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 | * Based on elements of hwmon and input subsystems. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/idr.h> |
| 15 | #include <linux/kdev_t.h> |
| 16 | #include <linux/err.h> |
| 17 | #include <linux/device.h> |
| 18 | #include <linux/fs.h> |
| 19 | #include <linux/interrupt.h> |
| 20 | #include <linux/poll.h> |
Jonathan Cameron | ffc18af | 2009-10-12 19:18:09 +0100 | [diff] [blame] | 21 | #include <linux/sched.h> |
Jeff Mahoney | 4439c93 | 2009-10-12 17:10:34 -0400 | [diff] [blame] | 22 | #include <linux/wait.h> |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 23 | #include <linux/cdev.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 24 | #include <linux/slab.h> |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 25 | #include "iio.h" |
| 26 | #include "trigger_consumer.h" |
| 27 | |
| 28 | #define IIO_ID_PREFIX "device" |
| 29 | #define IIO_ID_FORMAT IIO_ID_PREFIX "%d" |
| 30 | |
| 31 | /* IDR to assign each registered device a unique id*/ |
| 32 | static DEFINE_IDR(iio_idr); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 33 | /* IDR to allocate character device minor numbers */ |
| 34 | static DEFINE_IDR(iio_chrdev_idr); |
| 35 | /* Lock used to protect both of the above */ |
| 36 | static DEFINE_SPINLOCK(iio_idr_lock); |
| 37 | |
| 38 | dev_t iio_devt; |
| 39 | EXPORT_SYMBOL(iio_devt); |
| 40 | |
| 41 | #define IIO_DEV_MAX 256 |
Jonathan Cameron | 5aaaeba | 2010-05-04 14:43:00 +0100 | [diff] [blame] | 42 | struct bus_type iio_bus_type = { |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 43 | .name = "iio", |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 44 | }; |
Jonathan Cameron | 5aaaeba | 2010-05-04 14:43:00 +0100 | [diff] [blame] | 45 | EXPORT_SYMBOL(iio_bus_type); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 46 | |
| 47 | void __iio_change_event(struct iio_detected_event_list *ev, |
| 48 | int ev_code, |
| 49 | s64 timestamp) |
| 50 | { |
| 51 | ev->ev.id = ev_code; |
| 52 | ev->ev.timestamp = timestamp; |
| 53 | } |
| 54 | EXPORT_SYMBOL(__iio_change_event); |
| 55 | |
| 56 | /* Used both in the interrupt line put events and the ring buffer ones */ |
| 57 | |
| 58 | /* Note that in it's current form someone has to be listening before events |
| 59 | * are queued. Hence a client MUST open the chrdev before the ring buffer is |
| 60 | * switched on. |
| 61 | */ |
| 62 | int __iio_push_event(struct iio_event_interface *ev_int, |
| 63 | int ev_code, |
| 64 | s64 timestamp, |
| 65 | struct iio_shared_ev_pointer * |
| 66 | shared_pointer_p) |
| 67 | { |
| 68 | struct iio_detected_event_list *ev; |
| 69 | int ret = 0; |
| 70 | |
| 71 | /* Does anyone care? */ |
| 72 | mutex_lock(&ev_int->event_list_lock); |
| 73 | if (test_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags)) { |
Jonathan Cameron | 75c8075 | 2010-01-09 16:57:34 +0000 | [diff] [blame] | 74 | if (ev_int->current_events == ev_int->max_events) { |
| 75 | mutex_unlock(&ev_int->event_list_lock); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 76 | return 0; |
Jonathan Cameron | 75c8075 | 2010-01-09 16:57:34 +0000 | [diff] [blame] | 77 | } |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 78 | ev = kmalloc(sizeof(*ev), GFP_KERNEL); |
| 79 | if (ev == NULL) { |
| 80 | ret = -ENOMEM; |
Jonathan Cameron | 75c8075 | 2010-01-09 16:57:34 +0000 | [diff] [blame] | 81 | mutex_unlock(&ev_int->event_list_lock); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 82 | goto error_ret; |
| 83 | } |
| 84 | ev->ev.id = ev_code; |
| 85 | ev->ev.timestamp = timestamp; |
| 86 | ev->shared_pointer = shared_pointer_p; |
| 87 | if (ev->shared_pointer) |
| 88 | shared_pointer_p->ev_p = ev; |
| 89 | |
| 90 | list_add_tail(&ev->list, &ev_int->det_events.list); |
| 91 | ev_int->current_events++; |
| 92 | mutex_unlock(&ev_int->event_list_lock); |
| 93 | wake_up_interruptible(&ev_int->wait); |
