Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / wimax / i2400m / usb.c
diff --git a/kernel/drivers/net/wimax/i2400m/usb.c b/kernel/drivers/net/wimax/i2400m/usb.c
new file mode 100644 (file)
index 0000000..e7f5910
--- /dev/null
@@ -0,0 +1,817 @@
+/*
+ * Intel Wireless WiMAX Connection 2400m
+ * Linux driver model glue for USB device, reset & fw upload
+ *
+ *
+ * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com>
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ * Yanir Lubetkin <yanirx.lubetkin@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ *
+ * See i2400m-usb.h for a general description of this driver.
+ *
+ * This file implements driver model glue, and hook ups for the
+ * generic driver to implement the bus-specific functions (device
+ * communication setup/tear down, firmware upload and resetting).
+ *
+ * ROADMAP
+ *
+ * i2400mu_probe()
+ *   alloc_netdev()...
+ *     i2400mu_netdev_setup()
+ *       i2400mu_init()
+ *       i2400m_netdev_setup()
+ *   i2400m_setup()...
+ *
+ * i2400mu_disconnect
+ *   i2400m_release()
+ *   free_netdev()
+ *
+ * i2400mu_suspend()
+ *   i2400m_cmd_enter_powersave()
+ *   i2400mu_notification_release()
+ *
+ * i2400mu_resume()
+ *   i2400mu_notification_setup()
+ *
+ * i2400mu_bus_dev_start()        Called by i2400m_dev_start() [who is
+ *   i2400mu_tx_setup()           called by i2400m_setup()]
+ *   i2400mu_rx_setup()
+ *   i2400mu_notification_setup()
+ *
+ * i2400mu_bus_dev_stop()         Called by i2400m_dev_stop() [who is
+ *   i2400mu_notification_release()  called by i2400m_release()]
+ *   i2400mu_rx_release()
+ *   i2400mu_tx_release()
+ *
+ * i2400mu_bus_reset()            Called by i2400m_reset
+ *   __i2400mu_reset()
+ *     __i2400mu_send_barker()
+ *   usb_reset_device()
+ */
+#include "i2400m-usb.h"
+#include <linux/wimax/i2400m.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+
+#define D_SUBMODULE usb
+#include "usb-debug-levels.h"
+
+static char i2400mu_debug_params[128];
+module_param_string(debug, i2400mu_debug_params, sizeof(i2400mu_debug_params),
+                   0644);
+MODULE_PARM_DESC(debug,
+                "String of space-separated NAME:VALUE pairs, where NAMEs "
+                "are the different debug submodules and VALUE are the "
+                "initial debug value to set.");
+
+/* Our firmware file name */
+static const char *i2400mu_bus_fw_names_5x50[] = {
+#define I2400MU_FW_FILE_NAME_v1_5 "i2400m-fw-usb-1.5.sbcf"
+       I2400MU_FW_FILE_NAME_v1_5,
+#define I2400MU_FW_FILE_NAME_v1_4 "i2400m-fw-usb-1.4.sbcf"
+       I2400MU_FW_FILE_NAME_v1_4,
+       NULL,
+};
+
+
+static const char *i2400mu_bus_fw_names_6050[] = {
+#define I6050U_FW_FILE_NAME_v1_5 "i6050-fw-usb-1.5.sbcf"
+       I6050U_FW_FILE_NAME_v1_5,
+       NULL,
+};
+
+
+static
+int i2400mu_bus_dev_start(struct i2400m *i2400m)
+{
+       int result;
+       struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
+       struct device *dev = &i2400mu->usb_iface->dev;
+
+       d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+       result = i2400mu_tx_setup(i2400mu);
+       if (result < 0)
+               goto error_usb_tx_setup;
+       result = i2400mu_rx_setup(i2400mu);
+       if (result < 0)
+               goto error_usb_rx_setup;
+       result = i2400mu_notification_setup(i2400mu);
+       if (result < 0)
+               goto error_notif_setup;
+       d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
+       return result;
+
+error_notif_setup:
+       i2400mu_rx_release(i2400mu);
+error_usb_rx_setup:
+       i2400mu_tx_release(i2400mu);
+error_usb_tx_setup:
+       d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
+       return result;
+}
+
+
+static
+void i2400mu_bus_dev_stop(struct i2400m *i2400m)
+{
+       struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
+       struct device *dev = &i2400mu->usb_iface->dev;
+
+       d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+       i2400mu_notification_release(i2400mu);
+       i2400mu_rx_release(i2400mu);
+       i2400mu_tx_release(i2400mu);
+       d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
+}
+
+
+/*
+ * Sends a barker buffer to the device
+ *
+ * This helper will allocate a kmalloced buffer and use it to transmit
+ * (then free it). Reason for this is that other arches cannot use
+ * stack/vmalloc/text areas for DMA transfers.
