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  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
 100  * @scan_timestamp:     [INTERN] does the scan mode include a timestamp
 101  * @trig:               [INTERN] current device trigger (ring buffer modes)
 102  * @pollfunc:           [DRIVER] function run on trigger being recieved
 103  **/
 104 struct iio_dev {
 105         int                             id;
 106         void                            *dev_data;
 107         int                             modes;
 108         int                             currentmode;
 109         struct device                   dev;
 110         const struct attribute_group    *attrs;
 111         struct module                   *driver_module;
 112
 113         int                             num_interrupt_lines;
 114         struct iio_interrupt            **interrupts;
 115         struct attribute_group          *event_attrs;
 116         struct attribute_group          *event_conf_attrs;
 117
 118         struct iio_event_interface      *event_interfaces;
 119
 120         struct iio_ring_buffer          *ring;
 121         struct mutex                    mlock;
 122
 123         struct attribute_group          *scan_el_attrs;
 124         int                             scan_count;
 125
 126         u32                             scan_mask;
 127         u32                             *available_scan_masks;
 128         bool                            scan_timestamp;
 129         struct iio_trigger              *trig;
 130         struct iio_poll_func            *pollfunc;
 131 };
 132
 133 /*
 134  * These are mainly provided to allow for a change of implementation if a device
 135  * has a large number of scan elements
 136  */
 137 #define IIO_MAX_SCAN_LENGTH 31
 138
 139 /* note 0 used as error indicator as it doesn't make sense. */
 140 static inline u32 iio_scan_mask_match(u32 *av_masks, u32 mask)
 141 {
 142         while (*av_masks) {
 143                 if (!(~*av_masks & mask))
 144                         return *av_masks;
 145                 av_masks++;
 146         }
 147         return 0;
 148 }
 149
 150 static inline int iio_scan_mask_query(struct iio_dev *dev_info, int bit)
 151 {
 152         u32 mask;
 153
 154         if (bit > IIO_MAX_SCAN_LENGTH)
 155                 return -EINVAL;
 156
 157         if (!dev_info->scan_mask)
 158                 return 0;
 159
 160         if (dev_info->available_scan_masks)
 161                 mask = iio_scan_mask_match(dev_info->available_scan_masks,
 162                                         dev_info->scan_mask);
 163         else
 164                 mask = dev_info->scan_mask;
 165
 166         if (!mask)
 167                 return -EINVAL;
 168
 169         return !!(mask & (1 << bit));
 170 };
 171
 172 static inline int iio_scan_mask_set(struct iio_dev *dev_info, int bit)
 173 {
 174         u32 mask;
 175         u32 trialmask = dev_info->scan_mask | (1 << bit);
 176
 177         if (bit > IIO_MAX_SCAN_LENGTH)
 178                 return -EINVAL;
 179         if (dev_info->available_scan_masks) {
 180                 mask = iio_scan_mask_match(dev_info->available_scan_masks,
 181                                         trialmask);
 182                 if (!mask)
 183                         return -EINVAL;
 184         }
 185         dev_info->scan_mask = trialmask;
 186         dev_info->scan_count++;
 187
 188         return 0;
 189 };
 190
 191 static inline int iio_scan_mask_clear(struct iio_dev *dev_info, int bit)
 192 {
 193         if (bit > IIO_MAX_SCAN_LENGTH)
 194                 return -EINVAL;
 195         dev_info->scan_mask &= ~(1 << bit);
 196         dev_info->scan_count--;
 197         return 0;
 198 };
 199
 200 /**
 201  * iio_scan_mask_count_to_right() - how many scan elements occur before here
 202  * @dev_info: the iio_device whose scan mode we are querying
 203  * @bit: which number scan element is this
 204  **/
 205 static inline int iio_scan_mask_count_to_right(struct iio_dev *dev_info,
 206                                                 int bit)
 207 {
 208         int count = 0;
 209         int mask = (1 << bit);
 210         if (bit > IIO_MAX_SCAN_LENGTH)
 211                 return -EINVAL;
 212         while (mask) {
 213                 mask >>= 1;
 214                 if (mask & dev_info->scan_mask)
 215                         count++;
 216         }
 217
 218         return count;
 219 }
 220
 221 /**
 222  * iio_device_register() - register a device with the IIO subsystem
 223  * @dev_info:           Device structure filled by the device driver
 224  **/
 225 int iio_device_register(struct iio_dev *dev_info);
 226
 227 /**
 228  * iio_device_unregister() - unregister a device from the IIO subsystem
 229  * @dev_info:           Device structure representing the device.
