Merge tag 'iio-for-6.9b' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into char-misc-next

Jonathan writes:

IIO: 2nd set of new device support, cleanups and features for 6.9

New device support
=================
adi,hmc425a
- Add support for LTC6373 Instrumentation Amplifier.
microchip,pac1934
- New driver supporting PAC1931, PAC1932, PAC1933 and PAC1934 power monitoring
chips with accumulators.
voltafield,af8133j
- New driver for the AF8133J 3 axis magnetometer.

Docs
====

New general documentation of device buffers, and a specific section on
the adi,adis16475 IMU

Features
========

kionix,kxcjk-1013
 - Add support for ACPI ROTM (Microsoft defined ACPI method) to get rotation
   matrix.
ti,tmp117
- Add missing vcc-supply control and binding.

Cleanups and minor fixes
========================

Tree-wide
- Corrected headers to remove linux/of.h from a bunch of drivers
  that only had it to get to linux/mod_devicetable.h
- dt binding cleanup to drop redundant type from label properties.

adi,hmc425a
- Fix constraints on GPIO array sizes for different devices.
adi,ltc2983
- Use spi_get_device_match_data instead of open coding similar.
- Update naming of fw parsing function to reflect that it is not longer
  dt only.
- Set the chip name explicitly to reduce fragility resulting from different
  entries in the various ID tables.
bosch,bmg160
- Add spi-max-frequency property and limit to dt-binding.
microchip,mcp320x
- Use devm_* to simplify device removal and error handling.
nxp,imx93
- Drop a non existent 4th interrupt from bindings.
qcom,mp8xxx-xoadc
- Drop unused kerneldoc
renesas,isl29501
- Actually use the of_match table.
rockchip,saradc
- Fix channel bitmask
- Fix write masks
- Replace custom handling of optional reset control with how it should be
  done.
ti,ads1298
- Fix error code to not return a successfully obtained regulator.
- Avoid a divide by zero when setting frequency.
ti,hdc2010
- Add missing interrupts dt binding property
vishay,veml6075
- Make vdd-supply required in the dt-binding.

* tag 'iio-for-6.9b' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio: (42 commits)
  dt-bindings: iio: gyroscope: bosch,bmg160: add spi-max-frequency
  dt-bindings: iio: adc: imx93: drop the 4th interrupt
  iio: proximity: isl29501: make use of of_device_id table
  iio: adc: qcom-pm8xxx-xoadc: drop unused kerneldoc struct pm8xxx_chan_info member
  dt-bindings: iio: adc: drop redundant type from label
  dt-bindings: iio: ti,tmp117: add optional label property
  MAINTAINERS: Add an entry for AF8133J driver
  iio: magnetometer: add a driver for Voltafield AF8133J magnetometer
  dt-bindings: iio: magnetometer: Add Voltafield AF8133J
  dt-bindings: vendor-prefix: Add prefix for Voltafield
  iio: adc: rockchip_saradc: replace custom logic with devm_reset_control_get_optional_exclusive
  iio: adc: rockchip_saradc: use mask for write_enable bitfield
  iio: adc: rockchip_saradc: fix bitmask for channels on SARADCv2
  dt-bindings: iio: light: vishay,veml6075: make vdd-supply required
  iio: adc: adding support for PAC193x
  dt-bindings: iio: adc: adding support for PAC193X
  iio: temperature: ltc2983: explicitly set the name in chip_info
  iio: temperature: ltc2983: rename ltc2983_parse_dt()
  iio: temperature: ltc2983: make use of spi_get_device_match_data()
  iio: adc: ti-ads1298: prevent divide by zero in ads1298_set_samp_freq()
  ...

15 files changed, 822 insertions, 10 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-pac1934 b/Documentation/ABI/testing/sysfs-bus-iio-adc-pac1934
new file mode 100644
index 0000000000000..625b7f8678478
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-adc-pac1934
@@ -0,0 +1,9 @@
+What:		/sys/bus/iio/devices/iio:deviceX/in_shunt_resistorY
+KernelVersion:	6.7
+Contact:	linux-iio@vger.kernel.org
+Description:
+		The value of the shunt resistor may be known only at runtime
+		and set by a client application. This attribute allows to
+		set its value in micro-ohms. X is the IIO index of the device.
+		Y is the channel number. The value is used to calculate
+		current, power and accumulated energy.
diff --git a/Documentation/devicetree/bindings/iio/adc/adc.yaml b/Documentation/devicetree/bindings/iio/adc/adc.yaml
index 2616017297456..36775f8f71dfd 100644
--- a/Documentation/devicetree/bindings/iio/adc/adc.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/adc.yaml
@@ -22,7 +22,6 @@ properties:
     maxItems: 1
 
   label:
-    $ref: /schemas/types.yaml#/definitions/string
     description: Unique name to identify which channel this is.
 
