include/linux/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 #ifndef _INDUSTRIAL_IO_H_
  11 #define _INDUSTRIAL_IO_H_
  12
  13 #include <linux/device.h>
  14 #include <linux/cdev.h>
  15 #include <linux/iio/types.h>
  16 /* IIO TODO LIST */
  17 /*
  18  * Provide means of adjusting timer accuracy.
  19  * Currently assumes nano seconds.
  20  */
  21
  22 enum iio_chan_info_enum {
  23         IIO_CHAN_INFO_RAW = 0,
  24         IIO_CHAN_INFO_PROCESSED,
  25         IIO_CHAN_INFO_SCALE,
  26         IIO_CHAN_INFO_OFFSET,
  27         IIO_CHAN_INFO_CALIBSCALE,
  28         IIO_CHAN_INFO_CALIBBIAS,
  29         IIO_CHAN_INFO_PEAK,
  30         IIO_CHAN_INFO_PEAK_SCALE,
  31         IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW,
  32         IIO_CHAN_INFO_AVERAGE_RAW,
  33         IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY,
  34         IIO_CHAN_INFO_SAMP_FREQ,
  35         IIO_CHAN_INFO_FREQUENCY,
  36         IIO_CHAN_INFO_PHASE,
  37         IIO_CHAN_INFO_HARDWAREGAIN,
  38         IIO_CHAN_INFO_HYSTERESIS,
  39 };
  40
  41 #define IIO_CHAN_INFO_SHARED_BIT(type) BIT(type*2)
  42 #define IIO_CHAN_INFO_SEPARATE_BIT(type) BIT(type*2 + 1)
  43 #define IIO_CHAN_INFO_BITS(type) (IIO_CHAN_INFO_SHARED_BIT(type) | \
  44                                     IIO_CHAN_INFO_SEPARATE_BIT(type))
  45
  46 #define IIO_CHAN_INFO_RAW_SEPARATE_BIT                  \
  47         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_RAW)
  48 #define IIO_CHAN_INFO_PROCESSED_SEPARATE_BIT                    \
  49         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_PROCESSED)
  50 #define IIO_CHAN_INFO_SCALE_SEPARATE_BIT                \
  51         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_SCALE)
  52 #define IIO_CHAN_INFO_SCALE_SHARED_BIT                  \
  53         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_SCALE)
  54 #define IIO_CHAN_INFO_OFFSET_SEPARATE_BIT                       \
  55         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_OFFSET)
  56 #define IIO_CHAN_INFO_OFFSET_SHARED_BIT                 \
  57         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_OFFSET)
  58 #define IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT                   \
  59         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_CALIBSCALE)
  60 #define IIO_CHAN_INFO_CALIBSCALE_SHARED_BIT                     \
  61         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_CALIBSCALE)
  62 #define IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT                    \
  63         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_CALIBBIAS)
  64 #define IIO_CHAN_INFO_CALIBBIAS_SHARED_BIT                      \
  65         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_CALIBBIAS)
  66 #define IIO_CHAN_INFO_PEAK_SEPARATE_BIT                 \
  67         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_PEAK)
  68 #define IIO_CHAN_INFO_PEAK_SHARED_BIT                   \
  69         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_PEAK)
  70 #define IIO_CHAN_INFO_PEAKSCALE_SEPARATE_BIT                    \
  71         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_PEAKSCALE)
  72 #define IIO_CHAN_INFO_PEAKSCALE_SHARED_BIT                      \
  73         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_PEAKSCALE)
  74 #define IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SEPARATE_BIT    \
  75         IIO_CHAN_INFO_SEPARATE_BIT(                             \
  76                 IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW)
  77 #define IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SHARED_BIT      \
  78         IIO_CHAN_INFO_SHARED_BIT(                               \
  79                 IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW)
  80 #define IIO_CHAN_INFO_AVERAGE_RAW_SEPARATE_BIT                  \
  81         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_AVERAGE_RAW)
  82 #define IIO_CHAN_INFO_AVERAGE_RAW_SHARED_BIT                    \
  83         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_AVERAGE_RAW)
  84 #define IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY_SHARED_BIT \
  85         IIO_CHAN_INFO_SHARED_BIT(                              \
  86                 IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY)
  87 #define IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY_SEPARATE_BIT \
  88         IIO_CHAN_INFO_SEPARATE_BIT(                            \
  89                 IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY)
  90 #define IIO_CHAN_INFO_SAMP_FREQ_SEPARATE_BIT            \
  91         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_SAMP_FREQ)
  92 #define IIO_CHAN_INFO_SAMP_FREQ_SHARED_BIT                      \
  93         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_SAMP_FREQ)
  94 #define IIO_CHAN_INFO_FREQUENCY_SEPARATE_BIT                    \
  95         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_FREQUENCY)
