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 #ifndef _INDUSTRIAL_IO_H_
  11 #define _INDUSTRIAL_IO_H_
  12
  13 #include <linux/device.h>
  14 #include <linux/cdev.h>
  15 #include "types.h"
  16 /* IIO TODO LIST */
  17 /*
  18  * Provide means of adjusting timer accuracy.
  19  * Currently assumes nano seconds.
  20  */
  21
  22 enum iio_data_type {
  23         IIO_RAW,
  24         IIO_PROCESSED,
  25 };
  26
  27 /* Could add the raw attributes as well - allowing buffer only devices */
  28 enum iio_chan_info_enum {
  29         /* 0 is reserverd for raw attributes */
  30         IIO_CHAN_INFO_SCALE = 1,
  31         IIO_CHAN_INFO_OFFSET,
  32         IIO_CHAN_INFO_CALIBSCALE,
  33         IIO_CHAN_INFO_CALIBBIAS,
  34         IIO_CHAN_INFO_PEAK,
  35         IIO_CHAN_INFO_PEAK_SCALE,
  36         IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW,
  37         IIO_CHAN_INFO_AVERAGE_RAW,
  38         IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY,
  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
  44 #define IIO_CHAN_INFO_SCALE_SEPARATE_BIT                \
  45         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_SCALE)
  46 #define IIO_CHAN_INFO_SCALE_SHARED_BIT                  \
  47         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_SCALE)
  48 #define IIO_CHAN_INFO_OFFSET_SEPARATE_BIT                       \
  49         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_OFFSET)
  50 #define IIO_CHAN_INFO_OFFSET_SHARED_BIT                 \
  51         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_OFFSET)
  52 #define IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT                   \
  53         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_CALIBSCALE)
  54 #define IIO_CHAN_INFO_CALIBSCALE_SHARED_BIT                     \
  55         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_CALIBSCALE)
  56 #define IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT                    \
  57         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_CALIBBIAS)
  58 #define IIO_CHAN_INFO_CALIBBIAS_SHARED_BIT                      \
  59         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_CALIBBIAS)
  60 #define IIO_CHAN_INFO_PEAK_SEPARATE_BIT                 \
  61         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_PEAK)
  62 #define IIO_CHAN_INFO_PEAK_SHARED_BIT                   \
  63         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_PEAK)
  64 #define IIO_CHAN_INFO_PEAKSCALE_SEPARATE_BIT                    \
  65         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_PEAKSCALE)
  66 #define IIO_CHAN_INFO_PEAKSCALE_SHARED_BIT                      \
  67         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_PEAKSCALE)
  68 #define IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SEPARATE_BIT    \
  69         IIO_CHAN_INFO_SEPARATE_BIT(                             \
  70                 IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW)
  71 #define IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SHARED_BIT      \
  72         IIO_CHAN_INFO_SHARED_BIT(                               \
  73                 IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW)
  74 #define IIO_CHAN_INFO_AVERAGE_RAW_SEPARATE_BIT                  \
  75         IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_AVERAGE_RAW)
  76 #define IIO_CHAN_INFO_AVERAGE_RAW_SHARED_BIT                    \
  77         IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_AVERAGE_RAW)
  78 #define IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY_SHARED_BIT \
  79         IIO_CHAN_INFO_SHARED_BIT(                              \
  80                 IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY)
  81 #define IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY_SEPARATE_BIT \
  82         IIO_CHAN_INFO_SEPARATE_BIT(                            \
  83                 IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY)
  84
  85 enum iio_endian {
  86         IIO_CPU,
  87         IIO_BE,
  88         IIO_LE,
  89 };
  90
  91 /**
  92  * struct iio_chan_spec - specification of a single channel
  93  * @type:               What type of measurement is the channel making.
  94  * @channel:            What number or name do we wish to asign the channel.
  95  * @channel2:           If there is a second number for a differential
  96  *                      channel then this is it. If modified is set then the
  97  *                      value here specifies the modifier.
  98  * @address:            Driver specific identifier.
  99  * @scan_index: Monotonic index to give ordering in scans when read
 100  *                      from a buffer.
 101  * @scan_type:          Sign:           's' or 'u' to specify signed or unsigned
 102  *                      realbits:       Number of valid bits of data
 103  *                      storage_bits:   Realbits + padding
 104  *                      shift:          Shift right by this before masking out
 105  *                                      realbits.
