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_VOLTAGE_DIFF,
  35         IIO_GYRO,
  36         IIO_MAGN,
  37         IIO_LIGHT,
  38         IIO_INTENSITY,
  39         IIO_PROXIMITY,
  40         IIO_TEMP,
  41         IIO_INCLI,
  42         IIO_ROT,
  43         IIO_ANGL,
  44         IIO_TIMESTAMP,
  45 };
  46
  47 /* Nasty hack to avoid massive churn */
  48 #define IIO_IN IIO_VOLTAGE
  49 #define IIO_IN_DIFF IIO_VOLTAGE_DIFF
  50
  51 #define IIO_MOD_X                       0
  52 #define IIO_MOD_LIGHT_BOTH              0
  53 #define IIO_MOD_Y                       1
  54 #define IIO_MOD_LIGHT_IR                1
  55 #define IIO_MOD_Z                       2
  56 #define IIO_MOD_X_AND_Y                 3
  57 #define IIO_MOD_X_ANX_Z                 4
  58 #define IIO_MOD_Y_AND_Z                 5
  59 #define IIO_MOD_X_AND_Y_AND_Z           6
  60 #define IIO_MOD_X_OR_Y                  7
  61 #define IIO_MOD_X_OR_Z                  8
  62 #define IIO_MOD_Y_OR_Z                  9
  63 #define IIO_MOD_X_OR_Y_OR_Z             10
  64
  65 /* Could add the raw attributes as well - allowing buffer only devices */
  66 enum iio_chan_info_enum {
  67         IIO_CHAN_INFO_SCALE_SHARED,
  68         IIO_CHAN_INFO_SCALE_SEPARATE,
  69         IIO_CHAN_INFO_OFFSET_SHARED,
  70         IIO_CHAN_INFO_OFFSET_SEPARATE,
  71         IIO_CHAN_INFO_CALIBSCALE_SHARED,
  72         IIO_CHAN_INFO_CALIBSCALE_SEPARATE,
  73         IIO_CHAN_INFO_CALIBBIAS_SHARED,
  74         IIO_CHAN_INFO_CALIBBIAS_SEPARATE,
  75         IIO_CHAN_INFO_PEAK_SHARED,
  76         IIO_CHAN_INFO_PEAK_SEPARATE,
  77         IIO_CHAN_INFO_PEAK_SCALE_SHARED,
  78         IIO_CHAN_INFO_PEAK_SCALE_SEPARATE,
  79         IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SHARED,
  80         IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SEPARATE,
  81 };
  82
  83 enum iio_endian {
  84         IIO_CPU,
  85         IIO_BE,
  86         IIO_LE,
  87 };
  88
  89 /**
  90  * struct iio_chan_spec - specification of a single channel
  91  * @type:               What type of measurement is the channel making.
  92  * @channel:            What number or name do we wish to asign the channel.
  93  * @channel2:           If there is a second number for a differential
  94  *                      channel then this is it. If modified is set then the
  95  *                      value here specifies the modifier.
  96  * @address:            Driver specific identifier.
  97  * @scan_index: Monotonic index to give ordering in scans when read
  98  *                      from a buffer.
  99  * @scan_type:          Sign:           's' or 'u' to specify signed or unsigned
 100  *                      realbits:       Number of valid bits of data
 101  *                      storage_bits:   Realbits + padding
 102  *                      shift:          Shift right by this before masking out
 103  *                                      realbits.
 104  *                      endianness:     little or big endian
 105  * @info_mask:          What information is to be exported about this channel.
 106  *                      This includes calibbias, scale etc.
 107  * @event_mask: What events can this channel produce.
 108  * @extend_name:        Allows labeling of channel attributes with an
 109  *                      informative name. Note this has no effect codes etc,
 110  *                      unlike modifiers.
 111  * @processed_val:      Flag to specify the data access attribute should be
 112  *                      *_input rather than *_raw.
 113  * @modified:           Does a modifier apply to this channel. What these are
 114  *                      depends on the channel type.  Modifier is set in
 115  *                      channel2. Examples are IIO_MOD_X for axial sensors about
 116  *                      the 'x' axis.
 117  * @indexed:            Specify the channel has a numerical index. If not,
 118  *                      the value in channel will be suppressed for attribute
 119  *                      but not for event codes. Typically set it to 0 when
 120  *                      the index is false.
