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 27struct iio_dev; 28 29/** 30 * iio_get_time_ns() - utility function to get a time stamp for events etc 31 **/ 32static 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 **/ 51void 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 **/ 61void 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 * @scan_el_attrs: [DRIVER] control of scan elements if that scan mode 94 * control method is used 95 * @scan_count: [INTERN] the number of elements in the current scan mode 96 * @scan_mask: [INTERN] bitmask used in masking scan mode elements 97 * @available_scan_masks: [DRIVER] optional array of allowed bitmasks 98 * @scan_timestamp: [INTERN] does the scan mode include a timestamp 99 * @trig: [INTERN] current device trigger (ring buffer modes) 100 * @pollfunc: [DRIVER] function run on trigger being recieved 101 **/ 102struct iio_dev { 103 int id; 104 void *dev_data; 105 int modes; 106 int currentmode; 107 struct device dev; 108 const struct attribute_group *attrs; 109 struct module *driver_module; 110 111 int num_interrupt_lines; 112 struct iio_interrupt **interrupts; 113 struct attribute_group *event_attrs; 114 struct attribute_group *event_conf_attrs; 115 116 struct iio_event_interface *event_interfaces; 117 118 struct iio_ring_buffer *ring; 119 struct mutex mlock; 120 121 struct attribute_group *scan_el_attrs; 122 int scan_count; 123 124 u32 scan_mask; 125 u32 *available_scan_masks; 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 31 136 137/* note 0 used as error indicator as it doesn't make sense. */ 138static inline u32 iio_scan_mask_match(u32 *av_masks, u32 mask) 139{ 140 while (*av_masks) { 141 if (!(~*av_masks & mask)) 142 return *av_masks; 143 av_masks++; 144 } 145 return 0; 146} 147 148static inline int iio_scan_mask_query(struct iio_dev *dev_info, int bit) 149{ 150 u32 mask; 151 152 if (bit > IIO_MAX_SCAN_LENGTH) 153 return -EINVAL; 154 155 if (!dev_info->scan_mask) 156 return 0; 157 158 if (dev_info->available_scan_masks) 159 mask = iio_scan_mask_match(dev_info->available_scan_masks, 160 dev_info->scan_mask); 161 else 162 mask = dev_info->scan_mask; 163 164 if (!mask) 165 return -EINVAL; 166 167 return !!(mask & (1 << bit)); 168}; 169 170static inline int iio_scan_mask_set(struct iio_dev *dev_info, int bit) 171{ 172 u32 mask; 173 u32 trialmask = dev_info->scan_mask | (1 << bit); 174 175 if (bit > IIO_MAX_SCAN_LENGTH) 176 return -EINVAL; 177 if (dev_info->available_scan_masks) { 178 mask = iio_scan_mask_match(dev_info->available_scan_masks, 179 trialmask); 180 if (!mask) 181 return -EINVAL; 182 } 183 dev_info->scan_mask = trialmask; 184 dev_info->scan_count++; 185 186 return 0; 187}; 188 189static inline int iio_scan_mask_clear(struct iio_dev *dev_info, int bit) 190{ 191 if (bit > IIO_MAX_SCAN_LENGTH) 192 return -EINVAL; 193 dev_info->scan_mask &= ~(1 << bit); 194 dev_info->scan_count--; 195 return 0; 196}; 197 198/** 199 * iio_scan_mask_count_to_right() - how many scan elements occur before here 200 * @dev_info: the iio_device whose scan mode we are querying 201 * @bit: which number scan element is this 202 **/ 203static inline int iio_scan_mask_count_to_right(struct iio_dev *dev_info, 204 int bit) 205{ 206 int count = 0; 207 int mask = (1 << bit); 208 if (bit > IIO_MAX_SCAN_LENGTH) 209 return -EINVAL; 210 while (mask) { 211 mask >>= 1; 212 if (mask & dev_info->scan_mask) 213 count++; 214 } 215 216 return count; 217} 218 219/** 220 * iio_device_register() - register a device with the IIO subsystem 221 * @dev_info: Device structure filled by the device driver 222 **/ 223int iio_device_register(struct iio_dev *dev_info); 224 225/** 226 * iio_device_unregister() - unregister a device from the IIO subsystem 227 * @dev_info: Device structure representing the device. 228 **/ 229void iio_device_unregister(struct iio_dev *dev_info); 230 231/** 232 * struct iio_interrupt - wrapper used to allow easy handling of multiple 233 * physical interrupt lines 234 * @dev_info: the iio device for which the is an interrupt line 235 * @line_number: associated line number 236 * @id: idr allocated unique id number 237 * @irq: associate interrupt number 238 * @ev_list: event handler list for associated events 239 * @ev_list_lock: ensure only one access to list at a time 240 **/ 241struct iio_interrupt { 242 struct iio_dev *dev_info; 243 int line_number; 244 int id; 245 int irq; 246 struct list_head ev_list; 247 spinlock_t ev_list_lock; 248}; 249 250#define to_iio_interrupt(i) container_of(i, struct iio_interrupt, ev_list) 251 252/** 253 * iio_register_interrupt_line() - Tell IIO about interrupt lines 254 * 255 * @irq: Typically provided via platform data 256 * @dev_info: IIO device info structure for device 257 * @line_number: Which interrupt line of the device is this? 258 * @type: Interrupt type (e.g. edge triggered etc) 259 * @name: Identifying name. 260 **/ 261int iio_register_interrupt_line(unsigned int irq, 262 struct iio_dev *dev_info, 263 int line_number, 264 unsigned long type, 265 const char *name); 266 267void iio_unregister_interrupt_line(struct iio_dev *dev_info, 268 int line_number); 269 270 271 272/** 273 * iio_push_event() - try to add event to the list for userspace reading 274 * @dev_info: IIO device structure 275 * @ev_line: Which event line (hardware interrupt) 276 * @ev_code: What event 277 * @timestamp: When the event occurred 278 **/ 279int iio_push_event(struct iio_dev *dev_info, 280 int ev_line, 281 int ev_code, 282 s64 timestamp); 283 284/** 285 * __iio_push_event() - tries to add an event to the list associated with a chrdev 286 * @ev_int: the event interface to which we are pushing the event 287 * @ev_code: the outgoing event code 288 * @timestamp: timestamp of the event 289 * @shared_pointer_p: the shared event pointer 290 **/ 291int __iio_push_event(struct iio_event_interface *ev_int, 292 int ev_code, 293 s64 timestamp, 294 struct iio_shared_ev_pointer* 295 shared_pointer_p); 296/** 297 * __iio_change_event() - change an event code in case of event escalation 298 * @ev: the event to be changed 299 * @ev_code: new event code 300 * @timestamp: new timestamp 301 **/ 302void __iio_change_event(struct iio_detected_event_list *ev, 303 int ev_code, 304 s64 timestamp); 305 306/** 307 * iio_setup_ev_int() - configure an event interface (chrdev) 308 * @name: name used for resulting sysfs directory etc. 309 * @ev_int: interface we are configuring 310 * @owner: module that is responsible for registering this ev_int 311 * @dev: device whose ev_int this is 312 **/ 313int iio_setup_ev_int(struct iio_event_interface *ev_int, 314 const char *name, 315 struct module *owner, 316 struct device *dev); 317 318void iio_free_ev_int(struct iio_event_interface *ev_int); 319 320/** 321 * iio_allocate_chrdev() - Allocate a chrdev 322 * @handler: struct that contains relevant file handling for chrdev 323 * @dev_info: iio_dev for which chrdev is being created 324 **/ 325int iio_allocate_chrdev(struct iio_handler *handler, struct iio_dev *dev_info); 326void iio_deallocate_chrdev(struct iio_handler *handler); 327 328/* Used to distinguish between bipolar and unipolar scan elemenents. 329 * Whilst this may seem obvious, we may well want to change the representation 330 * in the future!*/ 331#define IIO_SIGNED(a) -(a) 332#define IIO_UNSIGNED(a) (a) 333 334extern dev_t iio_devt; 335extern struct bus_type iio_bus_type; 336 337/** 338 * iio_put_device() - reference counted deallocation of struct device 339 * @dev: the iio_device containing the device 340 **/ 341static inline void iio_put_device(struct iio_dev *dev) 342{ 343 if (dev) 344 put_device(&dev->dev); 345}; 346 347/** 348 * to_iio_dev() - get iio_dev for which we have the struct device 349 * @d: the struct device 350 **/ 351static inline struct iio_dev *to_iio_dev(struct device *d) 352{ 353 return container_of(d, struct iio_dev, dev); 354}; 355 356/** 357 * iio_dev_get_devdata() - helper function gets device specific data 358 * @d: the iio_dev associated with the device 359 **/ 360static inline void *iio_dev_get_devdata(struct iio_dev *d) 361{ 362 return d->dev_data; 363} 364 365/** 366 * iio_allocate_device() - allocate an iio_dev from a driver 367 **/ 368struct iio_dev *iio_allocate_device(void); 369 370/** 371 * iio_free_device() - free an iio_dev from a driver 372 * @dev: the iio_dev associated with the device 373 **/ 374void iio_free_device(struct iio_dev *dev); 375 376/** 377 * iio_put() - internal module reference count reduce 378 **/ 379void iio_put(void); 380 381/** 382 * iio_get() - internal module reference count increase 383 **/ 384void iio_get(void); 385 386/** 387 * iio_device_get_chrdev_minor() - get an unused minor number 388 **/ 389int iio_device_get_chrdev_minor(void); 390void iio_device_free_chrdev_minor(int val); 391 392/** 393 * iio_ring_enabled() - helper function to test if any form of ring is enabled 394 * @dev_info: IIO device info structure for device 395 **/ 396static inline bool iio_ring_enabled(struct iio_dev *dev_info) 397{ 398 return dev_info->currentmode 399 & (INDIO_RING_TRIGGERED 400 | INDIO_RING_HARDWARE_BUFFER); 401}; 402 403struct idr; 404 405int iio_get_new_idr_val(struct idr *this_idr); 406void iio_free_idr_val(struct idr *this_idr, int id); 407#endif /* _INDUSTRIAL_IO_H_ */ 408