428 lines
15 KiB
C
428 lines
15 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Industrial I/O in kernel consumer interface
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*
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* Copyright (c) 2011 Jonathan Cameron
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*/
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#ifndef _IIO_INKERN_CONSUMER_H_
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#define _IIO_INKERN_CONSUMER_H_
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#include <linux/types.h>
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#include <linux/iio/types.h>
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struct iio_dev;
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struct iio_chan_spec;
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struct device;
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struct fwnode_handle;
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/**
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* struct iio_channel - everything needed for a consumer to use a channel
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* @indio_dev: Device on which the channel exists.
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* @channel: Full description of the channel.
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* @data: Data about the channel used by consumer.
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*/
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struct iio_channel {
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struct iio_dev *indio_dev;
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const struct iio_chan_spec *channel;
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void *data;
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};
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/**
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* iio_channel_get() - get description of all that is needed to access channel.
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* @dev: Pointer to consumer device. Device name must match
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* the name of the device as provided in the iio_map
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* with which the desired provider to consumer mapping
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* was registered.
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* @consumer_channel: Unique name to identify the channel on the consumer
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* side. This typically describes the channels use within
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* the consumer. E.g. 'battery_voltage'
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*/
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struct iio_channel *iio_channel_get(struct device *dev,
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const char *consumer_channel);
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/**
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* iio_channel_release() - release channels obtained via iio_channel_get
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* @chan: The channel to be released.
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*/
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void iio_channel_release(struct iio_channel *chan);
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/**
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* devm_iio_channel_get() - Resource managed version of iio_channel_get().
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* @dev: Pointer to consumer device. Device name must match
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* the name of the device as provided in the iio_map
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* with which the desired provider to consumer mapping
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* was registered.
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* @consumer_channel: Unique name to identify the channel on the consumer
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* side. This typically describes the channels use within
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* the consumer. E.g. 'battery_voltage'
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*
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* Returns a pointer to negative errno if it is not able to get the iio channel
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* otherwise returns valid pointer for iio channel.
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*
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* The allocated iio channel is automatically released when the device is
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* unbound.
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*/
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struct iio_channel *devm_iio_channel_get(struct device *dev,
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const char *consumer_channel);
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/**
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* iio_channel_get_all() - get all channels associated with a client
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* @dev: Pointer to consumer device.
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*
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* Returns an array of iio_channel structures terminated with one with
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* null iio_dev pointer.
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* This function is used by fairly generic consumers to get all the
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* channels registered as having this consumer.
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*/
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struct iio_channel *iio_channel_get_all(struct device *dev);
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/**
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* iio_channel_release_all() - reverse iio_channel_get_all
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* @chan: Array of channels to be released.
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*/
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void iio_channel_release_all(struct iio_channel *chan);
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/**
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* devm_iio_channel_get_all() - Resource managed version of
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* iio_channel_get_all().
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* @dev: Pointer to consumer device.
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*
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* Returns a pointer to negative errno if it is not able to get the iio channel
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* otherwise returns an array of iio_channel structures terminated with one with
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* null iio_dev pointer.
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*
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* This function is used by fairly generic consumers to get all the
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* channels registered as having this consumer.
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*
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* The allocated iio channels are automatically released when the device is
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* unbounded.
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*/
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struct iio_channel *devm_iio_channel_get_all(struct device *dev);
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/**
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* fwnode_iio_channel_get_by_name() - get description of all that is needed to access channel.
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* @fwnode: Pointer to consumer Firmware node
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* @consumer_channel: Unique name to identify the channel on the consumer
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* side. This typically describes the channels use within
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* the consumer. E.g. 'battery_voltage'
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*/
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struct iio_channel *fwnode_iio_channel_get_by_name(struct fwnode_handle *fwnode,
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const char *name);
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/**
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* devm_fwnode_iio_channel_get_by_name() - Resource managed version of
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* fwnode_iio_channel_get_by_name().
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* @dev: Pointer to consumer device.
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* @fwnode: Pointer to consumer Firmware node
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* @consumer_channel: Unique name to identify the channel on the consumer
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* side. This typically describes the channels use within
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* the consumer. E.g. 'battery_voltage'
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*
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* Returns a pointer to negative errno if it is not able to get the iio channel
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* otherwise returns valid pointer for iio channel.
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*
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* The allocated iio channel is automatically released when the device is
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* unbound.
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*/
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struct iio_channel *devm_fwnode_iio_channel_get_by_name(struct device *dev,
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struct fwnode_handle *fwnode,
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const char *consumer_channel);
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struct iio_cb_buffer;
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/**
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* iio_channel_get_all_cb() - register callback for triggered capture
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* @dev: Pointer to client device.
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* @cb: Callback function.
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* @private: Private data passed to callback.