  96 #define IIO_CHAN_INFO_FREQUENCY_SHARED_BIT                      \
  97         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_FREQUENCY)
  98 #define IIO_CHAN_INFO_PHASE_SEPARATE_BIT                        \
  99         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_PHASE)
 100 #define IIO_CHAN_INFO_PHASE_SHARED_BIT                  \
 101         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_PHASE)
 102 #define IIO_CHAN_INFO_HARDWAREGAIN_SEPARATE_BIT                 \
 103         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_HARDWAREGAIN)
 104 #define IIO_CHAN_INFO_HARDWAREGAIN_SHARED_BIT                   \
 105         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_HARDWAREGAIN)
 106 #define IIO_CHAN_INFO_HYSTERESIS_SEPARATE_BIT                   \
 107         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_HYSTERESIS)
 108 #define IIO_CHAN_INFO_HYSTERESIS_SHARED_BIT                     \
 109         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_HYSTERESIS)
 110
 111 enum iio_endian {
 112         IIO_CPU,
 113         IIO_BE,
 114         IIO_LE,
 115 };
 116
 117 struct iio_chan_spec;
 118 struct iio_dev;
 119
 120 /**
 121  * struct iio_chan_spec_ext_info - Extended channel info attribute
 122  * @name:       Info attribute name
 123  * @shared:     Whether this attribute is shared between all channels.
 124  * @read:       Read callback for this info attribute, may be NULL.
 125  * @write:      Write callback for this info attribute, may be NULL.
 126  * @private:    Data private to the driver.
 127  */
 128 struct iio_chan_spec_ext_info {
 129         const char *name;
 130         bool shared;
 131         ssize_t (*read)(struct iio_dev *, uintptr_t private,
 132                         struct iio_chan_spec const *, char *buf);
 133         ssize_t (*write)(struct iio_dev *, uintptr_t private,
 134                          struct iio_chan_spec const *, const char *buf,
 135                          size_t len);
 136         uintptr_t private;
 137 };
 138
 139 /**
 140  * struct iio_enum - Enum channel info attribute
 141  * @items:      An array of strings.
 142  * @num_items:  Length of the item array.
 143  * @set:        Set callback function, may be NULL.
 144  * @get:        Get callback function, may be NULL.
 145  *
 146  * The iio_enum struct can be used to implement enum style channel attributes.
 147  * Enum style attributes are those which have a set of strings which map to
 148  * unsigned integer values. The IIO enum helper code takes care of mapping
 149  * between value and string as well as generating a "_available" file which
 150  * contains a list of all available items. The set callback will be called when
 151  * the attribute is updated. The last parameter is the index to the newly
 152  * activated item. The get callback will be used to query the currently active
 153  * item and is supposed to return the index for it.
 154  */
 155 struct iio_enum {
 156         const char * const *items;
 157         unsigned int num_items;
 158         int (*set)(struct iio_dev *, const struct iio_chan_spec *, unsigned int);
 159         int (*get)(struct iio_dev *, const struct iio_chan_spec *);
 160 };
 161
 162 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 163         uintptr_t priv, const struct iio_chan_spec *chan, char *buf);
 164 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 165         uintptr_t priv, const struct iio_chan_spec *chan, char *buf);
 166 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 167         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 168         size_t len);
 169
 170 /**
 171  * IIO_ENUM() - Initialize enum extended channel attribute
 172  * @_name:      Attribute name
 173  * @_shared:    Whether the attribute is shared between all channels
 174  * @_e:         Pointer to an iio_enum struct
 175  *
 176  * This should usually be used together with IIO_ENUM_AVAILABLE()
 177  */
 178 #define IIO_ENUM(_name, _shared, _e) \
 179 { \
 180         .name = (_name), \
 181         .shared = (_shared), \
 182         .read = iio_enum_read, \
 183         .write = iio_enum_write, \
 184         .private = (uintptr_t)(_e), \
 185 }
 186
 187 /**
 188  * IIO_ENUM_AVAILABLE() - Initialize enum available extended channel attribute
 189  * @_name:      Attribute name ("_available" will be appended to the name)
 190  * @_e:         Pointer to an iio_enum struct
 191  *
 192  * Creates a read only attribute which lists all the available enum items in a
 193  * space separated list. This should usually be used together with IIO_ENUM()
 194  */
 195 #define IIO_ENUM_AVAILABLE(_name, _e) \
 196 { \
 197         .name = (_name "_available"), \
 198         .shared = true, \
 199         .read = iio_enum_available_read, \
 200         .private = (uintptr_t)(_e), \
 201 }
 202
 203 /**
 204  * struct iio_chan_spec - specification of a single channel
 205  * @type:               What type of measurement is the channel making.
