| /* |
| * Industrial I/O in kernel consumer interface |
| * |
| * Copyright (c) 2011 Jonathan Cameron |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 as published by |
| * the Free Software Foundation. |
| */ |
| #ifndef _IIO_INKERN_CONSUMER_H_ |
| #define _IIO_INKERN_CONSUMER_H_ |
| #include <linux/iio/types.h> |
| |
| struct iio_dev; |
| struct iio_chan_spec; |
| |
| /** |
| * struct iio_channel - everything needed for a consumer to use a channel |
| * @indio_dev: Device on which the channel exists. |
| * @channel: Full description of the channel. |
| * @data: Data about the channel used by consumer. |
| */ |
| struct iio_channel { |
| struct iio_dev *indio_dev; |
| const struct iio_chan_spec *channel; |
| void *data; |
| }; |
| |
| /** |
| * iio_channel_get() - get description of all that is needed to access channel. |
| * @name: Unique name of the device as provided in the iio_map |
| * with which the desired provider to consumer mapping |
| * was registered. |
| * @consumer_channel: Unique name to identify the channel on the consumer |
| * side. This typically describes the channels use within |
| * the consumer. E.g. 'battery_voltage' |
| */ |
| struct iio_channel *iio_channel_get(const char *name, |
| const char *consumer_channel); |
| |
| /** |
| * iio_channel_release() - release channels obtained via iio_channel_get |
| * @chan: The channel to be released. |
| */ |
| void iio_channel_release(struct iio_channel *chan); |
| |
| /** |
| * iio_channel_get_all() - get all channels associated with a client |
| * @name: name of consumer device. |
| * |
| * Returns an array of iio_channel structures terminated with one with |
| * null iio_dev pointer. |
| * This function is used by fairly generic consumers to get all the |
| * channels registered as having this consumer. |
| */ |
| struct iio_channel *iio_channel_get_all(const char *name); |
| |
| /** |
| * iio_channel_release_all() - reverse iio_channel_get_all |
| * @chan: Array of channels to be released. |
| */ |
| void iio_channel_release_all(struct iio_channel *chan); |
| |
| /** |
| * iio_read_channel_raw() - read from a given channel |
| * @chan: The channel being queried. |
| * @val: Value read back. |
| * |
| * Note raw reads from iio channels are in adc counts and hence |
| * scale will need to be applied if standard units required. |
| */ |
| int iio_read_channel_raw(struct iio_channel *chan, |
| int *val); |
| |
| /** |
| * iio_read_channel_processed() - read processed value from a given channel |
| * @chan: The channel being queried. |
| * @val: Value read back. |
| * |
| * Returns an error code or 0. |
| * |
| * This function will read a processed value from a channel. A processed value |
| * means that this value will have the correct unit and not some device internal |
| * representation. If the device does not support reporting a processed value |
| * the function will query the raw value and the channels scale and offset and |
| * do the appropriate transformation. |
| */ |
| int iio_read_channel_processed(struct iio_channel *chan, int *val); |
| |
| /** |
| * iio_get_channel_type() - get the type of a channel |
| * @channel: The channel being queried. |
| * @type: The type of the channel. |
| * |
| * returns the enum iio_chan_type of the channel |
| */ |
| int iio_get_channel_type(struct iio_channel *channel, |
| enum iio_chan_type *type); |
| |
| /** |
| * iio_read_channel_scale() - read the scale value for a channel |
| * @chan: The channel being queried. |
| * @val: First part of value read back. |
| * @val2: Second part of value read back. |
| * |
| * Note returns a description of what is in val and val2, such |
| * as IIO_VAL_INT_PLUS_MICRO telling us we have a value of val |
| * + val2/1e6 |
| */ |
| int iio_read_channel_scale(struct iio_channel *chan, int *val, |
| int *val2); |
| |
| /** |
| * iio_convert_raw_to_processed() - Converts a raw value to a processed value |
| * @chan: The channel being queried |
| * @raw: The raw IIO to convert |
| * @processed: The result of the conversion |
| * @scale: Scale factor to apply during the conversion |
| * |
| * Returns an error code or 0. |
| * |
| * This function converts a raw value to processed value for a specific channel. |
| * A raw value is the device internal representation of a sample and the value |
| * returned by iio_read_channel_raw, so the unit of that value is device |
| * depended. A processed value on the other hand is value has a normed unit |
| * according with the IIO specification. |
| * |
| * The scale factor allows to increase the precession of the returned value. For |
| * a scale factor of 1 the function will return the result in the normal IIO |
| * unit for the channel type. E.g. millivolt for voltage channels, if you want |
| * nanovolts instead pass 1000 as the scale factor. |
| */ |
| int iio_convert_raw_to_processed(struct iio_channel *chan, int raw, |
| int *processed, unsigned int scale); |
| |
| #endif |