 230  **/
 231 void iio_device_unregister(struct iio_dev *dev_info);
 232
 233 /**
 234  * struct iio_interrupt - wrapper used to allow easy handling of multiple
 235  *                      physical interrupt lines
 236  * @dev_info:           the iio device for which the is an interrupt line
 237  * @line_number:        associated line number
 238  * @id:                 idr allocated unique id number
 239  * @irq:                associate interrupt number
 240  * @ev_list:            event handler list for associated events
 241  * @ev_list_lock:       ensure only one access to list at a time
 242  **/
 243 struct iio_interrupt {
 244         struct iio_dev                  *dev_info;
 245         int                             line_number;
 246         int                             id;
 247         int                             irq;
 248         struct list_head                ev_list;
 249         spinlock_t                      ev_list_lock;
 250 };
 251
 252 #define to_iio_interrupt(i) container_of(i, struct iio_interrupt, ev_list)
 253
 254 /**
 255  * iio_register_interrupt_line() - Tell IIO about interrupt lines
 256  *
 257  * @irq:                Typically provided via platform data
 258  * @dev_info:           IIO device info structure for device
 259  * @line_number:        Which interrupt line of the device is this?
 260  * @type:               Interrupt type (e.g. edge triggered etc)
 261  * @name:               Identifying name.
 262  **/
 263 int iio_register_interrupt_line(unsigned int                    irq,
 264                                 struct iio_dev                  *dev_info,
 265                                 int                             line_number,
 266                                 unsigned long                   type,
 267                                 const char                      *name);
 268
 269 void iio_unregister_interrupt_line(struct iio_dev *dev_info,
 270                                    int line_number);
 271
 272
 273
 274 /**
 275  * iio_push_event() - try to add event to the list for userspace reading
 276  * @dev_info:           IIO device structure
 277  * @ev_line:            Which event line (hardware interrupt)
 278  * @ev_code:            What event
 279  * @timestamp:          When the event occurred
 280  **/
 281 int iio_push_event(struct iio_dev *dev_info,
 282                   int ev_line,
 283                   int ev_code,
 284                   s64 timestamp);
 285
 286 /**
 287  * struct iio_work_cont - container for when singleton handler case matters
 288  * @ws:                 [DEVICE] work_struct when not only possible event
 289  * @ws_nocheck:         [DEVICE] work_struct when only possible event
 290  * @address:            [DEVICE] associated register address
 291  * @mask:               [DEVICE] associated mask for identifying event source
 292  * @st:                 [DEVICE] device specific state information
 293  **/
 294 struct iio_work_cont {
 295         struct work_struct      ws;
 296         struct work_struct      ws_nocheck;
 297         int                     address;
 298         int                     mask;
 299         void                    *st;
 300 };
 301
 302 #define to_iio_work_cont_check(_ws)                     \
 303         container_of(_ws, struct iio_work_cont, ws)
 304
 305 #define to_iio_work_cont_no_check(_ws)                          \
 306         container_of(_ws, struct iio_work_cont, ws_nocheck)
 307
 308 /**
 309  * iio_init_work_cont() - intiialize the elements of a work container
 310  * @cont: the work container
 311  * @_checkfunc: function called when there are multiple possible int sources
 312  * @_nocheckfunc: function for when there is only one int source
 313  * @_add: driver dependent, typically a register address
 314  * @_mask: driver dependent, typically a bit mask for a register
 315  * @_st: driver dependent, typically pointer to a device state structure
 316  **/
 317 static inline void
 318 iio_init_work_cont(struct iio_work_cont *cont,
 319                    void (*_checkfunc)(struct work_struct *),
 320                    void (*_nocheckfunc)(struct work_struct *),
 321                    int _add, int _mask, void *_st)
 322 {
 323         INIT_WORK(&(cont)->ws, _checkfunc);
 324         INIT_WORK(&(cont)->ws_nocheck, _nocheckfunc);
 325         cont->address = _add;
 326         cont->mask = _mask;
 327         cont->st = _st;
 328 }
 329 /**
 330  * __iio_push_event() - tries to add an event to the list associated with a chrdev
 331  * @ev_int:             the event interface to which we are pushing the event
 332  * @ev_code:            the outgoing event code
 333  * @timestamp:          timestamp of the event
 334  * @shared_pointer_p:   the shared event pointer
 335  **/
 336 int __iio_push_event(struct iio_event_interface *ev_int,
 337                     int ev_code,
 338                     s64 timestamp,
 339                     struct iio_shared_ev_pointer*
 340                     shared_pointer_p);
 341 /**
 342  * __iio_change_event() - change an event code in case of event escalation
 343  * @ev:                 the event to be changed
 344  * @ev_code:            new event code
 345  * @timestamp:          new timestamp
 346  **/
 347 void __iio_change_event(struct iio_detected_event_list *ev,
 348                         int ev_code,
 349                         s64 timestamp);
 350
 351 /**
 352  * iio_setup_ev_int() - configure an event interface (chrdev)
 353  * @name:               name used for resulting sysfs directory etc.
