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 #include <linux/slab.h>
  70
  71
  72 #define D_SUBMODULE usb
  73 #include "usb-debug-levels.h"
  74
  75 static char i2400mu_debug_params[128];
  76 module_param_string(debug, i2400mu_debug_params, sizeof(i2400mu_debug_params),
  77                     0644);
  78 MODULE_PARM_DESC(debug,
  79                  "String of space-separated NAME:VALUE pairs, where NAMEs "
  80                  "are the different debug submodules and VALUE are the "
  81                  "initial debug value to set.");
  82
  83 /* Our firmware file name */
  84 static const char *i2400mu_bus_fw_names_5x50[] = {
  85 #define I2400MU_FW_FILE_NAME_v1_5 "i2400m-fw-usb-1.5.sbcf"
  86         I2400MU_FW_FILE_NAME_v1_5,
  87 #define I2400MU_FW_FILE_NAME_v1_4 "i2400m-fw-usb-1.4.sbcf"
  88         I2400MU_FW_FILE_NAME_v1_4,
  89         NULL,
  90 };
  91
  92
  93 static const char *i2400mu_bus_fw_names_6050[] = {
  94 #define I6050U_FW_FILE_NAME_v1_5 "i6050-fw-usb-1.5.sbcf"
  95         I6050U_FW_FILE_NAME_v1_5,
  96         NULL,
  97 };
  98
  99
 100 static
 101 int i2400mu_bus_dev_start(struct i2400m *i2400m)
 102 {
 103         int result;
 104         struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 105         struct device *dev = &i2400mu->usb_iface->dev;
 106
 107         d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
 108         result = i2400mu_tx_setup(i2400mu);
 109         if (result < 0)
 110                 goto error_usb_tx_setup;
 111         result = i2400mu_rx_setup(i2400mu);
 112         if (result < 0)
 113                 goto error_usb_rx_setup;
 114         result = i2400mu_notification_setup(i2400mu);
 115         if (result < 0)
 116                 goto error_notif_setup;
 117         d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
 118         return result;
 119
 120 error_notif_setup:
 121         i2400mu_rx_release(i2400mu);
 122 error_usb_rx_setup:
 123         i2400mu_tx_release(i2400mu);
 124 error_usb_tx_setup:
 125         d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
 126         return result;
 127 }
 128
 129
 130 static
 131 void i2400mu_bus_dev_stop(struct i2400m *i2400m)
 132 {
 133         struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 134         struct device *dev = &i2400mu->usb_iface->dev;
 135
 136         d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
 137         i2400mu_notification_release(i2400mu);
 138         i2400mu_rx_release(i2400mu);
 139         i2400mu_tx_release(i2400mu);
 140         d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
 141 }
 142
 143
 144 /*
 145  * Sends a barker buffer to the device
 146  *
 147  * This helper will allocate a kmalloced buffer and use it to transmit
 148  * (then free it). Reason for this is that other arches cannot use
 149  * stack/vmalloc/text areas for DMA transfers.
 150  *
 151  * Error recovery here is simpler: anything is considered a hard error
 152  * and will move the reset code to use a last-resort bus-based reset.
 153  */
 154 static
 155 int __i2400mu_send_barker(struct i2400mu *i2400mu,
 156                           const __le32 *barker,
 157                           size_t barker_size,
 158                           unsigned endpoint)
 159 {
 160         struct usb_endpoint_descriptor *epd = NULL;
 161         int pipe, actual_len, ret;
 162         struct device *dev = &i2400mu->usb_iface->dev;
 163         void *buffer;
 164         int do_autopm = 1;
 165
 166         ret = usb_autopm_get_interface(i2400mu->usb_iface);
 167         if (ret < 0) {
 168                 dev_err(dev, "RESET: can't get autopm: %d\n", ret);
 169                 do_autopm = 0;
 170         }
 171         ret = -ENOMEM;
 172         buffer = kmalloc(barker_size, GFP_KERNEL);
 173         if (buffer == NULL)
 174                 goto error_kzalloc;
 175         epd = usb_get_epd(i2400mu->usb_iface, endpoint);
 176         pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
 177         memcpy(buffer, barker, barker_size);
 178 retry:
 179         ret = usb_bulk_msg(i2400mu->usb_dev, pipe, buffer, barker_size,
 180                            &actual_len, 200);
 181         switch (ret) {
 182         case 0:
 183                 if (actual_len != barker_size) {        /* Too short? drop it */
 184                         dev_err(dev, "E: %s: short write (%d B vs %zu "
 185                                 "expected)\n",
 186                                 __func__, actual_len, barker_size);
 187                         ret = -EIO;
 188                 }
 189                 break;
 190         case -EPIPE:
 191                 /*
 192                  * Stall -- maybe the device is choking with our
 193                  * requests. Clear it and give it some time. If they
 194                  * happen to often, it might be another symptom, so we
 195                  * reset.