| 94 | } else |
| 95 | mutex_unlock(&ev_int->event_list_lock); |
| 96 | |
| 97 | error_ret: |
| 98 | return ret; |
| 99 | } |
| 100 | EXPORT_SYMBOL(__iio_push_event); |
| 101 | |
| 102 | int iio_push_event(struct iio_dev *dev_info, |
| 103 | int ev_line, |
| 104 | int ev_code, |
| 105 | s64 timestamp) |
| 106 | { |
| 107 | return __iio_push_event(&dev_info->event_interfaces[ev_line], |
| 108 | ev_code, timestamp, NULL); |
| 109 | } |
| 110 | EXPORT_SYMBOL(iio_push_event); |
| 111 | |
| 112 | /* Generic interrupt line interrupt handler */ |
Mark Brown | 77712e5 | 2010-02-18 17:19:17 +0000 | [diff] [blame] | 113 | static irqreturn_t iio_interrupt_handler(int irq, void *_int_info) |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 114 | { |
| 115 | struct iio_interrupt *int_info = _int_info; |
| 116 | struct iio_dev *dev_info = int_info->dev_info; |
| 117 | struct iio_event_handler_list *p; |
| 118 | s64 time_ns; |
| 119 | unsigned long flags; |
| 120 | |
| 121 | spin_lock_irqsave(&int_info->ev_list_lock, flags); |
| 122 | if (list_empty(&int_info->ev_list)) { |
| 123 | spin_unlock_irqrestore(&int_info->ev_list_lock, flags); |
| 124 | return IRQ_NONE; |
| 125 | } |
| 126 | |
| 127 | time_ns = iio_get_time_ns(); |
| 128 | /* detect single element list*/ |
| 129 | if (list_is_singular(&int_info->ev_list)) { |
| 130 | disable_irq_nosync(irq); |
| 131 | p = list_first_entry(&int_info->ev_list, |
| 132 | struct iio_event_handler_list, |
| 133 | list); |
| 134 | /* single event handler - maybe shared */ |
| 135 | p->handler(dev_info, 1, time_ns, !(p->refcount > 1)); |
| 136 | } else |
| 137 | list_for_each_entry(p, &int_info->ev_list, list) { |
| 138 | disable_irq_nosync(irq); |
| 139 | p->handler(dev_info, 1, time_ns, 0); |
| 140 | } |
| 141 | spin_unlock_irqrestore(&int_info->ev_list_lock, flags); |
| 142 | |
| 143 | return IRQ_HANDLED; |
| 144 | } |
| 145 | |
| 146 | static struct iio_interrupt *iio_allocate_interrupt(void) |
| 147 | { |
| 148 | struct iio_interrupt *i = kmalloc(sizeof *i, GFP_KERNEL); |
| 149 | if (i) { |
| 150 | spin_lock_init(&i->ev_list_lock); |
| 151 | INIT_LIST_HEAD(&i->ev_list); |
| 152 | } |
| 153 | return i; |
| 154 | } |
| 155 | |
| 156 | /* Confirming the validity of supplied irq is left to drivers.*/ |
| 157 | int iio_register_interrupt_line(unsigned int irq, |
| 158 | struct iio_dev *dev_info, |
| 159 | int line_number, |
| 160 | unsigned long type, |
| 161 | const char *name) |
| 162 | { |
| 163 | int ret; |
| 164 | |
| 165 | dev_info->interrupts[line_number] = iio_allocate_interrupt(); |
| 166 | if (dev_info->interrupts[line_number] == NULL) { |
| 167 | ret = -ENOMEM; |
| 168 | goto error_ret; |
| 169 | } |
| 170 | dev_info->interrupts[line_number]->line_number = line_number; |
| 171 | dev_info->interrupts[line_number]->irq = irq; |
| 172 | dev_info->interrupts[line_number]->dev_info = dev_info; |
| 173 | |
| 174 | /* Possibly only request on demand? |
| 175 | * Can see this may complicate the handling of interrupts. |
| 176 | * However, with this approach we might end up handling lots of |
| 177 | * events no-one cares about.*/ |
| 178 | ret = request_irq(irq, |
| 179 | &iio_interrupt_handler, |
| 180 | type, |
| 181 | name, |
| 182 | dev_info->interrupts[line_number]); |
| 183 | |
| 184 | error_ret: |
| 185 | return ret; |
| 186 | } |
| 187 | EXPORT_SYMBOL(iio_register_interrupt_line); |
| 188 | |
| 189 | /* This turns up an awful lot */ |
| 190 | ssize_t iio_read_const_attr(struct device *dev, |
| 191 | struct device_attribute *attr, |
| 192 | char *buf) |
| 193 | { |
| 194 | return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string); |
| 195 | } |
| 196 | EXPORT_SYMBOL(iio_read_const_attr); |
| 197 | |
| 198 | /* Before this runs the interrupt generator must have been disabled */ |
| 199 | void iio_unregister_interrupt_line(struct iio_dev *dev_info, int line_number) |
