Merge tag 'iio-for-5.16a-split-take4' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into char-misc-next

Jonathan writes:

First set of IIO new device and feature support for the 5.16 cycle

Counter subsystem changes now sent separately.

This has been a busy cycle, so lots here and a few more stragglers to
come next week.

Big new feature in this cycle is probably output buffer support.
This has been in the works for a very long time so it's great to see
Mihail pick up the challenge and build upon his predecessors work to finally
bring this feature to mainline.

New device support
------------------

* adi,adxl313
  - New driver and dt bindings for this low power accelerometer.
* adi,adxl355
  - New driver and dt bindings for this accelerometer.
  - Later series adds buffer support.
* asahi-kasei,ak8975
  - Minor additions to driver to support ak09916
* aspeed,aspeed-adc
  - Substantial rework plus feature additions to add support for the
    ast2600 including a new dt bindings doc.
* atmel,at91_sama5d2
  - Rework and support introduced for the sama7g5 parts.
* maxim,max31865
  - New driver and bindings for this RTD temperature sensor chip.
* nxp,imx8qxp
  - New driver and bindings for the ADC found on the i.MX 8QuadXPlus Soc.
* senseair,sunrise
  - New driver and bindings for this family of carbon dioxide gas sensors.
* sensiron,scd4x
  - New driver and bindings for this carbon dioxide gas sensor.

New features
------------

* Output buffer support.  Works in a similar fashion to input buffers, but
  in this case userspace pushes data into the kfifo which is then drained
  to the device when a trigger occurs.  Support added to the ad5766 DAC
  driver.
* Core, devm_iio_map_array_register() to avoid need for
  devm_add_action_or_reset() based cleanup in fully managed allocation
  drivers.
* Core iio_push_to_buffers_with_ts_unaligned() function to safely handle a
  few drivers where it really hard to ensure the correct data alignment in
  an iio_push_to_buffers_with_timestamp() call. Note this uses a bounce
  buffer so should be avoided whenever possible.  Used in the ti,adc108s102,
  invense,mpu3050 and adi,adis16400.  This closes the last   known set
  of drivers with alignment issues at this interface.
* maxim,max1027
  - Substantial rework to this driver main target of which was supporting
    use of other triggers than it's own EOC interrupt.
  - Transfer optimization.
* nxp,fxls8962af
  - Threshold even support including using it as a wakeup source.

Cleanups, minor fixes etc
-------------------------

Chances of a common type to multiple drivers:

* devm_ conversion and drop of .remove() callbacks in:
  - adi,ad5064
  - adi,ad7291
  - adi,ad7303
  - adi,ad7746
  - adi,ad9832
  - adi,adis16080
  - dialog,da9150-gpadc
  - intel,mrfld_adc
  - marvell,berlin2
  - maxim,max1363
  - maxim,max44000
  - nuvoton,nau7802
  - st_sensors (includes a lot of rework!)
  - ti,ads8344
  - ti,lp8788

* devm_platform_ioremap_resource() used to reduce boilerplate
  - cirrus,ep93xx
  - rockchip,saradc
  - stm,stm32-dac

* Use dev_err_probe() in more places to both not print on deferred probe and
  ensure a reason for the deferral is available for debug purposes.
  - adi,ad8801
  - capella,cm36651
  - linear,ltc1660
  - maxim,ds4424
  - maxim,max5821
  - microchip,mcp4922
  - nxp,lpc18xx
  - onnn,noa1305
  - st,lsm9ds0
  - st,st_sensors
  - st,stm32-dac
  - ti,afe4403
  - ti,afe4404
  - ti,dac7311

* Drop error returns in SPI and I2C remove() functions as they are ignored and
  long term plan is to change these all over to returning void. In some cases
  these patches just make it 'obvious' they always return 0 where it was the
  case before but not easy to tell.
  - adi,ad5380
  - adi,ad5446
  - adi,ad5686
  - adi,ad5592r
  - bosch,bma400
  - bosch,bmc150
  - fsl,mma7455
  - honeywell,hmc5843
  - kionix,kxsd9
  - maxim,max5487
  - meas,ms5611
  - ti,afe4403