 206  * @channel:            What number do we wish to assign the channel.
 207  * @channel2:           If there is a second number for a differential
 208  *                      channel then this is it. If modified is set then the
 209  *                      value here specifies the modifier.
 210  * @address:            Driver specific identifier.
 211  * @scan_index:         Monotonic index to give ordering in scans when read
 212  *                      from a buffer.
 213  * @scan_type:          Sign:           's' or 'u' to specify signed or unsigned
 214  *                      realbits:       Number of valid bits of data
 215  *                      storage_bits:   Realbits + padding
 216  *                      shift:          Shift right by this before masking out
 217  *                                      realbits.
 218  *                      endianness:     little or big endian
 219  * @info_mask:          What information is to be exported about this channel.
 220  *                      This includes calibbias, scale etc.
 221  * @event_mask:         What events can this channel produce.
 222  * @ext_info:           Array of extended info attributes for this channel.
 223  *                      The array is NULL terminated, the last element should
 224  *                      have its name field set to NULL.
 225  * @extend_name:        Allows labeling of channel attributes with an
 226  *                      informative name. Note this has no effect codes etc,
 227  *                      unlike modifiers.
 228  * @datasheet_name:     A name used in in-kernel mapping of channels. It should
 229  *                      correspond to the first name that the channel is referred
 230  *                      to by in the datasheet (e.g. IND), or the nearest
 231  *                      possible compound name (e.g. IND-INC).
 232  * @modified:           Does a modifier apply to this channel. What these are
 233  *                      depends on the channel type.  Modifier is set in
 234  *                      channel2. Examples are IIO_MOD_X for axial sensors about
 235  *                      the 'x' axis.
 236  * @indexed:            Specify the channel has a numerical index. If not,
 237  *                      the channel index number will be suppressed for sysfs
 238  *                      attributes but not for event codes.
 239  * @output:             Channel is output.
 240  * @differential:       Channel is differential.
 241  */
 242 struct iio_chan_spec {
 243         enum iio_chan_type      type;
 244         int                     channel;
 245         int                     channel2;
 246         unsigned long           address;
 247         int                     scan_index;
 248         struct {
 249                 char    sign;
 250                 u8      realbits;
 251                 u8      storagebits;
 252                 u8      shift;
 253                 enum iio_endian endianness;
 254         } scan_type;
 255         long                    info_mask;
 256         long                    event_mask;
 257         const struct iio_chan_spec_ext_info *ext_info;
 258         const char              *extend_name;
 259         const char              *datasheet_name;
 260         unsigned                modified:1;
 261         unsigned                indexed:1;
 262         unsigned                output:1;
 263         unsigned                differential:1;
 264 };
 265
 266
 267 /**
 268  * iio_channel_has_info() - Checks whether a channel supports a info attribute
 269  * @chan: The channel to be queried
 270  * @type: Type of the info attribute to be checked
 271  *
 272  * Returns true if the channels supports reporting values for the given info
 273  * attribute type, false otherwise.
 274  */
 275 static inline bool iio_channel_has_info(const struct iio_chan_spec *chan,
 276         enum iio_chan_info_enum type)
 277 {
 278         return chan->info_mask & IIO_CHAN_INFO_BITS(type);
 279 }
 280
 281 #define IIO_ST(si, rb, sb, sh)                                          \
 282         { .sign = si, .realbits = rb, .storagebits = sb, .shift = sh }
 283
 284 #define IIO_CHAN_SOFT_TIMESTAMP(_si)                                    \
 285         { .type = IIO_TIMESTAMP, .channel = -1,                         \
 286                         .scan_index = _si, .scan_type = IIO_ST('s', 64, 64, 0) }
 287
 288 /**
 289  * iio_get_time_ns() - utility function to get a time stamp for events etc
 290  **/
 291 static inline s64 iio_get_time_ns(void)
 292 {
 293         struct timespec ts;
 294         /*
 295          * calls getnstimeofday.
