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 #include <linux/irq.h>
  17 #include "sysfs.h"
  18
  19 /* IIO TODO LIST */
  20 /*
  21  * Provide means of adjusting timer accuracy.
  22  * Currently assumes nano seconds.
  23  */
  24
  25 enum iio_chan_type {
  26         /* real channel types */
  27         IIO_IN,
  28         IIO_OUT,
  29         IIO_CURRENT,
  30         IIO_POWER,
  31         IIO_ACCEL,
  32         IIO_IN_DIFF,
  33         IIO_GYRO,
  34         IIO_MAGN,
  35         IIO_LIGHT,
  36         IIO_INTENSITY,
  37         IIO_PROXIMITY,
  38         IIO_TEMP,
  39         IIO_INCLI,
  40         IIO_ROT,
  41         IIO_ANGL,
  42         IIO_TIMESTAMP,
  43 };
  44
  45 #define IIO_MOD_X                       0
  46 #define IIO_MOD_LIGHT_BOTH              0
  47 #define IIO_MOD_Y                       1
  48 #define IIO_MOD_LIGHT_IR                1
  49 #define IIO_MOD_Z                       2
  50 #define IIO_MOD_X_AND_Y                 3
  51 #define IIO_MOD_X_ANX_Z                 4
  52 #define IIO_MOD_Y_AND_Z                 5
  53 #define IIO_MOD_X_AND_Y_AND_Z           6
  54 #define IIO_MOD_X_OR_Y                  7
  55 #define IIO_MOD_X_OR_Z                  8
  56 #define IIO_MOD_Y_OR_Z                  9
  57 #define IIO_MOD_X_OR_Y_OR_Z             10
  58
  59 /* Could add the raw attributes as well - allowing buffer only devices */
  60 enum iio_chan_info_enum {
  61         IIO_CHAN_INFO_SCALE_SHARED,
  62         IIO_CHAN_INFO_SCALE_SEPARATE,
  63         IIO_CHAN_INFO_OFFSET_SHARED,
  64         IIO_CHAN_INFO_OFFSET_SEPARATE,
  65         IIO_CHAN_INFO_CALIBSCALE_SHARED,
  66         IIO_CHAN_INFO_CALIBSCALE_SEPARATE,
  67         IIO_CHAN_INFO_CALIBBIAS_SHARED,
  68         IIO_CHAN_INFO_CALIBBIAS_SEPARATE,
  69         IIO_CHAN_INFO_PEAK_SHARED,
  70         IIO_CHAN_INFO_PEAK_SEPARATE,
  71         IIO_CHAN_INFO_PEAK_SCALE_SHARED,
  72         IIO_CHAN_INFO_PEAK_SCALE_SEPARATE,
  73         IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SHARED,
  74         IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SEPARATE,
  75 };
  76
  77 /**
  78  * struct iio_chan_spec - specification of a single channel
  79  * @type:               What type of measurement is the channel making.
  80  * @channel:            What number or name do we wish to asign the channel.
  81  * @channel2:           If there is a second number for a differential
  82  *                      channel then this is it. If modified is set then the
  83  *                      value here specifies the modifier.
  84  * @address:            Driver specific identifier.
  85  * @scan_index: Monotonic index to give ordering in scans when read
  86  *                      from a buffer.
  87  * @scan_type:          Sign:           's' or 'u' to specify signed or unsigned
  88  *                      realbits:       Number of valid bits of data
  89  *                      storage_bits:   Realbits + padding
  90  *                      shift:          Shift right by this before masking out
  91  *                                      realbits.
  92  * @info_mask:          What information is to be exported about this channel.
  93  *                      This includes calibbias, scale etc.
  94  * @event_mask: What events can this channel produce.
  95  * @extend_name:        Allows labeling of channel attributes with an
  96  *                      informative name. Note this has no effect codes etc,
  97  *                      unlike modifiers.
  98  * @processed_val:      Flag to specify the data access attribute should be
  99  *                      *_input rather than *_raw.
 100  * @modified:           Does a modifier apply to this channel. What these are
 101  *                      depends on the channel type.  Modifier is set in
 102  *                      channel2. Examples are IIO_MOD_X for axial sensors about
 103  *                      the 'x' axis.
 104  * @indexed:            Specify the channel has a numerical index. If not,
 105  *                      the value in channel will be suppressed for attribute
 106  *                      but not for event codes. Typically set it to 0 when
 107  *                      the index is false.