   bipolar:
diff --git a/Documentation/devicetree/bindings/iio/adc/microchip,pac1934.yaml b/Documentation/devicetree/bindings/iio/adc/microchip,pac1934.yaml
new file mode 100644
index 0000000000000..47a11a9ac95e2
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/microchip,pac1934.yaml
@@ -0,0 +1,120 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/microchip,pac1934.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip PAC1934 Power Monitors with Accumulator
+
+maintainers:
+  - Marius Cristea <marius.cristea@microchip.com>
+
+description: |
+  This device is part of the Microchip family of Power Monitors with
+  Accumulator.
+  The datasheet for PAC1931, PAC1932, PAC1933 and PAC1934 can be found here:
+    https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/PAC1931-Family-Data-Sheet-DS20005850E.pdf
+
+properties:
+  compatible:
+    enum:
+      - microchip,pac1931
+      - microchip,pac1932
+      - microchip,pac1933
+      - microchip,pac1934
+
+  reg:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  interrupts:
+    maxItems: 1
+
+  slow-io-gpios:
+    description:
+      A GPIO used to trigger a change is sampling rate (lowering the chip power
+      consumption). If configured in SLOW mode, if this pin is forced high,
+      sampling rate is forced to eight samples/second. When it is forced low,
+      the sampling rate is 1024 samples/second unless a different sample rate
+      has been programmed.
+
+patternProperties:
+  "^channel@[1-4]+$":
+    type: object
+    $ref: adc.yaml
+    description:
+      Represents the external channels which are connected to the ADC.
+
+    properties:
+      reg:
+        items:
+          minimum: 1
+          maximum: 4
+
+      shunt-resistor-micro-ohms:
+        description:
+          Value in micro Ohms of the shunt resistor connected between
+          the SENSE+ and SENSE- inputs, across which the current is measured.
+          Value is needed to compute the scaling of the measured current.
+
+    required:
+      - reg
+      - shunt-resistor-micro-ohms
+
+    unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        power-monitor@10 {
+            compatible = "microchip,pac1934";
+            reg = <0x10>;
+
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            channel@1 {
+                reg = <0x1>;
+                shunt-resistor-micro-ohms = <24900000>;
+                label = "CPU";
+            };
+
+            channel@2 {
+                reg = <0x2>;
+                shunt-resistor-micro-ohms = <49900000>;
+                label = "GPU";
+            };
+
+            channel@3 {
+                reg = <0x3>;
+                shunt-resistor-micro-ohms = <75000000>;
+                label = "MEM";
+                bipolar;
+            };
+
+            channel@4 {
+                reg = <0x4>;
+                shunt-resistor-micro-ohms = <100000000>;
+                label = "NET";
+                bipolar;
+            };
+        };
+    };
+
+...
diff --git a/Documentation/devicetree/bindings/iio/adc/nxp,imx93-adc.yaml b/Documentation/devicetree/bindings/iio/adc/nxp,imx93-adc.yaml
index dacc526dc6953..dfc3f512918f6 100644
--- a/Documentation/devicetree/bindings/iio/adc/nxp,imx93-adc.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/nxp,imx93-adc.yaml
@@ -31,7 +31,6 @@ properties:
       - description: normal conversion, include EOC (End of Conversion),
           ECH (End of Chain), JEOC (End of Injected Conversion) and
           JECH (End of injected Chain).
-      - description: Self-testing Interrupts.
 
   clocks:
     maxItems: 1
@@ -70,8 +69,7 @@ examples:
             reg = <0x44530000 0x10000>;
             interrupts = <GIC_SPI 217 IRQ_TYPE_LEVEL_HIGH>,
                          <GIC_SPI 218 IRQ_TYPE_LEVEL_HIGH>,
-                         <GIC_SPI 219 IRQ_TYPE_LEVEL_HIGH>,
-                         <GIC_SPI 268 IRQ_TYPE_LEVEL_HIGH>;
+                         <GIC_SPI 219 IRQ_TYPE_LEVEL_HIGH>;
             clocks = <&clk IMX93_CLK_ADC1_GATE>;
             clock-names = "ipg";
             vref-supply = <&reg_vref_1v8>;
diff --git a/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.yaml b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.yaml
index 40fa0710f1f0f..c28db0d635a0a 100644
--- a/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.yaml
@@ -75,7 +75,6 @@ patternProperties:
           in the PMIC-specific files in include/dt-bindings/iio/.
 
       label:
-        $ref: /schemas/types.yaml#/definitions/string
         description: |
             ADC input of the platform as seen in the schematics.
             For thermistor inputs connected to generic AMUX or GPIO inputs
diff --git a/Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml b/Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
index 67de9d4e3a1df..3a470459b9658 100644
--- a/Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
+++ b/Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
@@ -21,6 +21,8 @@ description: |
   HMC540S 1 dB LSB Silicon MMIC 4-Bit Digital Positive Control Attenuator, 0.1 - 8 GHz
     https://www.analog.com/media/en/technical-documentation/data-sheets/hmc540s.pdf
 
