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 "sysfs.h"
  16 #include "chrdev.h"
  17
  18 /* IIO TODO LIST */
  19 /* Static device specific elements (conversion factors etc)
  20  * should be exported via sysfs
  21  *
  22  * Provide means of adjusting timer accuracy.
  23  * Currently assumes nano seconds.
  24  */
  25
  26 /* Event interface flags */
  27 #define IIO_BUSY_BIT_POS 1
  28
  29 struct iio_dev;
  30
  31 /**
  32  * iio_get_time_ns() - utility function to get a time stamp for events etc
  33  **/
  34 static inline s64 iio_get_time_ns(void)
  35 {
  36         struct timespec ts;
  37         /*
  38          * calls getnstimeofday.
  39          * If hrtimers then up to ns accurate, if not microsecond.
  40          */
  41         ktime_get_real_ts(&ts);
  42
  43         return timespec_to_ns(&ts);
  44 }
  45
  46 /**
  47  * iio_add_event_to_list() - Wraps adding to event lists
  48  * @el:         the list element of the event to be handled.
  49  * @head:       the list associated with the event handler being used.
  50  *
  51  * Does reference counting to allow shared handlers.
  52  **/
  53 void iio_add_event_to_list(struct iio_event_handler_list *el,
  54                            struct list_head *head);
  55
  56 /**
  57  * iio_remove_event_from_list() - Wraps removing from event list
  58  * @el:         element to be removed
  59  * @head:       associate list head for the interrupt handler.
  60  *
  61  * Does reference counting to allow shared handlers.
  62  **/
  63 void iio_remove_event_from_list(struct iio_event_handler_list *el,
  64                                 struct list_head *head);
  65
  66 /* Device operating modes */
  67 #define INDIO_DIRECT_MODE               0x01
  68 #define INDIO_RING_TRIGGERED            0x02
  69 #define INDIO_RING_HARDWARE_BUFFER      0x08
  70
  71 #define INDIO_ALL_RING_MODES (INDIO_RING_TRIGGERED | INDIO_RING_HARDWARE_BUFFER)
  72
  73 /* Vast majority of this is set by the industrialio subsystem on a
  74  * call to iio_device_register. */
  75
  76 /**
  77  * struct iio_dev - industrial I/O device
  78  * @id:                 [INTERN] used to identify device internally
  79  * @dev_data:           [DRIVER] device specific data
  80  * @modes:              [DRIVER] operating modes supported by device
  81  * @currentmode:        [DRIVER] current operating mode
  82  * @dev:                [DRIVER] device structure, should be assigned a parent
  83  *                      and owner
  84  * @attrs:              [DRIVER] general purpose device attributes
  85  * @driver_module:      [DRIVER] module structure used to ensure correct
  86  *                      ownership of chrdevs etc
  87  * @num_interrupt_lines:[DRIVER] number of physical interrupt lines from device
  88  * @interrupts:         [INTERN] interrupt line specific event lists etc
  89  * @event_attrs:        [DRIVER] event control attributes
  90  * @event_conf_attrs:   [DRIVER] event configuration attributes
  91  * @event_interfaces:   [INTERN] event chrdevs associated with interrupt lines
  92  * @ring:               [DRIVER] any ring buffer present
  93  * @mlock:              [INTERN] lock used to prevent simultaneous device state
  94  *                      changes
  95  * @scan_el_attrs:      [DRIVER] control of scan elements if that scan mode
  96  *                      control method is used
  97  * @scan_count: [INTERN] the number of elements in the current scan mode
  98  * @scan_mask:          [INTERN] bitmask used in masking scan mode elements
  99  * @scan_timestamp:     [INTERN] does the scan mode include a timestamp
 100  * @trig:               [INTERN] current device trigger (ring buffer modes)
 101  * @pollfunc:           [DRIVER] function run on trigger being recieved
 102  **/
 103 struct iio_dev {
 104         int                             id;
 105         void                            *dev_data;
 106         int                             modes;
 107         int                             currentmode;
 108         struct device                   dev;
 109         const struct attribute_group    *attrs;
 110         struct module                   *driver_module;
 111
