drivers/net/wimax/i2400m/usb.c

   1 /*
   2  * Intel Wireless WiMAX Connection 2400m
   3  * Linux driver model glue for USB device, reset & fw upload
   4  *
   5  *
   6  * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com>
   7  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   8  * Yanir Lubetkin <yanirx.lubetkin@intel.com>
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License version
  12  * 2 as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  22  * 02110-1301, USA.
  23  *
  24  *
  25  * See i2400m-usb.h for a general description of this driver.
  26  *
  27  * This file implements driver model glue, and hook ups for the
  28  * generic driver to implement the bus-specific functions (device
  29  * communication setup/tear down, firmware upload and resetting).
  30  *
  31  * ROADMAP
  32  *
  33  * i2400mu_probe()
  34  *   alloc_netdev()...
  35  *     i2400mu_netdev_setup()
  36  *       i2400mu_init()
  37  *       i2400m_netdev_setup()
  38  *   i2400m_setup()...
  39  *
  40  * i2400mu_disconnect
  41  *   i2400m_release()
  42  *   free_netdev()
  43  *
  44  * i2400mu_suspend()
  45  *   i2400m_cmd_enter_powersave()
  46  *   i2400mu_notification_release()
  47  *
  48  * i2400mu_resume()
  49  *   i2400mu_notification_setup()
  50  *
  51  * i2400mu_bus_dev_start()        Called by i2400m_dev_start() [who is
  52  *   i2400mu_tx_setup()           called by i2400m_setup()]
  53  *   i2400mu_rx_setup()
  54  *   i2400mu_notification_setup()
  55  *
  56  * i2400mu_bus_dev_stop()         Called by i2400m_dev_stop() [who is
  57  *   i2400mu_notification_release()  called by i2400m_release()]
  58  *   i2400mu_rx_release()
  59  *   i2400mu_tx_release()
  60  *
  61  * i2400mu_bus_reset()            Called by i2400m_reset
  62  *   __i2400mu_reset()
  63  *     __i2400mu_send_barker()
  64  *   usb_reset_device()
  65  */
  66 #include "i2400m-usb.h"
  67 #include <linux/wimax/i2400m.h>
  68 #include <linux/debugfs.h>
  69
  70
  71 #define D_SUBMODULE usb
  72 #include "usb-debug-levels.h"
  73
  74 static char i2400mu_debug_params[128];
  75 module_param_string(debug, i2400mu_debug_params, sizeof(i2400mu_debug_params),
  76                     0644);
  77 MODULE_PARM_DESC(debug,
  78                  "String of space-separated NAME:VALUE pairs, where NAMEs "
  79                  "are the different debug submodules and VALUE are the "
  80                  "initial debug value to set.");
  81
  82 /* Our firmware file name */
  83 static const char *i2400mu_bus_fw_names_5x50[] = {
  84 #define I2400MU_FW_FILE_NAME_v1_4 "i2400m-fw-usb-1.4.sbcf"
  85         I2400MU_FW_FILE_NAME_v1_4,
  86         NULL,
  87 };
  88
  89
  90 static const char *i2400mu_bus_fw_names_6050[] = {
  91 #define I6050U_FW_FILE_NAME_v1_5 "i6050-fw-usb-1.5.sbcf"
  92         I6050U_FW_FILE_NAME_v1_5,
  93         NULL,
  94 };
  95
  96
  97 static
  98 int i2400mu_bus_dev_start(struct i2400m *i2400m)
  99 {
 100         int result;
 101         struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 102         struct device *dev = &i2400mu->usb_iface->dev;
 103
 104         d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
 105         result = i2400mu_tx_setup(i2400mu);
 106         if (result < 0)
 107                 goto error_usb_tx_setup;
 108         result = i2400mu_rx_setup(i2400mu);
 109         if (result < 0)
 110                 goto error_usb_rx_setup;
 111         result = i2400mu_notification_setup(i2400mu);
 112         if (result < 0)
 113                 goto error_notif_setup;
 114         d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
 115         return result;
 116
 117 error_notif_setup:
 118         i2400mu_rx_release(i2400mu);
 119 error_usb_rx_setup:
 120         i2400mu_tx_release(i2400mu);
 121 error_usb_tx_setup:
 122         d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
 123         return result;
 124 }
 125
 126
 127 static
 128 void i2400mu_bus_dev_stop(struct i2400m *i2400m)
 129 {
 130         struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 131         struct device *dev = &i2400mu->usb_iface->dev;
 132
 133         d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
 134         i2400mu_notification_release(i2400mu);
 135         i2400mu_rx_release(i2400mu);
 136         i2400mu_tx_release(i2400mu);
 137         d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
 138 }
 139
 140
 141 /*
 142  * Sends a barker buffer to the device
 143  *
 144  * This helper will allocate a kmalloced buffer and use it to transmit
 145  * (then free it). Reason for this is that other arches cannot use
 146  * stack/vmalloc/text areas for DMA transfers.