Driver specific changes

* adi,ad5770r
  - Bring driver inline with documented bindings.
* adi,ad7746
  - Trivial style fix
* adi,ad7949
  - Express some magic values as the underlying parts via new #defines.
  - Make it work with SPI controllers that don't support 14 or 16 bit messages
  - Support selection of voltage reference from dt including expanding the
    dt-bindings to cover this new functionality.
* adi,ad799x
  - Implement selection of external reference voltage on AD7991, AD7995 and
    AD7999.
  - Add missing dt-bindings doc for devices supported by this driver.
* adi,adislib
  - Move interrupt startup to better location in startup flow.
  - Handle devices that cannot mask/unmask the drdy pin and must instead mask
    at the interrupt controller.  Applies to the adis16460 and adis16475 from
    which we then drop equivalent code.
* adi,ltc2983
  - Add support for optional reset pin.
  - Fail to probe if no channels specified in dt binding.
* asahi-kasei,ak8975
  - dt-binding additions of missing vid-supply regulator.
* aspeed,aspeed-adc
  - Typo fix.
* fsl,mma7660
  - Mark acpi_device_id table __maybe_unused to avoid build warning.
* fsl,imx25-gcq
  - Avoid initializing regulators that aren't used.
* invensense,mpu3050
  - Drop a dead protection against a clash with the old input driver.
* invensense,mpu6050
  - Rework code to not use strcpy() and hence avoid possibility of wrong sized
    buffers. Note this wasn't a bug, but the new code is a lot more readable.
  - Mark acpi_device_id table __maybe_unused to avoid build warning.
* kionix,kxcjk1013
  - dt-binding addition to note it supports interrupts.
* marvell,berlin2-adc
  - Enable COMPILE_TEST building.
* maxim,max1027
  - Avoid returning success in an error path.
* nxp,imx8qxp
  - Fix warning when runtime pm not enabled via __maybe_unused.
* ricoh,rn5t618
  - Use the new devm_iio_map_array_register() instead of open coding the same.
* samsung,exynos_adc
  - Improve kconfig help text.
* st,lsm6dsx
  - Move max_fifo_size into the fifo_ops structure where the other configuration
    parameters are found.
* st,st_sensors:
  - Reorder to ensure we turn the power off after removing userspace interfaces.
* senseair,sunrise
  - Add missing I2C dependency.
* ti,twl6030
  - Small code tidy up.

* tag 'iio-for-5.16a-split-take4' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio: (148 commits)
  iio: imx8qxp-adc: mark PM functions as __maybe_unused
  iio: pressure: ms5611: Make ms5611_remove() return void
  iio: potentiometer: max5487: Don't return an error in .remove()
  iio: magn: hmc5843: Make hmc5843_common_remove() return void
  iio: health: afe4403: Don't return an error in .remove()
  iio: dac: ad5686: Make ad5686_remove() return void
  iio: dac: ad5592r: Make ad5592r_remove() return void
  iio: dac: ad5446: Make ad5446_remove() return void
  iio: dac: ad5380: Make ad5380_remove() return void
  iio: accel: mma7455: Make mma7455_core_remove() return void
  iio: accel: kxsd9: Make kxsd9_common_remove() return void
  iio: accel: bmi088: Make bmi088_accel_core_remove() return void
  iio: accel: bmc150: Make bmc150_accel_core_remove() return void
  iio: accel: bma400: Make bma400_remove() return void
  drivers:iio:dac:ad5766.c: Add trigger buffer
  iio: triggered-buffer: extend support to configure output buffers
  iio: kfifo-buffer: Add output buffer support
  iio: Add output buffer support
  iio: documentation: Document scd4x calibration use
  drivers: iio: chemical: Add support for Sensirion SCD4x CO2 sensor
  ...