+  LTC6373 is a 3-Bit precision instrumentation amplifier with fully differential outputs
+    https://www.analog.com/media/en/technical-documentation/data-sheets/ltc6373.pdf
 
 properties:
   compatible:
@@ -28,16 +30,55 @@ properties:
       - adi,adrf5740
       - adi,hmc425a
       - adi,hmc540s
+      - adi,ltc6373
 
   vcc-supply: true
 
   ctrl-gpios:
     description:
-      Must contain an array of 6 GPIO specifiers, referring to the GPIO pins
-      connected to the control pins V1-V6.
-    minItems: 6
+      Must contain an array of GPIO specifiers, referring to the GPIO pins
+      connected to the control pins.
+        ADRF5740  - 4 GPIO connected to D2-D5
+        HMC540S   - 4 GPIO connected to V1-V4
+        HMC425A   - 6 GPIO connected to V1-V6
+        LTC6373   - 3 GPIO connected to A0-A2
+    minItems: 1
     maxItems: 6
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: adi,hmc425a
+    then:
+      properties:
+        ctrl-gpios:
+          minItems: 6
+          maxItems: 6
+  - if:
+      properties:
+        compatible:
+          contains:
+            anyOf:
+              - const: adi,adrf5740
+              - const: adi,hmc540s
+    then:
+      properties:
+        ctrl-gpios:
+          minItems: 4
+          maxItems: 4
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: adi,ltc6373
+    then:
+      properties:
+        ctrl-gpios:
+          minItems: 3
+          maxItems: 3
+
 required:
   - compatible
   - ctrl-gpios
diff --git a/Documentation/devicetree/bindings/iio/gyroscope/bosch,bmg160.yaml b/Documentation/devicetree/bindings/iio/gyroscope/bosch,bmg160.yaml
index 1414ba9977c16..3c6fe74af0b83 100644
--- a/Documentation/devicetree/bindings/iio/gyroscope/bosch,bmg160.yaml
+++ b/Documentation/devicetree/bindings/iio/gyroscope/bosch,bmg160.yaml
@@ -22,6 +22,9 @@ properties:
   vdd-supply: true
   vddio-supply: true
 
+  spi-max-frequency:
+    maximum: 10000000
+
   interrupts:
     minItems: 1
     maxItems: 2
@@ -33,7 +36,10 @@ required:
   - compatible
   - reg
 
-additionalProperties: false
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+unevaluatedProperties: false
 
 examples:
   - |
diff --git a/Documentation/devicetree/bindings/iio/humidity/ti,hdc2010.yaml b/Documentation/devicetree/bindings/iio/humidity/ti,hdc2010.yaml
index 79e75a8675cba..e3eca89175175 100644
--- a/Documentation/devicetree/bindings/iio/humidity/ti,hdc2010.yaml
+++ b/Documentation/devicetree/bindings/iio/humidity/ti,hdc2010.yaml
@@ -27,6 +27,9 @@ properties:
   reg:
     maxItems: 1
 
+  interrupts:
+    maxItems: 1
+
 required:
   - compatible
   - reg
diff --git a/Documentation/devicetree/bindings/iio/light/vishay,veml6075.yaml b/Documentation/devicetree/bindings/iio/light/vishay,veml6075.yaml
index abee04cd126e4..91c318746bf30 100644
--- a/Documentation/devicetree/bindings/iio/light/vishay,veml6075.yaml
+++ b/Documentation/devicetree/bindings/iio/light/vishay,veml6075.yaml
@@ -21,6 +21,7 @@ properties:
 required:
   - compatible
   - reg
+  - vdd-supply
 
 additionalProperties: false
 
diff --git a/Documentation/devicetree/bindings/iio/magnetometer/voltafield,af8133j.yaml b/Documentation/devicetree/bindings/iio/magnetometer/voltafield,af8133j.yaml
new file mode 100644
index 0000000000000..b6ab01a6914ad
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/magnetometer/voltafield,af8133j.yaml
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/magnetometer/voltafield,af8133j.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Voltafield AF8133J magnetometer sensor
+
+maintainers:
+  - Ondřej Jirman <megi@xff.cz>
+
+properties:
+  compatible:
+    const: voltafield,af8133j
+
+  reg:
+    maxItems: 1
+
+  reset-gpios:
+    description:
+      A signal for active low reset input of the sensor. (optional; if not
+      used, software reset over I2C will be used instead)
+
+  avdd-supply:
+    description:
+      A regulator that provides AVDD power (Working power, usually 3.3V) to
+      the sensor.
+
+  dvdd-supply:
+    description:
+      A regulator that provides DVDD power (Digital IO power, 1.8V - AVDD)
+      to the sensor.
+
+  mount-matrix:
+    description: An optional 3x3 mounting rotation matrix.
+
+required:
+  - compatible
+  - reg
+  - avdd-supply
+  - dvdd-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        magnetometer@1c {
+            compatible = "voltafield,af8133j";
+            reg = <0x1c>;
+            avdd-supply = <&reg_dldo1>;
+            dvdd-supply = <&reg_dldo1>;
+            reset-gpios = <&pio 1 1 GPIO_ACTIVE_LOW>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/iio/temperature/ti,tmp117.yaml b/Documentation/devicetree/bindings/iio/temperature/ti,tmp117.yaml
index 8c6d7735e8750..58aa1542776b5 100644
--- a/Documentation/devicetree/bindings/iio/temperature/ti,tmp117.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/ti,tmp117.yaml
@@ -24,9 +24,16 @@ properties:
   reg:
     maxItems: 1
 
