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 /*
  20  * Provide means of adjusting timer accuracy.
  21  * Currently assumes nano seconds.
  22  */
  23
  24 /* Event interface flags */
  25 #define IIO_BUSY_BIT_POS 1
  26
  27 struct iio_dev;
  28
  29 /**
  30  * iio_get_time_ns() - utility function to get a time stamp for events etc
  31  **/
  32 static inline s64 iio_get_time_ns(void)
  33 {
  34         struct timespec ts;
  35         /*
  36          * calls getnstimeofday.
  37          * If hrtimers then up to ns accurate, if not microsecond.
  38          */
  39         ktime_get_real_ts(&ts);
  40
  41         return timespec_to_ns(&ts);
  42 }
  43
  44 /**
  45  * iio_add_event_to_list() - Wraps adding to event lists
  46  * @el:         the list element of the event to be handled.
  47  * @head:       the list associated with the event handler being used.
  48  *
  49  * Does reference counting to allow shared handlers.
  50  **/
  51 void iio_add_event_to_list(struct iio_event_handler_list *el,
  52                            struct list_head *head);
  53
  54 /**
  55  * iio_remove_event_from_list() - Wraps removing from event list
  56  * @el:         element to be removed
  57  * @head:       associate list head for the interrupt handler.
  58  *
  59  * Does reference counting to allow shared handlers.
  60  **/
  61 void iio_remove_event_from_list(struct iio_event_handler_list *el,
  62                                 struct list_head *head);
  63
  64 /* Device operating modes */
  65 #define INDIO_DIRECT_MODE               0x01
  66 #define INDIO_RING_TRIGGERED            0x02
  67 #define INDIO_RING_HARDWARE_BUFFER      0x08
  68
  69 #define INDIO_ALL_RING_MODES (INDIO_RING_TRIGGERED | INDIO_RING_HARDWARE_BUFFER)
  70
  71 /* Vast majority of this is set by the industrialio subsystem on a
  72  * call to iio_device_register. */
  73
  74 /**
  75  * struct iio_dev - industrial I/O device
  76  * @id:                 [INTERN] used to identify device internally
  77  * @dev_data:           [DRIVER] device specific data
  78  * @modes:              [DRIVER] operating modes supported by device
  79  * @currentmode:        [DRIVER] current operating mode
  80  * @dev:                [DRIVER] device structure, should be assigned a parent
  81  *                      and owner
  82  * @attrs:              [DRIVER] general purpose device attributes
  83  * @driver_module:      [DRIVER] module structure used to ensure correct
  84  *                      ownership of chrdevs etc
  85  * @num_interrupt_lines:[DRIVER] number of physical interrupt lines from device
  86  * @interrupts:         [INTERN] interrupt line specific event lists etc
  87  * @event_attrs:        [DRIVER] event control attributes
  88  * @event_conf_attrs:   [DRIVER] event configuration attributes
  89  * @event_interfaces:   [INTERN] event chrdevs associated with interrupt lines
  90  * @ring:               [DRIVER] any ring buffer present
  91  * @mlock:              [INTERN] lock used to prevent simultaneous device state
  92  *                      changes
  93  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
  94  * @trig:               [INTERN] current device trigger (ring buffer modes)
  95  * @pollfunc:           [DRIVER] function run on trigger being recieved
  96  **/
  97 struct iio_dev {
  98         int                             id;
  99         void                            *dev_data;
 100         int                             modes;
 101         int                             currentmode;
 102         struct device                   dev;
 103         const struct attribute_group    *attrs;
 104         struct module                   *driver_module;
 105
 106         int                             num_interrupt_lines;
 107         struct iio_interrupt            **interrupts;
 108         struct attribute_group          *event_attrs;
 109         struct attribute_group          *event_conf_attrs;
 110
 111         struct iio_event_interface      *event_interfaces;
 112
 113         struct iio_ring_buffer          *ring;
 114         struct mutex                    mlock;
 115
 116         u32                             *available_scan_masks;
 117         struct iio_trigger              *trig;
 118         struct iio_poll_func            *pollfunc;
 119 };
 120
 121 /**
 122  * iio_device_register() - register a device with the IIO subsystem
 123  * @dev_info:           Device structure filled by the device driver
 124  **/
 125 int iio_device_register(struct iio_dev *dev_info);
 126
 127 /**
 128  * iio_device_unregister() - unregister a device from the IIO subsystem
 129  * @dev_info:           Device structure representing the device.
 130  **/
 131 void iio_device_unregister(struct iio_dev *dev_info);
 132
 133 /**
 134  * struct iio_interrupt - wrapper used to allow easy handling of multiple
 135  *                      physical interrupt lines
 136  * @dev_info:           the iio device for which the is an interrupt line
 137  * @line_number:        associated line number
 138  * @id:                 ida allocated unique id number
 139  * @irq:                associate interrupt number
 140  * @ev_list:            event handler list for associated events
 141  * @ev_list_lock:       ensure only one access to list at a time
 142  **/
 143 struct iio_interrupt {
 144         struct iio_dev                  *dev_info;
 145         int                             line_number;
 146         int                             id;
 147         int                             irq;
 148         struct list_head                ev_list;
 149         spinlock_t                      ev_list_lock;
 150 };
 151
 152 #define to_iio_interrupt(i) container_of(i, struct iio_interrupt, ev_list)
 153
 154 /**
 155  * iio_register_interrupt_line() - Tell IIO about interrupt lines
 156  *
 157  * @irq:                Typically provided via platform data
 158  * @dev_info:           IIO device info structure for device
 159  * @line_number:        Which interrupt line of the device is this?