+ *
+ * Error recovery here is simpler: anything is considered a hard error
+ * and will move the reset code to use a last-resort bus-based reset.
+ */
+static
+int __i2400mu_send_barker(struct i2400mu *i2400mu,
+                         const __le32 *barker,
+                         size_t barker_size,
+                         unsigned endpoint)
+{
+       struct usb_endpoint_descriptor *epd = NULL;
+       int pipe, actual_len, ret;
+       struct device *dev = &i2400mu->usb_iface->dev;
+       void *buffer;
+       int do_autopm = 1;
+
+       ret = usb_autopm_get_interface(i2400mu->usb_iface);
+       if (ret < 0) {
+               dev_err(dev, "RESET: can't get autopm: %d\n", ret);
+               do_autopm = 0;
+       }
+       ret = -ENOMEM;
+       buffer = kmalloc(barker_size, GFP_KERNEL);
+       if (buffer == NULL)
+               goto error_kzalloc;
+       epd = usb_get_epd(i2400mu->usb_iface, endpoint);
+       pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
+       memcpy(buffer, barker, barker_size);
+retry:
+       ret = usb_bulk_msg(i2400mu->usb_dev, pipe, buffer, barker_size,
+                          &actual_len, 200);
+       switch (ret) {
+       case 0:
+               if (actual_len != barker_size) {        /* Too short? drop it */
+                       dev_err(dev, "E: %s: short write (%d B vs %zu "
+                               "expected)\n",
+                               __func__, actual_len, barker_size);
+                       ret = -EIO;
+               }
+               break;
+       case -EPIPE:
+               /*
+                * Stall -- maybe the device is choking with our
+                * requests. Clear it and give it some time. If they
+                * happen to often, it might be another symptom, so we
+                * reset.
+                *
+                * No error handling for usb_clear_halt(0; if it
+                * works, the retry works; if it fails, this switch
+                * does the error handling for us.
+                */
+               if (edc_inc(&i2400mu->urb_edc,
+                           10 * EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
+                       dev_err(dev, "E: %s: too many stalls in "
+                               "URB; resetting device\n", __func__);
+                       usb_queue_reset_device(i2400mu->usb_iface);
+                       /* fallthrough */
+               } else {
+                       usb_clear_halt(i2400mu->usb_dev, pipe);
+                       msleep(10);     /* give the device some time */
+                       goto retry;
+               }
+       case -EINVAL:                   /* while removing driver */
+       case -ENODEV:                   /* dev disconnect ... */
+       case -ENOENT:                   /* just ignore it */
+       case -ESHUTDOWN:                /* and exit */
+       case -ECONNRESET:
+               ret = -ESHUTDOWN;
+               break;
+       default:                        /* Some error? */
+               if (edc_inc(&i2400mu->urb_edc,
+                           EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
+                       dev_err(dev, "E: %s: maximum errors in URB "
+                               "exceeded; resetting device\n",
+                               __func__);
+                       usb_queue_reset_device(i2400mu->usb_iface);
+               } else {
+                       dev_warn(dev, "W: %s: cannot send URB: %d\n",
+                                __func__, ret);
+                       goto retry;
+               }
+       }
+       kfree(buffer);
+error_kzalloc:
+       if (do_autopm)
+               usb_autopm_put_interface(i2400mu->usb_iface);
+       return ret;
+}
+
+
+/*
+ * Reset a device at different levels (warm, cold or bus)
+ *
+ * @i2400m: device descriptor
+ * @reset_type: soft, warm or bus reset (I2400M_RT_WARM/SOFT/BUS)
+ *
+ * Warm and cold resets get a USB reset if they fail.
+ *
+ * Warm reset:
+ *
+ * The device will be fully reset internally, but won't be
+ * disconnected from the USB bus (so no reenumeration will
+ * happen). Firmware upload will be necessary.
+ *
+ * The device will send a reboot barker in the notification endpoint
+ * that will trigger the driver to reinitialize the state
+ * automatically from notif.c:i2400m_notification_grok() into
+ * i2400m_dev_bootstrap_delayed().
+ *
+ * Cold and bus (USB) reset:
+ *
+ * The device will be fully reset internally, disconnected from the
+ * USB bus an a reenumeration will happen. Firmware upload will be
+ * necessary. Thus, we don't do any locking or struct
+ * reinitialization, as we are going to be fully disconnected and
+ * reenumerated.