 121  */
 122 struct iio_chan_spec {
 123         enum iio_chan_type      type;
 124         int                     channel;
 125         int                     channel2;
 126         unsigned long           address;
 127         int                     scan_index;
 128         struct {
 129                 char    sign;
 130                 u8      realbits;
 131                 u8      storagebits;
 132                 u8      shift;
 133                 enum iio_endian endianness;
 134         } scan_type;
 135         long                    info_mask;
 136         long                    event_mask;
 137         char                    *extend_name;
 138         unsigned                processed_val:1;
 139         unsigned                modified:1;
 140         unsigned                indexed:1;
 141         unsigned                output:1;
 142 };
 143
 144 #define IIO_ST(si, rb, sb, sh)                                          \
 145         { .sign = si, .realbits = rb, .storagebits = sb, .shift = sh }
 146
 147 /* Macro assumes input channels */
 148 #define IIO_CHAN(_type, _mod, _indexed, _proc, _name, _chan, _chan2, \
 149                  _inf_mask, _address, _si, _stype, _event_mask)         \
 150         { .type = _type,                                                \
 151           .output = 0,                                                  \
 152           .modified = _mod,                                             \
 153           .indexed = _indexed,                                          \
 154           .processed_val = _proc,                                       \
 155           .extend_name = _name,                                         \
 156           .channel = _chan,                                             \
 157           .channel2 = _chan2,                                           \
 158           .info_mask = _inf_mask,                                       \
 159           .address = _address,                                          \
 160           .scan_index = _si,                                            \
 161           .scan_type = _stype,                                          \
 162           .event_mask = _event_mask }
 163
 164 #define IIO_CHAN_SOFT_TIMESTAMP(_si)                                    \
 165         { .type = IIO_TIMESTAMP, .channel = -1,                         \
 166                         .scan_index = _si, .scan_type = IIO_ST('s', 64, 64, 0) }
 167
 168 /**
 169  * iio_get_time_ns() - utility function to get a time stamp for events etc
 170  **/
 171 static inline s64 iio_get_time_ns(void)
 172 {
 173         struct timespec ts;
 174         /*
 175          * calls getnstimeofday.
 176          * If hrtimers then up to ns accurate, if not microsecond.
 177          */
 178         ktime_get_real_ts(&ts);
 179
 180         return timespec_to_ns(&ts);
 181 }
 182
 183 /* Device operating modes */
 184 #define INDIO_DIRECT_MODE               0x01
 185 #define INDIO_RING_TRIGGERED            0x02
 186 #define INDIO_RING_HARDWARE_BUFFER      0x08
 187
 188 #define INDIO_ALL_RING_MODES (INDIO_RING_TRIGGERED | INDIO_RING_HARDWARE_BUFFER)
 189
 190 /* Vast majority of this is set by the industrialio subsystem on a
 191  * call to iio_device_register. */
 192 #define IIO_VAL_INT 1
 193 #define IIO_VAL_INT_PLUS_MICRO 2
 194 #define IIO_VAL_INT_PLUS_NANO 3
 195
 196 struct iio_trigger; /* forward declaration */
 197 struct iio_dev;
 198
 199 /**
 200  * struct iio_info - constant information about device
 201  * @driver_module:      module structure used to ensure correct
 202  *                      ownership of chrdevs etc
 203  * @event_attrs:        event control attributes
 204  * @attrs:              general purpose device attributes
 205  * @read_raw:           function to request a value from the device.
 206  *                      mask specifies which value. Note 0 means a reading of
 207  *                      the channel in question.  Return value will specify the
 208  *                      type of value returned by the device. val and val2 will
 209  *                      contain the elements making up the returned value.
 210  * @write_raw:          function to write a value to the device.
 211  *                      Parameters are the same as for read_raw.
 212  * @write_raw_get_fmt:  callback function to query the expected
 213  *                      format/precision. If not set by the driver, write_raw
 214  *                      returns IIO_VAL_INT_PLUS_MICRO.
 215  * @read_event_config:  find out if the event is enabled.
 216  * @write_event_config: set if the event is enabled.
 217  * @read_event_value:   read a value associated with the event. Meaning
 218  *                      is event dependant. event_code specifies which event.
 219  * @write_event_value:  write the value associate with the event.
 220  *                      Meaning is event dependent.
 221  * @validate_trigger:   function to validate the trigger when the
 222  *                      current trigger gets changed.