 147  *
 148  * Error recovery here is simpler: anything is considered a hard error
 149  * and will move the reset code to use a last-resort bus-based reset.
 150  */
 151 static
 152 int __i2400mu_send_barker(struct i2400mu *i2400mu,
 153                           const __le32 *barker,
 154                           size_t barker_size,
 155                           unsigned endpoint)
 156 {
 157         struct usb_endpoint_descriptor *epd = NULL;
 158         int pipe, actual_len, ret;
 159         struct device *dev = &i2400mu->usb_iface->dev;
 160         void *buffer;
 161         int do_autopm = 1;
 162
 163         ret = usb_autopm_get_interface(i2400mu->usb_iface);
 164         if (ret < 0) {
 165                 dev_err(dev, "RESET: can't get autopm: %d\n", ret);
 166                 do_autopm = 0;
 167         }
 168         ret = -ENOMEM;
 169         buffer = kmalloc(barker_size, GFP_KERNEL);
 170         if (buffer == NULL)
 171                 goto error_kzalloc;
 172         epd = usb_get_epd(i2400mu->usb_iface, endpoint);
 173         pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
 174         memcpy(buffer, barker, barker_size);
 175 retry:
 176         ret = usb_bulk_msg(i2400mu->usb_dev, pipe, buffer, barker_size,
 177                            &actual_len, 200);
 178         switch (ret) {
 179         case 0:
 180                 if (actual_len != barker_size) {        /* Too short? drop it */
 181                         dev_err(dev, "E: %s: short write (%d B vs %zu "
 182                                 "expected)\n",
 183                                 __func__, actual_len, barker_size);
 184                         ret = -EIO;
 185                 }
 186                 break;
 187         case -EPIPE:
 188                 /*
 189                  * Stall -- maybe the device is choking with our
 190                  * requests. Clear it and give it some time. If they
 191                  * happen to often, it might be another symptom, so we
 192                  * reset.
 193                  *
 194                  * No error handling for usb_clear_halt(0; if it
 195                  * works, the retry works; if it fails, this switch
 196                  * does the error handling for us.
 197                  */
 198                 if (edc_inc(&i2400mu->urb_edc,
 199                             10 * EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
 200                         dev_err(dev, "E: %s: too many stalls in "
 201                                 "URB; resetting device\n", __func__);
 202                         usb_queue_reset_device(i2400mu->usb_iface);
 203                         /* fallthrough */
 204                 } else {
 205                         usb_clear_halt(i2400mu->usb_dev, pipe);
 206                         msleep(10);     /* give the device some time */
 207                         goto retry;
 208                 }
 209         case -EINVAL:                   /* while removing driver */
 210         case -ENODEV:                   /* dev disconnect ... */
 211         case -ENOENT:                   /* just ignore it */
 212         case -ESHUTDOWN:                /* and exit */
 213         case -ECONNRESET:
 214                 ret = -ESHUTDOWN;
 215                 break;
 216         default:                        /* Some error? */
 217                 if (edc_inc(&i2400mu->urb_edc,
 218                             EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
 219                         dev_err(dev, "E: %s: maximum errors in URB "
 220                                 "exceeded; resetting device\n",
 221                                 __func__);
 222                         usb_queue_reset_device(i2400mu->usb_iface);
 223                 } else {
 224                         dev_warn(dev, "W: %s: cannot send URB: %d\n",
 225                                  __func__, ret);
 226                         goto retry;
 227                 }
 228         }
 229         kfree(buffer);
 230 error_kzalloc:
 231         if (do_autopm)
 232                 usb_autopm_put_interface(i2400mu->usb_iface);
 233         return ret;
 234 }
 235
 236
 237 /*
 238  * Reset a device at different levels (warm, cold or bus)
 239  *
 240  * @i2400m: device descriptor
 241  * @reset_type: soft, warm or bus reset (I2400M_RT_WARM/SOFT/BUS)
 242  *
 243  * Warm and cold resets get a USB reset if they fail.