| 200 | { |
| 201 | /* make sure the interrupt handlers are all done */ |
| 202 | flush_scheduled_work(); |
| 203 | free_irq(dev_info->interrupts[line_number]->irq, |
| 204 | dev_info->interrupts[line_number]); |
| 205 | kfree(dev_info->interrupts[line_number]); |
| 206 | } |
| 207 | EXPORT_SYMBOL(iio_unregister_interrupt_line); |
| 208 | |
| 209 | /* Reference counted add and remove */ |
| 210 | void iio_add_event_to_list(struct iio_event_handler_list *el, |
| 211 | struct list_head *head) |
| 212 | { |
| 213 | unsigned long flags; |
| 214 | struct iio_interrupt *inter = to_iio_interrupt(head); |
| 215 | |
| 216 | /* take mutex to protect this element */ |
| 217 | mutex_lock(&el->exist_lock); |
| 218 | if (el->refcount == 0) { |
| 219 | /* Take the event list spin lock */ |
| 220 | spin_lock_irqsave(&inter->ev_list_lock, flags); |
| 221 | list_add(&el->list, head); |
| 222 | spin_unlock_irqrestore(&inter->ev_list_lock, flags); |
| 223 | } |
| 224 | el->refcount++; |
| 225 | mutex_unlock(&el->exist_lock); |
| 226 | } |
| 227 | EXPORT_SYMBOL(iio_add_event_to_list); |
| 228 | |
| 229 | void iio_remove_event_from_list(struct iio_event_handler_list *el, |
| 230 | struct list_head *head) |
| 231 | { |
| 232 | unsigned long flags; |
| 233 | struct iio_interrupt *inter = to_iio_interrupt(head); |
| 234 | |
| 235 | mutex_lock(&el->exist_lock); |
| 236 | el->refcount--; |
| 237 | if (el->refcount == 0) { |
| 238 | /* Take the event list spin lock */ |
| 239 | spin_lock_irqsave(&inter->ev_list_lock, flags); |
| 240 | list_del_init(&el->list); |
| 241 | spin_unlock_irqrestore(&inter->ev_list_lock, flags); |
| 242 | } |
| 243 | mutex_unlock(&el->exist_lock); |
| 244 | } |
| 245 | EXPORT_SYMBOL(iio_remove_event_from_list); |
| 246 | |
Mark Brown | 77712e5 | 2010-02-18 17:19:17 +0000 | [diff] [blame] | 247 | static ssize_t iio_event_chrdev_read(struct file *filep, |
| 248 | char __user *buf, |
| 249 | size_t count, |
| 250 | loff_t *f_ps) |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 251 | { |
| 252 | struct iio_event_interface *ev_int = filep->private_data; |
| 253 | struct iio_detected_event_list *el; |
| 254 | int ret; |
| 255 | size_t len; |
| 256 | |
| 257 | mutex_lock(&ev_int->event_list_lock); |
| 258 | if (list_empty(&ev_int->det_events.list)) { |
| 259 | if (filep->f_flags & O_NONBLOCK) { |
| 260 | ret = -EAGAIN; |
| 261 | goto error_mutex_unlock; |
| 262 | } |
| 263 | mutex_unlock(&ev_int->event_list_lock); |
| 264 | /* Blocking on device; waiting for something to be there */ |
| 265 | ret = wait_event_interruptible(ev_int->wait, |
| 266 | !list_empty(&ev_int |
| 267 | ->det_events.list)); |
| 268 | if (ret) |
| 269 | goto error_ret; |
| 270 | /* Single access device so noone else can get the data */ |
| 271 | mutex_lock(&ev_int->event_list_lock); |
| 272 | } |
| 273 | |
| 274 | el = list_first_entry(&ev_int->det_events.list, |
| 275 | struct iio_detected_event_list, |
| 276 | list); |
| 277 | len = sizeof el->ev; |
| 278 | if (copy_to_user(buf, &(el->ev), len)) { |
| 279 | ret = -EFAULT; |
| 280 | goto error_mutex_unlock; |
| 281 | } |
| 282 | list_del(&el->list); |
| 283 | ev_int->current_events--; |
| 284 | mutex_unlock(&ev_int->event_list_lock); |
| 285 | /* |
| 286 | * Possible concurency issue if an update of this event is on its way |
Jonathan Cameron | 75b1601 | 2010-01-09 17:01:33 +0000 | [diff] [blame] | 287 | * through. May lead to new event being removed whilst the reported |
| 288 | * event was the unescalated event. In typical use case this is not a |
| 289 | * problem as userspace will say read half the buffer due to a 50% |
| 290 | * full event which would make the correct 100% full incorrect anyway. |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 291 | */ |
Jonathan Cameron | 75b1601 | 2010-01-09 17:01:33 +0000 | [diff] [blame] | 292 | if (el->shared_pointer) { |
