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
  23 enum iio_data_type {
  24         IIO_RAW,
  25         IIO_PROCESSED,
  26 };
  27
  28 enum iio_chan_type {
  29         /* real channel types */
  30         IIO_VOLTAGE,
  31         IIO_CURRENT,
  32         IIO_POWER,
  33         IIO_ACCEL,
  34         IIO_GYRO,
  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
  47 enum 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 */
  65 enum 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
  84 enum 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  */
 124 struct 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  **/
 174 static 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
 200 struct iio_trigger; /* forward declaration */
 201 struct 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  **/
 228 struct 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  **/
 294 struct 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  * @dev_info:           Device structure filled by the device driver
 327  **/
 328 int iio_device_register(struct iio_dev *dev_info);
 329
 330 /**
 331  * iio_device_unregister() - unregister a device from the IIO subsystem
 332  * @dev_info:           Device structure representing the device.
 333  **/
 334 void iio_device_unregister(struct iio_dev *dev_info);
 335
 336 /**
 337  * iio_push_event() - try to add event to the list for userspace reading
 338  * @dev_info:           IIO device structure
 339  * @ev_code:            What event
 340  * @timestamp:          When the event occurred
 341  **/
 342 int iio_push_event(struct iio_dev *dev_info, u64 ev_code, s64 timestamp);
 343
 344 extern 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  **/
 350 static inline void iio_put_device(struct iio_dev *dev)
 351 {
 352         if (dev)
 353                 put_device(&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  **/
 362 struct iio_dev *iio_allocate_device(int sizeof_priv);
 363
 364 static inline void *iio_priv(const struct iio_dev *dev)
 365 {
 366         return (char *)dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
 367 }
 368
 369 static 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  **/
 379 void iio_free_device(struct iio_dev *dev);
 380
 381 /**
 382  * iio_buffer_enabled() - helper function to test if the buffer is enabled
 383  * @dev_info:           IIO device info structure for device
 384  **/
 385 static inline bool iio_buffer_enabled(struct iio_dev *dev_info)
 386 {
 387         return dev_info->currentmode
 388                 & (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE);
 389 };
 390
 391 #endif /* _INDUSTRIAL_IO_H_ */