 196                  *
 197                  * No error handling for usb_clear_halt(0; if it
 198                  * works, the retry works; if it fails, this switch
 199                  * does the error handling for us.
 200                  */
 201                 if (edc_inc(&i2400mu->urb_edc,
 202                             10 * EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
 203                         dev_err(dev, "E: %s: too many stalls in "
 204                                 "URB; resetting device\n", __func__);
 205                         usb_queue_reset_device(i2400mu->usb_iface);
 206                         /* fallthrough */
 207                 } else {
 208                         usb_clear_halt(i2400mu->usb_dev, pipe);
 209                         msleep(10);     /* give the device some time */
 210                         goto retry;
 211                 }
 212         case -EINVAL:                   /* while removing driver */
 213         case -ENODEV:                   /* dev disconnect ... */
 214         case -ENOENT:                   /* just ignore it */
 215         case -ESHUTDOWN:                /* and exit */
 216         case -ECONNRESET:
 217                 ret = -ESHUTDOWN;
 218                 break;
 219         default:                        /* Some error? */
 220                 if (edc_inc(&i2400mu->urb_edc,
 221                             EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
 222                         dev_err(dev, "E: %s: maximum errors in URB "
 223                                 "exceeded; resetting device\n",
 224                                 __func__);
 225                         usb_queue_reset_device(i2400mu->usb_iface);
 226                 } else {
 227                         dev_warn(dev, "W: %s: cannot send URB: %d\n",
 228                                  __func__, ret);
 229                         goto retry;
 230                 }
 231         }
 232         kfree(buffer);
 233 error_kzalloc:
 234         if (do_autopm)
 235                 usb_autopm_put_interface(i2400mu->usb_iface);
 236         return ret;
 237 }
 238
 239
 240 /*
 241  * Reset a device at different levels (warm, cold or bus)
 242  *
 243  * @i2400m: device descriptor
 244  * @reset_type: soft, warm or bus reset (I2400M_RT_WARM/SOFT/BUS)
 245  *
 246  * Warm and cold resets get a USB reset if they fail.
 247  *
 248  * Warm reset:
 249  *
 250  * The device will be fully reset internally, but won't be
 251  * disconnected from the USB bus (so no reenumeration will
 252  * happen). Firmware upload will be necessary.
 253  *
 254  * The device will send a reboot barker in the notification endpoint
 255  * that will trigger the driver to reinitialize the state
 256  * automatically from notif.c:i2400m_notification_grok() into
 257  * i2400m_dev_bootstrap_delayed().
 258  *
 259  * Cold and bus (USB) reset:
 260  *
 261  * The device will be fully reset internally, disconnected from the
 262  * USB bus an a reenumeration will happen. Firmware upload will be
 263  * necessary. Thus, we don't do any locking or struct
 264  * reinitialization, as we are going to be fully disconnected and
 265  * reenumerated.
 266  *
 267  * Note we need to return -ENODEV if a warm reset was requested and we
 268  * had to resort to a bus reset. See i2400m_op_reset(), wimax_reset()
 269  * and wimax_dev->op_reset.