| 293 | spin_lock(&el->shared_pointer->lock); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 294 | (el->shared_pointer->ev_p) = NULL; |
Jonathan Cameron | 75b1601 | 2010-01-09 17:01:33 +0000 | [diff] [blame] | 295 | spin_unlock(&el->shared_pointer->lock); |
| 296 | } |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 297 | kfree(el); |
| 298 | |
| 299 | return len; |
| 300 | |
| 301 | error_mutex_unlock: |
| 302 | mutex_unlock(&ev_int->event_list_lock); |
| 303 | error_ret: |
| 304 | |
| 305 | return ret; |
| 306 | } |
| 307 | |
Mark Brown | 77712e5 | 2010-02-18 17:19:17 +0000 | [diff] [blame] | 308 | static int iio_event_chrdev_release(struct inode *inode, struct file *filep) |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 309 | { |
| 310 | struct iio_handler *hand = iio_cdev_to_handler(inode->i_cdev); |
| 311 | struct iio_event_interface *ev_int = hand->private; |
| 312 | struct iio_detected_event_list *el, *t; |
| 313 | |
| 314 | mutex_lock(&ev_int->event_list_lock); |
| 315 | clear_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags); |
| 316 | /* |
| 317 | * In order to maintain a clean state for reopening, |
| 318 | * clear out any awaiting events. The mask will prevent |
| 319 | * any new __iio_push_event calls running. |
| 320 | */ |
| 321 | list_for_each_entry_safe(el, t, &ev_int->det_events.list, list) { |
| 322 | list_del(&el->list); |
| 323 | kfree(el); |
| 324 | } |
| 325 | mutex_unlock(&ev_int->event_list_lock); |
| 326 | |
| 327 | return 0; |
| 328 | } |
| 329 | |
Mark Brown | 77712e5 | 2010-02-18 17:19:17 +0000 | [diff] [blame] | 330 | static int iio_event_chrdev_open(struct inode *inode, struct file *filep) |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 331 | { |
| 332 | struct iio_handler *hand = iio_cdev_to_handler(inode->i_cdev); |
| 333 | struct iio_event_interface *ev_int = hand->private; |
| 334 | |
| 335 | mutex_lock(&ev_int->event_list_lock); |
| 336 | if (test_and_set_bit(IIO_BUSY_BIT_POS, &hand->flags)) { |
| 337 | fops_put(filep->f_op); |
| 338 | mutex_unlock(&ev_int->event_list_lock); |
| 339 | return -EBUSY; |
| 340 | } |
| 341 | filep->private_data = hand->private; |
| 342 | mutex_unlock(&ev_int->event_list_lock); |
| 343 | |
| 344 | return 0; |
| 345 | } |
| 346 | |
| 347 | static const struct file_operations iio_event_chrdev_fileops = { |
| 348 | .read = iio_event_chrdev_read, |
| 349 | .release = iio_event_chrdev_release, |
| 350 | .open = iio_event_chrdev_open, |
| 351 | .owner = THIS_MODULE, |
| 352 | }; |
| 353 | |
| 354 | static void iio_event_dev_release(struct device *dev) |
| 355 | { |
| 356 | struct iio_event_interface *ev_int |
| 357 | = container_of(dev, struct iio_event_interface, dev); |
| 358 | cdev_del(&ev_int->handler.chrdev); |
| 359 | iio_device_free_chrdev_minor(MINOR(dev->devt)); |
| 360 | }; |
| 361 | |
| 362 | static struct device_type iio_event_type = { |
| 363 | .release = iio_event_dev_release, |
| 364 | }; |
| 365 | |
| 366 | int iio_device_get_chrdev_minor(void) |
| 367 | { |
| 368 | int ret, val; |
| 369 | |
| 370 | idr_again: |
| 371 | if (unlikely(idr_pre_get(&iio_chrdev_idr, GFP_KERNEL) == 0)) |
| 372 | return -ENOMEM; |
| 373 | spin_lock(&iio_idr_lock); |
| 374 | ret = idr_get_new(&iio_chrdev_idr, NULL, &val); |
| 375 | spin_unlock(&iio_idr_lock); |
| 376 | if (unlikely(ret == -EAGAIN)) |
| 377 | goto idr_again; |
| 378 | else if (unlikely(ret)) |
| 379 | return ret; |
| 380 | if (val > IIO_DEV_MAX) |
| 381 | return -ENOMEM; |
| 382 | return val; |
| 383 | } |
| 384 | |
| 385 | void iio_device_free_chrdev_minor(int val) |
| 386 | { |
| 387 | spin_lock(&iio_idr_lock); |
| 388 | idr_remove(&iio_chrdev_idr, val); |
| 389 | spin_unlock(&iio_idr_lock); |
| 390 | } |
| 391 | |
| 392 | int iio_setup_ev_int(struct iio_event_interface *ev_int, |
| 393 | const char *name, |
| 394 | struct module *owner, |
| 395 | struct device *dev) |
| 396 | { |
| 397 | int ret, minor; |
| 398 | |
