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path: root/drivers/hwmon/ntc_thermistor.c
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2015-08-03thermal: consistently use int for temperaturesSascha Hauer
The thermal code uses int, long and unsigned long for temperatures in different places. Using an unsigned type limits the thermal framework to positive temperatures without need. Also several drivers currently will report temperatures near UINT_MAX for temperatures below 0°C. This will probably immediately shut the machine down due to overtemperature if started below 0°C. 'long' is 64bit on several architectures. This is not needed since INT_MAX °mC is above the melting point of all known materials. Consistently use a plain 'int' for temperatures throughout the thermal code and the drivers. This only changes the places in the drivers where the temperature is passed around as pointer, when drivers internally use another type this is not changed. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Jean Delvare <jdelvare@suse.de> Reviewed-by: Lukasz Majewski <l.majewski@samsung.com> Reviewed-by: Darren Hart <dvhart@linux.intel.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Peter Feuerer <peter@piie.net> Cc: Punit Agrawal <punit.agrawal@arm.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Eduardo Valentin <edubezval@gmail.com> Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Jean Delvare <jdelvare@suse.de> Cc: Peter Feuerer <peter@piie.net> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Lukasz Majewski <l.majewski@samsung.com> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: linux-acpi@vger.kernel.org Cc: platform-driver-x86@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-omap@vger.kernel.org Cc: linux-samsung-soc@vger.kernel.org Cc: Guenter Roeck <linux@roeck-us.net> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Maxime Ripard <maxime.ripard@free-electrons.com> Cc: Darren Hart <dvhart@infradead.org> Cc: lm-sensors@lm-sensors.org Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2015-06-03hwmon: (ntc_thermistor) Improve precision of resistance calculationChris Lesiak
The function get_ohm_of_thermistor has both the measured voltage and the pullup voltage available in microvolts. But it was promptly converting both to millivolts before using them to calculate the thermistor resistance. That conversion unnecessarily hurt the precision of the calculation. For example, take the ncpXXwb473 connected to 5000 mV and pulled down through a 47000 ohm resistor. At 25 C, the resistance of the thermistor is 47000 ohms. The measured voltage will be 2500 mV. If we measure instead 2501 mV, then the calculated resistance will be 46962 ohms -- a difference of 38 ohms. So the precision of the resistance estimate could be increased by 38X by doing the calculations in microvolts. Signed-off-by: Chris Lesiak <chris.lesiak@licor.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2015-06-02hwmon: (ntc_thermistor) fix iio raw to microvolts conversionChris Lesiak
The function ntc_adc_iio_read was assuming both a 12 bit ADC and that pullup_uv is the same as the ADC reference voltage. If either assumption is false, then the result is incorrect. Attempt to use iio_convert_raw_to_processed to convert the raw value to microvolts. It will fail for iio channels that don't support support IIO_CHAN_INFO_SCALE; in that case fall back to the assumptions. Signed-off-by: Chris Lesiak <chris.lesiak@licor.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2015-05-31hwmon: (ntc_thermistor) Add support for ncpXXwf104Beomho Seo
This patch adds support for the ntc thermistor NCPXXWF104 series. Cc: Jean Delvare <jdelvare@suse.de> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Beomho Seo <beomho.seo@samsung.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2015-05-26hwmon: (ntc_thermistor) Ensure iio channel is of type IIO_VOLTAGEChris Lesiak
When configured via device tree, the associated iio device needs to be measuring voltage for the conversion to resistance to be correct. Return -EINVAL if that is not the case. Signed-off-by: Chris Lesiak <chris.lesiak@licor.com> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-12-17Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux Pull thermal management update from Zhang Rui: "Summary: - of-thermal extension to allow drivers to register and use its functionality in a better way, without exploiting thermal core. From Lukasz Majewski. - Fix a bug in intel_soc_dts_thermal driver which calls a sleep function in interrupt handler. From Maurice Petallo. - add a thermal UAPI header file for exporting the thermal generic netlink information to user-space. From Florian Fainelli. - First round of refactoring in Exynos driver. Bartlomiej and Lukasz are attempting to make it lean and easier to understand. - New thermal driver for Rockchip (rk3288), with support for DT thermal. From Caesar Wang. - New