drivers/staging/iio/iio.h

   1 /* The industrial I/O core
   2  *
   3  * Copyright (c) 2008 Jonathan Cameron
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  */
   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/irq.h>
  16 #include "sysfs.h"
  17 #include "chrdev.h"
  18
  19 /* IIO TODO LIST */
  20 /*
  21  * Provide means of adjusting timer accuracy.
  22  * Currently assumes nano seconds.
  23  */
  24
  25 /* Event interface flags */
  26 #define IIO_BUSY_BIT_POS 1
  27
  28 /* naughty temporary hack to match these against the event version
  29    - need to flattern these together */
  30 enum iio_chan_type {
  31         /* real channel types */
  32         IIO_IN,
  33         IIO_CURRENT,
  34         IIO_POWER,
  35         IIO_ACCEL,
  36         IIO_IN_DIFF,
  37         IIO_GYRO,
  38         IIO_MAGN,
  39         IIO_LIGHT,
  40         IIO_INTENSITY,
  41         IIO_PROXIMITY,
  42         IIO_TEMP,
  43         IIO_INCLI,
  44         IIO_ROT,
  45         IIO_ANGL,
  46         IIO_TIMESTAMP,
  47 };
  48
  49 #define IIO_MOD_X                       0
  50 #define IIO_MOD_LIGHT_BOTH              0
  51 #define IIO_MOD_Y                       1
  52 #define IIO_MOD_LIGHT_IR                1
  53 #define IIO_MOD_Z                       2
  54 #define IIO_MOD_X_AND_Y                 3
  55 #define IIO_MOD_X_ANX_Z                 4
  56 #define IIO_MOD_Y_AND_Z                 5
  57 #define IIO_MOD_X_AND_Y_AND_Z           6
  58 #define IIO_MOD_X_OR_Y                  7
  59 #define IIO_MOD_X_OR_Z                  8
  60 #define IIO_MOD_Y_OR_Z                  9
  61 #define IIO_MOD_X_OR_Y_OR_Z             10
  62
  63 /* Could add the raw attributes as well - allowing buffer only devices */
  64 enum iio_chan_info_enum {
  65         IIO_CHAN_INFO_SCALE_SHARED,
  66         IIO_CHAN_INFO_SCALE_SEPARATE,
  67         IIO_CHAN_INFO_OFFSET_SHARED,
  68         IIO_CHAN_INFO_OFFSET_SEPARATE,
  69         IIO_CHAN_INFO_CALIBSCALE_SHARED,
  70         IIO_CHAN_INFO_CALIBSCALE_SEPARATE,
  71         IIO_CHAN_INFO_CALIBBIAS_SHARED,
  72         IIO_CHAN_INFO_CALIBBIAS_SEPARATE,
  73         IIO_CHAN_INFO_PEAK_SHARED,
  74         IIO_CHAN_INFO_PEAK_SEPARATE,
  75         IIO_CHAN_INFO_PEAK_SCALE_SHARED,
  76         IIO_CHAN_INFO_PEAK_SCALE_SEPARATE,
  77 };
  78
  79 /**
  80  * struct iio_chan_spec - specification of a single channel
  81  * @type:               What type of measurement is the channel making.
  82  * @channel:            What number or name do we wish to asign the channel.
  83  * @channel2:           If there is a second number for a differential
  84  *                      channel then this is it. If modified is set then the
  85  *                      value here specifies the modifier.
  86  * @address:            Driver specific identifier.
  87  * @scan_index: Monotonic index to give ordering in scans when read
  88  *                      from a buffer.
  89  * @scan_type:          Sign:           's' or 'u' to specify signed or unsigned
  90  *                      realbits:       Number of valid bits of data
  91  *                      storage_bits:   Realbits + padding
  92  *                      shift:          Shift right by this before masking out
  93  *                                      realbits.
  94  * @info_mask:          What information is to be exported about this channel.
  95  *                      This includes calibbias, scale etc.
  96  * @event_mask: What events can this channel produce.
  97  * @extend_name:        Allows labeling of channel attributes with an
  98  *                      informative name. Note this has no effect codes etc,
  99  *                      unlike modifiers.
 100  * @processed_val:      Flag to specify the data access attribute should be
 101  *                      *_input rather than *_raw.