 106  *                      endianness:     little or big endian
 107  * @info_mask:          What information is to be exported about this channel.
 108  *                      This includes calibbias, scale etc.
 109  * @event_mask: What events can this channel produce.
 110  * @extend_name:        Allows labeling of channel attributes with an
 111  *                      informative name. Note this has no effect codes etc,
 112  *                      unlike modifiers.
 113  * @datasheet_name:     A name used in in kernel mapping of channels. It should
 114  *                      corrspond to the first name that the channel is referred
 115  *                      to by in the datasheet (e.g. IND), or the nearest
 116  *                      possible compound name (e.g. IND-INC).
 117  * @processed_val:      Flag to specify the data access attribute should be
 118  *                      *_input rather than *_raw.
 119  * @modified:           Does a modifier apply to this channel. What these are
 120  *                      depends on the channel type.  Modifier is set in
 121  *                      channel2. Examples are IIO_MOD_X for axial sensors about
 122  *                      the 'x' axis.
 123  * @indexed:            Specify the channel has a numerical index. If not,
 124  *                      the value in channel will be suppressed for attribute
 125  *                      but not for event codes. Typically set it to 0 when
 126  *                      the index is false.
 127  * @differential:       Channel is differential.
 128  */
 129 struct iio_chan_spec {
 130         enum iio_chan_type      type;
 131         int                     channel;
 132         int                     channel2;
 133         unsigned long           address;
 134         int                     scan_index;
 135         struct {
 136                 char    sign;
 137                 u8      realbits;
 138                 u8      storagebits;
 139                 u8      shift;
 140                 enum iio_endian endianness;
 141         } scan_type;
 142         long                    info_mask;
 143         long                    event_mask;
 144         char                    *extend_name;
 145         const char              *datasheet_name;
 146         unsigned                processed_val:1;
 147         unsigned                modified:1;
 148         unsigned                indexed:1;
 149         unsigned                output:1;
 150         unsigned                differential:1;
 151 };
 152
 153 #define IIO_ST(si, rb, sb, sh)                                          \
 154         { .sign = si, .realbits = rb, .storagebits = sb, .shift = sh }
 155
 156 /* Macro assumes input channels */
 157 #define IIO_CHAN(_type, _mod, _indexed, _proc, _name, _chan, _chan2, \
 158                  _inf_mask, _address, _si, _stype, _event_mask)         \
 159         { .type = _type,                                                \
 160           .output = 0,                                                  \
 161           .modified = _mod,                                             \
 162           .indexed = _indexed,                                          \
 163           .processed_val = _proc,                                       \
 164           .extend_name = _name,                                         \
 165           .channel = _chan,                                             \
 166           .channel2 = _chan2,                                           \
 167           .info_mask = _inf_mask,                                       \
 168           .address = _address,                                          \
 169           .scan_index = _si,                                            \
 170           .scan_type = _stype,                                          \
 171           .event_mask = _event_mask }
 172
 173 #define IIO_CHAN_SOFT_TIMESTAMP(_si)                                    \
 174         { .type = IIO_TIMESTAMP, .channel = -1,                         \
 175                         .scan_index = _si, .scan_type = IIO_ST('s', 64, 64, 0) }
 176
 177 /**
 178  * iio_get_time_ns() - utility function to get a time stamp for events etc
 179  **/
 180 static inline s64 iio_get_time_ns(void)
 181 {
 182         struct timespec ts;
 183         /*
 184          * calls getnstimeofday.
 185          * If hrtimers then up to ns accurate, if not microsecond.
 186          */
 187         ktime_get_real_ts(&ts);
 188
 189         return timespec_to_ns(&ts);
 190 }
 191
 192 /* Device operating modes */
 193 #define INDIO_DIRECT_MODE               0x01
 194 #define INDIO_BUFFER_TRIGGERED          0x02
 195 #define INDIO_BUFFER_HARDWARE           0x08
 196
 197 #define INDIO_ALL_BUFFER_MODES                                  \
 198         (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE)
 199
 200 /* Vast majority of this is set by the industrialio subsystem on a
 201  * call to iio_device_register. */
 202 #define IIO_VAL_INT 1
 203 #define IIO_VAL_INT_PLUS_MICRO 2
 204 #define IIO_VAL_INT_PLUS_NANO 3
 205
 206 struct iio_trigger; /* forward declaration */
 207 struct iio_dev;
 208
 209 /**
 210  * struct iio_info - constant information about device
 211  * @driver_module:      module structure used to ensure correct
 212  *                      ownership of chrdevs etc
 213  * @event_attrs:        event control attributes
 214  * @attrs:              general purpose device attributes
 215  * @read_raw:           function to request a value from the device.
