drivers/net/wimax/i2400m/usb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Intel Wireless WiMAX Connection 2400m
   4  * Linux driver model glue for USB device, reset & fw upload
   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  * See i2400m-usb.h for a general description of this driver.
  11  *
  12  * This file implements driver model glue, and hook ups for the
  13  * generic driver to implement the bus-specific functions (device
  14  * communication setup/tear down, firmware upload and resetting).
  15  *
  16  * ROADMAP
  17  *
  18  * i2400mu_probe()
  19  *   alloc_netdev()...
  20  *     i2400mu_netdev_setup()
  21  *       i2400mu_init()
  22  *       i2400m_netdev_setup()
  23  *   i2400m_setup()...
  24  *
  25  * i2400mu_disconnect
  26  *   i2400m_release()
  27  *   free_netdev()
  28  *
  29  * i2400mu_suspend()
  30  *   i2400m_cmd_enter_powersave()
  31  *   i2400mu_notification_release()
  32  *
  33  * i2400mu_resume()
  34  *   i2400mu_notification_setup()
  35  *
  36  * i2400mu_bus_dev_start()        Called by i2400m_dev_start() [who is
  37  *   i2400mu_tx_setup()           called by i2400m_setup()]
  38  *   i2400mu_rx_setup()
  39  *   i2400mu_notification_setup()
  40  *
  41  * i2400mu_bus_dev_stop()         Called by i2400m_dev_stop() [who is
  42  *   i2400mu_notification_release()  called by i2400m_release()]
  43  *   i2400mu_rx_release()
  44  *   i2400mu_tx_release()
  45  *
  46  * i2400mu_bus_reset()            Called by i2400m_reset
  47  *   __i2400mu_reset()
  48  *     __i2400mu_send_barker()
  49  *   usb_reset_device()
  50  */
  51 #include "i2400m-usb.h"
  52 #include <linux/wimax/i2400m.h>
  53 #include <linux/debugfs.h>
  54 #include <linux/slab.h>
  55 #include <linux/module.h>
  56
  57
  58 #define D_SUBMODULE usb
  59 #include "usb-debug-levels.h"
  60
  61 static char i2400mu_debug_params[128];
  62 module_param_string(debug, i2400mu_debug_params, sizeof(i2400mu_debug_params),
  63                     0644);
  64 MODULE_PARM_DESC(debug,
  65                  "String of space-separated NAME:VALUE pairs, where NAMEs "
  66                  "are the different debug submodules and VALUE are the "
  67                  "initial debug value to set.");
  68
  69 /* Our firmware file name */
  70 static const char *i2400mu_bus_fw_names_5x50[] = {
  71 #define I2400MU_FW_FILE_NAME_v1_5 "i2400m-fw-usb-1.5.sbcf"
  72         I2400MU_FW_FILE_NAME_v1_5,
  73 #define I2400MU_FW_FILE_NAME_v1_4 "i2400m-fw-usb-1.4.sbcf"
  74         I2400MU_FW_FILE_NAME_v1_4,
  75         NULL,
  76 };
  77
  78
  79 static const char *i2400mu_bus_fw_names_6050[] = {
  80 #define I6050U_FW_FILE_NAME_v1_5 "i6050-fw-usb-1.5.sbcf"
  81         I6050U_FW_FILE_NAME_v1_5,
  82         NULL,
  83 };
  84
  85
  86 static
  87 int i2400mu_bus_dev_start(struct i2400m *i2400m)
  88 {
  89         int result;
  90         struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
  91         struct device *dev = &i2400mu->usb_iface->dev;
  92
  93         d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
  94         result = i2400mu_tx_setup(i2400mu);
  95         if (result < 0)
  96                 goto error_usb_tx_setup;
  97         result = i2400mu_rx_setup(i2400mu);
  98         if (result < 0)
  99                 goto error_usb_rx_setup;
 100         result = i2400mu_notification_setup(i2400mu);
 101         if (result < 0)
 102                 goto error_notif_setup;
 103         d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
 104         return result;
 105
 106 error_notif_setup:
 107         i2400mu_rx_release(i2400mu);
 108 error_usb_rx_setup:
 109         i2400mu_tx_release(i2400mu);
 110 error_usb_tx_setup:
 111         d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
 112         return result;
 113 }
 114
 115
 116 static
 117 void i2400mu_bus_dev_stop(struct i2400m *i2400m)
 118 {
 119         struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 120         struct device *dev = &i2400mu->usb_iface->dev;
 121
 122         d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
 123         i2400mu_notification_release(i2400mu);
 124         i2400mu_rx_release(i2400mu);
 125         i2400mu_tx_release(i2400mu);
 126         d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
 127 }
 128
 129
 130 /*
 131  * Sends a barker buffer to the device
 132  *
 133  * This helper will allocate a kmalloced buffer and use it to transmit
 134  * (then free it). Reason for this is that other arches cannot use
 135  * stack/vmalloc/text areas for DMA transfers.