+  vcc-supply:
+    description: provide VCC power to the sensor.
+
+  label:
+    description: Unique name to identify which device this is.
+
 required:
   - compatible
   - reg
+  - vcc-supply
 
 additionalProperties: false
 
@@ -39,5 +46,6 @@ examples:
         tmp117@48 {
              compatible = "ti,tmp117";
              reg = <0x48>;
+             vcc-supply = <&pmic_reg_3v3>;
         };
     };
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index 1a0dc04f1db47..82e9f64c90ff4 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -1534,6 +1534,8 @@ patternProperties:
     description: VoCore Studio
   "^voipac,.*":
     description: Voipac Technologies s.r.o.
+  "^voltafield,.*":
+    description: Voltafield Technology Corp.
   "^vot,.*":
     description: Vision Optical Technology Co., Ltd.
   "^vxt,.*":
diff --git a/Documentation/iio/adis16475.rst b/Documentation/iio/adis16475.rst
new file mode 100644
index 0000000000000..91cabb7d8d057
--- /dev/null
+++ b/Documentation/iio/adis16475.rst
@@ -0,0 +1,407 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+================
+ADIS16475 driver
+================
+
+This driver supports Analog Device's IMUs on SPI bus.
+
+1. Supported devices
+====================
+
+* `ADIS16465 <https://www.analog.com/ADIS16465>`_
+* `ADIS16467 <https://www.analog.com/ADIS16467>`_
+* `ADIS16470 <https://www.analog.com/ADIS16470>`_
+* `ADIS16475 <https://www.analog.com/ADIS16475>`_
+* `ADIS16477 <https://www.analog.com/ADIS16477>`_
+* `ADIS16500 <https://www.analog.com/ADIS16500>`_
+* `ADIS16505 <https://www.analog.com/ADIS16505>`_
+* `ADIS16507 <https://www.analog.com/ADIS16507>`_
+
+Each supported device is a precision, miniature microelectromechanical system
+(MEMS) inertial measurement unit (IMU) that includes a triaxial gyroscope and a
+triaxial accelerometer. Each inertial sensor in the IMU device combines with
+signal conditioning that optimizes dynamic performance. The factory calibration
+characterizes each sensor for sensitivity, bias, alignment, linear acceleration
+(gyroscope bias), and point of percussion (accelerometer location). As a result,
+each sensor has dynamic compensation formulas that provide accurate sensor
+measurements over a broad set of conditions.
+
+2. Device attributes
+====================
+
+Accelerometer, gyroscope measurements are always provided. Furthermore, the
+driver offers the capability to retrieve the delta angle and the delta velocity
+measurements computed by the device.
+
+The delta angle measurements represent a calculation of angular displacement
+between each sample update, while the delta velocity measurements represent a
+calculation of linear velocity change between each sample update.
+
+Finally, temperature data are provided which show a coarse measurement of
+the temperature inside of the IMU device. This data is most useful for
+monitoring relative changes in the thermal environment.
+
+The signal chain of each inertial sensor (accelerometers and gyroscopes)
+includes the application of unique correction formulas, which are derived from
+extensive characterization of bias, sensitivity, alignment, response to linear
+acceleration (gyroscopes), and point of percussion (accelerometer location)
+over a temperature range of −40°C to +85°C, for each ADIS device. These
+correction formulas are not accessible, but users do have the opportunity to
+adjust the bias for each sensor individually through the calibbias attribute.
+
+Each IIO device, has a device folder under ``/sys/bus/iio/devices/iio:deviceX``,
+where X is the IIO index of the device. Under these folders reside a set of
+device files, depending on the characteristics and features of the hardware
+device in questions. These files are consistently generalized and documented in
+the IIO ABI documentation.
+
+The following tables show the adis16475 related device files, found in the
+specific device folder path ``/sys/bus/iio/devices/iio:deviceX``.
+
++-------------------------------------------+----------------------------------------------------------+
+| 3-Axis Accelerometer related device files | Description                                              |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_scale                            | Scale for the accelerometer channels.                    |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_x_calibbias                      | Calibration offset for the X-axis accelerometer channel. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_calibbias_x                      | x-axis acceleration offset correction                    |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_x_raw                            | Raw X-axis accelerometer channel value.                  |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_calibbias_y                      | y-axis acceleration offset correction                    |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_y_raw                            | Raw Y-axis accelerometer channel value.                  |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_z_calibbias                      | Calibration offset for the Z-axis accelerometer channel. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_z_raw                            | Raw Z-axis accelerometer channel value.                  |
++-------------------------------------------+----------------------------------------------------------+