 270  *
 271  * WARNING: no driver state saved/fixed
 272  */
 273 static
 274 int i2400mu_bus_reset(struct i2400m *i2400m, enum i2400m_reset_type rt)
 275 {
 276         int result;
 277         struct i2400mu *i2400mu =
 278                 container_of(i2400m, struct i2400mu, i2400m);
 279         struct device *dev = i2400m_dev(i2400m);
 280         static const __le32 i2400m_WARM_BOOT_BARKER[4] = {
 281                 cpu_to_le32(I2400M_WARM_RESET_BARKER),
 282                 cpu_to_le32(I2400M_WARM_RESET_BARKER),
 283                 cpu_to_le32(I2400M_WARM_RESET_BARKER),
 284                 cpu_to_le32(I2400M_WARM_RESET_BARKER),
 285         };
 286         static const __le32 i2400m_COLD_BOOT_BARKER[4] = {
 287                 cpu_to_le32(I2400M_COLD_RESET_BARKER),
 288                 cpu_to_le32(I2400M_COLD_RESET_BARKER),
 289                 cpu_to_le32(I2400M_COLD_RESET_BARKER),
 290                 cpu_to_le32(I2400M_COLD_RESET_BARKER),
 291         };
 292
 293         d_fnstart(3, dev, "(i2400m %p rt %u)\n", i2400m, rt);
 294         if (rt == I2400M_RT_WARM)
 295                 result = __i2400mu_send_barker(
 296                         i2400mu, i2400m_WARM_BOOT_BARKER,
 297                         sizeof(i2400m_WARM_BOOT_BARKER),
 298                         i2400mu->endpoint_cfg.bulk_out);
 299         else if (rt == I2400M_RT_COLD)
 300                 result = __i2400mu_send_barker(
 301                         i2400mu, i2400m_COLD_BOOT_BARKER,
 302                         sizeof(i2400m_COLD_BOOT_BARKER),
 303                         i2400mu->endpoint_cfg.reset_cold);
 304         else if (rt == I2400M_RT_BUS) {
 305                 result = usb_reset_device(i2400mu->usb_dev);
 306                 switch (result) {
 307                 case 0:
 308                 case -EINVAL:   /* device is gone */
 309                 case -ENODEV:
 310                 case -ENOENT:
 311                 case -ESHUTDOWN:
 312                         result = 0;
 313                         break;  /* We assume the device is disconnected */
 314                 default:
 315                         dev_err(dev, "USB reset failed (%d), giving up!\n",
 316                                 result);
 317                 }
 318         } else {
 319                 result = -EINVAL;       /* shut gcc up in certain arches */
 320                 BUG();
 321         }
 322         if (result < 0
 323             && result != -EINVAL        /* device is gone */
 324             && rt != I2400M_RT_BUS) {
 325                 /*
 326                  * Things failed -- resort to lower level reset, that
 327                  * we queue in another context; the reason for this is
 328                  * that the pre and post reset functionality requires
 329                  * the i2400m->init_mutex; RT_WARM and RT_COLD can
 330                  * come from areas where i2400m->init_mutex is taken.
 331                  */
 332                 dev_err(dev, "%s reset failed (%d); trying USB reset\n",
 333                         rt == I2400M_RT_WARM ? "warm" : "cold", result);
 334                 usb_queue_reset_device(i2400mu->usb_iface);
 335                 result = -ENODEV;
 336         }
 337         d_fnend(3, dev, "(i2400m %p rt %u) = %d\n", i2400m, rt, result);
 338         return result;
 339 }
 340
 341
 342 static
 343 void i2400mu_netdev_setup(struct net_device *net_dev)
 344 {
 345         struct i2400m *i2400m = net_dev_to_i2400m(net_dev);
 346         struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 347         i2400mu_init(i2400mu);
 348         i2400m_netdev_setup(net_dev);
 349 }
 350
 351
 352 /*
 353  * Debug levels control; see debug.h
 354  */
 355 struct d_level D_LEVEL[] = {
 356         D_SUBMODULE_DEFINE(usb),
 357         D_SUBMODULE_DEFINE(fw),
 358         D_SUBMODULE_DEFINE(notif),
 359         D_SUBMODULE_DEFINE(rx),
 360         D_SUBMODULE_DEFINE(tx),
 361 };
 362 size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
 363
 364
 365 #define __debugfs_register(prefix, name, parent)                        \
 366 do {                                                                    \
 367         result = d_level_register_debugfs(prefix, name, parent);        \
 368         if (result < 0)                                                 \
 369                 goto error;                                             \