 112         int                             num_interrupt_lines;
 113         struct iio_interrupt            **interrupts;
 114         struct attribute_group          *event_attrs;
 115         struct attribute_group          *event_conf_attrs;
 116
 117         struct iio_event_interface      *event_interfaces;
 118
 119         struct iio_ring_buffer          *ring;
 120         struct mutex                    mlock;
 121
 122         struct attribute_group          *scan_el_attrs;
 123         int                             scan_count;
 124
 125         u16                             scan_mask;
 126         bool                            scan_timestamp;
 127         struct iio_trigger              *trig;
 128         struct iio_poll_func            *pollfunc;
 129 };
 130
 131 /*
 132  * These are mainly provided to allow for a change of implementation if a device
 133  * has a large number of scan elements
 134  */
 135 #define IIO_MAX_SCAN_LENGTH 15
 136
 137 static inline int iio_scan_mask_query(struct iio_dev *dev_info, int bit)
 138 {
 139         if (bit > IIO_MAX_SCAN_LENGTH)
 140                 return -EINVAL;
 141         else
 142                 return !!(dev_info->scan_mask & (1 << bit));
 143 };
 144
 145 static inline int iio_scan_mask_set(struct iio_dev *dev_info, int bit)
 146 {
 147         if (bit > IIO_MAX_SCAN_LENGTH)
 148                 return -EINVAL;
 149         dev_info->scan_mask |= (1 << bit);
 150         dev_info->scan_count++;
 151         return 0;
 152 };
 153
 154 static inline int iio_scan_mask_clear(struct iio_dev *dev_info, int bit)
 155 {
 156         if (bit > IIO_MAX_SCAN_LENGTH)
 157                 return -EINVAL;
 158         dev_info->scan_mask &= ~(1 << bit);
 159         dev_info->scan_count--;
 160         return 0;
 161 };
 162
 163 /**
 164  * iio_scan_mask_count_to_right() - how many scan elements occur before here
 165  * @dev_info: the iio_device whose scan mode we are querying
 166  * @bit: which number scan element is this
 167  **/
 168 static inline int iio_scan_mask_count_to_right(struct iio_dev *dev_info,
 169 int bit)
 170 {
 171         int count = 0;
 172         int mask = (1 << bit);
 173         if (bit > IIO_MAX_SCAN_LENGTH)
 174                 return -EINVAL;
 175         while (mask) {
 176                 mask >>= 1;
 177                 if (mask & dev_info->scan_mask)
 178                         count++;
 179         }
 180
 181         return count;
 182 }
 183
 184 /**
 185  * iio_device_register() - register a device with the IIO subsystem
 186  * @dev_info:           Device structure filled by the device driver
 187  **/
 188 int iio_device_register(struct iio_dev *dev_info);
 189
 190 /**
 191  * iio_device_unregister() - unregister a device from the IIO subsystem
 192  * @dev_info:           Device structure representing the device.
 193  **/
 194 void iio_device_unregister(struct iio_dev *dev_info);
 195
 196 /**
 197  * struct iio_interrupt - wrapper used to allow easy handling of multiple
 198  *                      physical interrupt lines
 199  * @dev_info:           the iio device for which the is an interrupt line
 200  * @line_number:        associated line number
 201  * @id:                 idr allocated unique id number
 202  * @irq:                associate interrupt number
 203  * @ev_list:            event handler list for associated events
 204  * @ev_list_lock:       ensure only one access to list at a time
 205  **/
 206 struct iio_interrupt {
 207         struct iio_dev                  *dev_info;
 208         int                             line_number;
 209         int                             id;
 210         int                             irq;
 211         struct list_head                ev_list;
 212         spinlock_t                      ev_list_lock;
 213 };
 214
 215 #define to_iio_interrupt(i) container_of(i, struct iio_interrupt, ev_list)
 216
 217 /**
 218  * iio_register_interrupt_line() - Tell IIO about interrupt lines
 219  *
 220  * @irq:                Typically provided via platform data
 221  * @dev_info:           IIO device info structure for device
 222  * @line_number:        Which interrupt line of the device is this?