+| in_deltavelocity_scale                    | Scale for delta velocity channels.                       |
++-------------------------------------------+----------------------------------------------------------+
+| in_deltavelocity_x_raw                    | Raw X-axis delta velocity channel value.                 |
++-------------------------------------------+----------------------------------------------------------+
+| in_deltavelocity_y_raw                    | Raw Y-axis delta velocity channel value.                 |
++-------------------------------------------+----------------------------------------------------------+
+| in_deltavelocity_z_raw                    | Raw Z-axis delta velocity channel value.                 |
++-------------------------------------------+----------------------------------------------------------+
+
++---------------------------------------+------------------------------------------------------+
+| 3-Axis Gyroscope related device files | Description                                          |
++---------------------------------------+------------------------------------------------------+
+| in_anglvel_scale                      | Scale for the gyroscope channels.                    |
++---------------------------------------+------------------------------------------------------+
+| in_anglvel_x_calibbias                | Calibration offset for the X-axis gyroscope channel. |
++---------------------------------------+------------------------------------------------------+
+| in_anglvel_calibbias_x                | x-axis gyroscope offset correction                   |
++---------------------------------------+------------------------------------------------------+
+| in_anglvel_x_raw                      | Raw X-axis gyroscope channel value.                  |
++---------------------------------------+------------------------------------------------------+
+| in_anglvel_calibbias_y                | y-axis gyroscope offset correction                   |
++---------------------------------------+------------------------------------------------------+
+| in_anglvel_y_raw                      | Raw Y-axis gyroscope channel value.                  |
++---------------------------------------+------------------------------------------------------+
+| in_anglvel_z_calibbias                | Calibration offset for the Z-axis gyroscope channel. |
++---------------------------------------+------------------------------------------------------+
+| in_anglvel_z_raw                      | Raw Z-axis gyroscope channel value.                  |
++---------------------------------------+------------------------------------------------------+
+| in_deltaangl_scale                    | Scale for delta angle channels.                      |
++---------------------------------------+------------------------------------------------------+
+| in_deltaangl_x_raw                    | Raw X-axis delta angle channel value.                |
++---------------------------------------+------------------------------------------------------+
+| in_deltaangl_y_raw                    | Raw Y-axis delta angle channel value.                |
++---------------------------------------+------------------------------------------------------+
+| in_deltaangl_z_raw                    | Raw Z-axis delta angle channel value.                |
++---------------------------------------+------------------------------------------------------+
+
++----------------------------------+-------------------------------------------+
+| Temperature sensor related files | Description                               |
++----------------------------------+-------------------------------------------+
+| in_temp0_raw                     | Raw temperature channel value.            |
++----------------------------------+-------------------------------------------+
+| in_temp0_scale                   | Scale for the temperature sensor channel. |
++----------------------------------+-------------------------------------------+
+
++-------------------------------+---------------------------------------------------------+
+| Miscellaneous device files    | Description                                             |
++-------------------------------+---------------------------------------------------------+
+| name                          | Name of the IIO device.                                 |
++-------------------------------+---------------------------------------------------------+
+| sampling_frequency            | Currently selected sample rate.                         |
++-------------------------------+---------------------------------------------------------+
+| filter_low_pass_3db_frequency | Bandwidth for the accelerometer and gyroscope channels. |
++-------------------------------+---------------------------------------------------------+
+
+The following table shows the adis16475 related device debug files, found in the
+specific device debug folder path ``/sys/kernel/debug/iio/iio:deviceX``.
+
++----------------------+-------------------------------------------------------------------------+
+| Debugfs device files | Description                                                             |
++----------------------+-------------------------------------------------------------------------+
+| serial_number        | The serial number of the chip in hexadecimal format.                    |
