drivers/uwb/lc-dev.c

   1 /*
   2  * Ultra Wide Band
   3  * Life cycle of devices
   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 #include <linux/kernel.h>
  26 #include <linux/slab.h>
  27 #include <linux/device.h>
  28 #include <linux/err.h>
  29 #include <linux/kdev_t.h>
  30 #include <linux/random.h>
  31 #include "uwb-internal.h"
  32
  33 /* We initialize addresses to 0xff (invalid, as it is bcast) */
  34 static inline void uwb_dev_addr_init(struct uwb_dev_addr *addr)
  35 {
  36         memset(&addr->data, 0xff, sizeof(addr->data));
  37 }
  38
  39 static inline void uwb_mac_addr_init(struct uwb_mac_addr *addr)
  40 {
  41         memset(&addr->data, 0xff, sizeof(addr->data));
  42 }
  43
  44 /* @returns !0 if a device @addr is a broadcast address */
  45 static inline int uwb_dev_addr_bcast(const struct uwb_dev_addr *addr)
  46 {
  47         static const struct uwb_dev_addr bcast = { .data = { 0xff, 0xff } };
  48         return !uwb_dev_addr_cmp(addr, &bcast);
  49 }
  50
  51 /*
  52  * Add callback @new to be called when an event occurs in @rc.
  53  */
  54 int uwb_notifs_register(struct uwb_rc *rc, struct uwb_notifs_handler *new)
  55 {
  56         if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
  57                 return -ERESTARTSYS;
  58         list_add(&new->list_node, &rc->notifs_chain.list);
  59         mutex_unlock(&rc->notifs_chain.mutex);
  60         return 0;
  61 }
  62 EXPORT_SYMBOL_GPL(uwb_notifs_register);
  63
  64 /*
  65  * Remove event handler (callback)
  66  */
  67 int uwb_notifs_deregister(struct uwb_rc *rc, struct uwb_notifs_handler *entry)
  68 {
  69         if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
  70                 return -ERESTARTSYS;
  71         list_del(&entry->list_node);
  72         mutex_unlock(&rc->notifs_chain.mutex);
  73         return 0;
  74 }
  75 EXPORT_SYMBOL_GPL(uwb_notifs_deregister);
  76
  77 /*
  78  * Notify all event handlers of a given event on @rc
  79  *
  80  * We are called with a valid reference to the device, or NULL if the
  81  * event is not for a particular event (e.g., a BG join event).
  82  */
  83 void uwb_notify(struct uwb_rc *rc, struct uwb_dev *uwb_dev, enum uwb_notifs event)
  84 {
  85         struct uwb_notifs_handler *handler;
  86         if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
  87                 return;
  88         if (!list_empty(&rc->notifs_chain.list)) {
  89                 list_for_each_entry(handler, &rc->notifs_chain.list, list_node) {
  90                         handler->cb(handler->data, uwb_dev, event);
  91                 }
  92         }
  93         mutex_unlock(&rc->notifs_chain.mutex);
  94 }
  95
  96 /*
  97  * Release the backing device of a uwb_dev that has been dynamically allocated.
  98  */
  99 static void uwb_dev_sys_release(struct device *dev)
 100 {
 101         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 102
 103         uwb_bce_put(uwb_dev->bce);
 104         memset(uwb_dev, 0x69, sizeof(*uwb_dev));
 105         kfree(uwb_dev);
 106 }
 107
 108 /*
 109  * Initialize a UWB device instance
 110  *
 111  * Alloc, zero and call this function.
 112  */
 113 void uwb_dev_init(struct uwb_dev *uwb_dev)
 114 {
 115         mutex_init(&uwb_dev->mutex);
 116         device_initialize(&uwb_dev->dev);
 117         uwb_dev->dev.release = uwb_dev_sys_release;
 118         uwb_dev_addr_init(&uwb_dev->dev_addr);
 119         uwb_mac_addr_init(&uwb_dev->mac_addr);
 120         bitmap_fill(uwb_dev->streams, UWB_NUM_GLOBAL_STREAMS);
 121 }
 122
 123 static ssize_t uwb_dev_EUI_48_show(struct device *dev,
 124                                    struct device_attribute *attr, char *buf)
 125 {
 126         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 127         char addr[UWB_ADDR_STRSIZE];
 128
 129         uwb_mac_addr_print(addr, sizeof(addr), &uwb_dev->mac_addr);
 130         return sprintf(buf, "%s\n", addr);
 131 }
 132 static DEVICE_ATTR(EUI_48, S_IRUGO, uwb_dev_EUI_48_show, NULL);
 133
 134 static ssize_t uwb_dev_DevAddr_show(struct device *dev,
 135                                     struct device_attribute *attr, char *buf)
 136 {
 137         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 138         char addr[UWB_ADDR_STRSIZE];
 139
 140         uwb_dev_addr_print(addr, sizeof(addr), &uwb_dev->dev_addr);
 141         return sprintf(buf, "%s\n", addr);
 142 }
 143 static DEVICE_ATTR(DevAddr, S_IRUGO, uwb_dev_DevAddr_show, NULL);
 144
 145 /*
 146  * Show the BPST of this device.