 296          * If hrtimers then up to ns accurate, if not microsecond.
 297          */
 298         ktime_get_real_ts(&ts);
 299
 300         return timespec_to_ns(&ts);
 301 }
 302
 303 /* Device operating modes */
 304 #define INDIO_DIRECT_MODE               0x01
 305 #define INDIO_BUFFER_TRIGGERED          0x02
 306 #define INDIO_BUFFER_HARDWARE           0x08
 307
 308 #define INDIO_ALL_BUFFER_MODES                                  \
 309         (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE)
 310
 311 struct iio_trigger; /* forward declaration */
 312 struct iio_dev;
 313
 314 /**
 315  * struct iio_info - constant information about device
 316  * @driver_module:      module structure used to ensure correct
 317  *                      ownership of chrdevs etc
 318  * @event_attrs:        event control attributes
 319  * @attrs:              general purpose device attributes
 320  * @read_raw:           function to request a value from the device.
 321  *                      mask specifies which value. Note 0 means a reading of
 322  *                      the channel in question.  Return value will specify the
 323  *                      type of value returned by the device. val and val2 will
 324  *                      contain the elements making up the returned value.
 325  * @write_raw:          function to write a value to the device.
 326  *                      Parameters are the same as for read_raw.
 327  * @write_raw_get_fmt:  callback function to query the expected
 328  *                      format/precision. If not set by the driver, write_raw
 329  *                      returns IIO_VAL_INT_PLUS_MICRO.
 330  * @read_event_config:  find out if the event is enabled.
 331  * @write_event_config: set if the event is enabled.
 332  * @read_event_value:   read a value associated with the event. Meaning
 333  *                      is event dependant. event_code specifies which event.
 334  * @write_event_value:  write the value associated with the event.
 335  *                      Meaning is event dependent.
 336  * @validate_trigger:   function to validate the trigger when the
 337  *                      current trigger gets changed.
 338  * @update_scan_mode:   function to configure device and scan buffer when
 339  *                      channels have changed
 340  * @debugfs_reg_access: function to read or write register value of device
 341  **/
 342 struct iio_info {
 343         struct module                   *driver_module;
 344         struct attribute_group          *event_attrs;
 345         const struct attribute_group    *attrs;
 346
 347         int (*read_raw)(struct iio_dev *indio_dev,
 348                         struct iio_chan_spec const *chan,
 349                         int *val,
 350                         int *val2,
 351                         long mask);
 352
 353         int (*write_raw)(struct iio_dev *indio_dev,
 354                          struct iio_chan_spec const *chan,
 355                          int val,
 356                          int val2,
 357                          long mask);
 358
 359         int (*write_raw_get_fmt)(struct iio_dev *indio_dev,
 360                          struct iio_chan_spec const *chan,
 361                          long mask);
 362
 363         int (*read_event_config)(struct iio_dev *indio_dev,
 364                                  u64 event_code);
 365
 366         int (*write_event_config)(struct iio_dev *indio_dev,
 367                                   u64 event_code,
 368                                   int state);
 369
 370         int (*read_event_value)(struct iio_dev *indio_dev,
 371                                 u64 event_code,
 372                                 int *val);
 373         int (*write_event_value)(struct iio_dev *indio_dev,
 374                                  u64 event_code,
 375                                  int val);
 376         int (*validate_trigger)(struct iio_dev *indio_dev,
 377                                 struct iio_trigger *trig);
 378         int (*update_scan_mode)(struct iio_dev *indio_dev,
 379                                 const unsigned long *scan_mask);
 380         int (*debugfs_reg_access)(struct iio_dev *indio_dev,
 381                                   unsigned reg, unsigned writeval,
 382                                   unsigned *readval);
 383 };
 384
 385 /**
 386  * struct iio_buffer_setup_ops - buffer setup related callbacks
 387  * @preenable:          [DRIVER] function to run prior to marking buffer enabled
 388  * @postenable:         [DRIVER] function to run after marking buffer enabled
 389  * @predisable:         [DRIVER] function to run prior to marking buffer
 390  *                      disabled
 391  * @postdisable:        [DRIVER] function to run after marking buffer disabled
 392  * @validate_scan_mask: [DRIVER] function callback to check whether a given
 393  *                      scan mask is valid for the device.