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*
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* NB right now we have no ability to mux data from multiple devices.
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* So if the channels requested come from different devices this will
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* fail.
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*/
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struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
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int (*cb)(const void *data,
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void *private),
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void *private);
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/**
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* iio_channel_cb_set_buffer_watermark() - set the buffer watermark.
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* @cb_buffer: The callback buffer from whom we want the channel
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* information.
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* @watermark: buffer watermark in bytes.
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*
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* This function allows to configure the buffer watermark.
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*/
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int iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer *cb_buffer,
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size_t watermark);
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/**
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* iio_channel_release_all_cb() - release and unregister the callback.
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* @cb_buffer: The callback buffer that was allocated.
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*/
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void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buffer);
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/**
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* iio_channel_start_all_cb() - start the flow of data through callback.
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* @cb_buff: The callback buffer we are starting.
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*/
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int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff);
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/**
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* iio_channel_stop_all_cb() - stop the flow of data through the callback.
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* @cb_buff: The callback buffer we are stopping.
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*/
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void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff);
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/**
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* iio_channel_cb_get_channels() - get access to the underlying channels.
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* @cb_buffer: The callback buffer from whom we want the channel
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* information.
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*
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* This function allows one to obtain information about the channels.
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* Whilst this may allow direct reading if all buffers are disabled, the
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* primary aim is to allow drivers that are consuming a channel to query
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* things like scaling of the channel.
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*/
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struct iio_channel
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*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer);
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/**
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* iio_channel_cb_get_iio_dev() - get access to the underlying device.
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* @cb_buffer: The callback buffer from whom we want the device
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* information.
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*
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* This function allows one to obtain information about the device.
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* The primary aim is to allow drivers that are consuming a device to query
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* things like current trigger.
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*/
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struct iio_dev
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*iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer);
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/**
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* iio_read_channel_raw() - read from a given channel
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* @chan: The channel being queried.
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* @val: Value read back.
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*
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* Note raw reads from iio channels are in adc counts and hence
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* scale will need to be applied if standard units required.
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*/
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int iio_read_channel_raw(struct iio_channel *chan,
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int *val);
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/**
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* iio_read_channel_average_raw() - read from a given channel
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* @chan: The channel being queried.
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* @val: Value read back.
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*
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* Note raw reads from iio channels are in adc counts and hence
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* scale will need to be applied if standard units required.
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*
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* In opposit to the normal iio_read_channel_raw this function
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* returns the average of multiple reads.
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*/
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int iio_read_channel_average_raw(struct iio_channel *chan, int *val);
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/**
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* iio_read_channel_processed() - read processed value from a given channel
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* @chan: The channel being queried.
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* @val: Value read back.
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*
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* Returns an error code or 0.
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*
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* This function will read a processed value from a channel. A processed value
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* means that this value will have the correct unit and not some device internal
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* representation. If the device does not support reporting a processed value
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* the function will query the raw value and the channels scale and offset and
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* do the appropriate transformation.
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*/
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int iio_read_channel_processed(struct iio_channel *chan, int *val);
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/**
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* iio_read_channel_processed_scale() - read and scale a processed value
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* @chan: The channel being queried.
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* @val: Value read back.
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* @scale: Scale factor to apply during the conversion
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*
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* Returns an error code or 0.
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*
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* This function will read a processed value from a channel. This will work
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* like @iio_read_channel_processed() but also scale with an additional
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* scale factor while attempting to minimize any precision loss.
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*/
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int iio_read_channel_processed_scale(struct iio_channel *chan, int *val,
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unsigned int scale);
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/**
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* iio_write_channel_attribute() - Write values to the device attribute.
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* @chan: The channel being queried.
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* @val: Value being written.
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* @val2: Value being written.val2 use depends on attribute type.
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* @attribute: info attribute to be read.
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*
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* Returns an error code or 0.
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*/
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int iio_write_channel_attribute(struct iio_channel *chan, int val,
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int val2, enum iio_chan_info_enum attribute);
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/**
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* iio_read_channel_attribute() - Read values from the device attribute.
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* @chan: The channel being queried.
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* @val: Value being written.
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* @val2: Value being written.Val2 use depends on attribute type.
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* @attribute: info attribute to be written.
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*
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* Returns an error code if failed. Else returns a description of what is in val
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* and val2, such as IIO_VAL_INT_PLUS_MICRO telling us we have a value of val
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* + val2/1e6
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*/
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int iio_read_channel_attribute(struct iio_channel *chan, int *val,
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int *val2, enum iio_chan_info_enum attribute);
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/**
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* iio_write_channel_raw() - write to a given channel
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* @chan: The channel being queried.
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* @val: Value being written.