 223  **/
 224 struct iio_info {
 225         struct module                   *driver_module;
 226         struct attribute_group          *event_attrs;
 227         const struct attribute_group    *attrs;
 228
 229         int (*read_raw)(struct iio_dev *indio_dev,
 230                         struct iio_chan_spec const *chan,
 231                         int *val,
 232                         int *val2,
 233                         long mask);
 234
 235         int (*write_raw)(struct iio_dev *indio_dev,
 236                          struct iio_chan_spec const *chan,
 237                          int val,
 238                          int val2,
 239                          long mask);
 240
 241         int (*write_raw_get_fmt)(struct iio_dev *indio_dev,
 242                          struct iio_chan_spec const *chan,
 243                          long mask);
 244
 245         int (*read_event_config)(struct iio_dev *indio_dev,
 246                                  int event_code);
 247
 248         int (*write_event_config)(struct iio_dev *indio_dev,
 249                                   int event_code,
 250                                   int state);
 251
 252         int (*read_event_value)(struct iio_dev *indio_dev,
 253                                 int event_code,
 254                                 int *val);
 255         int (*write_event_value)(struct iio_dev *indio_dev,
 256                                  int event_code,
 257                                  int val);
 258         int (*validate_trigger)(struct iio_dev *indio_dev,
 259                                 struct iio_trigger *trig);
 260
 261 };
 262
 263 /**
 264  * struct iio_dev - industrial I/O device
 265  * @id:                 [INTERN] used to identify device internally
 266  * @modes:              [DRIVER] operating modes supported by device
 267  * @currentmode:        [DRIVER] current operating mode
 268  * @dev:                [DRIVER] device structure, should be assigned a parent
 269  *                      and owner
 270  * @event_interface:    [INTERN] event chrdevs associated with interrupt lines
 271  * @ring:               [DRIVER] any ring buffer present
 272  * @mlock:              [INTERN] lock used to prevent simultaneous device state
 273  *                      changes
 274  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
 275  * @trig:               [INTERN] current device trigger (ring buffer modes)
 276  * @pollfunc:           [DRIVER] function run on trigger being received
 277  * @channels:           [DRIVER] channel specification structure table
 278  * @num_channels:       [DRIVER] number of chanels specified in @channels.
 279  * @channel_attr_list:  [INTERN] keep track of automatically created channel
 280  *                      attributes
 281  * @name:               [DRIVER] name of the device.
 282  * @info:               [DRIVER] callbacks and constant info from driver
 283  * @chrdev:             [INTERN] associated character device
 284  **/
 285 struct iio_dev {
 286         int                             id;
 287
 288         int                             modes;
 289         int                             currentmode;
 290         struct device                   dev;
 291
 292         struct iio_event_interface      *event_interface;
 293
 294         struct iio_ring_buffer          *ring;
 295         struct mutex                    mlock;
 296
 297         u32                             *available_scan_masks;
 298         struct iio_trigger              *trig;
 299         struct iio_poll_func            *pollfunc;
 300
 301         struct iio_chan_spec const      *channels;
 302         int                             num_channels;
 303
 304         struct list_head                channel_attr_list;
 305         const char                      *name;
 306         const struct iio_info           *info;
 307         struct cdev                     chrdev;
 308 };
 309
 310 /**
 311  * iio_device_register() - register a device with the IIO subsystem
 312  * @dev_info:           Device structure filled by the device driver
 313  **/
 314 int iio_device_register(struct iio_dev *dev_info);
 315
 316 /**
 317  * iio_device_unregister() - unregister a device from the IIO subsystem
 318  * @dev_info:           Device structure representing the device.
 319  **/
 320 void iio_device_unregister(struct iio_dev *dev_info);
 321
 322 /**
 323  * iio_push_event() - try to add event to the list for userspace reading
 324  * @dev_info:           IIO device structure
 325  * @ev_code:            What event
 326  * @timestamp:          When the event occurred
 327  **/
 328 int iio_push_event(struct iio_dev *dev_info, int ev_code, s64 timestamp);
 329
 330 extern struct bus_type iio_bus_type;
 331
 332 /**
 333  * iio_put_device() - reference counted deallocation of struct device
 334  * @dev: the iio_device containing the device
 335  **/
 336 static inline void iio_put_device(struct iio_dev *dev)
 337 {
 338         if (dev)
 339                 put_device(&dev->dev);
 340 };
 341
 342 /* Can we make this smaller? */
 343 #define IIO_ALIGN L1_CACHE_BYTES
 344 /**
 345  * iio_allocate_device() - allocate an iio_dev from a driver
 346  * @sizeof_priv: Space to allocate for private structure.
 347  **/
 348 struct iio_dev *iio_allocate_device(int sizeof_priv);
 349
 350 static inline void *iio_priv(const struct iio_dev *dev)
 351 {
 352         return (char *)dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
 353 }
 354
 355 static inline struct iio_dev *iio_priv_to_dev(void *priv)
 356 {
 357         return (struct iio_dev *)((char *)priv -
 358                                   ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
 359 }
 360
 361 /**
 362  * iio_free_device() - free an iio_dev from a driver
 363  * @dev: the iio_dev associated with the device
 364  **/
 365 void iio_free_device(struct iio_dev *dev);
 366
 367 /**
 368  * iio_ring_enabled() - helper function to test if any form of ring is enabled
 369  * @dev_info:           IIO device info structure for device
 370  **/
 371 static inline bool iio_ring_enabled(struct iio_dev *dev_info)
 372 {
 373         return dev_info->currentmode
 374                 & (INDIO_RING_TRIGGERED
 375                    | INDIO_RING_HARDWARE_BUFFER);
 376 };
 377
 378 #endif /* _INDUSTRIAL_IO_H_ */