 394  */
 395 struct iio_buffer_setup_ops {
 396         int (*preenable)(struct iio_dev *);
 397         int (*postenable)(struct iio_dev *);
 398         int (*predisable)(struct iio_dev *);
 399         int (*postdisable)(struct iio_dev *);
 400         bool (*validate_scan_mask)(struct iio_dev *indio_dev,
 401                                    const unsigned long *scan_mask);
 402 };
 403
 404 /**
 405  * struct iio_dev - industrial I/O device
 406  * @id:                 [INTERN] used to identify device internally
 407  * @modes:              [DRIVER] operating modes supported by device
 408  * @currentmode:        [DRIVER] current operating mode
 409  * @dev:                [DRIVER] device structure, should be assigned a parent
 410  *                      and owner
 411  * @event_interface:    [INTERN] event chrdevs associated with interrupt lines
 412  * @buffer:             [DRIVER] any buffer present
 413  * @scan_bytes:         [INTERN] num bytes captured to be fed to buffer demux
 414  * @mlock:              [INTERN] lock used to prevent simultaneous device state
 415  *                      changes
 416  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
 417  * @masklength:         [INTERN] the length of the mask established from
 418  *                      channels
 419  * @active_scan_mask:   [INTERN] union of all scan masks requested by buffers
 420  * @scan_timestamp:     [INTERN] set if any buffers have requested timestamp
 421  * @scan_index_timestamp:[INTERN] cache of the index to the timestamp
 422  * @trig:               [INTERN] current device trigger (buffer modes)
 423  * @pollfunc:           [DRIVER] function run on trigger being received
 424  * @channels:           [DRIVER] channel specification structure table
 425  * @num_channels:       [DRIVER] number of channels specified in @channels.
 426  * @channel_attr_list:  [INTERN] keep track of automatically created channel
 427  *                      attributes
 428  * @chan_attr_group:    [INTERN] group for all attrs in base directory
 429  * @name:               [DRIVER] name of the device.
 430  * @info:               [DRIVER] callbacks and constant info from driver
 431  * @info_exist_lock:    [INTERN] lock to prevent use during removal
 432  * @setup_ops:          [DRIVER] callbacks to call before and after buffer
 433  *                      enable/disable
 434  * @chrdev:             [INTERN] associated character device
 435  * @groups:             [INTERN] attribute groups
 436  * @groupcounter:       [INTERN] index of next attribute group
 437  * @flags:              [INTERN] file ops related flags including busy flag.
 438  * @debugfs_dentry:     [INTERN] device specific debugfs dentry.
 439  * @cached_reg_addr:    [INTERN] cached register address for debugfs reads.
 440  */
 441 struct iio_dev {
 442         int                             id;
 443
 444         int                             modes;
 445         int                             currentmode;
 446         struct device                   dev;
 447
 448         struct iio_event_interface      *event_interface;
 449
 450         struct iio_buffer               *buffer;
 451         int                             scan_bytes;
 452         struct mutex                    mlock;
 453
 454         const unsigned long             *available_scan_masks;
 455         unsigned                        masklength;
 456         const unsigned long             *active_scan_mask;
 457         bool                            scan_timestamp;
 458         unsigned                        scan_index_timestamp;
 459         struct iio_trigger              *trig;
 460         struct iio_poll_func            *pollfunc;
 461
 462         struct iio_chan_spec const      *channels;
 463         int                             num_channels;
 464
 465         struct list_head                channel_attr_list;
 466         struct attribute_group          chan_attr_group;
 467         const char                      *name;
 468         const struct iio_info           *info;
 469         struct mutex                    info_exist_lock;
 470         const struct iio_buffer_setup_ops       *setup_ops;
 471         struct cdev                     chrdev;
 472 #define IIO_MAX_GROUPS 6
 473         const struct attribute_group    *groups[IIO_MAX_GROUPS + 1];
 474         int                             groupcounter;
 475
 476         unsigned long                   flags;
 477 #if defined(CONFIG_DEBUG_FS)
 478         struct dentry                   *debugfs_dentry;
 479         unsigned                        cached_reg_addr;
 480 #endif
 481 };
 482
 483 /**
 484  * iio_find_channel_from_si() - get channel from its scan index
 485  * @indio_dev:          device
 486  * @si:                 scan index to match
 487  */
 488 const struct iio_chan_spec
 489 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si);
 490
 491 /**
 492  * iio_device_register() - register a device with the IIO subsystem
 493  * @indio_dev:          Device structure filled by the device driver
 494  **/
 495 int iio_device_register(struct iio_dev *indio_dev);
 496
 497 /**
 498  * iio_device_unregister() - unregister a device from the IIO subsystem
 499  * @indio_dev:          Device structure representing the device.