4 files changed, 100 insertions, 34 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 6ad47a67521c..c551301b33f1 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -429,6 +429,7 @@ What:		/sys/bus/iio/devices/iio:deviceX/in_angl_scale
 What:		/sys/bus/iio/devices/iio:deviceX/in_intensity_x_scale
 What:		/sys/bus/iio/devices/iio:deviceX/in_intensity_y_scale
 What:		/sys/bus/iio/devices/iio:deviceX/in_intensity_z_scale
+What:		/sys/bus/iio/devices/iio:deviceX/in_concentration_co2_scale
 KernelVersion:	2.6.35
 Contact:	linux-iio@vger.kernel.org
 Description:
@@ -1957,3 +1958,44 @@ Description:
 		Specify the percent for light sensor relative to the channel
 		absolute value that a data field should change before an event
 		is generated. Units are a percentage of the prior reading.
+
+What:		/sys/bus/iio/devices/iio:deviceX/calibration_auto_enable
+Date:		June 2020
+KernelVersion:	5.8
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Some sensors have the ability to apply auto calibration at
+		runtime. For example, it may be necessary to compensate for
+		contaminant build-up in a measurement chamber or optical
+		element deterioration that would otherwise lead to sensor drift.
+
+		Writing 1 or 0 to this attribute will respectively activate or
+		deactivate this auto calibration function.
+
+		Upon reading, the current status is returned.
+
+What:		/sys/bus/iio/devices/iio:deviceX/calibration_forced_value
+Date:		June 2020
+KernelVersion:	5.8
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Some sensors have the ability to apply a manual calibration using
+		a known measurement value, perhaps obtained from an external
+		reference device.
+
+		Writing a value to this function will force such a calibration
+		change. For the scd30 the value should be from the range
+		[400 1 2000].
+
+		Note for the scd30 that a valid value may only be obtained once
+		it is has been written. Until then any read back of this value
+		should be ignored. As for the scd4x an error will be returned
+		immediately if the manual calibration has failed.
+
+What:		/sys/bus/iio/devices/iio:deviceX/calibration_forced_value_available
+KernelVersion:  5.15
+Contact:        linux-iio@vger.kernel.org
+Description:
+		Available range for the forced calibration value, expressed as:
+
+		- a range specified as "[min step max]"
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2 b/Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2
new file mode 100644
index 000000000000..ee7aeb11709b
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2
@@ -0,0 +1,38 @@
+What:		/sys/bus/iio/devices/iio:deviceX/in_concentration_co2_calibration_factory
+Date:		August 2021
+KernelVersion:	5.16
+Contact:	Jacopo Mondi <jacopo@jmondi.org>
+Description:
+		Writing '1' triggers a 'Factory' calibration cycle.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_concentration_co2_calibration_background
+Date:		August 2021
+KernelVersion:	5.16
+Contact:	Jacopo Mondi <jacopo@jmondi.org>
+Description:
+		Writing '1' triggers a 'Background' calibration cycle.
+
+What:		/sys/bus/iio/devices/iio:deviceX/error_status_available
+Date:		August 2021
+KernelVersion:	5.16
+Contact:	Jacopo Mondi <jacopo@jmondi.org>
+Description:
+		Reading returns the list of possible chip error status.
+		Available options are:
+		- 'error_fatal': Analog front-end initialization error
+		- 'error_i2c': Read/write to non-existing register
+		- 'error_algorithm': Corrupted parameters
+		- 'error_calibration': Calibration has failed
+		- 'error_self_diagnostic': Internal interface failure
+		- 'error_out_of_range': Measured concentration out of scale
+		- 'error_memory': Error during memory operations
+		- 'error_no_measurement': Cleared at first measurement
+		- 'error_low_voltage': Sensor regulated voltage too low
+		- 'error_measurement_timeout': Unable to complete measurement
+
+What:		/sys/bus/iio/devices/iio:deviceX/error_status
+Date:		August 2021
+KernelVersion:	5.16
+Contact:	Jacopo Mondi <jacopo@jmondi.org>
+Description:
+		Reading returns the current chip error status.
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-scd30 b/Documentation/ABI/testing/sysfs-bus-iio-scd30
deleted file mode 100644
index b9712f390bec..000000000000
--- a/Documentation/ABI/testing/sysfs-bus-iio-scd30
+++ /dev/null
@@ -1,34 +0,0 @@
-What:		/sys/bus/iio/devices/iio:deviceX/calibration_auto_enable
-Date:		June 2020
-KernelVersion:	5.8
-Contact:	linux-iio@vger.kernel.org
-Description:
-		Contaminants build-up in the measurement chamber or optical
-		elements deterioration leads to sensor drift.
-
-		One can compensate for sensor drift by using automatic self
-		calibration procedure (asc).
-
-		Writing 1 or 0 to this attribute will respectively activate or
-		deactivate asc.
-
-		Upon reading current asc status is returned.
-
-What:		/sys/bus/iio/devices/iio:deviceX/calibration_forced_value
-Date:		June 2020
-KernelVersion:	5.8
-Contact:	linux-iio@vger.kernel.org
-Description:
-		Contaminants build-up in the measurement chamber or optical
-		elements deterioration leads to sensor drift.
-
-		One can compensate for sensor drift by using forced
-		recalibration (frc). This is useful in case there's known
-		co2 reference available nearby the sensor.
-
-		Picking value from the range [400 1 2000] and writing it to the
-		sensor will set frc.
-
-		Upon reading current frc value is returned. Note that after
-		power cycling default value (i.e 400) is returned even though
-		internally sensor had recalibrated itself.
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-temperature-max31865 b/Documentation/ABI/testing/sysfs-bus-iio-temperature-max31865
new file mode 100644
index 000000000000..4b072da92218
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-temperature-max31865
@@ -0,0 +1,20 @@
+What:		/sys/bus/iio/devices/iio:deviceX/fault_ovuv
+KernelVersion:	5.11
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Overvoltage or Undervoltage Input fault. The internal circuitry
+		is protected from excessive voltages applied to the thermocouple
+		cables at FORCE+, FORCE2, RTDIN+ & RTDIN-. This circuitry turn
+		off when the input voltage is negative or greater than VDD.
+
+		Reading returns '1' if input voltage is negative or greater
+		than VDD, otherwise '0'.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_filter_notch_center_frequency
+KernelVersion:	5.11
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Notch frequency in Hz for a noise rejection filter. Used i.e for
+		line noise rejection.
+
+		Valid notch filter values are 50 Hz and 60 Hz.