 370 } while (0)
 371
 372
 373 static
 374 int i2400mu_debugfs_add(struct i2400mu *i2400mu)
 375 {
 376         int result;
 377         struct device *dev = &i2400mu->usb_iface->dev;
 378         struct dentry *dentry = i2400mu->i2400m.wimax_dev.debugfs_dentry;
 379         struct dentry *fd;
 380
 381         dentry = debugfs_create_dir("i2400m-usb", dentry);
 382         result = PTR_ERR(dentry);
 383         if (IS_ERR(dentry)) {
 384                 if (result == -ENODEV)
 385                         result = 0;     /* No debugfs support */
 386                 goto error;
 387         }
 388         i2400mu->debugfs_dentry = dentry;
 389         __debugfs_register("dl_", usb, dentry);
 390         __debugfs_register("dl_", fw, dentry);
 391         __debugfs_register("dl_", notif, dentry);
 392         __debugfs_register("dl_", rx, dentry);
 393         __debugfs_register("dl_", tx, dentry);
 394
 395         /* Don't touch these if you don't know what you are doing */
 396         fd = debugfs_create_u8("rx_size_auto_shrink", 0600, dentry,
 397                                &i2400mu->rx_size_auto_shrink);
 398         result = PTR_ERR(fd);
 399         if (IS_ERR(fd) && result != -ENODEV) {
 400                 dev_err(dev, "Can't create debugfs entry "
 401                         "rx_size_auto_shrink: %d\n", result);
 402                 goto error;
 403         }
 404
 405         fd = debugfs_create_size_t("rx_size", 0600, dentry,
 406                                    &i2400mu->rx_size);
 407         result = PTR_ERR(fd);
 408         if (IS_ERR(fd) && result != -ENODEV) {
 409                 dev_err(dev, "Can't create debugfs entry "
 410                         "rx_size: %d\n", result);
 411                 goto error;
 412         }
 413
 414         return 0;
 415
 416 error:
 417         debugfs_remove_recursive(i2400mu->debugfs_dentry);
 418         return result;
 419 }
 420
 421
 422 static struct device_type i2400mu_type = {
 423         .name   = "wimax",
 424 };
 425
 426 /*
 427  * Probe a i2400m interface and register it
 428  *
 429  * @iface:   USB interface to link to
 430  * @id:      USB class/subclass/protocol id
 431  * @returns: 0 if ok, < 0 errno code on error.
 432  *
 433  * Alloc a net device, initialize the bus-specific details and then
 434  * calls the bus-generic initialization routine. That will register
 435  * the wimax and netdev devices, upload the firmware [using
 436  * _bus_bm_*()], call _bus_dev_start() to finalize the setup of the
 437  * communication with the device and then will start to talk to it to
 438  * finnish setting it up.
 439  */
 440 static
 441 int i2400mu_probe(struct usb_interface *iface,
 442                   const struct usb_device_id *id)
 443 {
 444         int result;
 445         struct net_device *net_dev;
 446         struct device *dev = &iface->dev;
 447         struct i2400m *i2400m;
 448         struct i2400mu *i2400mu;
 449         struct usb_device *usb_dev = interface_to_usbdev(iface);
 450
 451         if (usb_dev->speed != USB_SPEED_HIGH)
 452                 dev_err(dev, "device not connected as high speed\n");
 453
 454         /* Allocate instance [calls i2400m_netdev_setup() on it]. */
 455         result = -ENOMEM;
 456         net_dev = alloc_netdev(sizeof(*i2400mu), "wmx%d",
 457                                i2400mu_netdev_setup);
 458         if (net_dev == NULL) {
 459                 dev_err(dev, "no memory for network device instance\n");
 460                 goto error_alloc_netdev;
 461         }
 462         SET_NETDEV_DEV(net_dev, dev);
 463         SET_NETDEV_DEVTYPE(net_dev, &i2400mu_type);
 464         i2400m = net_dev_to_i2400m(net_dev);
 465         i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 466         i2400m->wimax_dev.net_dev = net_dev;
 467         i2400mu->usb_dev = usb_get_dev(usb_dev);
 468         i2400mu->usb_iface = iface;
 469         usb_set_intfdata(iface, i2400mu);
 470
 471         i2400m->bus_tx_block_size = I2400MU_BLK_SIZE;
 472         /*
 473          * Room required in the Tx queue for USB message to accommodate
 474          * a smallest payload while allocating header space is 16 bytes.
 475          * Adding this room  for the new tx message increases the
 476          * possibilities of including any payload with size <= 16 bytes.
