summaryrefslogtreecommitdiff
path: root/drivers/iio/temperature/maxim_thermocouple.c
AgeCommit message (Collapse)AuthorFilesLines
2025-08-28iio: temperature: maxim_thermocouple: use DMA-safe buffer for spi_read()David Lechner1-10/+16
commit ae5bc07ec9f73a41734270ef3f800c5c8a7e0ad3 upstream. Replace using stack-allocated buffers with a DMA-safe buffer for use with spi_read(). This allows the driver to be safely used with DMA-enabled SPI controllers. The buffer array is also converted to a struct with a union to make the usage of the memory in the buffer more clear and ensure proper alignment. Fixes: 1f25ca11d84a ("iio: temperature: add support for Maxim thermocouple chips") Signed-off-by: David Lechner <dlechner@baylibre.com> Reviewed-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20250721-iio-use-more-iio_declare_buffer_with_ts-3-v2-1-0c68d41ccf6c@baylibre.com Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-22Merge tag 'iio-for-6.16a-take2' of ↵Greg Kroah-Hartman1-21/+16
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jic23/iio into char-misc-next Jonathan writes: IIO: New device support, features and cleanup for 6.16 - take 2 Note - last minute rebase was to drop a typo patch that I'd accidentally picked up (in the microblaze arch Kconfig) Take 2 is due to that rebase messing up some fixes tags that were referring to patches after that point. There is a known merge conflict due to changes in neighbouring lines. Stephen's resolution in linux-next is: https://lore.kernel.org/linux-next/20250506155728.65605bae@canb.auug.org.au/ Added 3 named IIO reviewers to MAINTAINERS. This is a reflection of those who have been doing much of this work for some time. Lars-Peter is removed from the entry having moved on to other topics. Thanks Nuno, David and Andy for stepping up and Lars-Peter for all your hard work in the past! Includes the usual mix of new device support, features and general cleanup. This time we also have some tree wide changes. - Rip out the iio_device_claim_direct_scoped() as it proved hard to work with. This series includes quite a few related cleanups such as use of guard or factoring code out to allow direct returns. - Switch from iio_device_claim/release_direct_mode() to new iio_device_claim/release_direct() which is structured so that sparse can warn on failed releases. There were a few false positives but those were mostly in code that benefited from being cleaned up as part of this process. - Introduce iio_push_to_buffers_with_ts() to replace the _timestamp() version over time. This version takes the size of the supplied buffer which the core checks is at least as big as expected by calculation from channel descriptions of those channels enabled. Use this in an initial set of drivers. - Add macros for IIO_DECLARE_BUFFER_WITH_TS() and IIO_DECLARE_DMA_BUFFER_WITH_TS() to avoid lots of fiddly code to ensure correctly aligned buffers for timestamps being added onto the end of channel data. New device support ------------------ adi,ad3530r - New driver for AD3530, AD3530R, AD3531 and AD3531R DACs with programmable gain controls. R variants have internal references. adi,ad7476 - Add support (dt compatible only) for the Rohm BU79100G ADC which is fully compatible with the ti,ads7866. adi,ad7606 - Support ad7606c-16 and ad7606c-18 devices. Includes switch to dynamic channel information allocation. adi,ad7380 - Add support for the AD7389-4 dfrobot,sen0322 - New driver for this oxygen sensor. mediatek,mt2701-auxadc - Add binding for MT6893 which is fully compatible with already supported MT8173. meson-saradc - Support the GXLX SoCs. Mostly this is a workaround for some unrelated clock control bits found in the ADC register map. nuvoton,nct7201 - New driver for NCT7201 and NCT7202 I2C ADCs. rohm,bd79124 - New driver for this 12-bit, 8-channel SAR ADC. - Switch to new set_rv etc gpio callbacks that were added in 6.15. rohm,bd79703 - Add support for BD79700, BD79701 and BD79702 DACs that have subsets of functionality of the already supported bd79703. Included making this driver suitable for support device variants. st,stm32-lptimer - Add support for stm32pm25 to this trigger. Features -------- Beyond IIO - Property iterator for named children. core - Enable writes for 64 bit integers used for standard IIO ABI elements. Previously these could be read only. - Helper library that should avoid code duplication for simpler ADC bindings that have a child node per channel. - Enforce that IIO_DMA_MINALIGN is always at least 8 (almost always true and simplifies code on all significant architectures) core/backend - Add support to control source of data - useful when the HDL includes things like generated