LXR linux/drivers/staging/iio/iio.h

   1
   2/* The industrial I/O core
   3 *
   4 * Copyright (c) 2008 Jonathan Cameron
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms of the GNU General Public License version 2 as published by
   8 * the Free Software Foundation.
   9 */
  10
  11#ifndef _INDUSTRIAL_IO_H_
  12#define _INDUSTRIAL_IO_H_
  13
  14#include <linux/device.h>
  15#include <linux/cdev.h>
  16
  17/* IIO TODO LIST */
  18/*
  19 * Provide means of adjusting timer accuracy.
  20 * Currently assumes nano seconds.
  21 */
  22
  23enum iio_data_type {
  24        IIO_RAW,
  25        IIO_PROCESSED,
  26};
  27
  28enum iio_chan_type {
  29        /* real channel types */
  30        IIO_VOLTAGE,
  31        IIO_CURRENT,
  32        IIO_POWER,
  33        IIO_ACCEL,
  34        IIO_ANGL_VEL,
  35        IIO_MAGN,
  36        IIO_LIGHT,
  37        IIO_INTENSITY,
  38        IIO_PROXIMITY,
  39        IIO_TEMP,
  40        IIO_INCLI,
  41        IIO_ROT,
  42        IIO_ANGL,
  43        IIO_TIMESTAMP,
  44        IIO_CAPACITANCE,
  45};
  46
  47enum iio_modifier {
  48        IIO_NO_MOD,
  49        IIO_MOD_X,
  50        IIO_MOD_Y,
  51        IIO_MOD_Z,
  52        IIO_MOD_X_AND_Y,
  53        IIO_MOD_X_ANX_Z,
  54        IIO_MOD_Y_AND_Z,
  55        IIO_MOD_X_AND_Y_AND_Z,
  56        IIO_MOD_X_OR_Y,
  57        IIO_MOD_X_OR_Z,
  58        IIO_MOD_Y_OR_Z,
  59        IIO_MOD_X_OR_Y_OR_Z,
  60        IIO_MOD_LIGHT_BOTH,
  61        IIO_MOD_LIGHT_IR,
  62};
  63
  64/* Could add the raw attributes as well - allowing buffer only devices */
  65enum iio_chan_info_enum {
  66        IIO_CHAN_INFO_SCALE_SHARED,
  67        IIO_CHAN_INFO_SCALE_SEPARATE,
  68        IIO_CHAN_INFO_OFFSET_SHARED,
  69        IIO_CHAN_INFO_OFFSET_SEPARATE,
  70        IIO_CHAN_INFO_CALIBSCALE_SHARED,
  71        IIO_CHAN_INFO_CALIBSCALE_SEPARATE,
  72        IIO_CHAN_INFO_CALIBBIAS_SHARED,
  73        IIO_CHAN_INFO_CALIBBIAS_SEPARATE,
  74        IIO_CHAN_INFO_PEAK_SHARED,
  75        IIO_CHAN_INFO_PEAK_SEPARATE,
  76        IIO_CHAN_INFO_PEAK_SCALE_SHARED,
  77        IIO_CHAN_INFO_PEAK_SCALE_SEPARATE,
  78        IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SHARED,
  79        IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SEPARATE,
  80        IIO_CHAN_INFO_AVERAGE_RAW_SHARED,
  81        IIO_CHAN_INFO_AVERAGE_RAW_SEPARATE,
  82};
  83
  84enum iio_endian {
  85        IIO_CPU,
  86        IIO_BE,
  87        IIO_LE,
  88};
  89
  90/**
  91 * struct iio_chan_spec - specification of a single channel
  92 * @type:               What type of measurement is the channel making.
  93 * @channel:            What number or name do we wish to asign the channel.
  94 * @channel2:           If there is a second number for a differential
  95 *                      channel then this is it. If modified is set then the
  96 *                      value here specifies the modifier.
  97 * @address:            Driver specific identifier.