 216  *                      mask specifies which value. Note 0 means a reading of
 217  *                      the channel in question.  Return value will specify the
 218  *                      type of value returned by the device. val and val2 will
 219  *                      contain the elements making up the returned value.
 220  * @write_raw:          function to write a value to the device.
 221  *                      Parameters are the same as for read_raw.
 222  * @write_raw_get_fmt:  callback function to query the expected
 223  *                      format/precision. If not set by the driver, write_raw
 224  *                      returns IIO_VAL_INT_PLUS_MICRO.
 225  * @read_event_config:  find out if the event is enabled.
 226  * @write_event_config: set if the event is enabled.
 227  * @read_event_value:   read a value associated with the event. Meaning
 228  *                      is event dependant. event_code specifies which event.
 229  * @write_event_value:  write the value associate with the event.
 230  *                      Meaning is event dependent.
 231  * @validate_trigger:   function to validate the trigger when the
 232  *                      current trigger gets changed.
 233  **/
 234 struct iio_info {
 235         struct module                   *driver_module;
 236         struct attribute_group          *event_attrs;
 237         const struct attribute_group    *attrs;
 238
 239         int (*read_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)(struct iio_dev *indio_dev,
 246                          struct iio_chan_spec const *chan,
 247                          int val,
 248                          int val2,
 249                          long mask);
 250
 251         int (*write_raw_get_fmt)(struct iio_dev *indio_dev,
 252                          struct iio_chan_spec const *chan,
 253                          long mask);
 254
 255         int (*read_event_config)(struct iio_dev *indio_dev,
 256                                  u64 event_code);
 257
 258         int (*write_event_config)(struct iio_dev *indio_dev,
 259                                   u64 event_code,
 260                                   int state);
 261
 262         int (*read_event_value)(struct iio_dev *indio_dev,
 263                                 u64 event_code,
 264                                 int *val);
 265         int (*write_event_value)(struct iio_dev *indio_dev,
 266                                  u64 event_code,
 267                                  int val);
 268         int (*validate_trigger)(struct iio_dev *indio_dev,
 269                                 struct iio_trigger *trig);
 270         int (*update_scan_mode)(struct iio_dev *indio_dev,
 271                                 const unsigned long *scan_mask);
 272 };
 273
 274 /**
 275  * struct iio_buffer_setup_ops - buffer setup related callbacks
 276  * @preenable:          [DRIVER] function to run prior to marking buffer enabled
 277  * @postenable:         [DRIVER] function to run after marking buffer enabled
 278  * @predisable:         [DRIVER] function to run prior to marking buffer
 279  *                      disabled
 280  * @postdisable:        [DRIVER] function to run after marking buffer disabled
 281  */
 282 struct iio_buffer_setup_ops {
 283         int                             (*preenable)(struct iio_dev *);
 284         int                             (*postenable)(struct iio_dev *);
 285         int                             (*predisable)(struct iio_dev *);
 286         int                             (*postdisable)(struct iio_dev *);
 287 };
 288
 289 /**
 290  * struct iio_dev - industrial I/O device
 291  * @id:                 [INTERN] used to identify device internally
 292  * @modes:              [DRIVER] operating modes supported by device
 293  * @currentmode:        [DRIVER] current operating mode
 294  * @dev:                [DRIVER] device structure, should be assigned a parent
 295  *                      and owner
 296  * @event_interface:    [INTERN] event chrdevs associated with interrupt lines
 297  * @buffer:             [DRIVER] any buffer present
 298  * @mlock:              [INTERN] lock used to prevent simultaneous device state
 299  *                      changes
 300  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
 301  * @masklength:         [INTERN] the length of the mask established from
 302  *                      channels
 303  * @active_scan_mask:   [INTERN] union of all scan masks requested by buffers
 304  * @trig:               [INTERN] current device trigger (buffer modes)
 305  * @pollfunc:           [DRIVER] function run on trigger being received
 306  * @channels:           [DRIVER] channel specification structure table
 307  * @num_channels:       [DRIVER] number of chanels specified in @channels.