++----------------------+-------------------------------------------------------------------------+
+| product_id           | Chip specific product id (e.g. 16475, 16500, 16505, etc.).              |
++----------------------+-------------------------------------------------------------------------+
+| flash_count          | The number of flash writes performed on the device.                     |
++----------------------+-------------------------------------------------------------------------+
+| firmware_revision    | String containing the firmware revision in the following format ##.##.  |
++----------------------+-------------------------------------------------------------------------+
+| firmware_date        | String containing the firmware date in the following format mm-dd-yyyy. |
++----------------------+-------------------------------------------------------------------------+
+
+Channels processed values
+-------------------------
+
+A channel value can be read from its _raw attribute. The value returned is the
+raw value as reported by the devices. To get the processed value of the channel,
+apply the following formula:
+
+.. code-block:: bash
+
+        processed value = (_raw + _offset) * _scale
+
+Where _offset and _scale are device attributes. If no _offset attribute is
+present, simply assume its value is 0.
+
+The adis16475 driver offers data for 5 types of channels, the table below shows
+the measurement units for the processed value, which are defined by the IIO
+framework:
+
++-------------------------------------+---------------------------+
+| Channel type                        | Measurement unit          |
++-------------------------------------+---------------------------+
+| Acceleration on X, Y, and Z axis    | Meters per Second squared |
++-------------------------------------+---------------------------+
+| Angular velocity on X, Y and Z axis | Radians per second        |
++-------------------------------------+---------------------------+
+| Delta velocity on X. Y, and Z axis  | Meters per Second         |
++-------------------------------------+---------------------------+
+| Delta angle on X, Y, and Z axis     | Radians                   |
++-------------------------------------+---------------------------+
+| Temperature                         | Millidegrees Celsius      |
++-------------------------------------+---------------------------+
+
+Usage examples
+--------------
+
+Show device name:
+
+.. code-block:: bash
+
+	root:/sys/bus/iio/devices/iio:device0> cat name
+        adis16505-2
+
+Show accelerometer channels value:
+
+.. code-block:: bash
+
+        root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_raw
+        -275924
+        root:/sys/bus/iio/devices/iio:device0> cat in_accel_y_raw
+        -30142222
+        root:/sys/bus/iio/devices/iio:device0> cat in_accel_z_raw
+        261265769
+        root:/sys/bus/iio/devices/iio:device0> cat in_accel_scale
+        0.000000037
+
+- X-axis acceleration = in_accel_x_raw * in_accel_scale = −0.010209188 m/s^2
+- Y-axis acceleration = in_accel_y_raw * in_accel_scale = −1.115262214 m/s^2
+- Z-axis acceleration = in_accel_z_raw * in_accel_scale = 9.666833453 m/s^2
+
+Show gyroscope channels value:
+
+.. code-block:: bash
+
+        root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_x_raw
+        -3324626
+        root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_raw
+        1336980
+        root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_z_raw
+        -602983
+        root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_scale
+        0.000000006
+
+- X-axis angular velocity = in_anglvel_x_raw * in_anglvel_scale = −0.019947756 rad/s
+- Y-axis angular velocity = in_anglvel_y_raw * in_anglvel_scale = 0.00802188 rad/s
+- Z-axis angular velocity = in_anglvel_z_raw * in_anglvel_scale = −0.003617898 rad/s
+
+Set calibration offset for accelerometer channels:
+
+.. code-block:: bash
+
+        root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_calibbias
+        0
+
+        root:/sys/bus/iio/devices/iio:device0> echo 5000 > in_accel_x_calibbias
+        root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_calibbias
+        5000
+
+Set calibration offset for gyroscope channels:
+
+.. code-block:: bash
+
+        root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_calibbias
+        0
+
+        root:/sys/bus/iio/devices/iio:device0> echo -5000 > in_anglvel_y_calibbias
+        root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_calibbias
+        -5000
+
+Set sampling frequency:
+
+.. code-block:: bash
+
+	root:/sys/bus/iio/devices/iio:device0> cat sampling_frequency
+        2000.000000
+
+        root:/sys/bus/iio/devices/iio:device0> echo 1000 > sampling_frequency
+        1000.000000
+
+Set bandwidth for accelerometer and gyroscope:
+
+.. code-block:: bash
+
+        root:/sys/bus/iio/devices/iio:device0> cat filter_low_pass_3db_frequency
+        720
+
+        root:/sys/bus/iio/devices/iio:device0> echo 360 > filter_low_pass_3db_frequency
+        root:/sys/bus/iio/devices/iio:device0> cat filter_low_pass_3db_frequency
+        360
+
+Show serial number:
+
+.. code-block:: bash
+
+        root:/sys/kernel/debug/iio/iio:device0> cat serial_number
+        0x04f9
+
+Show product id:
+
+.. code-block:: bash
+
+        root:/sys/kernel/debug/iio/iio:device0> cat product_id