ramps for testing purposes. Enable this for adi-axi-dac adi,ad3552-hs - Add debugfs related callbacks to allow debug access to register contents. adi,ad4000 - Support SPI offload with appropriate FPGA firmware along with improving documentation. adi,ad7293 - Add support for external reference voltage. adi,ad7606 - Support SPI offload. adi,ad7768-1 - Support reset GPIO. adi,admv8818 - Support filter frequencies beyond 2^32. adi,adxl345 - Add single and double tap events. hid-sensor-prox - Support 16-bit report sizes as seen on some Intel platforms. invensense,icm42600 - Enable use of named interrupts to avoid problems with some wiring choices. Get the interrupt by name, but fallback to previous assumption on the first being INT1 if no names are supplied. microchip,mcp3911 - Add reset gpio support. rohm,bh7150 - Add reset gpio support. st,stm32 - Add support to control oversampling. ti,adc128s052 - Add support for ROHM BD79104 which is early compatible with the TI parts already supported by this driver. Includes some general driver cleanup and a separate dt binding. - Simplify reference voltage handling by assuming it is fixed after enabling the supply. winsen,mhz19b - New driver for this C02 sensor. Cleanup and minor fixes ----------------------- dt-bindings - Correct indentation and style for DTS examples. - Use unevalutateProperties for SPI devices instead of additionalProperties to allow generic SPI properties from spi-peripheral-props.yaml ABI Docs - Add missing docs for sampling_frequency when it applies only to events. Treewide - Various minor tweaks, comment fixes and similar. - Sort TI ADCs in Kconfig that had gotten out of order. - Switch various drives that provide GPIO chip functionality to the new callbacks with return values. - Standardize on { } formatting for all array sentinels. - Make use of aligned_s64 in a few places to replace either wrong types or manually defined equivalents. - Drop places where spi bits_per_word is set to 8 because that is the default anyway. adi,ad_sigma_delta library - Avoid a potential use of uninitialized data if reg_size has a value that is not supported (no drivers hit this but it is reasonable hardening) adi,ad4030 - Add error checking for scan types and no longer store it in state. - Rework code to reduce duplication. - Move setting the mode from buffer preenable() to update_scan_mode(), better matching expected semantics of the two different callbacks. - Improve data marshalling comments. adi,ad4695 - Use u16 for buffer elements as oversampling is not yet supported except with SPI offload (which doesn't use this path). adi,ad5592r - Clean up destruction of mutexes. - Use lock guards to simplify code (later patch fixes a missed unlock) adi,ad5933 - Correct some incorrect settling times. adi,ad7091 - Deduplicate handling of writable vs volatile registers as they are the inverse of each other for this device. adi,ad7124 - Fix 3db Filter frequency. - Remove ability to directly write the filter frequency (which was broken) - Register naming improvements. adi,ad7606 - Add a missing return value check. - Fill in max sampling rates for all chips. - Use devm_mutex_init() - Fix up some kernel-doc formatting issues. - Remove some camel case that snuck in. - Drop setting address field in channels as easily established from other fields. - Drop unnecessary parameter to ad76060_scale_setup_cb_t. adi,ad7768-1 - Convert to regmap. - Factor out buffer allocation. - Tidy up headers. adi,ad7944 - Stop setting bits_per_word in SPI xfers with no data. adi,ad9832 - Add of_device_id table rather than just relying on fallbacks. - Use FIELD_PREP() to set values of fields. adi,admv1013 - Cleanup a pointless ternary. adi,admv8818 - Fix up LPF Band 5 frequency which was slightly wrong. - Fix an integer overflow. - Fix range calculation adi,adt7316 - Replace irqd_get_trigger_type(irq_get_irq_data()) with simpler irq_get_trigger_type() adi,adxl345 - Use regmap cache instead of various state variables that were there to reduce bus accesses. - Make regmap return value checking consistent across all call sites. adi,axi-dac - Add a check on number of channels (0 to 15 valid) allwinner,sun20i - Use new adc-helpers to replace local parsing code for channel nodes. bosch,bmp290 - Move to local variables for sensor data marshalling removing the need for a messy definition that has to work for all supported parts. Follow up fix adds a missing initialization. dynaimage,al3010 and dynaimage,al3320a - Various minor cleanup to bring these drivers inline with reviewed feedback given on a new driver. - Fix an error path in which power down is not called when it should be. - Switch to regmap. google,cros_ec - Fix up a flexible array in middle of structure warning. - Flush fifo when changing the timeout to avoid potential long wait for samples. hid-sensor-rotation - Remove an __aligned(16) marking that doesn't seem to be justified. kionix,kxcjk-1013 - Deduplicate code for setting up interrupts. microchip,mcp3911 - Fix handling of conversion results register which differs across supported devices. idt,zopt2201 - Avoid duplicating register lists as all volatile registers are the inverse of writeable registers on this device. renesas,rzg2l - Use new adc-helpers to replace local parsing code for channel nodes. ti,ads1298 - Fix a missing Kconfig dependency. * tag 'iio-for-6.16a-take2' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jic23/iio: (260 commits) dt-bindings: iio: adc: Add ROHM BD79100G iio: adc: add support for Nuvoton NCT7201 dt-bindings: iio: adc: add NCT7201 ADCs iio: chemical: Add driver for SEN0322 dt-bindings: trivial-devices: Document SEN0322 iio: adc: ad7768-1: reorganize driver headers iio: bmp280: zero-init buffer iio: ssp_sensors: optimalize -> optimize HID: sensor-hub: Fix typo and improve documentation iio: admv1013: replace redundant ternary operator with just len iio: chemical: mhz19b: Fix error code in probe() iio: adc: at91-sama5d2: use IIO_DECLARE_BUFFER_WITH_TS iio: accel: sca3300: use IIO_DECLARE_BUFFER_WITH_TS iio: adc: ad7380: use IIO_DECLARE_DMA_BUFFER_WITH_TS iio: adc: ad4695: rename AD4695_MAX_VIN_CHANNELS iio: adc: ad4695: use IIO_DECLARE_DMA_BUFFER_WITH_TS iio: introduce IIO_DECLARE_BUFFER_WITH_TS macros iio: make IIO_DMA_MINALIGN minimum of 8 bytes iio: pressure: zpa2326_spi: remove bits_per_word = 8 iio: pressure: ms5611_spi: remove bits_per_word = 8 ...
2025-05-21iio: temperature: Use iio_push_to_buffers_with_ts() to provide length for ↵Jonathan Cameron1-2/+3
runtime checks. This new function allows us to perform debug checks in the helper to ensure that the overrun does not occur. Use it in all the simple cases where either a static buffer or a structure is used in the drivers. Reviewed-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20250413103443.2420727-15-jic23@kernel.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-04-22iio: normalize array sentinel styleDavid Lechner1-1/+1
Use `\t(\{ ?\},|\{\}|\{\s*/\*.*\*/\s*\},?)$` regex to find and replace the array sentinel in all IIO drivers to the same style. For some time, we've been trying to consistently use `{ }` (no trailing comma, no comment, one space between braces) for array sentinels in the IIO subsystem. Still nearly 50% of existing code uses a different style. To save reviewers from having to request this trivial change as frequently, let's normalize the style in all existing IIO drivers. At least when code is copy/pasted to new drivers, the style will be consistent. Signed-off-by: David Lechner <dlechner@baylibre.com> Reviewed-by: Andy Shevchenko <andy@kernel.org> Link: https://patch.msgid.link/20250411-iio-sentinel-normalization-v1-1-d293de3e3d93@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-04-22iio: temp: maxim_thermocouple: Drop unused mutex.h include.Jonathan Cameron1-1/+0
There are no mutex related calls in this driver. Reviewed-by: David Lechner <dlechner@baylibre.com> Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com> Link: https://patch.msgid.link/20250331121317.1694135-36-jic23@kernel.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-04-22iio: temp: maxim_thermocouple: Switch to sparse friendly ↵Jonathan Cameron1-17/+12
iio_device_claim/release_direct() These new functions allow sparse to find failures to release direct mode reducing chances of bugs over the claim_direct_mode() functions that are deprecated. Tidy up a few direct returns whilst here. Reviewed-by: David Lechner <dlechner@baylibre.com> Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com> Link: https://patch.msgid.link/20250331121317.1694135-35-jic23@kernel.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2025-04-18iio: temp: maxim-thermocouple: Fix potential lack of DMA safe buffer.Jonathan Cameron1-1/+1
The trick of using __aligned(IIO_DMA_MINALIGN) ensures that there is no overlap between buffers used for DMA and those used for driver state storage that are before the marking. It doesn't ensure anything above state variables found after the marking. Hence move this particular bit of state earlier in the structure. Fixes: 10897f34309b ("iio: temp: maxim_thermocouple: Fix alignment for DMA safety") Reviewed-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20250413103443.2420727-14-jic23@kernel.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-06-14iio: temp: maxim_thermocouple: Fix alignment for DMA safetyJonathan Cameron1-1/+1