 477          */
 478         i2400m->bus_tx_room_min = I2400MU_BLK_SIZE;
 479         i2400m->bus_pl_size_max = I2400MU_PL_SIZE_MAX;
 480         i2400m->bus_setup = NULL;
 481         i2400m->bus_dev_start = i2400mu_bus_dev_start;
 482         i2400m->bus_dev_stop = i2400mu_bus_dev_stop;
 483         i2400m->bus_release = NULL;
 484         i2400m->bus_tx_kick = i2400mu_bus_tx_kick;
 485         i2400m->bus_reset = i2400mu_bus_reset;
 486         i2400m->bus_bm_retries = I2400M_USB_BOOT_RETRIES;
 487         i2400m->bus_bm_cmd_send = i2400mu_bus_bm_cmd_send;
 488         i2400m->bus_bm_wait_for_ack = i2400mu_bus_bm_wait_for_ack;
 489         i2400m->bus_bm_mac_addr_impaired = 0;
 490
 491         switch (id->idProduct) {
 492         case USB_DEVICE_ID_I6050:
 493         case USB_DEVICE_ID_I6050_2:
 494         case USB_DEVICE_ID_I6250:
 495                 i2400mu->i6050 = 1;
 496                 break;
 497         default:
 498                 break;
 499         }
 500
 501         if (i2400mu->i6050) {
 502                 i2400m->bus_fw_names = i2400mu_bus_fw_names_6050;
 503                 i2400mu->endpoint_cfg.bulk_out = 0;
 504                 i2400mu->endpoint_cfg.notification = 3;
 505                 i2400mu->endpoint_cfg.reset_cold = 2;
 506                 i2400mu->endpoint_cfg.bulk_in = 1;
 507         } else {
 508                 i2400m->bus_fw_names = i2400mu_bus_fw_names_5x50;
 509                 i2400mu->endpoint_cfg.bulk_out = 0;
 510                 i2400mu->endpoint_cfg.notification = 1;
 511                 i2400mu->endpoint_cfg.reset_cold = 2;
 512                 i2400mu->endpoint_cfg.bulk_in = 3;
 513         }
 514 #ifdef CONFIG_PM
 515         iface->needs_remote_wakeup = 1;         /* autosuspend (15s delay) */
 516         device_init_wakeup(dev, 1);
 517         pm_runtime_set_autosuspend_delay(&usb_dev->dev, 15000);
 518         usb_enable_autosuspend(usb_dev);
 519 #endif
 520
 521         result = i2400m_setup(i2400m, I2400M_BRI_MAC_REINIT);
 522         if (result < 0) {
 523                 dev_err(dev, "cannot setup device: %d\n", result);
 524                 goto error_setup;
 525         }
 526         result = i2400mu_debugfs_add(i2400mu);
 527         if (result < 0) {
 528                 dev_err(dev, "Can't register i2400mu's debugfs: %d\n", result);
 529                 goto error_debugfs_add;
 530         }
 531         return 0;
 532
 533 error_debugfs_add:
 534         i2400m_release(i2400m);
 535 error_setup:
 536         usb_set_intfdata(iface, NULL);
 537         usb_put_dev(i2400mu->usb_dev);
 538         free_netdev(net_dev);
 539 error_alloc_netdev:
 540         return result;
 541 }
 542
 543
 544 /*
 545  * Disconect a i2400m from the system.
 546  *
 547  * i2400m_stop() has been called before, so al the rx and tx contexts
 548  * have been taken down already. Make sure the queue is stopped,
 549  * unregister netdev and i2400m, free and kill.
 550  */
 551 static
 552 void i2400mu_disconnect(struct usb_interface *iface)
 553 {
 554         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 555         struct i2400m *i2400m = &i2400mu->i2400m;
 556         struct net_device *net_dev = i2400m->wimax_dev.net_dev;
 557         struct device *dev = &iface->dev;
 558
 559         d_fnstart(3, dev, "(iface %p i2400m %p)\n", iface, i2400m);
 560
 561         debugfs_remove_recursive(i2400mu->debugfs_dentry);
 562         i2400m_release(i2400m);
 563         usb_set_intfdata(iface, NULL);
 564         usb_put_dev(i2400mu->usb_dev);
 565         free_netdev(net_dev);
 566         d_fnend(3, dev, "(iface %p i2400m %p) = void\n", iface, i2400m);
 567 }
 568
 569
 570 /*
 571  * Get the device ready for USB port or system standby and hibernation
 572  *
 573  * USB port and system standby are handled the same.
 574  *
 575  * When the system hibernates, the USB device is powered down and then
 576  * up, so we don't really have to do much here, as it will be seen as
 577  * a reconnect. Still for simplicity we consider this case the same as
 578  * suspend, so that the device has a chance to do notify the base
 579  * station (if connected).