+        16505
+
+Show flash count:
+
+.. code-block:: bash
+
+        root:/sys/kernel/debug/iio/iio:device0> cat flash_count
+        150
+
+Show firmware revision:
+
+.. code-block:: bash
+
+        root:/sys/kernel/debug/iio/iio:device0> cat firmware_revision
+        1.6
+
+Show firmware date:
+
+.. code-block:: bash
+
+        root:/sys/kernel/debug/iio/iio:device0> cat firmware_date
+        06-27-2019
+
+3. Device buffers
+=================
+
+This driver supports IIO buffers.
+
+All devices support retrieving the raw acceleration, gyroscope and temperature
+measurements using buffers.
+
+The following device families also support retrieving the delta velocity, delta
+angle and temperature measurements using buffers:
+
+- ADIS16477
+- ADIS16500
+- ADIS16505
+- ADIS16507
+
+However, when retrieving acceleration or gyroscope data using buffers, delta
+readings will not be available and vice versa.
+
+Usage examples
+--------------
+
+Set device trigger in current_trigger, if not already set:
+
+.. code-block:: bash
+
+        root:/sys/bus/iio/devices/iio:device0> cat trigger/current_trigger
+
+        root:/sys/bus/iio/devices/iio:device0> echo adis16505-2-dev0 > trigger/current_trigger
+        root:/sys/bus/iio/devices/iio:device0> cat trigger/current_trigger
+        adis16505-2-dev0
+
+Select channels for buffer read:
+
+.. code-block:: bash
+
+        root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_deltavelocity_x_en
+        root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_deltavelocity_y_en
+        root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_deltavelocity_z_en
+        root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_temp0_en
+
+Set the number of samples to be stored in the buffer:
+
+.. code-block:: bash
+
+        root:/sys/bus/iio/devices/iio:device0> echo 10 > buffer/length
+
+Enable buffer readings:
+
+.. code-block:: bash
+
+        root:/sys/bus/iio/devices/iio:device0> echo 1 > buffer/enable
+
+Obtain buffered data:
+
+.. code-block:: bash
+
+        root:/sys/bus/iio/devices/iio:device0> hexdump -C /dev/iio\:device0
+        ...
+        00001680  01 1f 00 00 ff ff fe ef  00 00 47 bf 00 03 35 55  |..........G...5U|
+        00001690  01 1f 00 00 ff ff ff d9  00 00 46 f1 00 03 35 35  |..........F...55|
+        000016a0  01 1f 00 00 ff ff fe fc  00 00 46 cb 00 03 35 7b  |..........F...5{|
+        000016b0  01 1f 00 00 ff ff fe 41  00 00 47 0d 00 03 35 8b  |.......A..G...5.|
+        000016c0  01 1f 00 00 ff ff fe 37  00 00 46 b4 00 03 35 90  |.......7..F...5.|
+        000016d0  01 1d 00 00 ff ff fe 5a  00 00 45 d7 00 03 36 08  |.......Z..E...6.|
+        000016e0  01 1b 00 00 ff ff fe fb  00 00 45 e7 00 03 36 60  |..........E...6`|
+        000016f0  01 1a 00 00 ff ff ff 17  00 00 46 bc 00 03 36 de  |..........F...6.|
+        00001700  01 1a 00 00 ff ff fe 59  00 00 46 d7 00 03 37 b8  |.......Y..F...7.|
+        00001710  01 1a 00 00 ff ff fe ae  00 00 46 95 00 03 37 ba  |..........F...7.|
+        00001720  01 1a 00 00 ff ff fe c5  00 00 46 63 00 03 37 9f  |..........Fc..7.|
+        00001730  01 1a 00 00 ff ff fe 55  00 00 46 89 00 03 37 c1  |.......U..F...7.|
+        00001740  01 1a 00 00 ff ff fe 31  00 00 46 aa 00 03 37 f7  |.......1..F...7.|
+        ...
+
+See ``Documentation/iio/iio_devbuf.rst`` for more information about how buffered
+data is structured.
+
+4. IIO Interfacing Tools
+========================
+
+Linux Kernel Tools
+------------------
+
+Linux Kernel provides some userspace tools that can be used to retrieve data
+from IIO sysfs:
+
+* lsiio: example application that provides a list of IIO devices and triggers
+* iio_event_monitor: example application that reads events from an IIO device
+  and prints them
+* iio_generic_buffer: example application that reads data from buffer
+* iio_utils: set of APIs, typically used to access sysfs files.
+
+LibIIO
+------
+
+LibIIO is a C/C++ library that provides generic access to IIO devices. The
+library abstracts the low-level details of the hardware, and provides a simple
+yet complete programming interface that can be used for advanced projects.
+
+For more information about LibIIO, please see:
+https://github.com/analogdevicesinc/libiio
diff --git a/Documentation/iio/iio_devbuf.rst b/Documentation/iio/iio_devbuf.rst
new file mode 100644
index 0000000000000..9919e4792d0e4
--- /dev/null
+++ b/Documentation/iio/iio_devbuf.rst
@@ -0,0 +1,152 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=============================
+Industrial IIO device buffers
+=============================
+
+1. Overview
+===========
+
+The Industrial I/O core offers a way for continuous data capture based on a
+trigger source. Multiple data channels can be read at once from
+``/dev/iio:deviceX`` character device node, thus reducing the CPU load.
+
+Devices with buffer support feature an additional sub-directory in the
+``/sys/bus/iio/devices/iio:deviceX/`` directory hierarchy, called bufferY, where
+Y defaults to 0, for devices with a single buffer.
+
+2. Buffer attributes
+====================
+
+An IIO buffer has an associated attributes directory under
+``/sys/bus/iio/iio:deviceX/bufferY/``. The attributes are described below.
+
+``length``
+----------
+
+Read / Write attribute which states the total number of data samples (capacity)
+that can be stored by the buffer.
+
+``enable``
+----------
+
