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path: root/drivers/iio/temperature/max31856.c
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2019-11-23iio: max31856: add support for runtime-configuring the thermocouple typeAndrea Merello
The sensor support various thermocouple types (e.g. J, K, N, ...). The driver allows to configure this parameter using a DT property. This is useful when i.e. the thermocouple is physically tied to the sensor and it is usually not removed, or when it is at least known in advance which sensor will be connected to the circuit. However, if the user can randomly connect any kind of thermocouples (i.e. the device exposes a connector, and the user is free to connect its own sensors), it would be more appropriate to provide a mechanism to dynamically switch from one thermocouple type to another. This can be i.e. handled in userspace by a GUI, a configuration file or a program that detects the thermocouple type by reading a GPIO, or a eeprom on the probe, or whatever. This patch adds a IIO attribute that can be used to override, at run-time, the DT-provided setting (which serves as default). 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 Signed-off-by: Andrea Merello <andrea.merello@gmail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-11-23iio: max31856: add support for configuring the HW averagingAndrea Merello
This sensor can perform samples averaging in hardware, but currently the driver leaves this setting alone (default is no averaging). This patch binds this HW setting to the "oversampling_ratio" IIO attribute and allows the user to set the averaging as desired (the HW supports averaging of 2, 5, 8 or 16 samples; in-between values are rounded up). 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 Signed-off-by: Andrea Merello <andrea.merello@gmail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-11-23iio: max31856: add option for setting mains filter rejection frequencyAndrea Merello
This sensor has an embedded notch filter for reducing interferences caused by the power mains. This filter can be tuned to reject either 50Hz or 60Hz (and harmonics). Currently the said setting is left alone (the sensor defaults to 60Hz). This patch introduces a IIO attribute that allows the user to set the said filter to the desired frequency. NOTE: this has been intentionally not tied to any DT property to allow the configuration of this setting from userspace, e.g. with a GUI or by reading a configuration file, or maybe reading a GPIO tied to a physical switch or accessing some device that can autodetect the line frequency. 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 Signed-off-by: Andrea Merello <andrea.merello@gmail.com> Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-09-15iio: max31856: add missing of_node and parent references to iio_devAndrea Merello
Adding missing indio_dev->dev.of_node references so that, in case multiple max31856 are present, users can get some clues to being able to distinguish each of them. While at it, add also the missing parent reference. Signed-off-by: Andrea Merello <andrea.merello@gmail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-04-14iio: temperature: max31856: fix uninitialized error returnColin Ian King
Currently if mask is neither CHAN_INFO_RAW or CHAN_INFO_SCALE then then an uninitialized error return 'ret' is returned. Fix this by adding a default case that ensures -EINVAL is returned for this specific case. Addresses-Coverity: ("Uninitialized scalar variable") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-04-04iio:temperature: Add MAX31856 thermocouple supportParesh Chaudhary
This patch adds support for Maxim MAX31856 thermocouple temperature sensor support. More information can be found in: https://www.maximintegrated.com/en/ds/MAX31856.pdf NOTE: Driver support only Comparator Mode. Signed-off-by: Paresh Chaudhary <paresh.chaudhary@rockwellcollins.com> Signed-off-by: Matt Weber <matthew.weber@rockwellcollins.com> Signed-off-by: Patrick Havelange <patrick.havelange@essensium.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>