 102  * @modified:           Does a modifier apply to this channel. What these are
 103  *                      depends on the channel type.  Modifier is set in
 104  *                      channel2. Examples are IIO_MOD_X for axial sensors about
 105  *                      the 'x' axis.
 106  * @indexed:            Specify the channel has a numerical index. If not,
 107  *                      the value in channel will be suppressed for attribute
 108  *                      but not for event codes. Typically set it to 0 when
 109  *                      the index is false.
 110  */
 111 struct iio_chan_spec {
 112         enum iio_chan_type      type;
 113         int                     channel;
 114         int                     channel2;
 115         unsigned long           address;
 116         int                     scan_index;
 117         struct {
 118                 char    sign;
 119                 u8      realbits;
 120                 u8      storagebits;
 121                 u8      shift;
 122         } scan_type;
 123         const long              info_mask;
 124         const long              event_mask;
 125         const char              *extend_name;
 126         unsigned                processed_val:1;
 127         unsigned                modified:1;
 128         unsigned                indexed:1;
 129 };
 130 /* Meant for internal use only */
 131 void __iio_device_attr_deinit(struct device_attribute *dev_attr);
 132 int __iio_device_attr_init(struct device_attribute *dev_attr,
 133                            const char *postfix,
 134                            struct iio_chan_spec const *chan,
 135                            ssize_t (*readfunc)(struct device *dev,
 136                                                struct device_attribute *attr,
 137                                                char *buf),
 138                            ssize_t (*writefunc)(struct device *dev,
 139                                                 struct device_attribute *attr,
 140                                                 const char *buf,
 141                                                 size_t len),
 142                            bool generic);
 143 #define IIO_ST(si, rb, sb, sh)                                          \
 144         { .sign = si, .realbits = rb, .storagebits = sb, .shift = sh }
 145
 146 #define IIO_CHAN(_type, _mod, _indexed, _proc, _name, _chan, _chan2,    \
 147                  _inf_mask, _address, _si, _stype, _event_mask)         \
 148         { .type = _type,                                                \
 149           .modified = _mod,                                             \
 150           .indexed = _indexed,                                          \
 151           .processed_val = _proc,                                       \
 152           .extend_name = _name,                                         \
 153           .channel = _chan,                                             \
 154           .channel2 = _chan2,                                           \
 155           .info_mask = _inf_mask,                                       \
 156           .address = _address,                                          \
 157           .scan_index = _si,                                            \
 158           .scan_type = _stype,                                          \
 159           .event_mask = _event_mask }
 160
 161 #define IIO_CHAN_SOFT_TIMESTAMP(_si)                                    \
 162         { .type = IIO_TIMESTAMP, .channel = -1,                         \
 163                         .scan_index = _si, .scan_type = IIO_ST('s', 64, 64, 0) }
 164
 165 int __iio_add_chan_devattr(const char *postfix,
 166                            const char *group,
 167                            struct iio_chan_spec const *chan,
 168                            ssize_t (*func)(struct device *dev,
 169                                            struct device_attribute *attr,
 170                                            char *buf),
 171                            ssize_t (*writefunc)(struct device *dev,
 172                                                 struct device_attribute *attr,
 173                                                 const char *buf,
 174                                                 size_t len),
 175                            int mask,
 176                            bool generic,
 177                            struct device *dev,
 178                            struct list_head *attr_list);
 179 /**
 180  * iio_get_time_ns() - utility function to get a time stamp for events etc
 181  **/
 182 static inline s64 iio_get_time_ns(void)
 183 {
 184         struct timespec ts;
 185         /*
 186          * calls getnstimeofday.
 187          * If hrtimers then up to ns accurate, if not microsecond.
 188          */
 189         ktime_get_real_ts(&ts);
 190
 191         return timespec_to_ns(&ts);
 192 }
 193
 194 /* Device operating modes */
 195 #define INDIO_DIRECT_MODE               0x01
 196 #define INDIO_RING_TRIGGERED            0x02
 197 #define INDIO_RING_HARDWARE_BUFFER      0x08
 198
 199 #define INDIO_ALL_RING_MODES (INDIO_RING_TRIGGERED | INDIO_RING_HARDWARE_BUFFER)
 200
 201 /* Vast majority of this is set by the industrialio subsystem on a
 202  * call to iio_device_register. */
 203 #define IIO_VAL_INT 1
 204 #define IIO_VAL_INT_PLUS_MICRO 2
 205 #define IIO_VAL_INT_PLUS_NANO 3
 206
 207 struct iio_trigger; /* forward declaration */
 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  * @num_interrupt_lines:number of physical interrupt lines from device
 214  * @event_attrs:        event control attributes
 215  * @attrs:              general purpose device attributes
 216  * @read_raw:           function to request a value from the device.