 354  * @ev_int:             interface we are configuring
 355  * @owner:              module that is responsible for registering this ev_int
 356  * @dev:                device whose ev_int this is
 357  **/
 358 int iio_setup_ev_int(struct iio_event_interface *ev_int,
 359                      const char *name,
 360                      struct module *owner,
 361                      struct device *dev);
 362
 363 void iio_free_ev_int(struct iio_event_interface *ev_int);
 364
 365 /**
 366  * iio_allocate_chrdev() - Allocate a chrdev
 367  * @handler:    struct that contains relevant file handling for chrdev
 368  * @dev_info:   iio_dev for which chrdev is being created
 369  **/
 370 int iio_allocate_chrdev(struct iio_handler *handler, struct iio_dev *dev_info);
 371 void iio_deallocate_chrdev(struct iio_handler *handler);
 372
 373 /* Used to distinguish between bipolar and unipolar scan elemenents.
 374  * Whilst this may seem obvious, we may well want to change the representation
 375  * in the future!*/
 376 #define IIO_SIGNED(a) -(a)
 377 #define IIO_UNSIGNED(a) (a)
 378
 379 extern dev_t iio_devt;
 380 extern struct bus_type iio_bus_type;
 381
 382 /**
 383  * iio_put_device() - reference counted deallocation of struct device
 384  * @dev: the iio_device containing the device
 385  **/
 386 static inline void iio_put_device(struct iio_dev *dev)
 387 {
 388         if (dev)
 389                 put_device(&dev->dev);
 390 };
 391
 392 /**
 393  * to_iio_dev() - get iio_dev for which we have the struct device
 394  * @d: the struct device
 395  **/
 396 static inline struct iio_dev *to_iio_dev(struct device *d)
 397 {
 398         return container_of(d, struct iio_dev, dev);
 399 };
 400
 401 /**
 402  * iio_dev_get_devdata() - helper function gets device specific data
 403  * @d: the iio_dev associated with the device
 404  **/
 405 static inline void *iio_dev_get_devdata(struct iio_dev *d)
 406 {
 407         return d->dev_data;
 408 }
 409
 410 /**
 411  * iio_allocate_device() - allocate an iio_dev from a driver
 412  **/
 413 struct iio_dev *iio_allocate_device(void);
 414
 415 /**
 416  * iio_free_device() - free an iio_dev from a driver
 417  * @dev: the iio_dev associated with the device
 418  **/
 419 void iio_free_device(struct iio_dev *dev);
 420
 421 /**
 422  * iio_put() - internal module reference count reduce
 423  **/
 424 void iio_put(void);
 425
 426 /**
 427  * iio_get() - internal module reference count increase
 428  **/
 429 void iio_get(void);
 430
 431 /* Ring buffer related */
 432 int iio_device_get_chrdev_minor(void);
 433 void iio_device_free_chrdev_minor(int val);
 434
 435 /**
 436  * iio_ring_enabled() - helper function to test if any form of ring is enabled
 437  * @dev_info:           IIO device info structure for device
 438  **/
 439 static inline bool iio_ring_enabled(struct iio_dev *dev_info)
 440 {
 441         return dev_info->currentmode
 442                 & (INDIO_RING_TRIGGERED
 443                    | INDIO_RING_HARDWARE_BUFFER);
 444 };
 445
 446 struct idr;
 447
 448 int iio_get_new_idr_val(struct idr *this_idr);
 449 void iio_free_idr_val(struct idr *this_idr, int id);
 450 #endif /* _INDUSTRIAL_IO_H_ */