 108  */
 109 struct iio_chan_spec {
 110         enum iio_chan_type      type;
 111         int                     channel;
 112         int                     channel2;
 113         unsigned long           address;
 114         int                     scan_index;
 115         struct {
 116                 char    sign;
 117                 u8      realbits;
 118                 u8      storagebits;
 119                 u8      shift;
 120         } scan_type;
 121         long                    info_mask;
 122         long                    event_mask;
 123         char                    *extend_name;
 124         unsigned                processed_val:1;
 125         unsigned                modified:1;
 126         unsigned                indexed:1;
 127 };
 128
 129 #define IIO_ST(si, rb, sb, sh)                                          \
 130         { .sign = si, .realbits = rb, .storagebits = sb, .shift = sh }
 131
 132 #define IIO_CHAN(_type, _mod, _indexed, _proc, _name, _chan, _chan2,    \
 133                  _inf_mask, _address, _si, _stype, _event_mask)         \
 134         { .type = _type,                                                \
 135           .modified = _mod,                                             \
 136           .indexed = _indexed,                                          \
 137           .processed_val = _proc,                                       \
 138           .extend_name = _name,                                         \
 139           .channel = _chan,                                             \
 140           .channel2 = _chan2,                                           \
 141           .info_mask = _inf_mask,                                       \
 142           .address = _address,                                          \
 143           .scan_index = _si,                                            \
 144           .scan_type = _stype,                                          \
 145           .event_mask = _event_mask }
 146
 147 #define IIO_CHAN_SOFT_TIMESTAMP(_si)                                    \
 148         { .type = IIO_TIMESTAMP, .channel = -1,                         \
 149                         .scan_index = _si, .scan_type = IIO_ST('s', 64, 64, 0) }
 150
 151 /**
 152  * iio_get_time_ns() - utility function to get a time stamp for events etc
 153  **/
 154 static inline s64 iio_get_time_ns(void)
 155 {
 156         struct timespec ts;
 157         /*
 158          * calls getnstimeofday.
 159          * If hrtimers then up to ns accurate, if not microsecond.
 160          */
 161         ktime_get_real_ts(&ts);
 162
 163         return timespec_to_ns(&ts);
 164 }
 165
 166 /* Device operating modes */
 167 #define INDIO_DIRECT_MODE               0x01
 168 #define INDIO_RING_TRIGGERED            0x02
 169 #define INDIO_RING_HARDWARE_BUFFER      0x08
 170
 171 #define INDIO_ALL_RING_MODES (INDIO_RING_TRIGGERED | INDIO_RING_HARDWARE_BUFFER)
 172
 173 /* Vast majority of this is set by the industrialio subsystem on a
 174  * call to iio_device_register. */
 175 #define IIO_VAL_INT 1
 176 #define IIO_VAL_INT_PLUS_MICRO 2
 177 #define IIO_VAL_INT_PLUS_NANO 3
 178
 179 struct iio_trigger; /* forward declaration */
 180 struct iio_dev;
 181
 182 /**
 183  * struct iio_info - constant information about device
 184  * @driver_module:      module structure used to ensure correct
 185  *                      ownership of chrdevs etc
 186  * @num_interrupt_lines:number of physical interrupt lines from device
 187  * @event_attrs:        event control attributes
 188  * @attrs:              general purpose device attributes
 189  * @read_raw:           function to request a value from the device.
 190  *                      mask specifies which value. Note 0 means a reading of
 191  *                      the channel in question.  Return value will specify the
 192  *                      type of value returned by the device. val and val2 will
 193  *                      contain the elements making up the returned value.
 194  * @write_raw:          function to write a value to the device.
 195  *                      Parameters are the same as for read_raw.
 196  * @write_raw_get_fmt:  callback function to query the expected
 197  *                      format/precision. If not set by the driver, write_raw
 198  *                      returns IIO_VAL_INT_PLUS_MICRO.
 199  * @read_event_config:  find out if the event is enabled.
 200  * @write_event_config: set if the event is enabled.
 201  * @read_event_value:   read a value associated with the event. Meaning
 202  *                      is event dependant. event_code specifies which event.
 203  * @write_event_value:  write the value associate with the event.
 204  *                      Meaning is event dependent.
 205  * @validate_trigger:   function to validate the trigger when the
 206  *                      current trigger gets changed.