 160  * @type:               Interrupt type (e.g. edge triggered etc)
 161  * @name:               Identifying name.
 162  **/
 163 int iio_register_interrupt_line(unsigned int                    irq,
 164                                 struct iio_dev                  *dev_info,
 165                                 int                             line_number,
 166                                 unsigned long                   type,
 167                                 const char                      *name);
 168
 169 void iio_unregister_interrupt_line(struct iio_dev *dev_info,
 170                                    int line_number);
 171
 172
 173
 174 /**
 175  * iio_push_event() - try to add event to the list for userspace reading
 176  * @dev_info:           IIO device structure
 177  * @ev_line:            Which event line (hardware interrupt)
 178  * @ev_code:            What event
 179  * @timestamp:          When the event occurred
 180  **/
 181 int iio_push_event(struct iio_dev *dev_info,
 182                   int ev_line,
 183                   int ev_code,
 184                   s64 timestamp);
 185
 186 /**
 187  * __iio_push_event() - tries to add an event to the list associated with a chrdev
 188  * @ev_int:             the event interface to which we are pushing the event
 189  * @ev_code:            the outgoing event code
 190  * @timestamp:          timestamp of the event
 191  * @shared_pointer_p:   the shared event pointer
 192  **/
 193 int __iio_push_event(struct iio_event_interface *ev_int,
 194                     int ev_code,
 195                     s64 timestamp,
 196                     struct iio_shared_ev_pointer*
 197                     shared_pointer_p);
 198 /**
 199  * __iio_change_event() - change an event code in case of event escalation
 200  * @ev:                 the event to be changed
 201  * @ev_code:            new event code
 202  * @timestamp:          new timestamp
 203  **/
 204 void __iio_change_event(struct iio_detected_event_list *ev,
 205                         int ev_code,
 206                         s64 timestamp);
 207
 208 /**
 209  * iio_setup_ev_int() - configure an event interface (chrdev)
 210  * @name:               name used for resulting sysfs directory etc.
 211  * @ev_int:             interface we are configuring
 212  * @owner:              module that is responsible for registering this ev_int
 213  * @dev:                device whose ev_int this is
 214  **/
 215 int iio_setup_ev_int(struct iio_event_interface *ev_int,
 216                      const char *name,
 217                      struct module *owner,
 218                      struct device *dev);
 219
 220 void iio_free_ev_int(struct iio_event_interface *ev_int);
 221
 222 /**
 223  * iio_allocate_chrdev() - Allocate a chrdev
 224  * @handler:    struct that contains relevant file handling for chrdev
 225  * @dev_info:   iio_dev for which chrdev is being created
 226  **/
 227 int iio_allocate_chrdev(struct iio_handler *handler, struct iio_dev *dev_info);
 228 void iio_deallocate_chrdev(struct iio_handler *handler);
 229
 230 /* Used to distinguish between bipolar and unipolar scan elemenents.
 231  * Whilst this may seem obvious, we may well want to change the representation
 232  * in the future!*/
 233 #define IIO_SIGNED(a) -(a)
 234 #define IIO_UNSIGNED(a) (a)
 235
 236 extern dev_t iio_devt;
 237 extern struct bus_type iio_bus_type;
 238
 239 /**
 240  * iio_put_device() - reference counted deallocation of struct device
 241  * @dev: the iio_device containing the device
 242  **/
 243 static inline void iio_put_device(struct iio_dev *dev)
 244 {
 245         if (dev)
 246                 put_device(&dev->dev);
 247 };
 248
 249 /**
 250  * to_iio_dev() - get iio_dev for which we have the struct device
 251  * @d: the struct device
 252  **/
 253 static inline struct iio_dev *to_iio_dev(struct device *d)
 254 {
 255         return container_of(d, struct iio_dev, dev);
 256 };
 257
 258 /**
 259  * iio_dev_get_devdata() - helper function gets device specific data
 260  * @d: the iio_dev associated with the device
 261  **/
 262 static inline void *iio_dev_get_devdata(struct iio_dev *d)
 263 {
 264         return d->dev_data;
 265 }
 266
 267 /**
 268  * iio_allocate_device() - allocate an iio_dev from a driver
 269  **/
 270 struct iio_dev *iio_allocate_device(void);
 271
 272 /**
 273  * iio_free_device() - free an iio_dev from a driver
 274  * @dev: the iio_dev associated with the device
 275  **/
 276 void iio_free_device(struct iio_dev *dev);
 277
 278 /**
 279  * iio_put() - internal module reference count reduce
 280  **/
 281 void iio_put(void);
 282
 283 /**
 284  * iio_get() - internal module reference count increase
 285  **/
 286 void iio_get(void);
 287
 288 /**
 289  * iio_device_get_chrdev_minor() - get an unused minor number
 290  **/
 291 int iio_device_get_chrdev_minor(void);
 292 void iio_device_free_chrdev_minor(int val);
 293
 294 /**
 295  * iio_ring_enabled() - helper function to test if any form of ring is enabled
 296  * @dev_info:           IIO device info structure for device
 297  **/
 298 static inline bool iio_ring_enabled(struct iio_dev *dev_info)
 299 {
 300         return dev_info->currentmode
 301                 & (INDIO_RING_TRIGGERED
 302                    | INDIO_RING_HARDWARE_BUFFER);
 303 };
 304
 305 struct ida;
 306
 307 int iio_get_new_ida_val(struct ida *this_ida);
 308 void iio_free_ida_val(struct ida *this_ida, int id);
 309 #endif /* _INDUSTRIAL_IO_H_ */