  98 * @scan_index: Monotonic index to give ordering in scans when read
  99 *                      from a buffer.
 100 * @scan_type:          Sign:           's' or 'u' to specify signed or unsigned
 101 *                      realbits:       Number of valid bits of data
 102 *                      storage_bits:   Realbits + padding
 103 *                      shift:          Shift right by this before masking out
 104 *                                      realbits.
 105 *                      endianness:     little or big endian
 106 * @info_mask:          What information is to be exported about this channel.
 107 *                      This includes calibbias, scale etc.
 108 * @event_mask: What events can this channel produce.
 109 * @extend_name:        Allows labeling of channel attributes with an
 110 *                      informative name. Note this has no effect codes etc,
 111 *                      unlike modifiers.
 112 * @processed_val:      Flag to specify the data access attribute should be
 113 *                      *_input rather than *_raw.
 114 * @modified:           Does a modifier apply to this channel. What these are
 115 *                      depends on the channel type.  Modifier is set in
 116 *                      channel2. Examples are IIO_MOD_X for axial sensors about
 117 *                      the 'x' axis.
 118 * @indexed:            Specify the channel has a numerical index. If not,
 119 *                      the value in channel will be suppressed for attribute
 120 *                      but not for event codes. Typically set it to 0 when
 121 *                      the index is false.
 122 * @differential:       Channel is differential.
 123 */
 124struct iio_chan_spec {
 125        enum iio_chan_type      type;
 126        int                     channel;
 127        int                     channel2;
 128        unsigned long           address;
 129        int                     scan_index;
 130        struct {
 131                char    sign;
 132                u8      realbits;
 133                u8      storagebits;
 134                u8      shift;
 135                enum iio_endian endianness;
 136        } scan_type;
 137        long                    info_mask;
 138        long                    event_mask;
 139        char                    *extend_name;
 140        unsigned                processed_val:1;
 141        unsigned                modified:1;
 142        unsigned                indexed:1;
 143        unsigned                output:1;
 144        unsigned                differential:1;
 145};
 146
 147#define IIO_ST(si, rb, sb, sh)                                          \
 148        { .sign = si, .realbits = rb, .storagebits = sb, .shift = sh }
 149
 150/* Macro assumes input channels */
 151#define IIO_CHAN(_type, _mod, _indexed, _proc, _name, _chan, _chan2, \
 152                 _inf_mask, _address, _si, _stype, _event_mask)         \
 153        { .type = _type,                                                \
 154          .output = 0,                                                  \
 155          .modified = _mod,                                             \
 156          .indexed = _indexed,                                          \
 157          .processed_val = _proc,                                       \
 158          .extend_name = _name,                                         \
 159          .channel = _chan,                                             \
 160          .channel2 = _chan2,                                           \
 161          .info_mask = _inf_mask,                                       \
 162          .address = _address,                                          \
 163          .scan_index = _si,                                            \
 164          .scan_type = _stype,                                          \
 165          .event_mask = _event_mask }
 166
 167#define IIO_CHAN_SOFT_TIMESTAMP(_si)                                    \
 168        { .type = IIO_TIMESTAMP, .channel = -1,                         \
 169                        .scan_index = _si, .scan_type = IIO_ST('s', 64, 64, 0) }
 170
 171/**
 172 * iio_get_time_ns() - utility function to get a time stamp for events etc
 173 **/
 174static inline s64 iio_get_time_ns(void)
 175{
 176        struct timespec ts;
 177        /*
 178         * calls getnstimeofday.
 179         * If hrtimers then up to ns accurate, if not microsecond.