 136  *
 137  * Error recovery here is simpler: anything is considered a hard error
 138  * and will move the reset code to use a last-resort bus-based reset.
 139  */
 140 static
 141 int __i2400mu_send_barker(struct i2400mu *i2400mu,
 142                           const __le32 *barker,
 143                           size_t barker_size,
 144                           unsigned endpoint)
 145 {
 146         struct usb_endpoint_descriptor *epd = NULL;
 147         int pipe, actual_len, ret;
 148         struct device *dev = &i2400mu->usb_iface->dev;
 149         void *buffer;
 150         int do_autopm = 1;
 151
 152         ret = usb_autopm_get_interface(i2400mu->usb_iface);
 153         if (ret < 0) {
 154                 dev_err(dev, "RESET: can't get autopm: %d\n", ret);
 155                 do_autopm = 0;
 156         }
 157         ret = -ENOMEM;
 158         buffer = kmalloc(barker_size, GFP_KERNEL);
 159         if (buffer == NULL)
 160                 goto error_kzalloc;
 161         epd = usb_get_epd(i2400mu->usb_iface, endpoint);
 162         pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
 163         memcpy(buffer, barker, barker_size);
 164 retry:
 165         ret = usb_bulk_msg(i2400mu->usb_dev, pipe, buffer, barker_size,
 166                            &actual_len, 200);
 167         switch (ret) {
 168         case 0:
 169                 if (actual_len != barker_size) {        /* Too short? drop it */
 170                         dev_err(dev, "E: %s: short write (%d B vs %zu "
 171                                 "expected)\n",
 172                                 __func__, actual_len, barker_size);
 173                         ret = -EIO;
 174                 }
 175                 break;
 176         case -EPIPE:
 177                 /*
 178                  * Stall -- maybe the device is choking with our
 179                  * requests. Clear it and give it some time. If they
 180                  * happen to often, it might be another symptom, so we
 181                  * reset.
 182                  *
 183                  * No error handling for usb_clear_halt(0; if it
 184                  * works, the retry works; if it fails, this switch
 185                  * does the error handling for us.
 186                  */
 187                 if (edc_inc(&i2400mu->urb_edc,
 188                             10 * EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
 189                         dev_err(dev, "E: %s: too many stalls in "
 190                                 "URB; resetting device\n", __func__);
 191                         usb_queue_reset_device(i2400mu->usb_iface);
 192                         /* fallthrough */
 193                 } else {
 194                         usb_clear_halt(i2400mu->usb_dev, pipe);
 195                         msleep(10);     /* give the device some time */
 196                         goto retry;
 197                 }
 198                 fallthrough;
 199         case -EINVAL:                   /* while removing driver */
 200         case -ENODEV:                   /* dev disconnect ... */
 201         case -ENOENT:                   /* just ignore it */
 202         case -ESHUTDOWN:                /* and exit */
 203         case -ECONNRESET:
 204                 ret = -ESHUTDOWN;
 205                 break;
 206         default:                        /* Some error? */
 207                 if (edc_inc(&i2400mu->urb_edc,
 208                             EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
 209                         dev_err(dev, "E: %s: maximum errors in URB "
 210                                 "exceeded; resetting device\n",
 211                                 __func__);
 212                         usb_queue_reset_device(i2400mu->usb_iface);
 213                 } else {
 214                         dev_warn(dev, "W: %s: cannot send URB: %d\n",
 215                                  __func__, ret);
 216                         goto retry;
 217                 }
 218         }
 219         kfree(buffer);
 220 error_kzalloc:
 221         if (do_autopm)
 222                 usb_autopm_put_interface(i2400mu->usb_iface);
 223         return ret;
 224 }
 225
 226
 227 /*
 228  * Reset a device at different levels (warm, cold or bus)
 229  *
 230  * @i2400m: device descriptor
 231  * @reset_type: soft, warm or bus reset (I2400M_RT_WARM/SOFT/BUS)
 232  *
 233  * Warm and cold resets get a USB reset if they fail.