thermal driver for Nvidia, Tegra124 SOCTHERM driver, with support for DT thermal. From Mikko Perttunen. - New cooling device, based on common clock framework. From Eduardo Valentin. - a couple of small fixes in thermal core framework. From Srinivas Pandruvada, Javi Merino, Luis Henriques. - Dropping Armada A375-Z1 SoC thermal support as the chip is not in the market, armada folks decided to drop its support. - a couple of small fixes and cleanups in int340x thermal driver" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux: (58 commits) thermal: provide an UAPI header file Thermal/int340x: Clear the error value of the last acpi_bus_get_device() call thermal/powerclamp: add id for braswell cpu thermal: Intel SoC DTS: Don't do thermal zone update inside spin_lock Thermal: fix platform_no_drv_owner.cocci warnings Thermal/int340x: avoid unnecessary pointer casting thermal: int3403: Delete a check before thermal_zone_device_unregister() thermal/int3400: export uuids thermal: of: Extend current of-thermal.c code to allow setting emulated temp thermal: of: Extend of-thermal to export table of trip points thermal: of: Rename struct __thermal_trip to struct thermal_trip thermal: of: Extend of-thermal.c to provide check if trip point is valid thermal: of: Extend of-thermal.c to provide number of trip points thermal: Fix error path in thermal_init() thermal: lock the thermal zone when switching governors thermal: core: ignore invalid trip temperature thermal: armada: Remove support for A375-Z1 SoC thermal: rockchip: add driver for thermal dt-bindings: document Rockchip thermal thermal: exynos: remove exynos_tmu_data.h include ...
2014-11-20thermal: of: improve of-thermal sensor registration APIEduardo Valentin
Different drivers request API extensions in of-thermal. For this reason, additional callbacks are required to fit the new drivers needs. The current API implementation expects the registering sensor driver to provide a get_temp and get_trend callbacks as function parameters. As the amount of callbacks is growing, this patch changes the existing implementation to use a .ops field to hold all the of thermal callbacks to sensor drivers. This patch also changes the existing of-thermal users to fit the new API design. No functional change is introduced in this patch. Cc: Alexandre Courbot <gnurou@gmail.com> Cc: devicetree@vger.kernel.org Cc: Grant Likely <grant.likely@linaro.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Jean Delvare <jdelvare@suse.de> Cc: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-tegra@vger.kernel.org Cc: lm-sensors@lm-sensors.org Cc: Rob Herring <robh+dt@kernel.org> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Zhang Rui <rui.zhang@intel.com> Acked-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Mikko Perttunen <mikko.perttunen@kapsi.fi> Reviewed-by: Mikko Perttunen <mikko.perttunen@kapsi.fi> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Lukasz Majewski <l.majewski@samsung.com> Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2014-10-20hwmon: drop owner assignment from platform_driversWolfram Sang
A platform_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-09-22hwmon: (ntc_thermistor) Add ntc thermistor to thermal subsystem as a sensor.Jonghwa Lee
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.lee@samsung.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-08-04hwmon: (ntc_thermistor) Support B57330V2103 from EPCOSJohannes Pointner
This patch adds support for the ntc thermistor B57330V2103 from EPCOS. Signed-off-by: Johannes Pointner <johannes.pointner@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-06-29hwmon: (ntc_thermistor) Correct information printed during probeNaveen Krishna Chatradhi
Currently, dev_info() at the end of the probe says "type:%s ". But, prints pdev->name. This patch uses "pdev_id->name" which prints the thermistor type. Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-06-25hwmon: (ntc_thermistor) Use the manufacturer name properlyNaveen Krishna Chatradhi
Murata Manufacturing Co., Ltd is the vendor for NTC (Negative Temperature coefficient) based Thermistors. But, the driver extensively uses "NTC" as the vendor name. This patch corrects the vendor name also updates the compatibility strings according to the vendor-prefix.txt Note: Drivers continue to support the previous compatible strings but further addition of these compatible strings in device tree is deprecated. Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-05-25hwmon: (ntc_thermistor) Fix OF device ID mappingJean Delvare
The mapping from OF device IDs to platform device IDs is wrong. TYPE_NCPXXWB473 is 0, TYPE_NCPXXWL333 is 1, so ntc_thermistor_id[TYPE_NCPXXWB473] is { "ncp15wb473", TYPE_NCPXXWB473 } while ntc_thermistor_id[TYPE_NCPXXWL333] is { "ncp18wb473", TYPE_NCPXXWB473 }. So the name is wrong for all but the "ntc,ncp15wb473" entry, and the type is wrong for the "ntc,ncp15wl333" entry. So map the entries by index, it is neither elegant nor robust but at least it is correct. Signed-off-by: Jean Delvare <jdelvare@suse.de> Fixes: 9e8269de hwmon: (ntc_thermistor) Add DT with IIO support to NTC thermistor driver Reviewed-by: Guenter Roeck <linux@roeck-us.net> Cc: Naveen Krishna Chatradhi <ch.naveen@samsung.com> Cc: Doug Anderson <dianders@chromium.org>