 580  *
 581  * So at the end, the three cases require common handling.
 582  *
 583  * If at the time of this call the device's firmware is not loaded,
 584  * nothing has to be done. Note we can be "loose" about not reading
 585  * i2400m->updown under i2400m->init_mutex. If it happens to change
 586  * inmediately, other parts of the call flow will fail and effectively
 587  * catch it.
 588  *
 589  * If the firmware is loaded, we need to:
 590  *
 591  *  - tell the device to go into host interface power save mode, wait
 592  *    for it to ack
 593  *
 594  *    This is quite more interesting than it is; we need to execute a
 595  *    command, but this time, we don't want the code in usb-{tx,rx}.c
 596  *    to call the usb_autopm_get/put_interface() barriers as it'd
 597  *    deadlock, so we need to decrement i2400mu->do_autopm, that acts
 598  *    as a poor man's semaphore. Ugly, but it works.
 599  *
 600  *    As well, the device might refuse going to sleep for whichever
 601  *    reason. In this case we just fail. For system suspend/hibernate,
 602  *    we *can't* fail. We check PM_EVENT_AUTO to see if the
 603  *    suspend call comes from the USB stack or from the system and act
 604  *    in consequence.
 605  *
 606  *  - stop the notification endpoint polling
 607  */
 608 static
 609 int i2400mu_suspend(struct usb_interface *iface, pm_message_t pm_msg)
 610 {
 611         int result = 0;
 612         struct device *dev = &iface->dev;
 613         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 614         unsigned is_autosuspend = 0;
 615         struct i2400m *i2400m = &i2400mu->i2400m;
 616
 617 #ifdef CONFIG_PM
 618         if (pm_msg.event & PM_EVENT_AUTO)
 619                 is_autosuspend = 1;
 620 #endif
 621
 622         d_fnstart(3, dev, "(iface %p pm_msg %u)\n", iface, pm_msg.event);
 623         rmb();          /* see i2400m->updown's documentation  */
 624         if (i2400m->updown == 0)
 625                 goto no_firmware;
 626         if (i2400m->state == I2400M_SS_DATA_PATH_CONNECTED && is_autosuspend) {
 627                 /* ugh -- the device is connected and this suspend
 628                  * request is an autosuspend one (not a system standby
 629                  * / hibernate).
 630                  *
 631                  * The only way the device can go to standby is if the
 632                  * link with the base station is in IDLE mode; that
 633                  * were the case, we'd be in status
 634                  * I2400M_SS_CONNECTED_IDLE. But we are not.
 635                  *
 636                  * If we *tell* him to go power save now, it'll reset
 637                  * as a precautionary measure, so if this is an
 638                  * autosuspend thing, say no and it'll come back
 639                  * later, when the link is IDLE
 640                  */
 641                 result = -EBADF;
 642                 d_printf(1, dev, "fw up, link up, not-idle, autosuspend: "
 643                          "not entering powersave\n");
 644                 goto error_not_now;
 645         }
 646         d_printf(1, dev, "fw up: entering powersave\n");
 647         atomic_dec(&i2400mu->do_autopm);
 648         result = i2400m_cmd_enter_powersave(i2400m);
 649         atomic_inc(&i2400mu->do_autopm);
 650         if (result < 0 && !is_autosuspend) {
 651                 /* System suspend, can't fail */
 652                 dev_err(dev, "failed to suspend, will reset on resume\n");
 653                 result = 0;
 654         }
 655         if (result < 0)
 656                 goto error_enter_powersave;
 657         i2400mu_notification_release(i2400mu);
 658         d_printf(1, dev, "powersave requested\n");
 659 error_enter_powersave:
 660 error_not_now:
 661 no_firmware:
 662         d_fnend(3, dev, "(iface %p pm_msg %u) = %d\n",
 663                 iface, pm_msg.event, result);
 664         return result;
 665 }
 666
 667
 668 static
 669 int i2400mu_resume(struct usb_interface *iface)
 670 {
 671         int ret = 0;
 672         struct device *dev = &iface->dev;
 673         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 674         struct i2400m *i2400m = &i2400mu->i2400m;
 675
 676         d_fnstart(3, dev, "(iface %p)\n", iface);
 677         rmb();          /* see i2400m->updown's documentation  */
 678         if (i2400m->updown == 0) {
 679                 d_printf(1, dev, "fw was down, no resume neeed\n");
 680                 goto out;
 681         }
 682         d_printf(1, dev, "fw was up, resuming\n");
 683         i2400mu_notification_setup(i2400mu);
 684         /* USB has flow control, so we don't need to give it time to
 685          * come back; otherwise, we'd use something like a get-state
 686          * command... */
 687 out:
 688         d_fnend(3, dev, "(iface %p) = %d\n", iface, ret);
 689         return ret;
 690 }
 691
 692
 693 static
 694 int i2400mu_reset_resume(struct usb_interface *iface)
 695 {
 696         int result;
 697         struct device *dev = &iface->dev;
 698         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 699         struct i2400m *i2400m = &i2400mu->i2400m;
 700
 701         d_fnstart(3, dev, "(iface %p)\n", iface);
 702         result = i2400m_dev_reset_handle(i2400m, "device reset on resume");
 703         d_fnend(3, dev, "(iface %p) = %d\n", iface, result);
 704         return result < 0 ? result : 0;
 705 }
 706
 707
 708 /*
 709  * Another driver or user space is triggering a reset on the device
 710  * which contains the interface passed as an argument. Cease IO and
 711  * save any device state you need to restore.