 234  *
 235  * Warm reset:
 236  *
 237  * The device will be fully reset internally, but won't be
 238  * disconnected from the USB bus (so no reenumeration will
 239  * happen). Firmware upload will be necessary.
 240  *
 241  * The device will send a reboot barker in the notification endpoint
 242  * that will trigger the driver to reinitialize the state
 243  * automatically from notif.c:i2400m_notification_grok() into
 244  * i2400m_dev_bootstrap_delayed().
 245  *
 246  * Cold and bus (USB) reset:
 247  *
 248  * The device will be fully reset internally, disconnected from the
 249  * USB bus an a reenumeration will happen. Firmware upload will be
 250  * necessary. Thus, we don't do any locking or struct
 251  * reinitialization, as we are going to be fully disconnected and
 252  * reenumerated.
 253  *
 254  * Note we need to return -ENODEV if a warm reset was requested and we
 255  * had to resort to a bus reset. See i2400m_op_reset(), wimax_reset()
 256  * and wimax_dev->op_reset.
 257  *
 258  * WARNING: no driver state saved/fixed
 259  */
 260 static
 261 int i2400mu_bus_reset(struct i2400m *i2400m, enum i2400m_reset_type rt)
 262 {
 263         int result;
 264         struct i2400mu *i2400mu =
 265                 container_of(i2400m, struct i2400mu, i2400m);
 266         struct device *dev = i2400m_dev(i2400m);
 267         static const __le32 i2400m_WARM_BOOT_BARKER[4] = {
 268                 cpu_to_le32(I2400M_WARM_RESET_BARKER),
 269                 cpu_to_le32(I2400M_WARM_RESET_BARKER),
 270                 cpu_to_le32(I2400M_WARM_RESET_BARKER),
 271                 cpu_to_le32(I2400M_WARM_RESET_BARKER),
 272         };
 273         static const __le32 i2400m_COLD_BOOT_BARKER[4] = {
 274                 cpu_to_le32(I2400M_COLD_RESET_BARKER),
 275                 cpu_to_le32(I2400M_COLD_RESET_BARKER),
 276                 cpu_to_le32(I2400M_COLD_RESET_BARKER),
 277                 cpu_to_le32(I2400M_COLD_RESET_BARKER),
 278         };
 279
 280         d_fnstart(3, dev, "(i2400m %p rt %u)\n", i2400m, rt);
 281         if (rt == I2400M_RT_WARM)
 282                 result = __i2400mu_send_barker(
 283                         i2400mu, i2400m_WARM_BOOT_BARKER,
 284                         sizeof(i2400m_WARM_BOOT_BARKER),
 285                         i2400mu->endpoint_cfg.bulk_out);
 286         else if (rt == I2400M_RT_COLD)
 287                 result = __i2400mu_send_barker(
 288                         i2400mu, i2400m_COLD_BOOT_BARKER,
 289                         sizeof(i2400m_COLD_BOOT_BARKER),
 290                         i2400mu->endpoint_cfg.reset_cold);
 291         else if (rt == I2400M_RT_BUS) {
 292                 result = usb_reset_device(i2400mu->usb_dev);
 293                 switch (result) {
 294                 case 0:
 295                 case -EINVAL:   /* device is gone */
 296                 case -ENODEV:
 297                 case -ENOENT:
 298                 case -ESHUTDOWN:
 299                         result = 0;
 300                         break;  /* We assume the device is disconnected */
 301                 default:
 302                         dev_err(dev, "USB reset failed (%d), giving up!\n",
 303                                 result);
 304                 }
 305         } else {
 306                 result = -EINVAL;       /* shut gcc up in certain arches */
 307                 BUG();
 308         }
 309         if (result < 0
 310             && result != -EINVAL        /* device is gone */
 311             && rt != I2400M_RT_BUS) {
 312                 /*
 313                  * Things failed -- resort to lower level reset, that
 314                  * we queue in another context; the reason for this is
 315                  * that the pre and post reset functionality requires
 316                  * the i2400m->init_mutex; RT_WARM and RT_COLD can
 317                  * come from areas where i2400m->init_mutex is taken.