 180         */
 181        ktime_get_real_ts(&ts);
 182
 183        return timespec_to_ns(&ts);
 184}
 185
 186/* Device operating modes */
 187#define INDIO_DIRECT_MODE               0x01
 188#define INDIO_BUFFER_TRIGGERED          0x02
 189#define INDIO_BUFFER_HARDWARE           0x08
 190
 191#define INDIO_ALL_BUFFER_MODES                                  \
 192        (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE)
 193
 194/* Vast majority of this is set by the industrialio subsystem on a
 195 * call to iio_device_register. */
 196#define IIO_VAL_INT 1
 197#define IIO_VAL_INT_PLUS_MICRO 2
 198#define IIO_VAL_INT_PLUS_NANO 3
 199
 200struct iio_trigger; /* forward declaration */
 201struct iio_dev;
 202
 203/**
 204 * struct iio_info - constant information about device
 205 * @driver_module:      module structure used to ensure correct
 206 *                      ownership of chrdevs etc
 207 * @event_attrs:        event control attributes
 208 * @attrs:              general purpose device attributes
 209 * @read_raw:           function to request a value from the device.
 210 *                      mask specifies which value. Note 0 means a reading of
 211 *                      the channel in question.  Return value will specify the
 212 *                      type of value returned by the device. val and val2 will
 213 *                      contain the elements making up the returned value.
 214 * @write_raw:          function to write a value to the device.
 215 *                      Parameters are the same as for read_raw.
 216 * @write_raw_get_fmt:  callback function to query the expected
 217 *                      format/precision. If not set by the driver, write_raw
 218 *                      returns IIO_VAL_INT_PLUS_MICRO.
 219 * @read_event_config:  find out if the event is enabled.
 220 * @write_event_config: set if the event is enabled.
 221 * @read_event_value:   read a value associated with the event. Meaning
 222 *                      is event dependant. event_code specifies which event.
 223 * @write_event_value:  write the value associate with the event.
 224 *                      Meaning is event dependent.
 225 * @validate_trigger:   function to validate the trigger when the
 226 *                      current trigger gets changed.
 227 **/
 228struct iio_info {
 229        struct module                   *driver_module;
 230        struct attribute_group          *event_attrs;
 231        const struct attribute_group    *attrs;
 232
 233        int (*read_raw)(struct iio_dev *indio_dev,
 234                        struct iio_chan_spec const *chan,
 235                        int *val,
 236                        int *val2,
 237                        long mask);
 238
 239        int (*write_raw)(struct iio_dev *indio_dev,
 240                         struct iio_chan_spec const *chan,
 241                         int val,
 242                         int val2,
 243                         long mask);
 244
 245        int (*write_raw_get_fmt)(struct iio_dev *indio_dev,
 246                         struct iio_chan_spec const *chan,
 247                         long mask);
 248
 249        int (*read_event_config)(struct iio_dev *indio_dev,
 250                                 u64 event_code);
 251
 252        int (*write_event_config)(struct iio_dev *indio_dev,
 253                                  u64 event_code,
 254                                  int state);
 255
 256        int (*read_event_value)(struct iio_dev *indio_dev,
 257                                u64 event_code,
 258                                int *val);
 259        int (*write_event_value)(struct iio_dev *indio_dev,
 260                                 u64 event_code,
 261                                 int val);
 262        int (*validate_trigger)(struct iio_dev *indio_dev,
 263                                struct iio_trigger *trig);
 264
 265};
 266
 267/**
 268 * struct iio_dev - industrial I/O device
 269 * @id:                 [INTERN] used to identify device internally
 270 * @modes:              [DRIVER] operating modes supported by device
 271 * @currentmode:        [DRIVER] current operating mode
 272 * @dev:                [DRIVER] device structure, should be assigned a parent
 273 *                      and owner
 274 * @event_interface:    [INTERN] event chrdevs associated with interrupt lines
 275 * @buffer:             [DRIVER] any buffer present
 276 * @mlock:              [INTERN] lock used to prevent simultaneous device state
 277 *                      changes
 278 * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
 279 * @masklength:         [INTERN] the length of the mask established from
 280 *                      channels
 281 * @trig:               [INTERN] current device trigger (buffer modes)
 282 * @pollfunc:           [DRIVER] function run on trigger being received
 283 * @channels:           [DRIVER] channel specification structure table
 284 * @num_channels:       [DRIVER] number of chanels specified in @channels.