 217  *                      mask specifies which value. Note 0 means a reading of
 218  *                      the channel in question.  Return value will specify the
 219  *                      type of value returned by the device. val and val2 will
 220  *                      contain the elements making up the returned value.
 221  * @write_raw:          function to write a value to the device.
 222  *                      Parameters are the same as for read_raw.
 223  * @write_raw_get_fmt:  callback function to query the expected
 224  *                      format/precision. If not set by the driver, write_raw
 225  *                      returns IIO_VAL_INT_PLUS_MICRO.
 226  * @read_event_config:  find out if the event is enabled.
 227  * @write_event_config: set if the event is enabled.
 228  * @read_event_value:   read a value associated with the event. Meaning
 229  *                      is event dependant. event_code specifies which event.
 230  * @write_event_value:  write the value associate with the event.
 231  *                      Meaning is event dependent.
 232  * @validate_trigger:   function to validate the trigger when the
 233  *                      current trigger gets changed.
 234  **/
 235 struct iio_info {
 236         struct module                   *driver_module;
 237         int                             num_interrupt_lines;
 238         struct attribute_group          *event_attrs;
 239         const struct attribute_group    *attrs;
 240
 241         int (*read_raw)(struct iio_dev *indio_dev,
 242                         struct iio_chan_spec const *chan,
 243                         int *val,
 244                         int *val2,
 245                         long mask);
 246
 247         int (*write_raw)(struct iio_dev *indio_dev,
 248                          struct iio_chan_spec const *chan,
 249                          int val,
 250                          int val2,
 251                          long mask);
 252
 253         int (*write_raw_get_fmt)(struct iio_dev *indio_dev,
 254                          struct iio_chan_spec const *chan,
 255                          long mask);
 256
 257         int (*read_event_config)(struct iio_dev *indio_dev,
 258                                  int event_code);
 259
 260         int (*write_event_config)(struct iio_dev *indio_dev,
 261                                   int event_code,
 262                                   int state);
 263
 264         int (*read_event_value)(struct iio_dev *indio_dev,
 265                                 int event_code,
 266                                 int *val);
 267         int (*write_event_value)(struct iio_dev *indio_dev,
 268                                  int event_code,
 269                                  int val);
 270         int (*validate_trigger)(struct iio_dev *indio_dev,
 271                                 struct iio_trigger *trig);
 272
 273 };
 274
 275 /**
 276  * struct iio_dev - industrial I/O device
 277  * @id:                 [INTERN] used to identify device internally
 278  * @dev_data:           [DRIVER] device specific data
 279  * @modes:              [DRIVER] operating modes supported by device
 280  * @currentmode:        [DRIVER] current operating mode
 281  * @dev:                [DRIVER] device structure, should be assigned a parent
 282  *                      and owner
 283  * @event_interfaces:   [INTERN] event chrdevs associated with interrupt lines
 284  * @ring:               [DRIVER] any ring buffer present
 285  * @mlock:              [INTERN] lock used to prevent simultaneous device state
 286  *                      changes
 287  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
 288  * @trig:               [INTERN] current device trigger (ring buffer modes)
 289  * @pollfunc:           [DRIVER] function run on trigger being received
 290  * @channels:           [DRIVER] channel specification structure table
 291  * @num_channels:       [DRIVER] number of chanels specified in @channels.
 292  * @channel_attr_list:  [INTERN] keep track of automatically created channel
 293  *                      attributes.
 294  * @name:               [DRIVER] name of the device.
