diff options
Diffstat (limited to 'include/linux/iio/consumer.h')
| -rw-r--r-- | include/linux/iio/consumer.h | 307 |
1 files changed, 297 insertions, 10 deletions
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h index 833926c91aa8..5039558267e4 100644 --- a/include/linux/iio/consumer.h +++ b/include/linux/iio/consumer.h @@ -1,11 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * 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_ @@ -16,6 +13,7 @@ struct iio_dev; struct iio_chan_spec; struct device; +struct fwnode_handle; /** * struct iio_channel - everything needed for a consumer to use a channel @@ -49,6 +47,24 @@ struct iio_channel *iio_channel_get(struct device *dev, 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. * @@ -65,11 +81,58 @@ struct iio_channel *iio_channel_get_all(struct device *dev); */ 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. + * @cb: Callback function. Must be safe to call from any context + * (e.g. must not sleep). * @private: Private data passed to callback. * * NB right now we have no ability to mux data from multiple devices. @@ -77,10 +140,21 @@ struct iio_cb_buffer; * fail. */ struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev, - int (*cb)(u8 *data, + 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. */ @@ -100,7 +174,7 @@ void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff); /** * iio_channel_cb_get_channels() - get access to the underlying channels. - * @cb_buff: The callback buffer from whom we want the channel + * @cb_buffer: The callback buffer from whom we want the channel * information. * * This function allows one to obtain information about the channels. @@ -112,17 +186,44 @@ 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 raw reads from iio channels are in adc counts and hence - * scale will need to be applied if standard units required. + * 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. @@ -138,6 +239,114 @@ int iio_read_channel_raw(struct iio_channel *chan, 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. @@ -148,6 +357,19 @@ 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. @@ -161,6 +383,24 @@ int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2); /** + * iio_multiply_value() - Multiply an IIO value + * @result: Destination pointer for the multiplication result + * @multiplier: Multiplier. + * @type: One of the IIO_VAL_* constants. This decides how the @val and + * @val2 parameters are interpreted. + * @val: Value being multiplied. + * @val2: Value being multiplied. @val2 use depends on type. + * + * Multiply an IIO value with a s64 multiplier storing the result as + * IIO_VAL_INT. This is typically used for scaling. + * + * Returns: + * IIO_VAL_INT on success or a negative error-number on failure. + */ +int iio_multiply_value(int *result, s64 multiplier, + unsigned int type, 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 @@ -178,9 +418,56 @@ int iio_read_channel_scale(struct iio_channel *chan, int *val, * 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. + * 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 and to be aligned at PAGE_SIZE. + * + * 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); + +/** + * iio_read_channel_label() - read label for a given channel + * @chan: The channel being queried. + * @buf: Where to store the attribute value. Assumed to hold + * at least PAGE_SIZE bytes and to be aligned at PAGE_SIZE. + * + * Returns the number of bytes written to buf, or an error code. + */ +ssize_t iio_read_channel_label(struct iio_channel *chan, char *buf); + #endif |