Jonathan Cameron | 5aaaeba | 2010-05-04 14:43:00 +0100 | [diff] [blame] | 399 | ev_int->dev.bus = &iio_bus_type; |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 400 | ev_int->dev.parent = dev; |
| 401 | ev_int->dev.type = &iio_event_type; |
| 402 | device_initialize(&ev_int->dev); |
| 403 | |
| 404 | minor = iio_device_get_chrdev_minor(); |
| 405 | if (minor < 0) { |
| 406 | ret = minor; |
| 407 | goto error_device_put; |
| 408 | } |
| 409 | ev_int->dev.devt = MKDEV(MAJOR(iio_devt), minor); |
| 410 | dev_set_name(&ev_int->dev, "%s", name); |
| 411 | |
| 412 | ret = device_add(&ev_int->dev); |
| 413 | if (ret) |
| 414 | goto error_free_minor; |
| 415 | |
| 416 | cdev_init(&ev_int->handler.chrdev, &iio_event_chrdev_fileops); |
| 417 | ev_int->handler.chrdev.owner = owner; |
| 418 | |
| 419 | mutex_init(&ev_int->event_list_lock); |
| 420 | /* discussion point - make this variable? */ |
| 421 | ev_int->max_events = 10; |
| 422 | ev_int->current_events = 0; |
| 423 | INIT_LIST_HEAD(&ev_int->det_events.list); |
| 424 | init_waitqueue_head(&ev_int->wait); |
| 425 | ev_int->handler.private = ev_int; |
| 426 | ev_int->handler.flags = 0; |
| 427 | |
| 428 | ret = cdev_add(&ev_int->handler.chrdev, ev_int->dev.devt, 1); |
| 429 | if (ret) |
| 430 | goto error_unreg_device; |
| 431 | |
| 432 | return 0; |
| 433 | |
| 434 | error_unreg_device: |
| 435 | device_unregister(&ev_int->dev); |
| 436 | error_free_minor: |
| 437 | iio_device_free_chrdev_minor(minor); |
| 438 | error_device_put: |
| 439 | put_device(&ev_int->dev); |
| 440 | |
| 441 | return ret; |
| 442 | } |
| 443 | |
| 444 | void iio_free_ev_int(struct iio_event_interface *ev_int) |
| 445 | { |
| 446 | device_unregister(&ev_int->dev); |
| 447 | put_device(&ev_int->dev); |
| 448 | } |
| 449 | |
| 450 | static int __init iio_dev_init(void) |
| 451 | { |
| 452 | int err; |
| 453 | |
| 454 | err = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio"); |
| 455 | if (err < 0) |
| 456 | printk(KERN_ERR "%s: failed to allocate char dev region\n", |
| 457 | __FILE__); |
| 458 | |
| 459 | return err; |
| 460 | } |
| 461 | |
| 462 | static void __exit iio_dev_exit(void) |
| 463 | { |
| 464 | if (iio_devt) |
| 465 | unregister_chrdev_region(iio_devt, IIO_DEV_MAX); |
| 466 | } |
| 467 | |
| 468 | static int __init iio_init(void) |
| 469 | { |
| 470 | int ret; |
| 471 | |
Jonathan Cameron | 5aaaeba | 2010-05-04 14:43:00 +0100 | [diff] [blame] | 472 | /* Register sysfs bus */ |
| 473 | ret = bus_register(&iio_bus_type); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 474 | if (ret < 0) { |
| 475 | printk(KERN_ERR |
Jonathan Cameron | 5aaaeba | 2010-05-04 14:43:00 +0100 | [diff] [blame] | 476 | "%s could not register bus type\n", |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 477 | __FILE__); |
| 478 | goto error_nothing; |
| 479 | } |
| 480 | |
| 481 | ret = iio_dev_init(); |
| 482 | if (ret < 0) |
Jonathan Cameron | 5aaaeba | 2010-05-04 14:43:00 +0100 | [diff] [blame] | 483 | goto error_unregister_bus_type; |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 484 | |
| 485 | return 0; |
| 486 | |
Jonathan Cameron | 5aaaeba | 2010-05-04 14:43:00 +0100 | [diff] [blame] | 487 | error_unregister_bus_type: |
| 488 | bus_unregister(&iio_bus_type); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 489 | error_nothing: |
| 490 | return ret; |
| 491 | } |
| 492 | |
| 493 | static void __exit iio_exit(void) |
| 494 | { |
| 495 | iio_dev_exit(); |
Jonathan Cameron | 5aaaeba | 2010-05-04 14:43:00 +0100 | [diff] [blame] | 496 | bus_unregister(&iio_bus_type); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 497 | } |
| 498 | |
| 499 | static int iio_device_register_sysfs(struct iio_dev *dev_info) |
| 500 | { |
| 501 | int ret = 0; |
| 502 | |
| 503 | ret = sysfs_create_group(&dev_info->dev.kobj, dev_info->attrs); |
| 504 | if (ret) { |
| 505 | dev_err(dev_info->dev.parent, |