 244  *
 245  * Warm reset:
 246  *
 247  * The device will be fully reset internally, but won't be
 248  * disconnected from the USB bus (so no reenumeration will
 249  * happen). Firmware upload will be necessary.
 250  *
 251  * The device will send a reboot barker in the notification endpoint
 252  * that will trigger the driver to reinitialize the state
 253  * automatically from notif.c:i2400m_notification_grok() into
 254  * i2400m_dev_bootstrap_delayed().
 255  *
 256  * Cold and bus (USB) reset:
 257  *
 258  * The device will be fully reset internally, disconnected from the
 259  * USB bus an a reenumeration will happen. Firmware upload will be
 260  * necessary. Thus, we don't do any locking or struct
 261  * reinitialization, as we are going to be fully disconnected and
 262  * reenumerated.
 263  *
 264  * Note we need to return -ENODEV if a warm reset was requested and we
 265  * had to resort to a bus reset. See i2400m_op_reset(), wimax_reset()
 266  * and wimax_dev->op_reset.
 267  *
 268  * WARNING: no driver state saved/fixed
 269  */
 270 static
 271 int i2400mu_bus_reset(struct i2400m *i2400m, enum i2400m_reset_type rt)
 272 {
 273         int result;
 274         struct i2400mu *i2400mu =
 275                 container_of(i2400m, struct i2400mu, i2400m);
 276         struct device *dev = i2400m_dev(i2400m);
 277         static const __le32 i2400m_WARM_BOOT_BARKER[4] = {
 278                 cpu_to_le32(I2400M_WARM_RESET_BARKER),
 279                 cpu_to_le32(I2400M_WARM_RESET_BARKER),
 280                 cpu_to_le32(I2400M_WARM_RESET_BARKER),
 281                 cpu_to_le32(I2400M_WARM_RESET_BARKER),
 282         };
 283         static const __le32 i2400m_COLD_BOOT_BARKER[4] = {
 284                 cpu_to_le32(I2400M_COLD_RESET_BARKER),
 285                 cpu_to_le32(I2400M_COLD_RESET_BARKER),
 286                 cpu_to_le32(I2400M_COLD_RESET_BARKER),
 287                 cpu_to_le32(I2400M_COLD_RESET_BARKER),
 288         };
 289
 290         d_fnstart(3, dev, "(i2400m %p rt %u)\n", i2400m, rt);
 291         if (rt == I2400M_RT_WARM)
 292                 result = __i2400mu_send_barker(
 293                         i2400mu, i2400m_WARM_BOOT_BARKER,
 294                         sizeof(i2400m_WARM_BOOT_BARKER),
 295                         i2400mu->endpoint_cfg.bulk_out);
 296         else if (rt == I2400M_RT_COLD)
 297                 result = __i2400mu_send_barker(
 298                         i2400mu, i2400m_COLD_BOOT_BARKER,
 299                         sizeof(i2400m_COLD_BOOT_BARKER),
 300                         i2400mu->endpoint_cfg.reset_cold);
 301         else if (rt == I2400M_RT_BUS) {
 302                 result = usb_reset_device(i2400mu->usb_dev);
 303                 switch (result) {
 304                 case 0:
 305                 case -EINVAL:   /* device is gone */
 306                 case -ENODEV:
 307                 case -ENOENT:
 308                 case -ESHUTDOWN:
 309                         result = 0;
 310                         break;  /* We assume the device is disconnected */
 311                 default:
 312                         dev_err(dev, "USB reset failed (%d), giving up!\n",
 313                                 result);
 314                 }
 315         } else {
 316                 result = -EINVAL;       /* shut gcc up in certain arches */
 317                 BUG();
 318         }
 319         if (result < 0
 320             && result != -EINVAL        /* device is gone */
 321             && rt != I2400M_RT_BUS) {
 322                 /*
 323                  * Things failed -- resort to lower level reset, that
 324                  * we queue in another context; the reason for this is
 325                  * that the pre and post reset functionality requires
 326                  * the i2400m->init_mutex; RT_WARM and RT_COLD can
 327                  * come from areas where i2400m->init_mutex is taken.