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*
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* Note raw writes to iio channels are in dac counts and hence
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* scale will need to be applied if standard units required.
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*/
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int iio_write_channel_raw(struct iio_channel *chan, int val);
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/**
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* iio_read_max_channel_raw() - read maximum available raw value from a given
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* channel, i.e. the maximum possible value.
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* @chan: The channel being queried.
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* @val: Value read back.
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*
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* Note raw reads from iio channels are in adc counts and hence
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* scale will need to be applied if standard units are required.
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*/
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int iio_read_max_channel_raw(struct iio_channel *chan, int *val);
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/**
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* iio_read_avail_channel_raw() - read available raw values from a given channel
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* @chan: The channel being queried.
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* @vals: Available values read back.
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* @length: Number of entries in vals.
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*
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* Returns an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST.
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*
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* For ranges, three vals are always returned; min, step and max.
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* For lists, all the possible values are enumerated.
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*
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* Note raw available values from iio channels are in adc counts and
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* hence scale will need to be applied if standard units are required.
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*/
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int iio_read_avail_channel_raw(struct iio_channel *chan,
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const int **vals, int *length);
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/**
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* iio_read_avail_channel_attribute() - read available channel attribute values
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* @chan: The channel being queried.
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* @vals: Available values read back.
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* @type: Type of values read back.
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* @length: Number of entries in vals.
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* @attribute: info attribute to be read back.
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*
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* Returns an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST.
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*/
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int iio_read_avail_channel_attribute(struct iio_channel *chan,
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const int **vals, int *type, int *length,
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enum iio_chan_info_enum attribute);
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/**
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* iio_get_channel_type() - get the type of a channel
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* @channel: The channel being queried.
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* @type: The type of the channel.
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*
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* returns the enum iio_chan_type of the channel
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*/
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int iio_get_channel_type(struct iio_channel *channel,
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enum iio_chan_type *type);
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/**
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* iio_read_channel_offset() - read the offset value for a channel
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* @chan: The channel being queried.
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* @val: First part of value read back.
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* @val2: Second part of value read back.
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*
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* Note returns a description of what is in val and val2, such
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* as IIO_VAL_INT_PLUS_MICRO telling us we have a value of val
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* + val2/1e6
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*/
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int iio_read_channel_offset(struct iio_channel *chan, int *val,
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int *val2);
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/**
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* iio_read_channel_scale() - read the scale value for a channel
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* @chan: The channel being queried.
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* @val: First part of value read back.
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* @val2: Second part of value read back.
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*
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* Note returns a description of what is in val and val2, such
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* as IIO_VAL_INT_PLUS_MICRO telling us we have a value of val
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* + val2/1e6
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*/
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int iio_read_channel_scale(struct iio_channel *chan, int *val,
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int *val2);
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/**
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* iio_convert_raw_to_processed() - Converts a raw value to a processed value
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* @chan: The channel being queried
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* @raw: The raw IIO to convert
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* @processed: The result of the conversion
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* @scale: Scale factor to apply during the conversion
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*
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* Returns an error code or 0.
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*
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* This function converts a raw value to processed value for a specific channel.
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* A raw value is the device internal representation of a sample and the value
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* returned by iio_read_channel_raw, so the unit of that value is device
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* depended. A processed value on the other hand is value has a normed unit
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* according with the IIO specification.
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*
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* The scale factor allows to increase the precession of the returned value. For
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* a scale factor of 1 the function will return the result in the normal IIO
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* unit for the channel type. E.g. millivolt for voltage channels, if you want
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* nanovolts instead pass 1000000 as the scale factor.
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*/
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int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
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int *processed, unsigned int scale);
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/**
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* iio_get_channel_ext_info_count() - get number of ext_info attributes
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* connected to the channel.
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* @chan: The channel being queried
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*
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* Returns the number of ext_info attributes
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*/
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unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan);
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/**
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* iio_read_channel_ext_info() - read ext_info attribute from a given channel
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* @chan: The channel being queried.
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* @attr: The ext_info attribute to read.
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* @buf: Where to store the attribute value. Assumed to hold
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* at least PAGE_SIZE bytes.
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*
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* Returns the number of bytes written to buf (perhaps w/o zero termination;
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* it need not even be a string), or an error code.
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*/
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ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
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const char *attr, char *buf);
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/**
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* iio_write_channel_ext_info() - write ext_info attribute from a given channel
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* @chan: The channel being queried.
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* @attr: The ext_info attribute to read.
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* @buf: The new attribute value. Strings needs to be zero-
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* terminated, but the terminator should not be included
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* in the below len.
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* @len: The size of the new attribute value.
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*
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* Returns the number of accepted bytes, which should be the same as len.
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* An error code can also be returned.
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*/
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ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
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const char *buf, size_t len);
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#endif
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