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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Industrial I/O in kernel consumer interface
*
* Copyright (c) 2011 Jonathan Cameron
*/
#ifndef _IIO_INKERN_CONSUMER_H_
#define _IIO_INKERN_CONSUMER_H_
#include <linux/types.h>
#include <linux/iio/types.h>
struct iio_dev;
struct iio_chan_spec;
struct device;
struct fwnode_handle;
/**
* 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.
* @dev: Pointer to consumer device. Device name must match
* the 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(struct device *dev,
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);
/**
* devm_iio_channel_get() - Resource managed version of iio_channel_get().
* @dev: Pointer to consumer device. Device name must match
* the 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'
*
* Returns a pointer to negative errno if it is not able to get the iio channel
* otherwise returns valid pointer for iio channel.
*
* The allocated iio channel is automatically released when the device is
* unbound.
*/
struct iio_channel *devm_iio_channel_get(struct device *dev,
const char *consumer_channel);
/**
* iio_channel_get_all() - get all channels associated with a client
* @dev: Pointer to 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(struct device *dev);
/**
* 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);
/**
* devm_iio_channel_get_all() - Resource managed version of
* iio_channel_get_all().
* @dev: Pointer to consumer device.
*
* Returns a pointer to negative errno if it is not able to get the iio channel
* otherwise 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.
*
* The allocated iio channels are automatically released when the device is
* unbounded.
*/
struct iio_channel *devm_iio_channel_get_all(struct device *dev);
/**
* fwnode_iio_channel_get_by_name() - get description of all that is needed to access channel.
* @fwnode: Pointer to consumer Firmware node
* @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 *fwnode_iio_channel_get_by_name(struct fwnode_handle *fwnode,
const char *name);
/**
* devm_fwnode_iio_channel_get_by_name() - Resource managed version of
* fwnode_iio_channel_get_by_name().
* @dev: Pointer to consumer device.
* @fwnode: Pointer to consumer Firmware node
* @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'
*
* Returns a pointer to negative errno if it is not able to get the iio channel
* otherwise returns valid pointer for iio channel.
*
* The allocated iio channel is automatically released when the device is
* unbound.
*/
struct iio_channel *devm_fwnode_iio_channel_get_by_name(struct device *dev,
struct fwnode_handle *fwnode,
const char *consumer_channel);
struct iio_cb_buffer;
/**
* iio_channel_get_all_cb() - register callback for triggered capture
* @dev: Pointer to client device.
* @cb: Callback function.
* @private: Private data passed to callback.
*
* NB right now we have no ability to mux data from multiple devices.
* So if the channels requested come from different devices this will
* fail.
*/
struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
int (*cb)(const void *data,
void *private),
void *private);
/**
* iio_channel_cb_set_buffer_watermark() - set the buffer watermark.
* @cb_buffer: The callback buffer from whom we want the channel
* information.
* @watermark: buffer watermark in bytes.
*
* This function allows to configure the buffer watermark.
*/
int iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer *cb_buffer,
size_t watermark);
/**
* iio_channel_release_all_cb() - release and unregister the callback.
* @cb_buffer: The callback buffer that was allocated.
*/
void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buffer);
/**
* iio_channel_start_all_cb() - start the flow of data through callback.
* @cb_buff: The callback buffer we are starting.
*/
int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff);
/**
* iio_channel_stop_all_cb() - stop the flow of data through the callback.
* @cb_buff: The callback buffer we are stopping.
*/
void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff);
/**
* iio_channel_cb_get_channels() - get access to the underlying channels.
* @cb_buffer: The callback buffer from whom we want the channel
* information.
*
* This function allows one to obtain information about the channels.
* Whilst this may allow direct reading if all buffers are disabled, the
* primary aim is to allow drivers that are consuming a channel to query
* things like scaling of the channel.
*/
struct iio_channel
*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer);
/**
* iio_channel_cb_get_iio_dev() - get access to the underlying device.
* @cb_buffer: The callback buffer from whom we want the device
* information.
*
* This function allows one to obtain information about the device.
* The primary aim is to allow drivers that are consuming a device to query
* things like current trigger.
*/
struct iio_dev
*iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer);
/**
* iio_read_channel_raw() - read from a given channel
* @chan: The channel being queried.
* @val: Value read back.
*
* Note, if standard units are required, raw reads from iio channels
* need the offset (default 0) and scale (default 1) to be applied
* as (raw + offset) * scale.
*/
int iio_read_channel_raw(struct iio_channel *chan,
int *val);
/**
* iio_read_channel_average_raw() - read from a given channel
* @chan: The channel being queried.
* @val: Value read back.
*
* Note, if standard units are required, raw reads from iio channels
* need the offset (default 0) and scale (default 1) to be applied
* as (raw + offset) * scale.