 328                  */
 329                 dev_err(dev, "%s reset failed (%d); trying USB reset\n",
 330                         rt == I2400M_RT_WARM ? "warm" : "cold", result);
 331                 usb_queue_reset_device(i2400mu->usb_iface);
 332                 result = -ENODEV;
 333         }
 334         d_fnend(3, dev, "(i2400m %p rt %u) = %d\n", i2400m, rt, result);
 335         return result;
 336 }
 337
 338
 339 static
 340 void i2400mu_netdev_setup(struct net_device *net_dev)
 341 {
 342         struct i2400m *i2400m = net_dev_to_i2400m(net_dev);
 343         struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 344         i2400mu_init(i2400mu);
 345         i2400m_netdev_setup(net_dev);
 346 }
 347
 348
 349 /*
 350  * Debug levels control; see debug.h
 351  */
 352 struct d_level D_LEVEL[] = {
 353         D_SUBMODULE_DEFINE(usb),
 354         D_SUBMODULE_DEFINE(fw),
 355         D_SUBMODULE_DEFINE(notif),
 356         D_SUBMODULE_DEFINE(rx),
 357         D_SUBMODULE_DEFINE(tx),
 358 };
 359 size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
 360
 361
 362 #define __debugfs_register(prefix, name, parent)                        \
 363 do {                                                                    \
 364         result = d_level_register_debugfs(prefix, name, parent);        \
 365         if (result < 0)                                                 \
 366                 goto error;                                             \
 367 } while (0)
 368
 369
 370 static
 371 int i2400mu_debugfs_add(struct i2400mu *i2400mu)
 372 {
 373         int result;
 374         struct device *dev = &i2400mu->usb_iface->dev;
 375         struct dentry *dentry = i2400mu->i2400m.wimax_dev.debugfs_dentry;
 376         struct dentry *fd;
 377
 378         dentry = debugfs_create_dir("i2400m-usb", dentry);
 379         result = PTR_ERR(dentry);
 380         if (IS_ERR(dentry)) {
 381                 if (result == -ENODEV)
 382                         result = 0;     /* No debugfs support */
 383                 goto error;
 384         }
 385         i2400mu->debugfs_dentry = dentry;
 386         __debugfs_register("dl_", usb, dentry);
 387         __debugfs_register("dl_", fw, dentry);
 388         __debugfs_register("dl_", notif, dentry);
 389         __debugfs_register("dl_", rx, dentry);
 390         __debugfs_register("dl_", tx, dentry);
 391
 392         /* Don't touch these if you don't know what you are doing */
 393         fd = debugfs_create_u8("rx_size_auto_shrink", 0600, dentry,
 394                                &i2400mu->rx_size_auto_shrink);
 395         result = PTR_ERR(fd);
 396         if (IS_ERR(fd) && result != -ENODEV) {
 397                 dev_err(dev, "Can't create debugfs entry "
 398                         "rx_size_auto_shrink: %d\n", result);
 399                 goto error;
 400         }
 401
 402         fd = debugfs_create_size_t("rx_size", 0600, dentry,
 403                                    &i2400mu->rx_size);
 404         result = PTR_ERR(fd);
 405         if (IS_ERR(fd) && result != -ENODEV) {
 406                 dev_err(dev, "Can't create debugfs entry "
 407                         "rx_size: %d\n", result);
 408                 goto error;
 409         }
 410
 411         return 0;
 412
 413 error:
 414         debugfs_remove_recursive(i2400mu->debugfs_dentry);
 415         return result;
 416 }
 417
 418
 419 static struct device_type i2400mu_type = {
 420         .name   = "wimax",
 421 };
 422
 423 /*
 424  * Probe a i2400m interface and register it
 425  *
 426  * @iface:   USB interface to link to
 427  * @id:      USB class/subclass/protocol id
 428  * @returns: 0 if ok, < 0 errno code on error.