____cacheline_aligned is an insufficient guarantee for non-coherent DMA on platforms with 128 byte cachelines above L1. Switch to the updated IIO_DMA_MINALIGN definition Fixes: 1f25ca11d84a ("iio: temperature: add support for Maxim thermocouple chips") Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Matt Ranostay <mranostay@gmail.com> Acked-by: Nuno Sá <nuno.sa@analog.com> Link: https://lore.kernel.org/r/20220508175712.647246-93-jic23@kernel.org
2022-02-06iio: temperature: maxim_thermocouple: Switch from of headers to ↵Andy Shevchenko1-3/+2
mod_devicetable.h There is nothing directly using of specific interfaces in this driver, so lets not include the headers. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220202205328.57837-1-andriy.shevchenko@linux.intel.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-06-14iio: remove explicit IIO device parent assignmentAlexandru Ardelean1-1/+0
This patch applies the semantic patch: @@ expression I, P, SP; @@ I = devm_iio_device_alloc(P, SP); ... - I->dev.parent = P; It updates 302 files and does 307 deletions. This semantic patch also removes some comments like '/* Establish that the iio_dev is a child of the i2c device */' But this is is only done in case where the block is left empty. The patch does not seem to cover all cases. It looks like in some cases a different variable is used in some cases to assign the parent, but it points to the same reference. In other cases, the block covered by ... may be just too big to be covered by the semantic patch. However, this looks pretty good as well, as it does cover a big bulk of the drivers that should remove the parent assignment. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-11-23iio: maxim_thermocouple: add thermocouple_type sysfs attributeAndrea Merello1-3/+41
We added a sysfs ABI for getting/setting the type of a thermocouple. This driver supports chips that support specific fixed thermocouple types; we cannot set it, but still we can add this sysfs attribute in RO mode to read-back the thermocouple type. This driver supports actually several chips: - max6675 - max31855[k/j/n/s/t/e/r]asa family Max6675 supports only K-type thermocouples, so we can just report that. Each chip in max31855 family supports just one specific thermocouple type (in the obvious way: i.e. max31855jasa supports J-type). This driver did accept a generic SPI ID and OF compatible "max31855" which does not give any clue about which chip is really involved (and unfortunately it seems we have no way to detect it). This patch introduces a new set of, more specific, SPI IDs and OF compatible strings to better match the chip type. The old, generic, "max31855" binding is kept for compatibility reasons, but this patch aims to deprecate it, so, should we hit it, a warning is spit. In such case the reported thermocouple type in sysfs is '?', because we have no way to know. Regarding the implementation: the thermocouple type information is stored in the driver private data and I've kept only two maxim_thermocouple_chip types in order to avoid a lot of duplications (seven chip types with just a different thermocouple type). RFT because I have no real HW to test this. Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net> Cc: Colin Ian King <colin.king@canonical.com> Cc: Patrick Havelange <patrick.havelange@essensium.com> Cc: Matt Weber <matthew.weber@rockwellcollins.com> Cc: Matt Ranostay <matt.ranostay@konsulko.com> Cc: Chuhong Yuan <hslester96@gmail.com> Cc: Daniel Gomez <dagmcr@gmail.com> Cc: linux-iio@vger.kernel.org Cc: Rob Herring <robh+dt@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: devicetree@vger.kernel.org Signed-off-by: Andrea Merello <andrea.merello@gmail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-10-18iio: temp: maxim thermocouple: Drop unneeded semi colon.Jonathan Cameron1-1/+1
Identified by coccinelle CHECK drivers/iio/temperature/maxim_thermocouple.c drivers/iio/temperature/maxim_thermocouple.c:197:3-4: Unneeded semicolon Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
2019-07-28iio: maxim_thermocouple: Use device-managed APIsChuhong Yuan1-22/+3
Use device-managed APIs to simplify the code. The remove functions are redundant now and can be deleted. Signed-off-by: Chuhong Yuan <hslester96@gmail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-04-27iio: temperature: maxim_thermocouple: declare missing of tableDaniel Gomez1-0/+10
