Commit Graph

37 Commits

Author SHA1 Message Date
Peter Rosin
e8fda2c864 hwmon: (ntc_thermistor): add support for B57891S0103 from Epcos
More of the same...

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2018-12-16 15:13:19 -08:00
Guenter Roeck
5e7f5994bd hwmon: (ntc_thermistor) Use devm_hwmon_device_register_with_groups
Simplify code, reduce code size, and drop remove function as no longer
needed.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2016-09-08 21:34:15 -07:00
Guenter Roeck
48001525c9 hwmon: (ntc_thermistor) Use dev instead of &pdev->dev where possible
Instead of repeatedly accessing &pdev->dev, use a local variable dev
instead where possible. Also drop 'dev' from private data since it is
unnecessary.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2016-09-08 21:34:14 -07:00
Guenter Roeck
6402085676 hwmon: (ntc_thermistor) Use devm_iio_channel_get
Use devm_iio_channel_get() instead of iio_channel_get to simplify error
handling and device removal.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2016-09-08 21:34:14 -07:00
Eduardo Valentin
0e058bc3ac hwmon: convert ntc_thermistor to use devm_thermal_zone_of_sensor_register
This changes the driver to use the devm_ version
of thermal_zone_of_sensor_register and cleans
up the  local points and unregister calls.

Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: lm-sensors@lm-sensors.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2016-05-17 07:28:25 -07:00
Joseph McNally
54ce3a0d80 hwmon: (ntc_thermistor) Add support for ncpXXxh103
This patch adds support for the Murata NCP15XH103 thermistor series.

Signed-off-by: Joseph McNally <jmcna06@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2016-03-05 06:25:34 -08:00
Sascha Hauer
17e8351a77 thermal: consistently use int for temperatures
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>
2015-08-03 23:15:50 +08:00
Chris Lesiak
f6725ae2f1 hwmon: (ntc_thermistor) Improve precision of resistance calculation
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>
2015-06-03 15:25:53 -07:00
Chris Lesiak
0315253b19 hwmon: (ntc_thermistor) fix iio raw to microvolts conversion
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>
2015-06-02 06:53:50 -07:00
Beomho Seo
887ee43477 hwmon: (ntc_thermistor) Add support for ncpXXwf104
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>
2015-05-31 22:58:36 -07:00
Chris Lesiak
adba657533 hwmon: (ntc_thermistor) Ensure iio channel is of type IIO_VOLTAGE
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>
2015-05-26 17:22:49 -07:00
Linus Torvalds
2efda9042d Merge branch 'next' of 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
  ...
2014-12-17 10:16:27 -08:00
Eduardo Valentin
2251aef64a thermal: of: improve of-thermal sensor registration API
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>
2014-11-20 10:44:54 -04:00
Wolfram Sang
2a1ed07718 hwmon: drop owner assignment from platform_drivers
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>
2014-10-20 16:20:36 +02:00
Jonghwa Lee
c08860ffe5 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.

Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-09-22 11:14:52 -07:00
Johannes Pointner
ed67f0872b hwmon: (ntc_thermistor) Support B57330V2103 from EPCOS
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>
2014-08-04 07:01:35 -07:00
Naveen Krishna Chatradhi
93a88ef305 hwmon: (ntc_thermistor) Correct information printed during probe
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>
2014-06-29 23:56:14 -07:00
Naveen Krishna Chatradhi
8b6f5e0f19 hwmon: (ntc_thermistor) Use the manufacturer name properly
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>
2014-06-25 07:09:13 -07:00
Jean Delvare
ead82d6792 hwmon: (ntc_thermistor) Fix OF device ID mapping
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>
2014-05-25 17:23:08 +02:00
Jean Delvare
59cf4243e5 hwmon: (ntc_thermistor) Fix dependencies
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>
2014-05-25 17:23:08 +02:00
Doug Anderson
d3d89c468c hwmon: (ntc_thermistor) Avoid math overflow
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>
2014-02-13 19:43:52 -08:00
Jingoo Han
a8b3a3a53f hwmon: use dev_get_platdata()
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>
2013-08-11 22:10:39 -07:00
Sachin Kamat
3a2af25d84 hwmon: (ntc_thermistor) Remove redundant platform_set_drvdata()
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>
2013-06-21 10:05:19 -07:00
Guenter Roeck
088ce2ac9e hwmon: Fix CamelCase checkpatch warnings
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2013-04-07 21:16:40 -07:00
Naveen Krishna Chatradhi
9e8269de10 hwmon: (ntc_thermistor) Add DT with IIO support to NTC thermistor driver
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>
2013-04-07 21:16:38 -07:00
Sachin Kamat
4626dcff78 hwmon: (ntc_thermistor): Fix sparse warnings
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>
2013-02-19 17:34:17 -08:00
Bill Pemberton
281dfd0b6e hwmon: remove use of __devexit
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>
2012-11-28 11:50:34 -08:00
Bill Pemberton
6c931ae1c0 hwmon: remove use of __devinit
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>
2012-11-28 11:49:40 -08:00
Bill Pemberton
9e5e9b7a92 hwmon: remove use of __devexit_p
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>
2012-11-28 11:48:59 -08:00
Guenter Roeck
0ef63e48f0 hwmon: (ntc_thermistor) Ensure that data->name string is terminated
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>
2012-07-21 21:48:44 -07:00
Guenter Roeck
a7871def65 hwmon: (ntc_thermistor) Fix checkpatch warning
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>
2012-05-20 19:41:50 -07:00
Guenter Roeck
dbe43a6276 hwmon: (ntc_thermistor) Optimize and fix build warning
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>
2012-05-20 19:41:49 -07:00
Guenter Roeck
425d247680 hwmon: (ntc_thermistor) Return error code from hwmon_device_register
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>
2012-05-20 19:41:49 -07:00
Guenter Roeck
41141e64e6 hwmon: (ntc_thermistor) Convert to devm_kzalloc
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>
2012-05-20 19:41:49 -07:00
Axel Lin
25a236a5db hwmon: convert drivers/hwmon/* to use module_platform_driver()
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>
2011-11-26 09:48:20 -08:00
Guenter Roeck
858a914324 hwmon: (ntc_thermistor) Simplify if sequence
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>
2011-08-22 14:04:05 -07:00
Donggeun Kim
f22aaaa70d hwmon: Driver for NTC Thermistors
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>
2011-07-28 00:17:33 -07:00