 318                  */
 319                 dev_err(dev, "%s reset failed (%d); trying USB reset\n",
 320                         rt == I2400M_RT_WARM ? "warm" : "cold", result);
 321                 usb_queue_reset_device(i2400mu->usb_iface);
 322                 result = -ENODEV;
 323         }
 324         d_fnend(3, dev, "(i2400m %p rt %u) = %d\n", i2400m, rt, result);
 325         return result;
 326 }
 327
 328 static void i2400mu_get_drvinfo(struct net_device *net_dev,
 329                                 struct ethtool_drvinfo *info)
 330 {
 331         struct i2400m *i2400m = net_dev_to_i2400m(net_dev);
 332         struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 333         struct usb_device *udev = i2400mu->usb_dev;
 334
 335         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
 336         strlcpy(info->fw_version, i2400m->fw_name ? : "",
 337                 sizeof(info->fw_version));
 338         usb_make_path(udev, info->bus_info, sizeof(info->bus_info));
 339 }
 340
 341 static const struct ethtool_ops i2400mu_ethtool_ops = {
 342         .get_drvinfo = i2400mu_get_drvinfo,
 343         .get_link = ethtool_op_get_link,
 344 };
 345
 346 static
 347 void i2400mu_netdev_setup(struct net_device *net_dev)
 348 {
 349         struct i2400m *i2400m = net_dev_to_i2400m(net_dev);
 350         struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 351         i2400mu_init(i2400mu);
 352         i2400m_netdev_setup(net_dev);
 353         net_dev->ethtool_ops = &i2400mu_ethtool_ops;
 354 }
 355
 356
 357 /*
 358  * Debug levels control; see debug.h
 359  */
 360 struct d_level D_LEVEL[] = {
 361         D_SUBMODULE_DEFINE(usb),
 362         D_SUBMODULE_DEFINE(fw),
 363         D_SUBMODULE_DEFINE(notif),
 364         D_SUBMODULE_DEFINE(rx),
 365         D_SUBMODULE_DEFINE(tx),
 366 };
 367 size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
 368
 369 static
 370 void i2400mu_debugfs_add(struct i2400mu *i2400mu)
 371 {
 372         struct dentry *dentry = i2400mu->i2400m.wimax_dev.debugfs_dentry;
 373
 374         dentry = debugfs_create_dir("i2400m-usb", dentry);
 375         i2400mu->debugfs_dentry = dentry;
 376
 377         d_level_register_debugfs("dl_", usb, dentry);
 378         d_level_register_debugfs("dl_", fw, dentry);
 379         d_level_register_debugfs("dl_", notif, dentry);
 380         d_level_register_debugfs("dl_", rx, dentry);
 381         d_level_register_debugfs("dl_", tx, dentry);
 382
 383         /* Don't touch these if you don't know what you are doing */
 384         debugfs_create_u8("rx_size_auto_shrink", 0600, dentry,
 385                           &i2400mu->rx_size_auto_shrink);
 386
 387         debugfs_create_size_t("rx_size", 0600, dentry, &i2400mu->rx_size);
 388 }
 389
 390
 391 static struct device_type i2400mu_type = {
 392         .name   = "wimax",
 393 };
 394
 395 /*
 396  * Probe a i2400m interface and register it
 397  *
 398  * @iface:   USB interface to link to
 399  * @id:      USB class/subclass/protocol id
 400  * @returns: 0 if ok, < 0 errno code on error.
