drivers/uwb/lc-rc.c

   1 /*
   2  * Ultra Wide Band
   3  * Life cycle of radio controllers
   4  *
   5  * Copyright (C) 2005-2006 Intel Corporation
   6  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License version
  10  * 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20  * 02110-1301, USA.
  21  *
  22  *
  23  * FIXME: docs
  24  *
  25  * A UWB radio controller is also a UWB device, so it embeds one...
  26  *
  27  * List of RCs comes from the 'struct class uwb_rc_class'.
  28  */
  29
  30 #include <linux/kernel.h>
  31 #include <linux/string.h>
  32 #include <linux/device.h>
  33 #include <linux/err.h>
  34 #include <linux/random.h>
  35 #include <linux/kdev_t.h>
  36 #include <linux/etherdevice.h>
  37 #include <linux/usb.h>
  38
  39 #include "uwb-internal.h"
  40
  41 static int uwb_rc_index_match(struct device *dev, void *data)
  42 {
  43         int *index = data;
  44         struct uwb_rc *rc = dev_get_drvdata(dev);
  45
  46         if (rc->index == *index)
  47                 return 1;
  48         return 0;
  49 }
  50
  51 static struct uwb_rc *uwb_rc_find_by_index(int index)
  52 {
  53         struct device *dev;
  54         struct uwb_rc *rc = NULL;
  55
  56         dev = class_find_device(&uwb_rc_class, NULL, &index, uwb_rc_index_match);
  57         if (dev)
  58                 rc = dev_get_drvdata(dev);
  59         return rc;
  60 }
  61
  62 static int uwb_rc_new_index(void)
  63 {
  64         int index = 0;
  65
  66         for (;;) {
  67                 if (!uwb_rc_find_by_index(index))
  68                         return index;
  69                 if (++index < 0)
  70                         index = 0;
  71         }
  72 }
  73
  74 /**
  75  * Release the backing device of a uwb_rc that has been dynamically allocated.
  76  */
  77 static void uwb_rc_sys_release(struct device *dev)
  78 {
  79         struct uwb_dev *uwb_dev = container_of(dev, struct uwb_dev, dev);
  80         struct uwb_rc *rc = container_of(uwb_dev, struct uwb_rc, uwb_dev);
  81
  82         uwb_rc_ie_release(rc);
  83         kfree(rc);
  84 }
  85
  86
  87 void uwb_rc_init(struct uwb_rc *rc)
  88 {
  89         struct uwb_dev *uwb_dev = &rc->uwb_dev;
  90
  91         uwb_dev_init(uwb_dev);
  92         rc->uwb_dev.dev.class = &uwb_rc_class;
  93         rc->uwb_dev.dev.release = uwb_rc_sys_release;
  94         uwb_rc_neh_create(rc);
  95         rc->beaconing = -1;
  96         rc->scan_type = UWB_SCAN_DISABLED;
  97         INIT_LIST_HEAD(&rc->notifs_chain.list);
  98         mutex_init(&rc->notifs_chain.mutex);
  99         INIT_LIST_HEAD(&rc->uwb_beca.list);
 100         mutex_init(&rc->uwb_beca.mutex);
 101         uwb_drp_avail_init(rc);
 102         uwb_rc_ie_init(rc);
 103         uwb_rsv_init(rc);
 104         uwb_rc_pal_init(rc);
 105 }
 106 EXPORT_SYMBOL_GPL(uwb_rc_init);
 107
 108
 109 struct uwb_rc *uwb_rc_alloc(void)
 110 {
 111         struct uwb_rc *rc;
 112         rc = kzalloc(sizeof(*rc), GFP_KERNEL);
 113         if (rc == NULL)
 114                 return NULL;
 115         uwb_rc_init(rc);
 116         return rc;
 117 }
 118 EXPORT_SYMBOL_GPL(uwb_rc_alloc);
 119
 120 static struct attribute *rc_attrs[] = {
 121                 &dev_attr_mac_address.attr,
 122                 &dev_attr_scan.attr,
 123                 &dev_attr_beacon.attr,
 124                 NULL,
 125 };
 126
 127 static struct attribute_group rc_attr_group = {
 128         .attrs = rc_attrs,
 129 };
 130
 131 /*
 132  * Registration of sysfs specific stuff
 133  */
 134 static int uwb_rc_sys_add(struct uwb_rc *rc)
 135 {
 136         return sysfs_create_group(&rc->uwb_dev.dev.kobj, &rc_attr_group);
 137 }
 138
 139
 140 static void __uwb_rc_sys_rm(struct uwb_rc *rc)
 141 {
 142         sysfs_remove_group(&rc->uwb_dev.dev.kobj, &rc_attr_group);
 143 }
 144
 145 /**
 146  * uwb_rc_mac_addr_setup - get an RC's EUI-48 address or set it
 147  * @rc:  the radio controller.