 285 * @channel_attr_list:  [INTERN] keep track of automatically created channel
 286 *                      attributes
 287 * @chan_attr_group:    [INTERN] group for all attrs in base directory
 288 * @name:               [DRIVER] name of the device.
 289 * @info:               [DRIVER] callbacks and constant info from driver
 290 * @chrdev:             [INTERN] associated character device
 291 * @groups:             [INTERN] attribute groups
 292 * @groupcounter:       [INTERN] index of next attribute group
 293 **/
 294struct iio_dev {
 295        int                             id;
 296
 297        int                             modes;
 298        int                             currentmode;
 299        struct device                   dev;
 300
 301        struct iio_event_interface      *event_interface;
 302
 303        struct iio_buffer               *buffer;
 304        struct mutex                    mlock;
 305
 306        unsigned long                   *available_scan_masks;
 307        unsigned                        masklength;
 308        struct iio_trigger              *trig;
 309        struct iio_poll_func            *pollfunc;
 310
 311        struct iio_chan_spec const      *channels;
 312        int                             num_channels;
 313
 314        struct list_head                channel_attr_list;
 315        struct attribute_group          chan_attr_group;
 316        const char                      *name;
 317        const struct iio_info           *info;
 318        struct cdev                     chrdev;
 319#define IIO_MAX_GROUPS 6
 320        const struct attribute_group    *groups[IIO_MAX_GROUPS + 1];
 321        int                             groupcounter;
 322};
 323
 324/**
 325 * iio_device_register() - register a device with the IIO subsystem
 326 * @indio_dev:          Device structure filled by the device driver
 327 **/
 328int iio_device_register(struct iio_dev *indio_dev);
 329
 330/**
 331 * iio_device_unregister() - unregister a device from the IIO subsystem
 332 * @indio_dev:          Device structure representing the device.
 333 **/
 334void iio_device_unregister(struct iio_dev *indio_dev);
 335
 336/**
 337 * iio_push_event() - try to add event to the list for userspace reading
 338 * @indio_dev:          IIO device structure
 339 * @ev_code:            What event
 340 * @timestamp:          When the event occurred
 341 **/
 342int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
 343
 344extern struct bus_type iio_bus_type;
 345
 346/**
 347 * iio_put_device() - reference counted deallocation of struct device
 348 * @dev: the iio_device containing the device
 349 **/
 350static inline void iio_put_device(struct iio_dev *indio_dev)
 351{
 352        if (indio_dev)
 353                put_device(&indio_dev->dev);
 354};
 355
 356/* Can we make this smaller? */
 357#define IIO_ALIGN L1_CACHE_BYTES
 358/**
 359 * iio_allocate_device() - allocate an iio_dev from a driver
 360 * @sizeof_priv: Space to allocate for private structure.
 361 **/
 362struct iio_dev *iio_allocate_device(int sizeof_priv);
 363
 364static inline void *iio_priv(const struct iio_dev *indio_dev)
 365{
 366        return (char *)indio_dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
 367}
 368
 369static inline struct iio_dev *iio_priv_to_dev(void *priv)
 370{
 371        return (struct iio_dev *)((char *)priv -
 372                                  ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
 373}
 374
 375/**
 376 * iio_free_device() - free an iio_dev from a driver
 377 * @dev: the iio_dev associated with the device
 378 **/
 379void iio_free_device(struct iio_dev *indio_dev);
 380
 381/**
 382 * iio_buffer_enabled() - helper function to test if the buffer is enabled
 383 * @indio_dev:          IIO device info structure for device
 384 **/
 385static inline bool iio_buffer_enabled(struct iio_dev *indio_dev)
 386{
 387        return indio_dev->currentmode
 388                & (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE);
 389};
 390
 391#endif /* _INDUSTRIAL_IO_H_ */
 392