 147  *
 148  * Calculated from the receive time of the device's beacon and it's
 149  * slot number.
 150  */
 151 static ssize_t uwb_dev_BPST_show(struct device *dev,
 152                                  struct device_attribute *attr, char *buf)
 153 {
 154         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 155         struct uwb_beca_e *bce;
 156         struct uwb_beacon_frame *bf;
 157         u16 bpst;
 158
 159         bce = uwb_dev->bce;
 160         mutex_lock(&bce->mutex);
 161         bf = (struct uwb_beacon_frame *)bce->be->BeaconInfo;
 162         bpst = bce->be->wBPSTOffset
 163                 - (u16)(bf->Beacon_Slot_Number * UWB_BEACON_SLOT_LENGTH_US);
 164         mutex_unlock(&bce->mutex);
 165
 166         return sprintf(buf, "%d\n", bpst);
 167 }
 168 static DEVICE_ATTR(BPST, S_IRUGO, uwb_dev_BPST_show, NULL);
 169
 170 /*
 171  * Show the IEs a device is beaconing
 172  *
 173  * We need to access the beacon cache, so we just lock it really
 174  * quick, print the IEs and unlock.
 175  *
 176  * We have a reference on the cache entry, so that should be
 177  * quite safe.
 178  */
 179 static ssize_t uwb_dev_IEs_show(struct device *dev,
 180                                 struct device_attribute *attr, char *buf)
 181 {
 182         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 183
 184         return uwb_bce_print_IEs(uwb_dev, uwb_dev->bce, buf, PAGE_SIZE);
 185 }
 186 static DEVICE_ATTR(IEs, S_IRUGO | S_IWUSR, uwb_dev_IEs_show, NULL);
 187
 188 static ssize_t uwb_dev_LQE_show(struct device *dev,
 189                                 struct device_attribute *attr, char *buf)
 190 {
 191         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 192         struct uwb_beca_e *bce = uwb_dev->bce;
 193         size_t result;
 194
 195         mutex_lock(&bce->mutex);
 196         result = stats_show(&uwb_dev->bce->lqe_stats, buf);
 197         mutex_unlock(&bce->mutex);
 198         return result;
 199 }
 200
 201 static ssize_t uwb_dev_LQE_store(struct device *dev,
 202                                  struct device_attribute *attr,
 203                                  const char *buf, size_t size)
 204 {
 205         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 206         struct uwb_beca_e *bce = uwb_dev->bce;
 207         ssize_t result;
 208
 209         mutex_lock(&bce->mutex);
 210         result = stats_store(&uwb_dev->bce->lqe_stats, buf, size);
 211         mutex_unlock(&bce->mutex);
 212         return result;
 213 }
 214 static DEVICE_ATTR(LQE, S_IRUGO | S_IWUSR, uwb_dev_LQE_show, uwb_dev_LQE_store);
 215
 216 static ssize_t uwb_dev_RSSI_show(struct device *dev,
 217                                  struct device_attribute *attr, char *buf)
 218 {
 219         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 220         struct uwb_beca_e *bce = uwb_dev->bce;
 221         size_t result;
 222
 223         mutex_lock(&bce->mutex);
 224         result = stats_show(&uwb_dev->bce->rssi_stats, buf);
 225         mutex_unlock(&bce->mutex);
 226         return result;
 227 }
 228
 229 static ssize_t uwb_dev_RSSI_store(struct device *dev,
 230                                   struct device_attribute *attr,
 231                                   const char *buf, size_t size)
 232 {
 233         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 234         struct uwb_beca_e *bce = uwb_dev->bce;
 235         ssize_t result;
 236
 237         mutex_lock(&bce->mutex);
 238         result = stats_store(&uwb_dev->bce->rssi_stats, buf, size);
 239         mutex_unlock(&bce->mutex);
 240         return result;
 241 }
 242 static DEVICE_ATTR(RSSI, S_IRUGO | S_IWUSR, uwb_dev_RSSI_show, uwb_dev_RSSI_store);
 243
 244
 245 static struct attribute *dev_attrs[] = {
 246         &dev_attr_EUI_48.attr,
 247         &dev_attr_DevAddr.attr,
 248         &dev_attr_BPST.attr,
 249         &dev_attr_IEs.attr,
 250         &dev_attr_LQE.attr,
 251         &dev_attr_RSSI.attr,
 252         NULL,
 253 };
 254
 255 static struct attribute_group dev_attr_group = {
 256         .attrs = dev_attrs,
 257 };
 258
 259 static const struct attribute_group *groups[] = {