 148  *
 149  * If the EUI-48 address is 00:00:00:00:00:00 or FF:FF:FF:FF:FF:FF
 150  * then a random locally administered EUI-48 is generated and set on
 151  * the device.  The probability of address collisions is sufficiently
 152  * unlikely (1/2^40 = 9.1e-13) that they're not checked for.
 153  */
 154 static
 155 int uwb_rc_mac_addr_setup(struct uwb_rc *rc)
 156 {
 157         int result;
 158         struct device *dev = &rc->uwb_dev.dev;
 159         struct uwb_dev *uwb_dev = &rc->uwb_dev;
 160         char devname[UWB_ADDR_STRSIZE];
 161         struct uwb_mac_addr addr;
 162
 163         result = uwb_rc_mac_addr_get(rc, &addr);
 164         if (result < 0) {
 165                 dev_err(dev, "cannot retrieve UWB EUI-48 address: %d\n", result);
 166                 return result;
 167         }
 168
 169         if (uwb_mac_addr_unset(&addr) || uwb_mac_addr_bcast(&addr)) {
 170                 addr.data[0] = 0x02; /* locally adminstered and unicast */
 171                 get_random_bytes(&addr.data[1], sizeof(addr.data)-1);
 172
 173                 result = uwb_rc_mac_addr_set(rc, &addr);
 174                 if (result < 0) {
 175                         uwb_mac_addr_print(devname, sizeof(devname), &addr);
 176                         dev_err(dev, "cannot set EUI-48 address %s: %d\n",
 177                                 devname, result);
 178                         return result;
 179                 }
 180         }
 181         uwb_dev->mac_addr = addr;
 182         return 0;
 183 }
 184
 185
 186
 187 static int uwb_rc_setup(struct uwb_rc *rc)
 188 {
 189         int result;
 190         struct device *dev = &rc->uwb_dev.dev;
 191
 192         result = uwb_radio_setup(rc);
 193         if (result < 0) {
 194                 dev_err(dev, "cannot setup UWB radio: %d\n", result);
 195                 goto error;
 196         }
 197         result = uwb_rc_mac_addr_setup(rc);
 198         if (result < 0) {
 199                 dev_err(dev, "cannot setup UWB MAC address: %d\n", result);
 200                 goto error;
 201         }
 202         result = uwb_rc_dev_addr_assign(rc);
 203         if (result < 0) {
 204                 dev_err(dev, "cannot assign UWB DevAddr: %d\n", result);
 205                 goto error;
 206         }
 207         result = uwb_rc_ie_setup(rc);
 208         if (result < 0) {
 209                 dev_err(dev, "cannot setup IE subsystem: %d\n", result);
 210                 goto error_ie_setup;
 211         }
 212         result = uwb_rsv_setup(rc);
 213         if (result < 0) {
 214                 dev_err(dev, "cannot setup reservation subsystem: %d\n", result);
 215                 goto error_rsv_setup;
 216         }
 217         uwb_dbg_add_rc(rc);
 218         return 0;
 219
 220 error_rsv_setup:
 221         uwb_rc_ie_release(rc);
 222 error_ie_setup:
 223 error:
 224         return result;
 225 }
 226
 227
 228 /**
 229  * Register a new UWB radio controller
 230  *
 231  * Did you call uwb_rc_init() on your rc?
 232  *
 233  * We assume that this is being called with a > 0 refcount on
 234  * it [through ops->{get|put}_device(). We'll take our own, though.