| 506 | "Failed to register sysfs hooks\n"); |
| 507 | goto error_ret; |
| 508 | } |
| 509 | |
| 510 | if (dev_info->scan_el_attrs) { |
| 511 | ret = sysfs_create_group(&dev_info->dev.kobj, |
| 512 | dev_info->scan_el_attrs); |
| 513 | if (ret) |
| 514 | dev_err(&dev_info->dev, |
| 515 | "Failed to add sysfs scan els\n"); |
| 516 | } |
| 517 | |
| 518 | error_ret: |
| 519 | return ret; |
| 520 | } |
| 521 | |
| 522 | static void iio_device_unregister_sysfs(struct iio_dev *dev_info) |
| 523 | { |
| 524 | if (dev_info->scan_el_attrs) |
| 525 | sysfs_remove_group(&dev_info->dev.kobj, |
| 526 | dev_info->scan_el_attrs); |
| 527 | |
| 528 | sysfs_remove_group(&dev_info->dev.kobj, dev_info->attrs); |
| 529 | } |
| 530 | |
Andrew Morton | f3cdc28 | 2010-04-27 11:29:54 -0700 | [diff] [blame] | 531 | /* Return a negative errno on failure */ |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 532 | int iio_get_new_idr_val(struct idr *this_idr) |
| 533 | { |
| 534 | int ret; |
| 535 | int val; |
| 536 | |
| 537 | idr_again: |
| 538 | if (unlikely(idr_pre_get(this_idr, GFP_KERNEL) == 0)) |
| 539 | return -ENOMEM; |
| 540 | |
| 541 | spin_lock(&iio_idr_lock); |
| 542 | ret = idr_get_new(this_idr, NULL, &val); |
| 543 | spin_unlock(&iio_idr_lock); |
| 544 | if (unlikely(ret == -EAGAIN)) |
| 545 | goto idr_again; |
| 546 | else if (unlikely(ret)) |
| 547 | return ret; |
| 548 | |
| 549 | return val; |
| 550 | } |
| 551 | EXPORT_SYMBOL(iio_get_new_idr_val); |
| 552 | |
| 553 | void iio_free_idr_val(struct idr *this_idr, int id) |
| 554 | { |
| 555 | spin_lock(&iio_idr_lock); |
| 556 | idr_remove(this_idr, id); |
| 557 | spin_unlock(&iio_idr_lock); |
| 558 | } |
| 559 | EXPORT_SYMBOL(iio_free_idr_val); |
| 560 | |
| 561 | static int iio_device_register_id(struct iio_dev *dev_info, |
| 562 | struct idr *this_idr) |
| 563 | { |
| 564 | |
| 565 | dev_info->id = iio_get_new_idr_val(&iio_idr); |
| 566 | if (dev_info->id < 0) |
| 567 | return dev_info->id; |
| 568 | return 0; |
| 569 | } |
| 570 | |
| 571 | static void iio_device_unregister_id(struct iio_dev *dev_info) |
| 572 | { |
| 573 | iio_free_idr_val(&iio_idr, dev_info->id); |
| 574 | } |
| 575 | |
| 576 | static inline int __iio_add_event_config_attrs(struct iio_dev *dev_info, int i) |
| 577 | { |
| 578 | int ret; |
| 579 | /*p for adding, q for removing */ |
| 580 | struct attribute **attrp, **attrq; |
| 581 | |
| 582 | if (dev_info->event_conf_attrs && dev_info->event_conf_attrs[i].attrs) { |
| 583 | attrp = dev_info->event_conf_attrs[i].attrs; |
| 584 | while (*attrp) { |
| 585 | ret = sysfs_add_file_to_group(&dev_info->dev.kobj, |
| 586 | *attrp, |
| 587 | dev_info |
| 588 | ->event_attrs[i].name); |
| 589 | if (ret) |
| 590 | goto error_ret; |
| 591 | attrp++; |
| 592 | } |
| 593 | } |
| 594 | return 0; |
| 595 | |
| 596 | error_ret: |
| 597 | attrq = dev_info->event_conf_attrs[i].attrs; |
| 598 | while (attrq != attrp) { |
| 599 | sysfs_remove_file_from_group(&dev_info->dev.kobj, |
| 600 | *attrq, |
| 601 | dev_info->event_attrs[i].name); |
| 602 | attrq++; |
| 603 | } |
| 604 | |
| 605 | return ret; |
| 606 | } |
| 607 | |
| 608 | static inline int __iio_remove_event_config_attrs(struct iio_dev *dev_info, |
| 609 | int i) |
| 610 | { |
| 611 | struct attribute **attrq; |
| 612 | |
| 613 | if (dev_info->event_conf_attrs |
| 614 | && dev_info->event_conf_attrs[i].attrs) { |
| 615 | attrq = dev_info->event_conf_attrs[i].attrs; |
| 616 | while (*attrq) { |
| 617 | sysfs_remove_file_from_group(&dev_info->dev.kobj, |
| 618 | *attrq, |
| 619 | dev_info |
| 620 | ->event_attrs[i].name); |
| 621 | attrq++; |
| 622 | } |
| 623 | } |
| 624 | |
| 625 | return 0; |
| 626 | } |
| 627 | |
| 628 | static int iio_device_register_eventset(struct iio_dev *dev_info) |
| 629 | { |
| 630 | int ret = 0, i, j; |
| 631 | |
| 632 | if (dev_info->num_interrupt_lines == 0) |
| 633 | return 0; |
| 634 | |