 223  * @type:               Interrupt type (e.g. edge triggered etc)
 224  * @name:               Identifying name.
 225  **/
 226 int iio_register_interrupt_line(unsigned int                    irq,
 227                                 struct iio_dev                  *dev_info,
 228                                 int                             line_number,
 229                                 unsigned long                   type,
 230                                 const char                      *name);
 231
 232 void iio_unregister_interrupt_line(struct iio_dev *dev_info,
 233                                    int line_number);
 234
 235
 236
 237 /**
 238  * iio_push_event() - try to add event to the list for userspace reading
 239  * @dev_info:           IIO device structure
 240  * @ev_line:            Which event line (hardware interrupt)
 241  * @ev_code:            What event
 242  * @timestamp:          When the event occured
 243  **/
 244 int iio_push_event(struct iio_dev *dev_info,
 245                   int ev_line,
 246                   int ev_code,
 247                   s64 timestamp);
 248
 249 /**
 250  * struct iio_work_cont - container for when singleton handler case matters
 251  * @ws:                 [DEVICE]work_struct when not only possible event
 252  * @ws_nocheck:         [DEVICE]work_struct when only possible event
 253  * @address:            [DEVICE]associated register address
 254  * @mask:               [DEVICE]associated mask for identifying event source
 255  * @st:                 [DEVICE]device specific state information
 256  **/
 257 struct iio_work_cont {
 258         struct work_struct      ws;
 259         struct work_struct      ws_nocheck;
 260         int                     address;
 261         int                     mask;
 262         void                    *st;
 263 };
 264
 265 #define to_iio_work_cont_check(_ws)                     \
 266         container_of(_ws, struct iio_work_cont, ws)
 267
 268 #define to_iio_work_cont_no_check(_ws)                          \
 269         container_of(_ws, struct iio_work_cont, ws_nocheck)
 270
 271 /**
 272  * iio_init_work_cont() - intiialize the elements of a work container
 273  * @cont: the work container
 274  * @_checkfunc: function called when there are multiple possible int sources
 275  * @_nocheckfunc: function for when there is only one int source
 276  * @_add: driver dependant, typically a register address
 277  * @_mask: driver dependant, typically a bit mask for a register
 278  * @_st: driver dependant, typically pointer to a device state structure
 279  **/
 280 static inline void
 281 iio_init_work_cont(struct iio_work_cont *cont,
 282                    void (*_checkfunc)(struct work_struct *),
 283                    void (*_nocheckfunc)(struct work_struct *),
 284                    int _add, int _mask, void *_st)
 285 {
 286         INIT_WORK(&(cont)->ws, _checkfunc);
 287         INIT_WORK(&(cont)->ws_nocheck, _nocheckfunc);
 288         cont->address = _add;
 289         cont->mask = _mask;
 290         cont->st = _st;
 291 }
 292 /**
 293  * __iio_push_event() tries to add an event to the list associated with a chrdev
 294  * @ev_int:             the event interface to which we are pushing the event
 295  * @ev_code:            the outgoing event code
 296  * @timestamp:          timestamp of the event
 297  * @shared_pointer_p:   the shared event pointer
 298  **/
 299 int __iio_push_event(struct iio_event_interface *ev_int,
 300                     int ev_code,
 301                     s64 timestamp,
 302                     struct iio_shared_ev_pointer*
 303                     shared_pointer_p);
 304 /**
 305  * __iio_change_event() change an event code in case of event escallation
 306  * @ev:                 the evnet to be changed
 307  * @ev_code:            new event code
 308  * @timestamp:          new timestamp
 309  **/
 310 void __iio_change_event(struct iio_detected_event_list *ev,
 311                         int ev_code,
 312                         s64 timestamp);
 313
 314 /**
 315  * iio_setup_ev_int() Configure an event interface (chrdev)
 316  * @name:               name used for resulting sysfs directory etc.