 500  **/
 501 void iio_device_unregister(struct iio_dev *indio_dev);
 502
 503 /**
 504  * iio_push_event() - try to add event to the list for userspace reading
 505  * @indio_dev:          IIO device structure
 506  * @ev_code:            What event
 507  * @timestamp:          When the event occurred
 508  **/
 509 int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
 510
 511 extern struct bus_type iio_bus_type;
 512
 513 /**
 514  * iio_device_put() - reference counted deallocation of struct device
 515  * @indio_dev:          IIO device structure containing the device
 516  **/
 517 static inline void iio_device_put(struct iio_dev *indio_dev)
 518 {
 519         if (indio_dev)
 520                 put_device(&indio_dev->dev);
 521 };
 522
 523 /**
 524  * dev_to_iio_dev() - Get IIO device struct from a device struct
 525  * @dev:                The device embedded in the IIO device
 526  *
 527  * Note: The device must be a IIO device, otherwise the result is undefined.
 528  */
 529 static inline struct iio_dev *dev_to_iio_dev(struct device *dev)
 530 {
 531         return container_of(dev, struct iio_dev, dev);
 532 }
 533
 534 /**
 535  * iio_device_get() - increment reference count for the device
 536  * @indio_dev:          IIO device structure
 537  *
 538  * Returns: The passed IIO device
 539  **/
 540 static inline struct iio_dev *iio_device_get(struct iio_dev *indio_dev)
 541 {
 542         return indio_dev ? dev_to_iio_dev(get_device(&indio_dev->dev)) : NULL;
 543 }
 544
 545
 546 /**
 547  * iio_device_set_drvdata() - Set device driver data
 548  * @indio_dev: IIO device structure
 549  * @data: Driver specific data
 550  *
 551  * Allows to attach an arbitrary pointer to an IIO device, which can later be
 552  * retrieved by iio_device_get_drvdata().
 553  */
 554 static inline void iio_device_set_drvdata(struct iio_dev *indio_dev, void *data)
 555 {
 556         dev_set_drvdata(&indio_dev->dev, data);
 557 }
 558
 559 /**
 560  * iio_device_get_drvdata() - Get device driver data
 561  * @indio_dev: IIO device structure
 562  *
 563  * Returns the data previously set with iio_device_set_drvdata()
 564  */
 565 static inline void *iio_device_get_drvdata(struct iio_dev *indio_dev)
 566 {
 567         return dev_get_drvdata(&indio_dev->dev);
 568 }
 569
 570 /* Can we make this smaller? */
 571 #define IIO_ALIGN L1_CACHE_BYTES
 572 /**
 573  * iio_device_alloc() - allocate an iio_dev from a driver
 574  * @sizeof_priv:        Space to allocate for private structure.
 575  **/
 576 struct iio_dev *iio_device_alloc(int sizeof_priv);
 577
 578 static inline void *iio_priv(const struct iio_dev *indio_dev)
 579 {
 580         return (char *)indio_dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
 581 }
 582
 583 static inline struct iio_dev *iio_priv_to_dev(void *priv)
 584 {
 585         return (struct iio_dev *)((char *)priv -
 586                                   ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
 587 }
 588
 589 /**
 590  * iio_device_free() - free an iio_dev from a driver
 591  * @indio_dev:          the iio_dev associated with the device
 592  **/
 593 void iio_device_free(struct iio_dev *indio_dev);
 594
 595 /**
 596  * iio_buffer_enabled() - helper function to test if the buffer is enabled
 597  * @indio_dev:          IIO device structure for device
 598  **/
 599 static inline bool iio_buffer_enabled(struct iio_dev *indio_dev)
 600 {
 601         return indio_dev->currentmode
 602                 & (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE);
 603 };
 604
 605 /**
 606  * iio_get_debugfs_dentry() - helper function to get the debugfs_dentry
 607  * @indio_dev:          IIO device structure for device
 608  **/
 609 #if defined(CONFIG_DEBUG_FS)
 610 static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
 611 {
 612         return indio_dev->debugfs_dentry;
 613 };
 614 #else
 615 static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
 616 {
 617         return NULL;
 618 };
 619 #endif
 620
 621 #endif /* _INDUSTRIAL_IO_H_ */