 235  *
 236  * @parent_dev is our real device, the one that provides the actual UWB device
 237  */
 238 int uwb_rc_add(struct uwb_rc *rc, struct device *parent_dev, void *priv)
 239 {
 240         int result;
 241         struct device *dev;
 242         char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
 243
 244         rc->index = uwb_rc_new_index();
 245
 246         dev = &rc->uwb_dev.dev;
 247         dev_set_name(dev, "uwb%d", rc->index);
 248
 249         rc->priv = priv;
 250
 251         init_waitqueue_head(&rc->uwbd.wq);
 252         INIT_LIST_HEAD(&rc->uwbd.event_list);
 253         spin_lock_init(&rc->uwbd.event_list_lock);
 254
 255         uwbd_start(rc);
 256
 257         result = rc->start(rc);
 258         if (result < 0)
 259                 goto error_rc_start;
 260
 261         result = uwb_rc_setup(rc);
 262         if (result < 0) {
 263                 dev_err(dev, "cannot setup UWB radio controller: %d\n", result);
 264                 goto error_rc_setup;
 265         }
 266
 267         result = uwb_dev_add(&rc->uwb_dev, parent_dev, rc);
 268         if (result < 0 && result != -EADDRNOTAVAIL)
 269                 goto error_dev_add;
 270
 271         result = uwb_rc_sys_add(rc);
 272         if (result < 0) {
 273                 dev_err(parent_dev, "cannot register UWB radio controller "
 274                         "dev attributes: %d\n", result);
 275                 goto error_sys_add;
 276         }
 277
 278         uwb_mac_addr_print(macbuf, sizeof(macbuf), &rc->uwb_dev.mac_addr);
 279         uwb_dev_addr_print(devbuf, sizeof(devbuf), &rc->uwb_dev.dev_addr);
 280         dev_info(dev,
 281                  "new uwb radio controller (mac %s dev %s) on %s %s\n",
 282                  macbuf, devbuf, parent_dev->bus->name, dev_name(parent_dev));
 283         rc->ready = 1;
 284         return 0;
 285
 286 error_sys_add:
 287         uwb_dev_rm(&rc->uwb_dev);
 288 error_dev_add:
 289 error_rc_setup:
 290         rc->stop(rc);
 291         uwbd_stop(rc);
 292 error_rc_start:
 293         return result;
 294 }
 295 EXPORT_SYMBOL_GPL(uwb_rc_add);
 296
 297
 298 static int uwb_dev_offair_helper(struct device *dev, void *priv)
 299 {
 300         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 301
 302         return __uwb_dev_offair(uwb_dev, uwb_dev->rc);
 303 }
 304
 305 /*
 306  * Remove a Radio Controller; stop beaconing/scanning, disconnect all children
 307  */
 308 void uwb_rc_rm(struct uwb_rc *rc)
 309 {
 310         rc->ready = 0;
 311
 312         uwb_dbg_del_rc(rc);
 313         uwb_rsv_remove_all(rc);
 314         uwb_radio_shutdown(rc);
 315
 316         rc->stop(rc);
 317
 318         uwbd_stop(rc);
 319         uwb_rc_neh_destroy(rc);
 320
 321         uwb_dev_lock(&rc->uwb_dev);
 322         rc->priv = NULL;
 323         rc->cmd = NULL;
 324         uwb_dev_unlock(&rc->uwb_dev);
 325         mutex_lock(&rc->uwb_beca.mutex);
 326         uwb_dev_for_each(rc, uwb_dev_offair_helper, NULL);
 327         __uwb_rc_sys_rm(rc);
 328         mutex_unlock(&rc->uwb_beca.mutex);
 329         uwb_rsv_cleanup(rc);
 330         uwb_beca_release(rc);
 331         uwb_dev_rm(&rc->uwb_dev);
 332 }
 333 EXPORT_SYMBOL_GPL(uwb_rc_rm);
 334
 335 static int find_rc_try_get(struct device *dev, void *data)
 336 {
 337         struct uwb_rc *target_rc = data;
 338         struct uwb_rc *rc = dev_get_drvdata(dev);
 339
 340         if (rc == NULL) {
 341                 WARN_ON(1);
 342                 return 0;
 343         }
 344         if (rc == target_rc) {
 345                 if (rc->ready == 0)
 346                         return 0;
 347                 else
 348                         return 1;
 349         }
 350         return 0;
 351 }
 352
 353 /**
 354  * Given a radio controller descriptor, validate and refcount it
 355  *
 356  * @returns NULL if the rc does not exist or is quiescing; the ptr to
 357  *               it otherwise.