+Read / Write attribute which starts / stops the buffer capture. This file should
+be written last, after length and selection of scan elements. Writing a non-zero
+value may result in an error, such as EINVAL, if, for example, an unsupported
+combination of channels is given.
+
+``watermark``
+-------------
+
+Read / Write positive integer attribute specifying the maximum number of scan
+elements to wait for.
+
+Poll will block until the watermark is reached.
+
+Blocking read will wait until the minimum between the requested read amount or
+the low watermark is available.
+
+Non-blocking read will retrieve the available samples from the buffer even if
+there are less samples than the watermark level. This allows the application to
+block on poll with a timeout and read the available samples after the timeout
+expires and thus have a maximum delay guarantee.
+
+Data available
+--------------
+
+Read-only attribute indicating the bytes of data available in the buffer. In the
+case of an output buffer, this indicates the amount of empty space available to
+write data to. In the case of an input buffer, this indicates the amount of data
+available for reading.
+
+Scan elements
+-------------
+
+The meta information associated with a channel data placed in a buffer is called
+a scan element. The scan elements attributes are presented below.
+
+**_en**
+
+Read / Write attribute used for enabling a channel. If and only if its value
+is non-zero, then a triggered capture will contain data samples for this
+channel.
+
+**_index**
+
+Read-only unsigned integer attribute specifying the position of the channel in
+the buffer. Note these are not dependent on what is enabled and may not be
+contiguous. Thus for userspace to establish the full layout these must be used
+in conjunction with all _en attributes to establish which channels are present,
+and the relevant _type attributes to establish the data storage format.
+
+**_type**
+
+Read-only attribute containing the description of the scan element data storage
+within the buffer and hence the form in which it is read from userspace. Format
+is [be|le]:[s|u]bits/storagebits[Xrepeat][>>shift], where:
+
+- **be** or **le** specifies big or little-endian.
+- **s** or **u** specifies if signed (2's complement) or unsigned.
+- **bits** is the number of valid data bits.
+- **storagebits** is the number of bits (after padding) that it occupies in the
+  buffer.
+- **repeat** specifies the number of bits/storagebits repetitions. When the
+  repeat element is 0 or 1, then the repeat value is omitted.
+- **shift** if specified, is the shift that needs to be applied prior to
+  masking out unused bits.
+
+For example, a driver for a 3-axis accelerometer with 12-bit resolution where
+data is stored in two 8-bit registers is as follows::
+
+          7   6   5   4   3   2   1   0
+        +---+---+---+---+---+---+---+---+
+        |D3 |D2 |D1 |D0 | X | X | X | X | (LOW byte, address 0x06)
+        +---+---+---+---+---+---+---+---+
+
+          7   6   5   4   3   2   1   0
+        +---+---+---+---+---+---+---+---+
+        |D11|D10|D9 |D8 |D7 |D6 |D5 |D4 | (HIGH byte, address 0x07)
+        +---+---+---+---+---+---+---+---+
+
+will have the following scan element type for each axis:
+
+.. code-block:: bash
+
+        $ cat /sys/bus/iio/devices/iio:device0/buffer0/in_accel_y_type
+        le:s12/16>>4
+
+A userspace application will interpret data samples read from the buffer as
+two-byte little-endian signed data, that needs a 4 bits right shift before
+masking out the 12 valid bits of data.
+
+It is also worth mentioning that the data in the buffer will be naturally
+aligned, so the userspace application has to handle the buffers accordingly.
+
+Take for example, a driver with four channels with the following description:
+- channel0: index: 0, type: be:u16/16>>0
+- channel1: index: 1, type: be:u32/32>>0
+- channel2: index: 2, type: be:u32/32>>0
+- channel3: index: 3, type: be:u64/64>>0
+
+If all channels are enabled, the data will be aligned in the buffer as follows::
+
+          0-1   2   3   4-7  8-11  12  13  14  15  16-23   -> buffer byte number
+        +-----+---+---+-----+-----+---+---+---+---+-----+
+        |CHN_0|PAD|PAD|CHN_1|CHN_2|PAD|PAD|PAD|PAD|CHN_3|  -> buffer content
+        +-----+---+---+-----+-----+---+---+---+---+-----+
+
+If only channel0 and channel3 are enabled, the data will be aligned in the
+buffer as follows::
+
+          0-1   2   3   4   5   6   7  8-15    -> buffer byte number
+        +-----+---+---+---+---+---+---+-----+
+        |CHN_0|PAD|PAD|PAD|PAD|PAD|PAD|CHN_3|  -> buffer content
+        +-----+---+---+---+---+---+---+-----+
+
+Typically the buffered data is found in raw format (unscaled with no offset
+applied), however there are corner cases in which the buffered data may be found
+in a processed form. Please note that these corner cases are not addressed by
+this documentation.
+
+Please see ``Documentation/ABI/testing/sysfs-bus-iio`` for a complete
+description of the attributes.
diff --git a/Documentation/iio/index.rst b/Documentation/iio/index.rst
index 1b7292c58cd07..30b09eefe75ed 100644
--- a/Documentation/iio/index.rst
+++ b/Documentation/iio/index.rst
@@ -8,7 +8,14 @@ Industrial I/O
    :maxdepth: 1
 
    iio_configfs
+   iio_devbuf
 
-   ep93xx_adc
+Industrial I/O Kernel Drivers
+=============================
 
+.. toctree::
+   :maxdepth: 1
+
+   adis16475
    bno055
+   ep93xx_adc