 429  *
 430  * Alloc a net device, initialize the bus-specific details and then
 431  * calls the bus-generic initialization routine. That will register
 432  * the wimax and netdev devices, upload the firmware [using
 433  * _bus_bm_*()], call _bus_dev_start() to finalize the setup of the
 434  * communication with the device and then will start to talk to it to
 435  * finnish setting it up.
 436  */
 437 static
 438 int i2400mu_probe(struct usb_interface *iface,
 439                   const struct usb_device_id *id)
 440 {
 441         int result;
 442         struct net_device *net_dev;
 443         struct device *dev = &iface->dev;
 444         struct i2400m *i2400m;
 445         struct i2400mu *i2400mu;
 446         struct usb_device *usb_dev = interface_to_usbdev(iface);
 447
 448         if (usb_dev->speed != USB_SPEED_HIGH)
 449                 dev_err(dev, "device not connected as high speed\n");
 450
 451         /* Allocate instance [calls i2400m_netdev_setup() on it]. */
 452         result = -ENOMEM;
 453         net_dev = alloc_netdev(sizeof(*i2400mu), "wmx%d",
 454                                i2400mu_netdev_setup);
 455         if (net_dev == NULL) {
 456                 dev_err(dev, "no memory for network device instance\n");
 457                 goto error_alloc_netdev;
 458         }
 459         SET_NETDEV_DEV(net_dev, dev);
 460         SET_NETDEV_DEVTYPE(net_dev, &i2400mu_type);
 461         i2400m = net_dev_to_i2400m(net_dev);
 462         i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 463         i2400m->wimax_dev.net_dev = net_dev;
 464         i2400mu->usb_dev = usb_get_dev(usb_dev);
 465         i2400mu->usb_iface = iface;
 466         usb_set_intfdata(iface, i2400mu);
 467
 468         i2400m->bus_tx_block_size = I2400MU_BLK_SIZE;
 469         i2400m->bus_pl_size_max = I2400MU_PL_SIZE_MAX;
 470         i2400m->bus_setup = NULL;
 471         i2400m->bus_dev_start = i2400mu_bus_dev_start;
 472         i2400m->bus_dev_stop = i2400mu_bus_dev_stop;
 473         i2400m->bus_release = NULL;
 474         i2400m->bus_tx_kick = i2400mu_bus_tx_kick;
 475         i2400m->bus_reset = i2400mu_bus_reset;
 476         i2400m->bus_bm_retries = I2400M_USB_BOOT_RETRIES;
 477         i2400m->bus_bm_cmd_send = i2400mu_bus_bm_cmd_send;
 478         i2400m->bus_bm_wait_for_ack = i2400mu_bus_bm_wait_for_ack;
 479         i2400m->bus_bm_mac_addr_impaired = 0;
 480
 481         switch (id->idProduct) {
 482         case USB_DEVICE_ID_I6050:
 483         case USB_DEVICE_ID_I6050_2:
 484                 i2400mu->i6050 = 1;
 485                 break;
 486         default:
 487                 break;
 488         }
 489
 490         if (i2400mu->i6050) {
 491                 i2400m->bus_fw_names = i2400mu_bus_fw_names_6050;
 492                 i2400mu->endpoint_cfg.bulk_out = 0;
 493                 i2400mu->endpoint_cfg.notification = 3;
 494                 i2400mu->endpoint_cfg.reset_cold = 2;
 495                 i2400mu->endpoint_cfg.bulk_in = 1;
 496         } else {
 497                 i2400m->bus_fw_names = i2400mu_bus_fw_names_5x50;