 295  **/
 296 struct iio_dev {
 297         int                             id;
 298         void                            *dev_data;
 299         int                             modes;
 300         int                             currentmode;
 301         struct device                   dev;
 302
 303         struct iio_event_interface      *event_interfaces;
 304
 305         struct iio_ring_buffer          *ring;
 306         struct mutex                    mlock;
 307
 308         u32                             *available_scan_masks;
 309         struct iio_trigger              *trig;
 310         struct iio_poll_func            *pollfunc;
 311
 312         struct iio_chan_spec const *channels;
 313         int num_channels;
 314
 315         struct list_head channel_attr_list;
 316         const char *name;
 317         const struct iio_info *info;
 318 };
 319
 320 /**
 321  * iio_device_register() - register a device with the IIO subsystem
 322  * @dev_info:           Device structure filled by the device driver
 323  **/
 324 int iio_device_register(struct iio_dev *dev_info);
 325
 326 /**
 327  * iio_device_unregister() - unregister a device from the IIO subsystem
 328  * @dev_info:           Device structure representing the device.
 329  **/
 330 void iio_device_unregister(struct iio_dev *dev_info);
 331
 332 /**
 333  * iio_push_event() - try to add event to the list for userspace reading
 334  * @dev_info:           IIO device structure
 335  * @ev_line:            Which event line (hardware interrupt)
 336  * @ev_code:            What event
 337  * @timestamp:          When the event occurred
 338  **/
 339 int iio_push_event(struct iio_dev *dev_info,
 340                   int ev_line,
 341                   int ev_code,
 342                   s64 timestamp);
 343
 344 /* Used to distinguish between bipolar and unipolar scan elemenents.
 345  * Whilst this may seem obvious, we may well want to change the representation
 346  * in the future!*/
 347 #define IIO_SIGNED(a) -(a)
 348 #define IIO_UNSIGNED(a) (a)
 349
 350 extern dev_t iio_devt;
 351 extern struct bus_type iio_bus_type;
 352
 353 /**
 354  * iio_put_device() - reference counted deallocation of struct device
 355  * @dev: the iio_device containing the device
 356  **/
 357 static inline void iio_put_device(struct iio_dev *dev)
 358 {
 359         if (dev)
 360                 put_device(&dev->dev);
 361 };
 362
 363 /**
 364  * to_iio_dev() - get iio_dev for which we have the struct device
 365  * @d: the struct device
 366  **/
 367 static inline struct iio_dev *to_iio_dev(struct device *d)
 368 {
 369         return container_of(d, struct iio_dev, dev);
 370 };
 371
 372 /**
 373  * iio_dev_get_devdata() - helper function gets device specific data
 374  * @d: the iio_dev associated with the device
 375  **/
 376 static inline void *iio_dev_get_devdata(struct iio_dev *d)
 377 {
 378         return d->dev_data;
 379 }
 380
 381
 382 /* Can we make this smaller? */
 383 #define IIO_ALIGN L1_CACHE_BYTES
 384 /**
 385  * iio_allocate_device() - allocate an iio_dev from a driver
 386  * @sizeof_priv: Space to allocate for private structure.
 387  **/
 388 struct iio_dev *iio_allocate_device(int sizeof_priv);
 389
 390 static inline void *iio_priv(const struct iio_dev *dev)
 391 {
 392         return (char *)dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
 393 }
 394
 395 static inline struct iio_dev *iio_priv_to_dev(void *priv)
 396 {
 397         return (struct iio_dev *)((char *)priv -
 398                                   ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
 399 }
 400
 401 /**
 402  * iio_free_device() - free an iio_dev from a driver
 403  * @dev: the iio_dev associated with the device
 404  **/
 405 void iio_free_device(struct iio_dev *dev);
 406
 407 /**
 408  * iio_put() - internal module reference count reduce
 409  **/
 410 void iio_put(void);
 411
 412 /**
 413  * iio_get() - internal module reference count increase
 414  **/
 415 void iio_get(void);
 416
 417 /**
 418  * iio_device_get_chrdev_minor() - get an unused minor number
 419  **/
 420 int iio_device_get_chrdev_minor(void);
 421 void iio_device_free_chrdev_minor(int val);
 422
 423 /**
 424  * iio_ring_enabled() - helper function to test if any form of ring is enabled
 425  * @dev_info:           IIO device info structure for device
 426  **/
 427 static inline bool iio_ring_enabled(struct iio_dev *dev_info)
 428 {
 429         return dev_info->currentmode
 430                 & (INDIO_RING_TRIGGERED
 431                    | INDIO_RING_HARDWARE_BUFFER);
 432 };
 433
 434 struct ida;
 435
 436 int iio_get_new_ida_val(struct ida *this_ida);
 437 void iio_free_ida_val(struct ida *this_ida, int id);
 438 #endif /* _INDUSTRIAL_IO_H_ */