 260         &dev_attr_group,
 261         NULL,
 262 };
 263
 264 /**
 265  * Device SYSFS registration
 266  *
 267  *
 268  */
 269 static int __uwb_dev_sys_add(struct uwb_dev *uwb_dev, struct device *parent_dev)
 270 {
 271         struct device *dev;
 272
 273         dev = &uwb_dev->dev;
 274         /* Device sysfs files are only useful for neighbor devices not
 275            local radio controllers. */
 276         if (&uwb_dev->rc->uwb_dev != uwb_dev)
 277                 dev->groups = groups;
 278         dev->parent = parent_dev;
 279         dev_set_drvdata(dev, uwb_dev);
 280
 281         return device_add(dev);
 282 }
 283
 284
 285 static void __uwb_dev_sys_rm(struct uwb_dev *uwb_dev)
 286 {
 287         dev_set_drvdata(&uwb_dev->dev, NULL);
 288         device_del(&uwb_dev->dev);
 289 }
 290
 291
 292 /**
 293  * Register and initialize a new UWB device
 294  *
 295  * Did you call uwb_dev_init() on it?
 296  *
 297  * @parent_rc: is the parent radio controller who has the link to the
 298  *             device. When registering the UWB device that is a UWB
 299  *             Radio Controller, we point back to it.
 300  *
 301  * If registering the device that is part of a radio, caller has set
 302  * rc->uwb_dev->dev. Otherwise it is to be left NULL--a new one will
 303  * be allocated.
 304  */
 305 int uwb_dev_add(struct uwb_dev *uwb_dev, struct device *parent_dev,
 306                 struct uwb_rc *parent_rc)
 307 {
 308         int result;
 309         struct device *dev;
 310
 311         BUG_ON(uwb_dev == NULL);
 312         BUG_ON(parent_dev == NULL);
 313         BUG_ON(parent_rc == NULL);
 314
 315         mutex_lock(&uwb_dev->mutex);
 316         dev = &uwb_dev->dev;
 317         uwb_dev->rc = parent_rc;
 318         result = __uwb_dev_sys_add(uwb_dev, parent_dev);
 319         if (result < 0)
 320                 printk(KERN_ERR "UWB: unable to register dev %s with sysfs: %d\n",
 321                        dev_name(dev), result);
 322         mutex_unlock(&uwb_dev->mutex);
 323         return result;
 324 }
 325
 326
 327 void uwb_dev_rm(struct uwb_dev *uwb_dev)
 328 {
 329         mutex_lock(&uwb_dev->mutex);
 330         __uwb_dev_sys_rm(uwb_dev);
 331         mutex_unlock(&uwb_dev->mutex);
 332 }
 333
 334
 335 static
 336 int __uwb_dev_try_get(struct device *dev, void *__target_uwb_dev)
 337 {
 338         struct uwb_dev *target_uwb_dev = __target_uwb_dev;
 339         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 340         if (uwb_dev == target_uwb_dev) {
 341                 uwb_dev_get(uwb_dev);
 342                 return 1;
 343         } else
 344                 return 0;
 345 }
 346
 347
 348 /**
 349  * Given a UWB device descriptor, validate and refcount it
 350  *
 351  * @returns NULL if the device does not exist or is quiescing; the ptr to
 352  *               it otherwise.
 353  */
 354 struct uwb_dev *uwb_dev_try_get(struct uwb_rc *rc, struct uwb_dev *uwb_dev)
 355 {
 356         if (uwb_dev_for_each(rc, __uwb_dev_try_get, uwb_dev))
 357                 return uwb_dev;
 358         else
 359                 return NULL;
 360 }
 361 EXPORT_SYMBOL_GPL(uwb_dev_try_get);
 362
 363
 364 /**
 365  * Remove a device from the system [grunt for other functions]
 366  */
 367 int __uwb_dev_offair(struct uwb_dev *uwb_dev, struct uwb_rc *rc)
 368 {
 369         struct device *dev = &uwb_dev->dev;
 370         char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
 371
 372         uwb_mac_addr_print(macbuf, sizeof(macbuf), &uwb_dev->mac_addr);
 373         uwb_dev_addr_print(devbuf, sizeof(devbuf), &uwb_dev->dev_addr);
 374         dev_info(dev, "uwb device (mac %s dev %s) disconnected from %s %s\n",
 375                  macbuf, devbuf,
 376                  rc ? rc->uwb_dev.dev.parent->bus->name : "n/a",
 377                  rc ? dev_name(rc->uwb_dev.dev.parent) : "");
 378         uwb_dev_rm(uwb_dev);
 379         list_del(&uwb_dev->bce->node);
 380         uwb_bce_put(uwb_dev->bce);
 381         uwb_dev_put(uwb_dev);   /* for the creation in _onair() */
 382
 383         return 0;
 384 }
 385
 386
 387 /**
 388  * A device went off the air, clean up after it!