 317  * @ev_int:             interface we are configuring
 318  * @owner:              module that is responsible for registering this ev_int
 319  * @dev:                device whose ev_int this is
 320  **/
 321 int iio_setup_ev_int(struct iio_event_interface *ev_int,
 322                      const char *name,
 323                      struct module *owner,
 324                      struct device *dev);
 325
 326 void iio_free_ev_int(struct iio_event_interface *ev_int);
 327
 328 /**
 329  * iio_allocate_chrdev() - Allocate a chrdev
 330  * @handler:    struct that contains relevant file handling for chrdev
 331  * @dev_info:   iio_dev for which chrdev is being created
 332  **/
 333 int iio_allocate_chrdev(struct iio_handler *handler, struct iio_dev *dev_info);
 334 void iio_deallocate_chrdev(struct iio_handler *handler);
 335
 336 /* Used to distinguish between bipolar and unipolar scan elemenents.
 337  * Whilst this may seem obvious, we may well want to change the representation
 338  * in the future!*/
 339 #define IIO_SIGNED(a) -(a)
 340 #define IIO_UNSIGNED(a) (a)
 341
 342 extern dev_t iio_devt;
 343 extern struct class iio_class;
 344
 345 /**
 346  * iio_put_device() - reference counted deallocated of struct device
 347  * @dev: the iio_device containing the device
 348  **/
 349 static inline void iio_put_device(struct iio_dev *dev)
 350 {
 351         if (dev)
 352                 put_device(&dev->dev);
 353 };
 354
 355 /**
 356  * to_iio_dev() - get iio_dev for which we have have the struct device
 357  * @d: the struct device
 358  **/
 359 static inline struct iio_dev *to_iio_dev(struct device *d)
 360 {
 361         return container_of(d, struct iio_dev, dev);
 362 };
 363
 364 /**
 365  * iio_dev_get_devdata() - helper function gets device specific data
 366  * @d: the iio_dev associated with the device
 367  **/
 368 static inline void *iio_dev_get_devdata(struct iio_dev *d)
 369 {
 370         return d->dev_data;
 371 }
 372
 373 /**
 374  * iio_allocate_device() - allocate an iio_dev from a driver
 375  **/
 376 struct iio_dev *iio_allocate_device(void);
 377
 378 /**
 379  * iio_free_device() - free an iio_dev from a driver
 380  **/
 381 void iio_free_device(struct iio_dev *dev);
 382
 383 /**
 384  * iio_put() - internal module reference count reduce
 385  **/
 386 void iio_put(void);
 387
 388 /**
 389  * iio_get() - internal module reference count increase
 390  **/
 391 void iio_get(void);
 392
 393 /* Ring buffer related */
 394 int iio_device_get_chrdev_minor(void);
 395 void iio_device_free_chrdev_minor(int val);
 396
 397 /**
 398  * iio_ring_enabled() helper function to test if any form of ring enabled
 399  **/
 400 static inline bool iio_ring_enabled(struct iio_dev *dev_info)
 401 {
 402         return dev_info->currentmode
 403                 & (INDIO_RING_TRIGGERED
 404                    | INDIO_RING_HARDWARE_BUFFER);
 405 };
 406
 407 struct idr;
 408
 409 int iio_get_new_idr_val(struct idr *this_idr);
 410 void iio_free_idr_val(struct idr *this_idr, int id);
 411 #endif /* _INDUSTRIAL_IO_H_ */