 498                 i2400mu->endpoint_cfg.bulk_out = 0;
 499                 i2400mu->endpoint_cfg.notification = 1;
 500                 i2400mu->endpoint_cfg.reset_cold = 2;
 501                 i2400mu->endpoint_cfg.bulk_in = 3;
 502         }
 503 #ifdef CONFIG_PM
 504         iface->needs_remote_wakeup = 1;         /* autosuspend (15s delay) */
 505         device_init_wakeup(dev, 1);
 506         usb_dev->autosuspend_delay = 15 * HZ;
 507         usb_dev->autosuspend_disabled = 0;
 508 #endif
 509
 510         result = i2400m_setup(i2400m, I2400M_BRI_MAC_REINIT);
 511         if (result < 0) {
 512                 dev_err(dev, "cannot setup device: %d\n", result);
 513                 goto error_setup;
 514         }
 515         result = i2400mu_debugfs_add(i2400mu);
 516         if (result < 0) {
 517                 dev_err(dev, "Can't register i2400mu's debugfs: %d\n", result);
 518                 goto error_debugfs_add;
 519         }
 520         return 0;
 521
 522 error_debugfs_add:
 523         i2400m_release(i2400m);
 524 error_setup:
 525         usb_set_intfdata(iface, NULL);
 526         usb_put_dev(i2400mu->usb_dev);
 527         free_netdev(net_dev);
 528 error_alloc_netdev:
 529         return result;
 530 }
 531
 532
 533 /*
 534  * Disconect a i2400m from the system.
 535  *
 536  * i2400m_stop() has been called before, so al the rx and tx contexts
 537  * have been taken down already. Make sure the queue is stopped,
 538  * unregister netdev and i2400m, free and kill.
 539  */
 540 static
 541 void i2400mu_disconnect(struct usb_interface *iface)
 542 {
 543         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 544         struct i2400m *i2400m = &i2400mu->i2400m;
 545         struct net_device *net_dev = i2400m->wimax_dev.net_dev;
 546         struct device *dev = &iface->dev;
 547
 548         d_fnstart(3, dev, "(iface %p i2400m %p)\n", iface, i2400m);
 549
 550         debugfs_remove_recursive(i2400mu->debugfs_dentry);
 551         i2400m_release(i2400m);
 552         usb_set_intfdata(iface, NULL);
 553         usb_put_dev(i2400mu->usb_dev);
 554         free_netdev(net_dev);
 555         d_fnend(3, dev, "(iface %p i2400m %p) = void\n", iface, i2400m);
 556 }
 557
 558
 559 /*
 560  * Get the device ready for USB port or system standby and hibernation
 561  *
 562  * USB port and system standby are handled the same.
 563  *
 564  * When the system hibernates, the USB device is powered down and then
 565  * up, so we don't really have to do much here, as it will be seen as
 566  * a reconnect. Still for simplicity we consider this case the same as
 567  * suspend, so that the device has a chance to do notify the base
 568  * station (if connected).
 569  *
 570  * So at the end, the three cases require common handling.
 571  *
 572  * If at the time of this call the device's firmware is not loaded,
 573  * nothing has to be done. Note we can be "loose" about not reading
 574  * i2400m->updown under i2400m->init_mutex. If it happens to change
 575  * inmediately, other parts of the call flow will fail and effectively
 576  * catch it.