 389  *
 390  * This is called by the UWB Daemon (through the beacon purge function
 391  * uwb_bcn_cache_purge) when it is detected that a device has been in
 392  * radio silence for a while.
 393  *
 394  * If this device is actually a local radio controller we don't need
 395  * to go through the offair process, as it is not registered as that.
 396  *
 397  * NOTE: uwb_bcn_cache.mutex is held!
 398  */
 399 void uwbd_dev_offair(struct uwb_beca_e *bce)
 400 {
 401         struct uwb_dev *uwb_dev;
 402
 403         uwb_dev = bce->uwb_dev;
 404         if (uwb_dev) {
 405                 uwb_notify(uwb_dev->rc, uwb_dev, UWB_NOTIF_OFFAIR);
 406                 __uwb_dev_offair(uwb_dev, uwb_dev->rc);
 407         }
 408 }
 409
 410
 411 /**
 412  * A device went on the air, start it up!
 413  *
 414  * This is called by the UWB Daemon when it is detected that a device
 415  * has popped up in the radio range of the radio controller.
 416  *
 417  * It will just create the freaking device, register the beacon and
 418  * stuff and yatla, done.
 419  *
 420  *
 421  * NOTE: uwb_beca.mutex is held, bce->mutex is held
 422  */
 423 void uwbd_dev_onair(struct uwb_rc *rc, struct uwb_beca_e *bce)
 424 {
 425         int result;
 426         struct device *dev = &rc->uwb_dev.dev;
 427         struct uwb_dev *uwb_dev;
 428         char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
 429
 430         uwb_mac_addr_print(macbuf, sizeof(macbuf), bce->mac_addr);
 431         uwb_dev_addr_print(devbuf, sizeof(devbuf), &bce->dev_addr);
 432         uwb_dev = kzalloc(sizeof(struct uwb_dev), GFP_KERNEL);
 433         if (uwb_dev == NULL) {
 434                 dev_err(dev, "new device %s: Cannot allocate memory\n",
 435                         macbuf);
 436                 return;
 437         }
 438         uwb_dev_init(uwb_dev);          /* This sets refcnt to one, we own it */
 439         uwb_dev->mac_addr = *bce->mac_addr;
 440         uwb_dev->dev_addr = bce->dev_addr;
 441         dev_set_name(&uwb_dev->dev, macbuf);
 442         result = uwb_dev_add(uwb_dev, &rc->uwb_dev.dev, rc);
 443         if (result < 0) {
 444                 dev_err(dev, "new device %s: cannot instantiate device\n",
 445                         macbuf);
 446                 goto error_dev_add;
 447         }
 448         /* plug the beacon cache */
 449         bce->uwb_dev = uwb_dev;
 450         uwb_dev->bce = bce;
 451         uwb_bce_get(bce);               /* released in uwb_dev_sys_release() */
 452         dev_info(dev, "uwb device (mac %s dev %s) connected to %s %s\n",
 453                  macbuf, devbuf, rc->uwb_dev.dev.parent->bus->name,
 454                  dev_name(rc->uwb_dev.dev.parent));
 455         uwb_notify(rc, uwb_dev, UWB_NOTIF_ONAIR);
 456         return;
 457
 458 error_dev_add:
 459         kfree(uwb_dev);
 460         return;
 461 }
 462
 463 /**
 464  * Iterate over the list of UWB devices, calling a @function on each
 465  *
 466  * See docs for bus_for_each()....
 467  *
 468  * @rc:       radio controller for the devices.
 469  * @function: function to call.
 470  * @priv:     data to pass to @function.
 471  * @returns:  0 if no invocation of function() returned a value
 472  *            different to zero. That value otherwise.
 473  */
 474 int uwb_dev_for_each(struct uwb_rc *rc, uwb_dev_for_each_f function, void *priv)
 475 {
 476         return device_for_each_child(&rc->uwb_dev.dev, priv, function);
 477 }
 478 EXPORT_SYMBOL_GPL(uwb_dev_for_each);