Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 | /* * 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_ #include <linux/types.h> #include <linux/iio/types.h> struct iio_dev; struct iio_chan_spec; /** * 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. * @name: Unique 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(const char *name, 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); /** * iio_channel_get_all() - get all channels associated with a client * @name: name of 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(const char *name); /** * 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); struct iio_cb_buffer; /** * iio_channel_get_all_cb() - register callback for triggered capture * @name: Name of 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(const char *name, int (*cb)(u8 *data, void *private), void *private); /** * 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_buff: 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_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_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_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_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 1000 as the scale factor. */ int iio_convert_raw_to_processed(struct iio_channel *chan, int raw, int *processed, unsigned int scale); #endif |