 401  *
 402  * Alloc a net device, initialize the bus-specific details and then
 403  * calls the bus-generic initialization routine. That will register
 404  * the wimax and netdev devices, upload the firmware [using
 405  * _bus_bm_*()], call _bus_dev_start() to finalize the setup of the
 406  * communication with the device and then will start to talk to it to
 407  * finnish setting it up.
 408  */
 409 static
 410 int i2400mu_probe(struct usb_interface *iface,
 411                   const struct usb_device_id *id)
 412 {
 413         int result;
 414         struct net_device *net_dev;
 415         struct device *dev = &iface->dev;
 416         struct i2400m *i2400m;
 417         struct i2400mu *i2400mu;
 418         struct usb_device *usb_dev = interface_to_usbdev(iface);
 419
 420         if (iface->cur_altsetting->desc.bNumEndpoints < 4)
 421                 return -ENODEV;
 422
 423         if (usb_dev->speed != USB_SPEED_HIGH)
 424                 dev_err(dev, "device not connected as high speed\n");
 425
 426         /* Allocate instance [calls i2400m_netdev_setup() on it]. */
 427         result = -ENOMEM;
 428         net_dev = alloc_netdev(sizeof(*i2400mu), "wmx%d", NET_NAME_UNKNOWN,
 429                                i2400mu_netdev_setup);
 430         if (net_dev == NULL) {
 431                 dev_err(dev, "no memory for network device instance\n");
 432                 goto error_alloc_netdev;
 433         }
 434         SET_NETDEV_DEV(net_dev, dev);
 435         SET_NETDEV_DEVTYPE(net_dev, &i2400mu_type);
 436         i2400m = net_dev_to_i2400m(net_dev);
 437         i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 438         i2400m->wimax_dev.net_dev = net_dev;
 439         i2400mu->usb_dev = usb_get_dev(usb_dev);
 440         i2400mu->usb_iface = iface;
 441         usb_set_intfdata(iface, i2400mu);
 442
 443         i2400m->bus_tx_block_size = I2400MU_BLK_SIZE;
 444         /*
 445          * Room required in the Tx queue for USB message to accommodate
 446          * a smallest payload while allocating header space is 16 bytes.
 447          * Adding this room  for the new tx message increases the
 448          * possibilities of including any payload with size <= 16 bytes.
 449          */
 450         i2400m->bus_tx_room_min = I2400MU_BLK_SIZE;
 451         i2400m->bus_pl_size_max = I2400MU_PL_SIZE_MAX;
 452         i2400m->bus_setup = NULL;
 453         i2400m->bus_dev_start = i2400mu_bus_dev_start;
 454         i2400m->bus_dev_stop = i2400mu_bus_dev_stop;
 455         i2400m->bus_release = NULL;
 456         i2400m->bus_tx_kick = i2400mu_bus_tx_kick;
 457         i2400m->bus_reset = i2400mu_bus_reset;
 458         i2400m->bus_bm_retries = I2400M_USB_BOOT_RETRIES;
 459         i2400m->bus_bm_cmd_send = i2400mu_bus_bm_cmd_send;
 460         i2400m->bus_bm_wait_for_ack = i2400mu_bus_bm_wait_for_ack;
 461         i2400m->bus_bm_mac_addr_impaired = 0;
 462
 463         switch (id->idProduct) {
 464         case USB_DEVICE_ID_I6050:
 465         case USB_DEVICE_ID_I6050_2:
 466         case USB_DEVICE_ID_I6150:
 467         case USB_DEVICE_ID_I6150_2:
 468         case USB_DEVICE_ID_I6150_3:
 469         case USB_DEVICE_ID_I6250:
 470                 i2400mu->i6050 = 1;
 471                 break;
 472         default:
 473                 break;
 474         }
 475
 476         if (i2400mu->i6050) {
 477                 i2400m->bus_fw_names = i2400mu_bus_fw_names_6050;
 478                 i2400mu->endpoint_cfg.bulk_out = 0;
 479                 i2400mu->endpoint_cfg.notification = 3;