 577  *
 578  * If the firmware is loaded, we need to:
 579  *
 580  *  - tell the device to go into host interface power save mode, wait
 581  *    for it to ack
 582  *
 583  *    This is quite more interesting than it is; we need to execute a
 584  *    command, but this time, we don't want the code in usb-{tx,rx}.c
 585  *    to call the usb_autopm_get/put_interface() barriers as it'd
 586  *    deadlock, so we need to decrement i2400mu->do_autopm, that acts
 587  *    as a poor man's semaphore. Ugly, but it works.
 588  *
 589  *    As well, the device might refuse going to sleep for whichever
 590  *    reason. In this case we just fail. For system suspend/hibernate,
 591  *    we *can't* fail. We check PM_EVENT_AUTO to see if the
 592  *    suspend call comes from the USB stack or from the system and act
 593  *    in consequence.
 594  *
 595  *  - stop the notification endpoint polling
 596  */
 597 static
 598 int i2400mu_suspend(struct usb_interface *iface, pm_message_t pm_msg)
 599 {
 600         int result = 0;
 601         struct device *dev = &iface->dev;
 602         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 603         unsigned is_autosuspend = 0;
 604         struct i2400m *i2400m = &i2400mu->i2400m;
 605
 606 #ifdef CONFIG_PM
 607         if (pm_msg.event & PM_EVENT_AUTO)
 608                 is_autosuspend = 1;
 609 #endif
 610
 611         d_fnstart(3, dev, "(iface %p pm_msg %u)\n", iface, pm_msg.event);
 612         rmb();          /* see i2400m->updown's documentation  */
 613         if (i2400m->updown == 0)
 614                 goto no_firmware;
 615         if (i2400m->state == I2400M_SS_DATA_PATH_CONNECTED && is_autosuspend) {
 616                 /* ugh -- the device is connected and this suspend
 617                  * request is an autosuspend one (not a system standby
 618                  * / hibernate).
 619                  *
 620                  * The only way the device can go to standby is if the
 621                  * link with the base station is in IDLE mode; that
 622                  * were the case, we'd be in status
 623                  * I2400M_SS_CONNECTED_IDLE. But we are not.
 624                  *
 625                  * If we *tell* him to go power save now, it'll reset
 626                  * as a precautionary measure, so if this is an
 627                  * autosuspend thing, say no and it'll come back
 628                  * later, when the link is IDLE
 629                  */
 630                 result = -EBADF;
 631                 d_printf(1, dev, "fw up, link up, not-idle, autosuspend: "
 632                          "not entering powersave\n");
 633                 goto error_not_now;
 634         }
 635         d_printf(1, dev, "fw up: entering powersave\n");
 636         atomic_dec(&i2400mu->do_autopm);
 637         result = i2400m_cmd_enter_powersave(i2400m);
 638         atomic_inc(&i2400mu->do_autopm);
 639         if (result < 0 && !is_autosuspend) {
 640                 /* System suspend, can't fail */
 641                 dev_err(dev, "failed to suspend, will reset on resume\n");
 642                 result = 0;
 643         }
 644         if (result < 0)
 645                 goto error_enter_powersave;
 646         i2400mu_notification_release(i2400mu);
 647         d_printf(1, dev, "powersave requested\n");
 648 error_enter_powersave:
 649 error_not_now:
 650 no_firmware:
 651         d_fnend(3, dev, "(iface %p pm_msg %u) = %d\n",
 652                 iface, pm_msg.event, result);
 653         return result;
 654 }
 655
 656
 657 static
 658 int i2400mu_resume(struct usb_interface *iface)
 659 {
 660         int ret = 0;
 661         struct device *dev = &iface->dev;
 662         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 663         struct i2400m *i2400m = &i2400mu->i2400m;
 664
 665         d_fnstart(3, dev, "(iface %p)\n", iface);
 666         rmb();          /* see i2400m->updown's documentation  */
 667         if (i2400m->updown == 0) {
 668                 d_printf(1, dev, "fw was down, no resume neeed\n");
 669                 goto out;
 670         }
 671         d_printf(1, dev, "fw was up, resuming\n");
 672         i2400mu_notification_setup(i2400mu);
 673         /* USB has flow control, so we don't need to give it time to
 674          * come back; otherwise, we'd use something like a get-state
 675          * command... */
 676 out:
 677         d_fnend(3, dev, "(iface %p) = %d\n", iface, ret);
 678         return ret;
 679 }
 680
 681
 682 static
 683 int i2400mu_reset_resume(struct usb_interface *iface)
 684 {
 685         int result;
 686         struct device *dev = &iface->dev;
 687         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 688         struct i2400m *i2400m = &i2400mu->i2400m;
 689
 690         d_fnstart(3, dev, "(iface %p)\n", iface);
 691         result = i2400m_dev_reset_handle(i2400m, "device reset on resume");
 692         d_fnend(3, dev, "(iface %p) = %d\n", iface, result);
 693         return result < 0 ? result : 0;
 694 }
 695
 696
 697 /*
 698  * Another driver or user space is triggering a reset on the device
 699  * which contains the interface passed as an argument. Cease IO and
 700  * save any device state you need to restore.