 712  *
 713  * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if
 714  * you are in atomic context.
 715  */
 716 static
 717 int i2400mu_pre_reset(struct usb_interface *iface)
 718 {
 719         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 720         return i2400m_pre_reset(&i2400mu->i2400m);
 721 }
 722
 723
 724 /*
 725  * The reset has completed.  Restore any saved device state and begin
 726  * using the device again.
 727  *
 728  * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if
 729  * you are in atomic context.
 730  */
 731 static
 732 int i2400mu_post_reset(struct usb_interface *iface)
 733 {
 734         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 735         return i2400m_post_reset(&i2400mu->i2400m);
 736 }
 737
 738
 739 static
 740 struct usb_device_id i2400mu_id_table[] = {
 741         { USB_DEVICE(0x8086, USB_DEVICE_ID_I6050) },
 742         { USB_DEVICE(0x8086, USB_DEVICE_ID_I6050_2) },
 743         { USB_DEVICE(0x8086, USB_DEVICE_ID_I6250) },
 744         { USB_DEVICE(0x8086, 0x0181) },
 745         { USB_DEVICE(0x8086, 0x1403) },
 746         { USB_DEVICE(0x8086, 0x1405) },
 747         { USB_DEVICE(0x8086, 0x0180) },
 748         { USB_DEVICE(0x8086, 0x0182) },
 749         { USB_DEVICE(0x8086, 0x1406) },
 750         { USB_DEVICE(0x8086, 0x1403) },
 751         { },
 752 };
 753 MODULE_DEVICE_TABLE(usb, i2400mu_id_table);
 754
 755
 756 static
 757 struct usb_driver i2400mu_driver = {
 758         .name = KBUILD_MODNAME,
 759         .suspend = i2400mu_suspend,
 760         .resume = i2400mu_resume,
 761         .reset_resume = i2400mu_reset_resume,
 762         .probe = i2400mu_probe,
 763         .disconnect = i2400mu_disconnect,
 764         .pre_reset = i2400mu_pre_reset,
 765         .post_reset = i2400mu_post_reset,
 766         .id_table = i2400mu_id_table,
 767         .supports_autosuspend = 1,
 768 };
 769
 770 static
 771 int __init i2400mu_driver_init(void)
 772 {
 773         d_parse_params(D_LEVEL, D_LEVEL_SIZE, i2400mu_debug_params,
 774                        "i2400m_usb.debug");
 775         return usb_register(&i2400mu_driver);
 776 }
 777 module_init(i2400mu_driver_init);
 778
 779
 780 static
 781 void __exit i2400mu_driver_exit(void)
 782 {
 783         usb_deregister(&i2400mu_driver);
 784 }
 785 module_exit(i2400mu_driver_exit);
 786
 787 MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
 788 MODULE_DESCRIPTION("Driver for USB based Intel Wireless WiMAX Connection 2400M "
 789                    "(5x50 & 6050)");
 790 MODULE_LICENSE("GPL");
 791 MODULE_FIRMWARE(I2400MU_FW_FILE_NAME_v1_5);
 792 MODULE_FIRMWARE(I6050U_FW_FILE_NAME_v1_5);