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