2014-05-25hwmon: (ntc_thermistor) Fix dependenciesJean Delvare
In commit 9e8269de, support was added for ntc_thermistor devices being declared in the device tree and implemented on top of IIO. With that change, a dependency was added to the ntc_thermistor driver: depends on (!OF && !IIO) || (OF && IIO) This construct has the drawback that the driver can no longer be selected when OF is set and IIO isn't, nor when IIO is set and OF is not. This is a regression for the original users of the driver. As the new code depends on IIO and is useless without OF, include it only if both are enabled, and set the dependencies accordingly. This is clearer, more simple and more correct. Signed-off-by: Jean Delvare <jdelvare@suse.de> Fixes: 9e8269de hwmon: (ntc_thermistor) Add DT with IIO support to NTC thermistor driver Reviewed-by: Guenter Roeck <linux@roeck-us.net> Cc: Naveen Krishna Chatradhi <ch.naveen@samsung.com> Cc: Doug Anderson <dianders@chromium.org>
2014-02-13hwmon: (ntc_thermistor) Avoid math overflowDoug Anderson
The ntc thermistor code was doing math whose temporary result might have overflowed 32-bits. We need some casts in there to make it safe. In one example I found: - pullup_uV: 1800000 - result of iio_read_channel_raw: 3226 - 1800000 * 3226 => 0x15a1cbc80 Signed-off-by: Doug Anderson <dianders@chromium.org> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2013-08-11hwmon: use dev_get_platdata()Jingoo Han
Use the wrapper function for retrieving the platform data instead of accessing dev->platform_data directly. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2013-06-21hwmon: (ntc_thermistor) Remove redundant platform_set_drvdata()Sachin Kamat
Commit 0998d06310 (device-core: Ensure drvdata = NULL when no driver is bound) removes the need to set driver data field to NULL. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Cc: MyungJoo Ham <myungjoo.ham@samsung.com> Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2013-04-07hwmon: Fix CamelCase checkpatch warningsGuenter Roeck
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2013-04-07hwmon: (ntc_thermistor) Add DT with IIO support to NTC thermistor driverNaveen Krishna Chatradhi
This patch adds DT support to NTC driver to parse the platform data. Also adds the support to work as an iio device client. During the probe ntc driver gets the respective channels of ADC and uses iio_raw_read calls to get the ADC converted value. Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> [Guenter Roeck: fixed Kconfig dependencies; use ERR_CAST] Tested-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2013-02-19hwmon: (ntc_thermistor): Fix sparse warningsSachin Kamat
Fixes the following sparse warnings: drivers/hwmon/ntc_thermistor.c:46:31: warning: symbol 'ncpXXwb473' was not declared. Should it be static? drivers/hwmon/ntc_thermistor.c:82:31: warning: symbol 'ncpXXwl333' was not declared. Should it be static? Cc: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2012-11-28hwmon: remove use of __devexitBill Pemberton
CONFIG_HOTPLUG is going away as an option so __devexit is no longer needed. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: Alistair John Strachan <alistair@devzero.co.uk> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Juerg Haefliger <juergh@gmail.com> Cc: Andreas Herrmann <herrmann.der.user@googlemail.com> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Jim Cromie <jim.cromie@gmail.com> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Cc: Roger Lucas <vt8231@hiddenengine.co.uk> Acked-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-28hwmon: remove use of __devinitBill Pemberton
CONFIG_HOTPLUG is going away as an option so __devinit is no longer needed. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: Alistair John Strachan <alistair@devzero.co.uk> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Juerg Haefliger <juergh@gmail.com> Cc: Andreas Herrmann <herrmann.der.user@googlemail.com> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Jim Cromie <jim.cromie@gmail.com> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Cc: Roger Lucas <vt8231@hiddenengine.co.uk> Acked-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-28hwmon: remove use of __devexit_pBill Pemberton
CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer needed. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: Alistair John Strachan <alistair@devzero.co.uk> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Juerg Haefliger <juergh@gmail.com> Cc: Andreas Herrmann <herrmann.der.user@googlemail.com> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Jim Cromie <jim.cromie@gmail.com> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Cc: Roger Lucas <vt8231@hiddenengine.co.uk> Acked-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-21hwmon: (ntc_thermistor) Ensure that data->name string is terminatedGuenter Roeck
Fix Coverity warning: Calling strncpy with a maximum size argument of 20 bytes on destination array "data->name" of size 20 bytes might leave the destination string unterminated. Fix by replacing strncpy() with strlcpy() and by using sizeof() to determine the maximum string length. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Jean Delvare <khali@linux-fr.org>
2012-05-20hwmon: (ntc_thermistor) Fix checkpatch warningGuenter Roeck
Fix checkpatch WARNING: quoted string split across lines Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
2012-05-20hwmon: (ntc_thermistor) Optimize and fix build warningGuenter Roeck
The following build warning is seen in some configurations: drivers/hwmon/ntc_thermistor.c: In function 'ntc_show_temp': drivers/hwmon/ntc_thermistor.c:293: warning: 'temp' may be used uninitialized in this function Fix the problem by re-arranging the code to overload return values with error codes, and by avoiding error returns whenever possible. Specifically, Simplify lookup_comp() to not return an error. Instead, return i_low == i_high if there is an exact match, or if the ohm value is outside the lookup table range. Modify get_temp_mC() to not return an error. Since it only returns an error after lookup_comp() returned an error, this is quite straightforward after above change. Separate ntc_thermistor_read() into a function to read the resistor value (which can return an error), and the call to get_temp_mC() which doesn't. Call the functions directly from ntc_show_temp(). Code was tested using a test program, comparing the result of the old and new versions of get_temp_mC() for resistor values between 0 and 2,000,000 ohm. As a side effect, this patch reduces code size by approximately 400 bytes on x86_64. Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Cc: Donggeun Kim <dg77.kim@samsung.com> Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
2012-05-20hwmon: (ntc_thermistor) Return error code from hwmon_device_registerGuenter Roeck
hwmon_device_register() never returns a NULL pointer in case of errors, but an error value. Use it. Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
2012-05-20hwmon: (ntc_thermistor) Convert to devm_kzallocGuenter Roeck
This avoids memory leaks, and makes the code a bit simpler and smaller. Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
2011-11-26hwmon: convert drivers/hwmon/* to use module_platform_driver()Axel Lin
This patch converts the drivers in drivers/hwmon/* to use the module_platform_driver() macro which makes the code smaller and a bit simpler. Cc: Donggeun Kim <dg77.kim@samsung.com> Cc: Simon Guinot <sguinot@lacie.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: MyungJoo Ham <myungjoo.ham@samsung.com> Cc: Ben Dooks <ben@simtec.co.uk> Cc: Hans de Goede <hdegoede@redhat.com> Cc: J Keerthy <j-keerthy@ti.com> Cc: David S. Miller <davem@davemloft.net> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Axel Lin <axel.lin@gmail.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
2011-08-22hwmon: (ntc_thermistor) Simplify if sequenceGuenter Roeck
Replace unnecessary if with else statement. This fixes the following (false) compile warning reported with some combinations of C compiler version and configuration. drivers/hwmon/ntc_thermistor.c: In function 'ntc_show_temp': drivers/hwmon/ntc_thermistor.c:225: warning: 'low' may be used uninitialized in this function drivers/hwmon/ntc_thermistor.c:225: note: 'low' was declared here drivers/hwmon/ntc_thermistor.c:225: warning: 'high' may be used uninitialized in this function drivers/hwmon/ntc_thermistor.c:225: note: 'high' was declared here drivers/hwmon/ntc_thermistor.c:294: warning: 'temp' may be used uninitialized in this function Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Acked-by: Jean Delvare <khali@linux-fr.org>
2011-07-28hwmon: Driver for NTC ThermistorsDonggeun Kim
Add support for NTC Thermistor series. In this release, the following thermistors are supported: NCP15WB473, NCP18WB473, NCP03WB473, and NCP15WL333. This driver is based on the datasheet of MURATA. The driver in the patch does conversion from the raw ADC value (either voltage or resistence) to temperature. In order to use voltage values as input, the circuit schematics should be provided with the platform data. A compensation table for each type of thermistor is provided for the conversion. Signed-off-by: Donggeun Kim <dg77.kim@samsung.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: KyungMin Park <kyungmin.park@samsung.com> Reviewed-by: Shubhrajyoti D <shubhrajyoti@ti.com> Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>