 480                 i2400mu->endpoint_cfg.reset_cold = 2;
 481                 i2400mu->endpoint_cfg.bulk_in = 1;
 482         } else {
 483                 i2400m->bus_fw_names = i2400mu_bus_fw_names_5x50;
 484                 i2400mu->endpoint_cfg.bulk_out = 0;
 485                 i2400mu->endpoint_cfg.notification = 1;
 486                 i2400mu->endpoint_cfg.reset_cold = 2;
 487                 i2400mu->endpoint_cfg.bulk_in = 3;
 488         }
 489 #ifdef CONFIG_PM
 490         iface->needs_remote_wakeup = 1;         /* autosuspend (15s delay) */
 491         device_init_wakeup(dev, 1);
 492         pm_runtime_set_autosuspend_delay(&usb_dev->dev, 15000);
 493         usb_enable_autosuspend(usb_dev);
 494 #endif
 495
 496         result = i2400m_setup(i2400m, I2400M_BRI_MAC_REINIT);
 497         if (result < 0) {
 498                 dev_err(dev, "cannot setup device: %d\n", result);
 499                 goto error_setup;
 500         }
 501         i2400mu_debugfs_add(i2400mu);
 502         return 0;
 503
 504 error_setup:
 505         usb_set_intfdata(iface, NULL);
 506         usb_put_dev(i2400mu->usb_dev);
 507         free_netdev(net_dev);
 508 error_alloc_netdev:
 509         return result;
 510 }
 511
 512
 513 /*
 514  * Disconnect a i2400m from the system.
 515  *
 516  * i2400m_stop() has been called before, so al the rx and tx contexts
 517  * have been taken down already. Make sure the queue is stopped,
 518  * unregister netdev and i2400m, free and kill.
 519  */
 520 static
 521 void i2400mu_disconnect(struct usb_interface *iface)
 522 {
 523         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 524         struct i2400m *i2400m = &i2400mu->i2400m;
 525         struct net_device *net_dev = i2400m->wimax_dev.net_dev;
 526         struct device *dev = &iface->dev;
 527
 528         d_fnstart(3, dev, "(iface %p i2400m %p)\n", iface, i2400m);
 529
 530         debugfs_remove_recursive(i2400mu->debugfs_dentry);
 531         i2400m_release(i2400m);
 532         usb_set_intfdata(iface, NULL);
 533         usb_put_dev(i2400mu->usb_dev);
 534         free_netdev(net_dev);
 535         d_fnend(3, dev, "(iface %p i2400m %p) = void\n", iface, i2400m);
 536 }
 537
 538
 539 /*
 540  * Get the device ready for USB port or system standby and hibernation
 541  *
 542  * USB port and system standby are handled the same.
 543  *
 544  * When the system hibernates, the USB device is powered down and then
 545  * up, so we don't really have to do much here, as it will be seen as
 546  * a reconnect. Still for simplicity we consider this case the same as
 547  * suspend, so that the device has a chance to do notify the base
 548  * station (if connected).
 549  *
 550  * So at the end, the three cases require common handling.
 551  *
 552  * If at the time of this call the device's firmware is not loaded,
 553  * nothing has to be done. Note we can be "loose" about not reading
 554  * i2400m->updown under i2400m->init_mutex. If it happens to change
 555  * inmediately, other parts of the call flow will fail and effectively
 556  * catch it.
 557  *
 558  * If the firmware is loaded, we need to:
 559  *
 560  *  - tell the device to go into host interface power save mode, wait
 561  *    for it to ack
 562  *
 563  *    This is quite more interesting than it is; we need to execute a
 564  *    command, but this time, we don't want the code in usb-{tx,rx}.c
 565  *    to call the usb_autopm_get/put_interface() barriers as it'd
 566  *    deadlock, so we need to decrement i2400mu->do_autopm, that acts
 567  *    as a poor man's semaphore. Ugly, but it works.
