diff options
Diffstat (limited to 'include/linux/iio/consumer.h')
| -rw-r--r-- | include/linux/iio/consumer.h | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h new file mode 100644 index 000000000..6802596b0 --- /dev/null +++ b/include/linux/iio/consumer.h @@ -0,0 +1,427 @@ +/* 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 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_average_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. + * + * 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 raw writes to iio channels are in dac counts and hence + * scale will need to be applied if standard units required. + */ +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 raw reads from iio channels are in adc counts and hence + * scale will need to be applied if standard units are required. + */ +int iio_read_max_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 raw available values from iio channels are in adc counts and + * hence scale will need to be applied if standard units are required. + */ +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 |