| 635 | dev_info->event_interfaces = |
| 636 | kzalloc(sizeof(struct iio_event_interface) |
| 637 | *dev_info->num_interrupt_lines, |
| 638 | GFP_KERNEL); |
| 639 | if (dev_info->event_interfaces == NULL) { |
| 640 | ret = -ENOMEM; |
| 641 | goto error_ret; |
| 642 | } |
| 643 | |
| 644 | dev_info->interrupts = kzalloc(sizeof(struct iio_interrupt *) |
| 645 | *dev_info->num_interrupt_lines, |
| 646 | GFP_KERNEL); |
| 647 | if (dev_info->interrupts == NULL) { |
| 648 | ret = -ENOMEM; |
| 649 | goto error_free_event_interfaces; |
| 650 | } |
| 651 | |
| 652 | for (i = 0; i < dev_info->num_interrupt_lines; i++) { |
| 653 | dev_info->event_interfaces[i].owner = dev_info->driver_module; |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 654 | |
| 655 | snprintf(dev_info->event_interfaces[i]._name, 20, |
Jonathan Cameron | ba5c6fb | 2010-05-04 14:43:06 +0100 | [diff] [blame] | 656 | "%s:event%d", |
| 657 | dev_name(&dev_info->dev), |
Jonathan Cameron | 3d550fb | 2010-06-26 12:54:18 +0100 | [diff] [blame^] | 658 | i); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 659 | |
| 660 | ret = iio_setup_ev_int(&dev_info->event_interfaces[i], |
| 661 | (const char *)(dev_info |
| 662 | ->event_interfaces[i] |
| 663 | ._name), |
| 664 | dev_info->driver_module, |
| 665 | &dev_info->dev); |
| 666 | if (ret) { |
| 667 | dev_err(&dev_info->dev, |
| 668 | "Could not get chrdev interface\n"); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 669 | goto error_free_setup_ev_ints; |
| 670 | } |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 671 | |
Jonathan Cameron | 5cba220 | 2010-05-04 14:43:01 +0100 | [diff] [blame] | 672 | dev_set_drvdata(&dev_info->event_interfaces[i].dev, |
| 673 | (void *)dev_info); |
| 674 | ret = sysfs_create_group(&dev_info |
| 675 | ->event_interfaces[i] |
| 676 | .dev.kobj, |
| 677 | &dev_info->event_attrs[i]); |
| 678 | |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 679 | if (ret) { |
| 680 | dev_err(&dev_info->dev, |
| 681 | "Failed to register sysfs for event attrs"); |
| 682 | goto error_remove_sysfs_interfaces; |
| 683 | } |
| 684 | } |
| 685 | |
| 686 | for (i = 0; i < dev_info->num_interrupt_lines; i++) { |
| 687 | ret = __iio_add_event_config_attrs(dev_info, i); |
| 688 | if (ret) |
| 689 | goto error_unregister_config_attrs; |
| 690 | } |
| 691 | |
| 692 | return 0; |
| 693 | |
| 694 | error_unregister_config_attrs: |
| 695 | for (j = 0; j < i; j++) |
| 696 | __iio_remove_event_config_attrs(dev_info, i); |
| 697 | i = dev_info->num_interrupt_lines - 1; |
| 698 | error_remove_sysfs_interfaces: |
| 699 | for (j = 0; j < i; j++) |
Jonathan Cameron | 5cba220 | 2010-05-04 14:43:01 +0100 | [diff] [blame] | 700 | sysfs_remove_group(&dev_info |
| 701 | ->event_interfaces[j].dev.kobj, |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 702 | &dev_info->event_attrs[j]); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 703 | error_free_setup_ev_ints: |
Jonathan Cameron | 3d550fb | 2010-06-26 12:54:18 +0100 | [diff] [blame^] | 704 | for (j = 0; j < i; j++) |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 705 | iio_free_ev_int(&dev_info->event_interfaces[j]); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 706 | kfree(dev_info->interrupts); |
| 707 | error_free_event_interfaces: |
| 708 | kfree(dev_info->event_interfaces); |
| 709 | error_ret: |
| 710 | |
| 711 | return ret; |
| 712 | } |
| 713 | |
| 714 | static void iio_device_unregister_eventset(struct iio_dev *dev_info) |
| 715 | { |
| 716 | int i; |
| 717 | |
| 718 | if (dev_info->num_interrupt_lines == 0) |
| 719 | return; |
| 720 | for (i = 0; i < dev_info->num_interrupt_lines; i++) |
Jonathan Cameron | 5cba220 | 2010-05-04 14:43:01 +0100 | [diff] [blame] | 721 | sysfs_remove_group(&dev_info |
| 722 | ->event_interfaces[i].dev.kobj, |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 723 | &dev_info->event_attrs[i]); |
| 724 | |