 568  *
 569  *    As well, the device might refuse going to sleep for whichever
 570  *    reason. In this case we just fail. For system suspend/hibernate,
 571  *    we *can't* fail. We check PMSG_IS_AUTO to see if the
 572  *    suspend call comes from the USB stack or from the system and act
 573  *    in consequence.
 574  *
 575  *  - stop the notification endpoint polling
 576  */
 577 static
 578 int i2400mu_suspend(struct usb_interface *iface, pm_message_t pm_msg)
 579 {
 580         int result = 0;
 581         struct device *dev = &iface->dev;
 582         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 583         unsigned is_autosuspend = 0;
 584         struct i2400m *i2400m = &i2400mu->i2400m;
 585
 586 #ifdef CONFIG_PM
 587         if (PMSG_IS_AUTO(pm_msg))
 588                 is_autosuspend = 1;
 589 #endif
 590
 591         d_fnstart(3, dev, "(iface %p pm_msg %u)\n", iface, pm_msg.event);
 592         rmb();          /* see i2400m->updown's documentation  */
 593         if (i2400m->updown == 0)
 594                 goto no_firmware;
 595         if (i2400m->state == I2400M_SS_DATA_PATH_CONNECTED && is_autosuspend) {
 596                 /* ugh -- the device is connected and this suspend
 597                  * request is an autosuspend one (not a system standby
 598                  * / hibernate).
 599                  *
 600                  * The only way the device can go to standby is if the
 601                  * link with the base station is in IDLE mode; that
 602                  * were the case, we'd be in status
 603                  * I2400M_SS_CONNECTED_IDLE. But we are not.
 604                  *
 605                  * If we *tell* him to go power save now, it'll reset
 606                  * as a precautionary measure, so if this is an
 607                  * autosuspend thing, say no and it'll come back
 608                  * later, when the link is IDLE
 609                  */
 610                 result = -EBADF;
 611                 d_printf(1, dev, "fw up, link up, not-idle, autosuspend: "
 612                          "not entering powersave\n");
 613                 goto error_not_now;
 614         }
 615         d_printf(1, dev, "fw up: entering powersave\n");
 616         atomic_dec(&i2400mu->do_autopm);
 617         result = i2400m_cmd_enter_powersave(i2400m);
 618         atomic_inc(&i2400mu->do_autopm);
 619         if (result < 0 && !is_autosuspend) {
 620                 /* System suspend, can't fail */
 621                 dev_err(dev, "failed to suspend, will reset on resume\n");
 622                 result = 0;
 623         }
 624         if (result < 0)
 625                 goto error_enter_powersave;
 626         i2400mu_notification_release(i2400mu);
 627         d_printf(1, dev, "powersave requested\n");
 628 error_enter_powersave:
 629 error_not_now:
 630 no_firmware:
 631         d_fnend(3, dev, "(iface %p pm_msg %u) = %d\n",
 632                 iface, pm_msg.event, result);
 633         return result;
 634 }
 635
 636
 637 static
 638 int i2400mu_resume(struct usb_interface *iface)
 639 {
 640         int ret = 0;
 641         struct device *dev = &iface->dev;
 642         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 643         struct i2400m *i2400m = &i2400mu->i2400m;
 644
 645         d_fnstart(3, dev, "(iface %p)\n", iface);
 646         rmb();          /* see i2400m->updown's documentation  */
 647         if (i2400m->updown == 0) {
 648                 d_printf(1, dev, "fw was down, no resume needed\n");
 649                 goto out;
 650         }
 651         d_printf(1, dev, "fw was up, resuming\n");
 652         i2400mu_notification_setup(i2400mu);
 653         /* USB has flow control, so we don't need to give it time to
 654          * come back; otherwise, we'd use something like a get-state
 655          * command... */
 656 out:
 657         d_fnend(3, dev, "(iface %p) = %d\n", iface, ret);
 658         return ret;
 659 }
 660
 661
 662 static
 663 int i2400mu_reset_resume(struct usb_interface *iface)
 664 {
 665         int result;
 666         struct device *dev = &iface->dev;
 667         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 668         struct i2400m *i2400m = &i2400mu->i2400m;
 669
 670         d_fnstart(3, dev, "(iface %p)\n", iface);
 671         result = i2400m_dev_reset_handle(i2400m, "device reset on resume");
 672         d_fnend(3, dev, "(iface %p) = %d\n", iface, result);
 673         return result < 0 ? result : 0;
 674 }
 675
 676
 677 /*
 678  * Another driver or user space is triggering a reset on the device
 679  * which contains the interface passed as an argument. Cease IO and
 680  * save any device state you need to restore.
