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>
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>
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>
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>
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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