*
* In opposit to the normal iio_read_channel_raw this function
* returns the average of multiple reads.
*/
int iio_read_channel_average_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_read_channel_processed_scale() - read and scale a processed value
* @chan: The channel being queried.
* @val: Value read back.
* @scale: Scale factor to apply during the conversion
*
* Returns an error code or 0.
*
* This function will read a processed value from a channel. This will work
* like @iio_read_channel_processed() but also scale with an additional
* scale factor while attempting to minimize any precision loss.
*/
int iio_read_channel_processed_scale(struct iio_channel *chan, int *val,
unsigned int scale);
/**
* iio_write_channel_attribute() - Write values to the device attribute.
* @chan: The channel being queried.
* @val: Value being written.
* @val2: Value being written.val2 use depends on attribute type.
* @attribute: info attribute to be read.
*
* Returns an error code or 0.
*/
int iio_write_channel_attribute(struct iio_channel *chan, int val,
int val2, enum iio_chan_info_enum attribute);
/**
* iio_read_channel_attribute() - Read values from the device attribute.
* @chan: The channel being queried.
* @val: Value being written.
* @val2: Value being written.Val2 use depends on attribute type.
* @attribute: info attribute to be written.
*
* Returns an error code if failed. Else 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_attribute(struct iio_channel *chan, int *val,
int *val2, enum iio_chan_info_enum attribute);
/**
* iio_write_channel_raw() - write to a given channel
* @chan: The channel being queried.
* @val: Value being written.
*
* Note that for raw writes to iio channels, if the value provided is
* in standard units, the affect of the scale and offset must be removed
* as (value / scale) - offset.
*/
int iio_write_channel_raw(struct iio_channel *chan, int val);
/**
* iio_read_max_channel_raw() - read maximum available raw value from a given
* channel, i.e. the maximum possible value.
* @chan: The channel being queried.
* @val: Value read back.
*
* Note, if standard units are required, raw reads from iio channels
* need the offset (default 0) and scale (default 1) to be applied
* as (raw + offset) * scale.
*/
int iio_read_max_channel_raw(struct iio_channel *chan, int *val);
/**
* iio_read_min_channel_raw() - read minimum available raw value from a given
* channel, i.e. the minimum possible value.
* @chan: The channel being queried.
* @val: Value read back.
*
* Note, if standard units are required, raw reads from iio channels
* need the offset (default 0) and scale (default 1) to be applied
* as (raw + offset) * scale.
*/
int iio_read_min_channel_raw(struct iio_channel *chan, int *val);
/**
* iio_read_avail_channel_raw() - read available raw values from a given channel
* @chan: The channel being queried.
* @vals: Available values read back.
* @length: Number of entries in vals.
*
* Returns an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST.
*
* For ranges, three vals are always returned; min, step and max.
* For lists, all the possible values are enumerated.
*
* Note, if standard units are required, raw available values from iio
* channels need the offset (default 0) and scale (default 1) to be applied
* as (raw + offset) * scale.
*/
int iio_read_avail_channel_raw(struct iio_channel *chan,
const int **vals, int *length);
/**
* iio_read_avail_channel_attribute() - read available channel attribute values
* @chan: The channel being queried.
* @vals: Available values read back.
* @type: Type of values read back.
* @length: Number of entries in vals.
* @attribute: info attribute to be read back.
*
* Returns an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST.
*/
int iio_read_avail_channel_attribute(struct iio_channel *chan,
const int **vals, int *type, int *length,
enum iio_chan_info_enum attribute);
/**
* 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_offset() - read the offset 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_offset(struct iio_channel *chan, int *val,
int *val2);
/**
* 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 1000000 as the scale factor.
*/
int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
int *processed, unsigned int scale);
/**
* iio_get_channel_ext_info_count() - get number of ext_info attributes
* connected to the channel.
* @chan: The channel being queried
*
* Returns the number of ext_info attributes
*/
unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan);
/**
* iio_read_channel_ext_info() - read ext_info attribute from a given channel
* @chan: The channel being queried.
* @attr: The ext_info attribute to read.
* @buf: Where to store the attribute value. Assumed to hold
* at least PAGE_SIZE bytes.
*
* Returns the number of bytes written to buf (perhaps w/o zero termination;
* it need not even be a string), or an error code.
*/
ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
const char *attr, char *buf);
/**
* iio_write_channel_ext_info() - write ext_info attribute from a given channel
* @chan: The channel being queried.
* @attr: The ext_info attribute to read.
* @buf: The new attribute value. Strings needs to be zero-
* terminated, but the terminator should not be included
* in the below len.
* @len: The size of the new attribute value.
*
* Returns the number of accepted bytes, which should be the same as len.
* An error code can also be returned.
*/
ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
const char *buf, size_t len);
#endif