1 milivolt is equal to 1000000 nanovolts. Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
		
			
				
	
	
		
			209 lines
		
	
	
	
		
			7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			209 lines
		
	
	
	
		
			7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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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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 * This program is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 as published by
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 * the Free Software Foundation.
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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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/**
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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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 * 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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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_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_buff:		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_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_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_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_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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#endif
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