 308  * @channel_attr_list:  [INTERN] keep track of automatically created channel
 309  *                      attributes
 310  * @chan_attr_group:    [INTERN] group for all attrs in base directory
 311  * @name:               [DRIVER] name of the device.
 312  * @info:               [DRIVER] callbacks and constant info from driver
 313  * @chrdev:             [INTERN] associated character device
 314  * @groups:             [INTERN] attribute groups
 315  * @groupcounter:       [INTERN] index of next attribute group
 316  * @flags:              [INTERN] file ops related flags including busy flag.
 317  **/
 318 struct iio_dev {
 319         int                             id;
 320
 321         int                             modes;
 322         int                             currentmode;
 323         struct device                   dev;
 324
 325         struct iio_event_interface      *event_interface;
 326
 327         struct iio_buffer               *buffer;
 328         struct mutex                    mlock;
 329
 330         unsigned long                   *available_scan_masks;
 331         unsigned                        masklength;
 332         unsigned long                   *active_scan_mask;
 333         struct iio_trigger              *trig;
 334         struct iio_poll_func            *pollfunc;
 335
 336         struct iio_chan_spec const      *channels;
 337         int                             num_channels;
 338
 339         struct list_head                channel_attr_list;
 340         struct attribute_group          chan_attr_group;
 341         const char                      *name;
 342         const struct iio_info           *info;
 343         const struct iio_buffer_setup_ops       *setup_ops;
 344         struct cdev                     chrdev;
 345 #define IIO_MAX_GROUPS 6
 346         const struct attribute_group    *groups[IIO_MAX_GROUPS + 1];
 347         int                             groupcounter;
 348
 349         unsigned long                   flags;
 350 };
 351
 352 /**
 353  * iio_find_channel_from_si() - get channel from its scan index
 354  * @indio_dev:          device
 355  * @si:                 scan index to match
 356  */
 357 const struct iio_chan_spec
 358 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si);
 359
 360 /**
 361  * iio_device_register() - register a device with the IIO subsystem
 362  * @indio_dev:          Device structure filled by the device driver
 363  **/
 364 int iio_device_register(struct iio_dev *indio_dev);
 365
 366 /**
 367  * iio_device_unregister() - unregister a device from the IIO subsystem
 368  * @indio_dev:          Device structure representing the device.
 369  **/
 370 void iio_device_unregister(struct iio_dev *indio_dev);
 371
 372 /**
 373  * iio_push_event() - try to add event to the list for userspace reading
 374  * @indio_dev:          IIO device structure
 375  * @ev_code:            What event
 376  * @timestamp:          When the event occurred
 377  **/
 378 int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
 379
 380 extern struct bus_type iio_bus_type;
 381
 382 /**
 383  * iio_put_device() - reference counted deallocation of struct device
 384  * @dev: the iio_device containing the device
 385  **/
 386 static inline void iio_put_device(struct iio_dev *indio_dev)
 387 {
 388         if (indio_dev)
 389                 put_device(&indio_dev->dev);
 390 };
 391
 392 /* Can we make this smaller? */
 393 #define IIO_ALIGN L1_CACHE_BYTES
 394 /**
 395  * iio_allocate_device() - allocate an iio_dev from a driver
 396  * @sizeof_priv: Space to allocate for private structure.
 397  **/
 398 struct iio_dev *iio_allocate_device(int sizeof_priv);
 399
 400 static inline void *iio_priv(const struct iio_dev *indio_dev)
 401 {
 402         return (char *)indio_dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
 403 }
 404
 405 static inline struct iio_dev *iio_priv_to_dev(void *priv)
 406 {
 407         return (struct iio_dev *)((char *)priv -
 408                                   ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
 409 }
 410
 411 /**
 412  * iio_free_device() - free an iio_dev from a driver
 413  * @dev: the iio_dev associated with the device
 414  **/
 415 void iio_free_device(struct iio_dev *indio_dev);
 416
 417 /**
 418  * iio_buffer_enabled() - helper function to test if the buffer is enabled
 419  * @indio_dev:          IIO device info structure for device
 420  **/
 421 static inline bool iio_buffer_enabled(struct iio_dev *indio_dev)
 422 {
 423         return indio_dev->currentmode
 424                 & (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE);
 425 };
 426
 427 #endif /* _INDUSTRIAL_IO_H_ */