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt b/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
index c6f66674f19..bdae6df488e 100644
--- a/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
+++ b/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
@@ -16,6 +16,9 @@ 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/Kconfig b/drivers/hwmon/Kconfig
index a8b0c7c62e3..5399c3252b9 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -945,6 +945,7 @@ config SENSORS_NCT6775
config SENSORS_NTC_THERMISTOR
tristate "NTC thermistor support"
depends on !OF || IIO=n || IIO
+ depends on THERMAL || !THERMAL_OF
help
This driver supports NTC thermistors sensor reading and its
interpretation. The driver can also monitor the temperature and
diff --git a/drivers/hwmon/ntc_thermistor.c b/drivers/hwmon/ntc_thermistor.c
index c64d3d497c5..1eccf1069f5 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;
@@ -140,6 +141,7 @@ 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)
@@ -372,6 +374,20 @@ 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)
{
@@ -502,6 +518,13 @@ static int ntc_thermistor_probe(struct platform_device *pdev)
dev_info(&pdev->dev, "Thermistor type: %s successfully probed.\n",
pdev->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);
@@ -519,6 +542,8 @@ static int ntc_thermistor_remove(struct platform_device *pdev)
ntc_iio_channel_release(pdata);
platform_set_drvdata(pdev, NULL);
+ thermal_zone_of_sensor_unregister(data->dev, data->tz);
+
return 0;
}