Add missing <of_device_id> table for SPI driver relying on SPI device match since compatible is in a DT binding or in a DTS. Before this patch: modinfo drivers/iio/temperature/maxim_thermocouple.ko | grep alias alias: spi:max31855 alias: spi:max6675 After this patch: modinfo drivers/iio/temperature/maxim_thermocouple.ko | grep alias alias: spi:max31855 alias: spi:max6675 alias: of:N*T*Cmaxim,max31855C* alias: of:N*T*Cmaxim,max31855 alias: of:N*T*Cmaxim,max6675C* alias: of:N*T*Cmaxim,max6675 Reported-by: Javier Martinez Canillas <javier@dowhile0.org> Signed-off-by: Daniel Gomez <dagmcr@gmail.com> Acked-by: Matt Ranostay <matt.ranostay@konsulko.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-09-02Revert "iio: temperature: maxim_thermocouple: add MAX31856 part"Matt Ranostay1-1/+0
This reverts commit 535fba29b3e1afef4ba201b3c69a6992583ec0bd. Seems the submitter (er me, hang head in shame) didn't look at the datasheet enough to see that the registers are quite different. This needs to be reverted because a) would never work b) to open it be added to a Maxim RTDs (Resistance Temperature Detectors) under development by author Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-02-18iio: add SPDX identifier for various driversMatt Ranostay1-12/+4
Add GPLv2+ SPDX identifier and update email for author's drivers. Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2017-08-23iio:temperature: drop assignment of iio_info.driver_moduleJonathan Cameron1-1/+0
The equivalent of this is now done via macro magic when the relevant register call is made. The actual structure elements will shortly go away. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
2017-05-07iio: temperature: maxim_thermocouple: add MAX31856 partMatt Ranostay1-0/+1
MAX31856 is register equivalent to the MAX31855 but suppports J, N, R, S, T, E and B type thermocouples in addition to K-type. Data conversion for the various types happens transparently to the driver via probe type detection, and a LUT on the sensor. Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-02-19iio: maxim_thermocouple: Set parent deviceLars-Peter Clausen1-0/+1
Initialize the parent of the IIO device to the device that registered it. This makes sure that the IIO device appears the right level in the device hierarchy. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-11-13iio: maxim_thermocouple: detect invalid storage size in read()Arnd Bergmann1-0/+2
As found by gcc -Wmaybe-uninitialized, having a storage_bytes value other than 2 or 4 will result in undefined behavior: drivers/iio/temperature/maxim_thermocouple.c: In function 'maxim_thermocouple_read': drivers/iio/temperature/maxim_thermocouple.c:141:5: error: 'ret' may be used uninitialized in this function [-Werror=maybe-uninitialized] This probably cannot happen, but returning -EINVAL here is appropriate and makes gcc happy and the code more robust. Fixes: 231147ee77f3 ("iio: maxim_thermocouple: Align 16 bit big endian value of raw reads") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org> (cherry picked from commit 32cb7d27e65df9daa7cee8f1fdf7b259f214bee2) Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-01iio: maxim_thermocouple: Align 16 bit big endian value of raw readssayli karnik1-7/+9
Driver was reporting invalid raw read values for MAX6675 on big endian architectures. MAX6675 buffered mode is not affected, nor is the MAX31855. The driver was losing a 2 byte read value when it used a 32 bit integer buffer to store a 16 bit big endian value. Use big endian types to properly align buffers on big endian architectures. Fixes following sparse endianness warnings: warning: cast to restricted __be16 warning: cast to restricted __be32 Fixes checkpatch issue: CHECK: No space is necessary after a cast Signed-off-by: sayli karnik <karniksayli1995@gmail.com> Fixes: 1f25ca11d84a ("iio: temperature: add support for Maxim thermocouple chips") Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-08-29iio: temperature: fix non static symbol warningsWei Yongjun1-3/+3
Fixes the following sparse warnings: drivers/iio/temperature/maxim_thermocouple.c:35:28: warning: symbol 'max6675_channels' was not declared. Should it be static? drivers/iio/temperature/maxim_thermocouple.c:52:28: warning: symbol 'max31855_channels' was not declared. Should it be static? drivers/iio/temperature/maxim_thermocouple.c:98:38: warning: symbol 'maxim_thermocouple_chips' was not declared. Should it be static? Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Reviewed-By: Matt Ranostay <mranostay@gmail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-07-10iio: temperature: add support for Maxim thermocouple chipsMatt Ranostay1-0/+281
Add initial driver support for MAX6675, and MAX31855 thermocouple chips. Cc: Marek Vasut <marex@denx.de> Cc: Matt Porter <mporter@konsulko.com> Signed-off-by: Matt Ranostay <mranostay@gmail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>