Jonathan Cameron | 3d550fb | 2010-06-26 12:54:18 +0100 | [diff] [blame^] | 725 | for (i = 0; i < dev_info->num_interrupt_lines; i++) |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 726 | iio_free_ev_int(&dev_info->event_interfaces[i]); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 727 | kfree(dev_info->interrupts); |
| 728 | kfree(dev_info->event_interfaces); |
| 729 | } |
| 730 | |
| 731 | static void iio_dev_release(struct device *device) |
| 732 | { |
| 733 | struct iio_dev *dev = to_iio_dev(device); |
| 734 | |
| 735 | iio_put(); |
| 736 | kfree(dev); |
| 737 | } |
| 738 | |
| 739 | static struct device_type iio_dev_type = { |
| 740 | .name = "iio_device", |
| 741 | .release = iio_dev_release, |
| 742 | }; |
| 743 | |
| 744 | struct iio_dev *iio_allocate_device(void) |
| 745 | { |
| 746 | struct iio_dev *dev = kzalloc(sizeof *dev, GFP_KERNEL); |
| 747 | |
| 748 | if (dev) { |
| 749 | dev->dev.type = &iio_dev_type; |
Jonathan Cameron | 5aaaeba | 2010-05-04 14:43:00 +0100 | [diff] [blame] | 750 | dev->dev.bus = &iio_bus_type; |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 751 | device_initialize(&dev->dev); |
| 752 | dev_set_drvdata(&dev->dev, (void *)dev); |
| 753 | mutex_init(&dev->mlock); |
| 754 | iio_get(); |
| 755 | } |
| 756 | |
| 757 | return dev; |
| 758 | } |
| 759 | EXPORT_SYMBOL(iio_allocate_device); |
| 760 | |
| 761 | void iio_free_device(struct iio_dev *dev) |
| 762 | { |
| 763 | if (dev) |
| 764 | iio_put_device(dev); |
| 765 | } |
| 766 | EXPORT_SYMBOL(iio_free_device); |
| 767 | |
| 768 | int iio_device_register(struct iio_dev *dev_info) |
| 769 | { |
| 770 | int ret; |
| 771 | |
| 772 | ret = iio_device_register_id(dev_info, &iio_idr); |
| 773 | if (ret) { |
| 774 | dev_err(&dev_info->dev, "Failed to get id\n"); |
| 775 | goto error_ret; |
| 776 | } |
| 777 | dev_set_name(&dev_info->dev, "device%d", dev_info->id); |
| 778 | |
| 779 | ret = device_add(&dev_info->dev); |
| 780 | if (ret) |
| 781 | goto error_free_idr; |
| 782 | ret = iio_device_register_sysfs(dev_info); |
| 783 | if (ret) { |
| 784 | dev_err(dev_info->dev.parent, |
| 785 | "Failed to register sysfs interfaces\n"); |
| 786 | goto error_del_device; |
| 787 | } |
| 788 | ret = iio_device_register_eventset(dev_info); |
| 789 | if (ret) { |
| 790 | dev_err(dev_info->dev.parent, |
Roel Van Nyen | c849d25 | 2010-04-29 19:27:31 +0200 | [diff] [blame] | 791 | "Failed to register event set\n"); |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 792 | goto error_free_sysfs; |
| 793 | } |
| 794 | if (dev_info->modes & INDIO_RING_TRIGGERED) |
| 795 | iio_device_register_trigger_consumer(dev_info); |
| 796 | |
| 797 | return 0; |
| 798 | |
| 799 | error_free_sysfs: |
| 800 | iio_device_unregister_sysfs(dev_info); |
| 801 | error_del_device: |
| 802 | device_del(&dev_info->dev); |
| 803 | error_free_idr: |
| 804 | iio_device_unregister_id(dev_info); |
| 805 | error_ret: |
| 806 | return ret; |
| 807 | } |
| 808 | EXPORT_SYMBOL(iio_device_register); |
| 809 | |
| 810 | void iio_device_unregister(struct iio_dev *dev_info) |
| 811 | { |
| 812 | if (dev_info->modes & INDIO_RING_TRIGGERED) |
| 813 | iio_device_unregister_trigger_consumer(dev_info); |
| 814 | iio_device_unregister_eventset(dev_info); |
| 815 | iio_device_unregister_sysfs(dev_info); |
| 816 | iio_device_unregister_id(dev_info); |
| 817 | device_unregister(&dev_info->dev); |
| 818 | } |
| 819 | EXPORT_SYMBOL(iio_device_unregister); |
| 820 | |
| 821 | void iio_put(void) |
| 822 | { |
| 823 | module_put(THIS_MODULE); |
| 824 | } |
| 825 | |
| 826 | void iio_get(void) |
| 827 | { |
| 828 | __module_get(THIS_MODULE); |
| 829 | } |
| 830 | |
| 831 | subsys_initcall(iio_init); |
| 832 | module_exit(iio_exit); |
| 833 | |
| 834 | MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>"); |
| 835 | MODULE_DESCRIPTION("Industrial I/O core"); |
| 836 | MODULE_LICENSE("GPL"); |