Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 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_ */ |