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 * @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 **/ 97struct 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 **/ 125int 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 **/ 131void 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 **/ 143struct 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 **/ 163int 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 169void 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 **/ 181int 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 **/ 193int __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 **/ 204void __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 **/ 215int iio_setup_ev_int(struct iio_event_interface *ev_int, 216 const char *name, 217 struct module *owner, 218 struct device *dev); 219 220void 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 **/ 227int iio_allocate_chrdev(struct iio_handler *handler, struct iio_dev *dev_info); 228void 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 236extern dev_t iio_devt; 237extern 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 **/ 243static 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 **/ 253static 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 **/ 262static 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 **/ 270struct 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 **/ 276void iio_free_device(struct iio_dev *dev); 277 278/** 279 * iio_put() - internal module reference count reduce 280 **/ 281void iio_put(void); 282 283/** 284 * iio_get() - internal module reference count increase 285 **/ 286void iio_get(void); 287 288/** 289 * iio_device_get_chrdev_minor() - get an unused minor number 290 **/ 291int iio_device_get_chrdev_minor(void); 292void 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 **/ 298static 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 305struct ida; 306 307int iio_get_new_ida_val(struct ida *this_ida); 308void iio_free_ida_val(struct ida *this_ida, int id); 309#endif /* _INDUSTRIAL_IO_H_ */ 310