 207  **/
 208 struct iio_info {
 209         struct module                   *driver_module;
 210         int                             num_interrupt_lines;
 211         struct attribute_group          *event_attrs;
 212         const struct attribute_group    *attrs;
 213
 214         int (*read_raw)(struct iio_dev *indio_dev,
 215                         struct iio_chan_spec const *chan,
 216                         int *val,
 217                         int *val2,
 218                         long mask);
 219
 220         int (*write_raw)(struct iio_dev *indio_dev,
 221                          struct iio_chan_spec const *chan,
 222                          int val,
 223                          int val2,
 224                          long mask);
 225
 226         int (*write_raw_get_fmt)(struct iio_dev *indio_dev,
 227                          struct iio_chan_spec const *chan,
 228                          long mask);
 229
 230         int (*read_event_config)(struct iio_dev *indio_dev,
 231                                  int event_code);
 232
 233         int (*write_event_config)(struct iio_dev *indio_dev,
 234                                   int event_code,
 235                                   int state);
 236
 237         int (*read_event_value)(struct iio_dev *indio_dev,
 238                                 int event_code,
 239                                 int *val);
 240         int (*write_event_value)(struct iio_dev *indio_dev,
 241                                  int event_code,
 242                                  int val);
 243         int (*validate_trigger)(struct iio_dev *indio_dev,
 244                                 struct iio_trigger *trig);
 245
 246 };
 247
 248 int iio_event_getfd(struct iio_dev *indio_dev);
 249 /**
 250  * struct iio_dev - industrial I/O device
 251  * @id:                 [INTERN] used to identify device internally
 252  * @modes:              [DRIVER] operating modes supported by device
 253  * @currentmode:        [DRIVER] current operating mode
 254  * @dev:                [DRIVER] device structure, should be assigned a parent
 255  *                      and owner
 256  * @event_interfaces:   [INTERN] event chrdevs associated with interrupt lines
 257  * @ring:               [DRIVER] any ring buffer present
 258  * @mlock:              [INTERN] lock used to prevent simultaneous device state
 259  *                      changes
 260  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
 261  * @trig:               [INTERN] current device trigger (ring buffer modes)
 262  * @pollfunc:           [DRIVER] function run on trigger being received
 263  * @channels:           [DRIVER] channel specification structure table
 264  * @num_channels:       [DRIVER] number of chanels specified in @channels.
 265  * @channel_attr_list:  [INTERN] keep track of automatically created channel
 266  *                      attributes.
 267  * @name:               [DRIVER] name of the device.
 268  **/
 269 struct iio_dev {
 270         int                             id;
 271
 272         int                             modes;
 273         int                             currentmode;
 274         struct device                   dev;
 275
 276         struct iio_event_interface      *event_interfaces;
 277
 278         struct iio_ring_buffer          *ring;
 279         struct mutex                    mlock;
 280
 281         u32                             *available_scan_masks;
 282         struct iio_trigger              *trig;
 283         struct iio_poll_func            *pollfunc;
 284
 285         struct iio_chan_spec const *channels;
 286         int num_channels;
 287
 288         struct list_head channel_attr_list;
 289         const char *name;
 290         const struct iio_info *info;
 291 };
 292
 293 /**
 294  * iio_device_register() - register a device with the IIO subsystem
 295  * @dev_info:           Device structure filled by the device driver
 296  **/
 297 int iio_device_register(struct iio_dev *dev_info);
 298
 299 /**
 300  * iio_device_unregister() - unregister a device from the IIO subsystem
 301  * @dev_info:           Device structure representing the device.
 302  **/
 303 void iio_device_unregister(struct iio_dev *dev_info);
 304
 305 /**
 306  * iio_push_event() - try to add event to the list for userspace reading
 307  * @dev_info:           IIO device structure
 308  * @ev_line:            Which event line (hardware interrupt)
 309  * @ev_code:            What event
 310  * @timestamp:          When the event occurred
 311  **/
 312 int iio_push_event(struct iio_dev *dev_info,
 313                   int ev_line,
 314                   int ev_code,
 315                   s64 timestamp);
 316
 317 extern struct bus_type iio_bus_type;
 318
 319 /**
 320  * iio_put_device() - reference counted deallocation of struct device
 321  * @dev: the iio_device containing the device
 322  **/
 323 static inline void iio_put_device(struct iio_dev *dev)
 324 {
 325         if (dev)
 326                 put_device(&dev->dev);
 327 };
 328
 329 /* Can we make this smaller? */
 330 #define IIO_ALIGN L1_CACHE_BYTES
 331 /**
 332  * iio_allocate_device() - allocate an iio_dev from a driver
 333  * @sizeof_priv: Space to allocate for private structure.
 334  **/
 335 struct iio_dev *iio_allocate_device(int sizeof_priv);
 336
 337 static inline void *iio_priv(const struct iio_dev *dev)
 338 {
 339         return (char *)dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
 340 }
 341
 342 static inline struct iio_dev *iio_priv_to_dev(void *priv)
 343 {
 344         return (struct iio_dev *)((char *)priv -
 345                                   ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
 346 }
 347
 348 /**
 349  * iio_free_device() - free an iio_dev from a driver
 350  * @dev: the iio_dev associated with the device
 351  **/
 352 void iio_free_device(struct iio_dev *dev);
 353
 354 /**
 355  * iio_ring_enabled() - helper function to test if any form of ring is enabled
 356  * @dev_info:           IIO device info structure for device
 357  **/
 358 static inline bool iio_ring_enabled(struct iio_dev *dev_info)
 359 {
 360         return dev_info->currentmode
 361                 & (INDIO_RING_TRIGGERED
 362                    | INDIO_RING_HARDWARE_BUFFER);
 363 };
 364
 365 #endif /* _INDUSTRIAL_IO_H_ */