For occasional contributor like me navigating the IIO channel types and modifiers may be a daunting task. One may have hard time finding out what type of channel should be used for device data and what units the data should be converted. There is a great documentation for the sysfs interfaces though. What is missing is mapping of the channel types and modifiers to the sysfs documentation (and entries in documentation). Give a hand to a driver writer by providing some documentation and by pointing to the sysfs document from the kernel doc of respective enums. Signed-off-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx> --- Changelog RFCv1 => v2: - add missing channel type docs provided by Jonathan - add @in front of member names and fix typos pointed by Andy - drop TODOs as Jonathan clarified the units Initial discussion about these docs can be found from: https://lore.kernel.org/all/0e0d45b7-e582-82b2-9bac-1f70f9dad9f7@xxxxxxxxx/ --- include/uapi/linux/iio/types.h | 134 +++++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) diff --git a/include/uapi/linux/iio/types.h b/include/uapi/linux/iio/types.h index c79f2f046a0b..78f4cfdc5e45 100644 --- a/include/uapi/linux/iio/types.h +++ b/include/uapi/linux/iio/types.h @@ -11,6 +11,124 @@ #ifndef _UAPI_IIO_TYPES_H_ #define _UAPI_IIO_TYPES_H_ +/** + * iio_chan_type - Type of data transferred via IIO channel. + * + * The 'main' type of data transferred via channel. Please note that most + * devices also need to specify a more accurate 'sub category'. See the + * enum iio_modifier for this. (For example, IIO_ACCEL channel often needs to + * specify the direction. IIO_CONCENTRATION specifies the type of substance + * it measures etc). + * + * These reflect the units of the measurement via processed or unit after + * application of scale and offset. See the enum iio_chan_info_enum for + * scale and offset. + * + * Please find the detailed documentation for reported values from the + * Documentation/ABI/testing/sysfs-bus-iio. + * + * @IIO_ACCEL: Acceleration, m/s^2 + * Doc keyword: in_accel_x_raw + * + * @IIO_ACTIVITY: Activity state. For example a pedometer signaling + * jogging, walking or staying still. + * Doc keyword: in_activity_still_thresh_rising_en + * + * @IIO_ALTVOLTAGE: Peak to peak voltage, millivolts + * + * @IIO_ANGL: Angle of rotation, radians. + * Doc keyword: in_angl_raw + * + * @IIO_ANGL_VEL: Angular velocity, rad/s + * Doc keyword: in_anglvel_x_raw + * + * @IIO_CAPACITANCE: Capacitance, nanofarads. + * Doc keyword: in_capacitanceY_raw + * + * @IIO_CCT: Correlated color temperature, Kelvins + * + * @IIO_CURRENT: Current, milliamps + * Doc keyword: in_currentY_raw + * + * @IIO_CONCENTRATION: Reading of a substance, percents. Used for example by + * devices measuring amount of CO2, O2, ethanol... + * Doc keyword: in_concentration_raw + * + * @IIO_COUNT: Deprecated, please use counter subsystem. + * + * @IIO_DISTANCE: Distance in meters. Typically used to report measured + * distance to an object or the distance covered by the + * user + * Doc keyword: in_distance_input + * + * @IIO_ELECTRICALCONDUCTIVITY: electric conductivity, siemens per meter + * Doc keyword: in_electricalconductivity_raw + * + * @IIO_ENERGY: Energy in Joules. Typically reported by a device + * measuring energy burnt by the user. + * Doc keyword: in_energy_input + * + * @IIO_GRAVITY: Gravity, m/s^2 + * Doc keyword: in_gravity_x_raw + * + * @IIO_HUMIDITYRELATIVE: Relative humidity, percents + * Doc keyword: in_humidityrelative_raw + * + * @IIO_INCLI: Inclination, degrees + * Doc keyword: in_incli_x_raw + * + * @IIO_INDEX: Deprecated, please use Counter subsystem + * + * @IIO_INTENSITY: Unitless intensity. + * Doc keyword: in_intensityY_raw + * + * @IIO_LIGHT: Visible light intensity, lux + * Doc keyword: in_illuminance_raw + * + * @IIO_MAGN: Magnetic field, Gauss. + * Doc keyword: in_magn_x_raw + * + * @IIO_MASSCONCENTRATION: Mass concentration, ug / m3 + * Doc keyword: in_massconcentration_pm1_input + * + * @IIO_PH: pH reading, negative base-10 logarithm of hydrodium + * ions in a litre of water + * Doc keyword: in_ph_raw + * + * @IIO_PHASE: Phase difference, radians + * Doc keyword: in_phaseY_raw + * + * @IIO_POSITIONRELATIVE: Relative position. + * Doc keyword: in_positionrelative_x_raw + * + * @IIO_POWER: Power, milliwatts + * Doc keyword: in_powerY_raw + * + * @IIO_PRESSURE: Pressure, kilopascal + * Doc keyword: in_pressureY_raw + * + * @IIO_RESISTANCE: Resistance, ohms + * Doc keyword: in_resistance_raw + * + * @IIO_ROT: Euler angles, deg + * Doc keyword: in_rot_yaw_raw + * + * @IIO_STEPS: Steps taken by the user + * Doc keyword: in_steps_input + * + * @IIO_TEMP: Temperature, milli degrees Celsius + * Doc keyword: in_temp_raw + * + * @IIO_UVINDEX: UV light intensity index + * Doc keyword: in_uvindex_input + * + * @IIO_VELOCITY: Current speed (norm or magnitude of the velocity + * vector), m/s + * Doc keyword: in_velocity_sqrt(x^2+y^2+z^2)_input + * + * @IIO_VOLTAGE: Voltage, millivolts + * Doc keyword: in_voltageY_raw + */ enum iio_chan_type { IIO_VOLTAGE, IIO_CURRENT, @@ -49,6 +167,22 @@ enum iio_chan_type { IIO_MASSCONCENTRATION, }; +/** + * iio_modifier - accurate class for channel data + * + * @IIO_MOD_<X,Y,Z>: Value represents <X,Y,Z>-axis data. + * Typically used by channels of type: + * IIO_ACCEL, IIO_TEMP, IIO_GRAVITY, IIO_POSITIONRELATIVE, + * IIO_ANGL_VEL, IIO_INCLI, IIO_MAGN + * @IIO_MOD_LIGHT_BOTH: Value contains visible and infrared light components + * @IIO_MOD_LIGHT_IR: Value represents infrared radiation + * @IIO_MOD_LIGHT_<RED, GREEN, BLUE>: + * Value represents visible <red, green, blue> light + * @IIO_MOD_LIGHT_CLEAR: Value represents all visible light frequencies + * + * Please find the detailed documentation for reported values from the + * Documentation/ABI/testing/sysfs-bus-iio. + */ enum iio_modifier { IIO_NO_MOD, IIO_MOD_X, -- 2.39.2 -- Matti Vaittinen, Linux device drivers ROHM Semiconductors, Finland SWDC Kiviharjunlenkki 1E 90220 OULU FINLAND ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~ Simon says - in Latin please. ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~ Thanks to Simon Glass for the translation =]
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