 358  */
 359 struct uwb_rc *__uwb_rc_try_get(struct uwb_rc *target_rc)
 360 {
 361         struct device *dev;
 362         struct uwb_rc *rc = NULL;
 363
 364         dev = class_find_device(&uwb_rc_class, NULL, target_rc,
 365                                 find_rc_try_get);
 366         if (dev) {
 367                 rc = dev_get_drvdata(dev);
 368                 __uwb_rc_get(rc);
 369         }
 370         return rc;
 371 }
 372 EXPORT_SYMBOL_GPL(__uwb_rc_try_get);
 373
 374 /*
 375  * RC get for external refcount acquirers...
 376  *
 377  * Increments the refcount of the device and it's backend modules
 378  */
 379 static inline struct uwb_rc *uwb_rc_get(struct uwb_rc *rc)
 380 {
 381         if (rc->ready == 0)
 382                 return NULL;
 383         uwb_dev_get(&rc->uwb_dev);
 384         return rc;
 385 }
 386
 387 static int find_rc_grandpa(struct device *dev, void *data)
 388 {
 389         struct device *grandpa_dev = data;
 390         struct uwb_rc *rc = dev_get_drvdata(dev);
 391
 392         if (rc->uwb_dev.dev.parent->parent == grandpa_dev) {
 393                 rc = uwb_rc_get(rc);
 394                 return 1;
 395         }
 396         return 0;
 397 }
 398
 399 /**
 400  * Locate and refcount a radio controller given a common grand-parent
 401  *
 402  * @grandpa_dev  Pointer to the 'grandparent' device structure.
 403  * @returns NULL If the rc does not exist or is quiescing; the ptr to
 404  *               it otherwise, properly referenced.
 405  *
 406  * The Radio Control interface (or the UWB Radio Controller) is always
 407  * an interface of a device. The parent is the interface, the
 408  * grandparent is the device that encapsulates the interface.
 409  *
 410  * There is no need to lock around as the "grandpa" would be
 411  * refcounted by the target, and to remove the referemes, the
 412  * uwb_rc_class->sem would have to be taken--we hold it, ergo we
 413  * should be safe.
 414  */
 415 struct uwb_rc *uwb_rc_get_by_grandpa(const struct device *grandpa_dev)
 416 {
 417         struct device *dev;
 418         struct uwb_rc *rc = NULL;
 419
 420         dev = class_find_device(&uwb_rc_class, NULL, (void *)grandpa_dev,
 421                                 find_rc_grandpa);
 422         if (dev)
 423                 rc = dev_get_drvdata(dev);
 424         return rc;
 425 }
 426 EXPORT_SYMBOL_GPL(uwb_rc_get_by_grandpa);
 427
 428 /**
 429  * Find a radio controller by device address
 430  *
 431  * @returns the pointer to the radio controller, properly referenced
 432  */
 433 static int find_rc_dev(struct device *dev, void *data)
 434 {
 435         struct uwb_dev_addr *addr = data;
 436         struct uwb_rc *rc = dev_get_drvdata(dev);
 437
 438         if (rc == NULL) {
 439                 WARN_ON(1);
 440                 return 0;
 441         }
 442         if (!uwb_dev_addr_cmp(&rc->uwb_dev.dev_addr, addr)) {
 443                 rc = uwb_rc_get(rc);
 444                 return 1;
 445         }
 446         return 0;
 447 }
 448
 449 struct uwb_rc *uwb_rc_get_by_dev(const struct uwb_dev_addr *addr)
 450 {
 451         struct device *dev;
 452         struct uwb_rc *rc = NULL;
 453
 454         dev = class_find_device(&uwb_rc_class, NULL, (void *)addr,
 455                                 find_rc_dev);
 456         if (dev)
 457                 rc = dev_get_drvdata(dev);
 458
 459         return rc;
 460 }
 461 EXPORT_SYMBOL_GPL(uwb_rc_get_by_dev);
 462
 463 /**
 464  * Drop a reference on a radio controller
 465  *
 466  * This is the version that should be done by entities external to the
 467  * UWB Radio Control stack (ie: clients of the API).
 468  */
 469 void uwb_rc_put(struct uwb_rc *rc)
 470 {
 471         __uwb_rc_put(rc);
 472 }
 473 EXPORT_SYMBOL_GPL(uwb_rc_put);