From a5ec87b1da6c588438516a2f3c1ec076c074b270 Mon Sep 17 00:00:00 2001 From: Jonghwa Lee Date: Wed, 20 Aug 2014 09:28:13 +0900 Subject: 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 --- .../devicetree/bindings/hwmon/ntc_thermistor.txt | 3 +++ drivers/hwmon/Kconfig | 1 + drivers/hwmon/ntc_thermistor.c | 25 ++++++++++++++++++++++ 3 files changed, 29 insertions(+) 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 #include +#include 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; } -- cgit v1.2.3