 681  *
 682  * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if
 683  * you are in atomic context.
 684  */
 685 static
 686 int i2400mu_pre_reset(struct usb_interface *iface)
 687 {
 688         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 689         return i2400m_pre_reset(&i2400mu->i2400m);
 690 }
 691
 692
 693 /*
 694  * The reset has completed.  Restore any saved device state and begin
 695  * using the device again.
 696  *
 697  * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if
 698  * you are in atomic context.
 699  */
 700 static
 701 int i2400mu_post_reset(struct usb_interface *iface)
 702 {
 703         struct i2400mu *i2400mu = usb_get_intfdata(iface);
 704         return i2400m_post_reset(&i2400mu->i2400m);
 705 }
 706
 707
 708 static
 709 struct usb_device_id i2400mu_id_table[] = {
 710         { USB_DEVICE(0x8086, USB_DEVICE_ID_I6050) },
 711         { USB_DEVICE(0x8086, USB_DEVICE_ID_I6050_2) },
 712         { USB_DEVICE(0x8087, USB_DEVICE_ID_I6150) },
 713         { USB_DEVICE(0x8087, USB_DEVICE_ID_I6150_2) },
 714         { USB_DEVICE(0x8087, USB_DEVICE_ID_I6150_3) },
 715         { USB_DEVICE(0x8086, USB_DEVICE_ID_I6250) },
 716         { USB_DEVICE(0x8086, 0x0181) },
 717         { USB_DEVICE(0x8086, 0x1403) },
 718         { USB_DEVICE(0x8086, 0x1405) },
 719         { USB_DEVICE(0x8086, 0x0180) },
 720         { USB_DEVICE(0x8086, 0x0182) },
 721         { USB_DEVICE(0x8086, 0x1406) },
 722         { USB_DEVICE(0x8086, 0x1403) },
 723         { },
 724 };
 725 MODULE_DEVICE_TABLE(usb, i2400mu_id_table);
 726
 727
 728 static
 729 struct usb_driver i2400mu_driver = {
 730         .name = KBUILD_MODNAME,
 731         .suspend = i2400mu_suspend,
 732         .resume = i2400mu_resume,
 733         .reset_resume = i2400mu_reset_resume,
 734         .probe = i2400mu_probe,
 735         .disconnect = i2400mu_disconnect,
 736         .pre_reset = i2400mu_pre_reset,
 737         .post_reset = i2400mu_post_reset,
 738         .id_table = i2400mu_id_table,
 739         .supports_autosuspend = 1,
 740 };
 741
 742 static
 743 int __init i2400mu_driver_init(void)
 744 {
 745         d_parse_params(D_LEVEL, D_LEVEL_SIZE, i2400mu_debug_params,
 746                        "i2400m_usb.debug");
 747         return usb_register(&i2400mu_driver);
 748 }
 749 module_init(i2400mu_driver_init);
 750
 751
 752 static
 753 void __exit i2400mu_driver_exit(void)
 754 {
 755         usb_deregister(&i2400mu_driver);
 756 }
 757 module_exit(i2400mu_driver_exit);
 758
 759 MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
 760 MODULE_DESCRIPTION("Driver for USB based Intel Wireless WiMAX Connection 2400M "
 761                    "(5x50 & 6050)");
 762 MODULE_LICENSE("GPL");
 763 MODULE_FIRMWARE(I2400MU_FW_FILE_NAME_v1_5);
 764 MODULE_FIRMWARE(I6050U_FW_FILE_NAME_v1_5);