 701  *
 702  * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if
 703  * you are in atomic context.
 704  */
 705 static
 706 int i2400mu_pre_reset(struct usb_interface *iface)
 707 {
 708         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 709         return i2400m_pre_reset(&i2400mu->i2400m);
 710 }
 711
 712
 713 /*
 714  * The reset has completed.  Restore any saved device state and begin
 715  * using the device again.
 716  *
 717  * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if
 718  * you are in atomic context.
 719  */
 720 static
 721 int i2400mu_post_reset(struct usb_interface *iface)
 722 {
 723         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 724         return i2400m_post_reset(&i2400mu->i2400m);
 725 }
 726
 727
 728 static
 729 struct usb_device_id i2400mu_id_table[] = {
 730         { USB_DEVICE(0x8086, USB_DEVICE_ID_I6050) },
 731         { USB_DEVICE(0x8086, USB_DEVICE_ID_I6050_2) },
 732         { USB_DEVICE(0x8086, 0x0181) },
 733         { USB_DEVICE(0x8086, 0x1403) },
 734         { USB_DEVICE(0x8086, 0x1405) },
 735         { USB_DEVICE(0x8086, 0x0180) },
 736         { USB_DEVICE(0x8086, 0x0182) },
 737         { USB_DEVICE(0x8086, 0x1406) },
 738         { USB_DEVICE(0x8086, 0x1403) },
 739         { },
 740 };
 741 MODULE_DEVICE_TABLE(usb, i2400mu_id_table);
 742
 743
 744 static
 745 struct usb_driver i2400mu_driver = {
 746         .name = KBUILD_MODNAME,
 747         .suspend = i2400mu_suspend,
 748         .resume = i2400mu_resume,
 749         .reset_resume = i2400mu_reset_resume,
 750         .probe = i2400mu_probe,
 751         .disconnect = i2400mu_disconnect,
 752         .pre_reset = i2400mu_pre_reset,
 753         .post_reset = i2400mu_post_reset,
 754         .id_table = i2400mu_id_table,
 755         .supports_autosuspend = 1,
 756 };
 757
 758 static
 759 int __init i2400mu_driver_init(void)
 760 {
 761         d_parse_params(D_LEVEL, D_LEVEL_SIZE, i2400mu_debug_params,
 762                        "i2400m_usb.debug");
 763         return usb_register(&i2400mu_driver);
 764 }
 765 module_init(i2400mu_driver_init);
 766
 767
 768 static
 769 void __exit i2400mu_driver_exit(void)
 770 {
 771         flush_scheduled_work(); /* for the stuff we schedule from sysfs.c */
 772         usb_deregister(&i2400mu_driver);
 773 }
 774 module_exit(i2400mu_driver_exit);
 775
 776 MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
 777 MODULE_DESCRIPTION("Driver for USB based Intel Wireless WiMAX Connection 2400M "
 778                    "(5x50 & 6050)");
 779 MODULE_LICENSE("GPL");
 780 MODULE_FIRMWARE(I2400MU_FW_FILE_NAME_v1_4);