+ *
+ * Note we need to return -ENODEV if a warm reset was requested and we
+ * had to resort to a bus reset. See i2400m_op_reset(), wimax_reset()
+ * and wimax_dev->op_reset.
+ *
+ * WARNING: no driver state saved/fixed
+ */
+static
+int i2400mu_bus_reset(struct i2400m *i2400m, enum i2400m_reset_type rt)
+{
+       int result;
+       struct i2400mu *i2400mu =
+               container_of(i2400m, struct i2400mu, i2400m);
+       struct device *dev = i2400m_dev(i2400m);
+       static const __le32 i2400m_WARM_BOOT_BARKER[4] = {
+               cpu_to_le32(I2400M_WARM_RESET_BARKER),
+               cpu_to_le32(I2400M_WARM_RESET_BARKER),
+               cpu_to_le32(I2400M_WARM_RESET_BARKER),
+               cpu_to_le32(I2400M_WARM_RESET_BARKER),
+       };
+       static const __le32 i2400m_COLD_BOOT_BARKER[4] = {
+               cpu_to_le32(I2400M_COLD_RESET_BARKER),
+               cpu_to_le32(I2400M_COLD_RESET_BARKER),
+               cpu_to_le32(I2400M_COLD_RESET_BARKER),
+               cpu_to_le32(I2400M_COLD_RESET_BARKER),
+       };
+
+       d_fnstart(3, dev, "(i2400m %p rt %u)\n", i2400m, rt);
+       if (rt == I2400M_RT_WARM)
+               result = __i2400mu_send_barker(
+                       i2400mu, i2400m_WARM_BOOT_BARKER,
+                       sizeof(i2400m_WARM_BOOT_BARKER),
+                       i2400mu->endpoint_cfg.bulk_out);
+       else if (rt == I2400M_RT_COLD)
+               result = __i2400mu_send_barker(
+                       i2400mu, i2400m_COLD_BOOT_BARKER,
+                       sizeof(i2400m_COLD_BOOT_BARKER),
+                       i2400mu->endpoint_cfg.reset_cold);
+       else if (rt == I2400M_RT_BUS) {
+               result = usb_reset_device(i2400mu->usb_dev);
+               switch (result) {
+               case 0:
+               case -EINVAL:   /* device is gone */
+               case -ENODEV:
+               case -ENOENT:
+               case -ESHUTDOWN:
+                       result = 0;
+                       break;  /* We assume the device is disconnected */
+               default:
+                       dev_err(dev, "USB reset failed (%d), giving up!\n",
+                               result);
+               }
+       } else {
+               result = -EINVAL;       /* shut gcc up in certain arches */
+               BUG();
+       }
+       if (result < 0
+           && result != -EINVAL        /* device is gone */
+           && rt != I2400M_RT_BUS) {
+               /*
+                * Things failed -- resort to lower level reset, that
+                * we queue in another context; the reason for this is
+                * that the pre and post reset functionality requires
+                * the i2400m->init_mutex; RT_WARM and RT_COLD can
+                * come from areas where i2400m->init_mutex is taken.
+                */
+               dev_err(dev, "%s reset failed (%d); trying USB reset\n",
+                       rt == I2400M_RT_WARM ? "warm" : "cold", result);
+               usb_queue_reset_device(i2400mu->usb_iface);
+               result = -ENODEV;
+       }
+       d_fnend(3, dev, "(i2400m %p rt %u) = %d\n", i2400m, rt, result);
+       return result;
+}
+
+static void i2400mu_get_drvinfo(struct net_device *net_dev,
+                                struct ethtool_drvinfo *info)
+{
+       struct i2400m *i2400m = net_dev_to_i2400m(net_dev);
+       struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
+       struct usb_device *udev = i2400mu->usb_dev;
+
+       strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
+       strlcpy(info->fw_version, i2400m->fw_name ? : "",
+               sizeof(info->fw_version));
+       usb_make_path(udev, info->bus_info, sizeof(info->bus_info));
+}
+
+static const struct ethtool_ops i2400mu_ethtool_ops = {
+       .get_drvinfo = i2400mu_get_drvinfo,
+       .get_link = ethtool_op_get_link,
+};
+
+static
+void i2400mu_netdev_setup(struct net_device *net_dev)
+{
+       struct i2400m *i2400m = net_dev_to_i2400m(net_dev);
+       struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
+       i2400mu_init(i2400mu);
+       i2400m_netdev_setup(net_dev);
+       net_dev->ethtool_ops = &i2400mu_ethtool_ops;
+}
+
+
+/*
+ * Debug levels control; see debug.h
+ */
+struct d_level D_LEVEL[] = {
+       D_SUBMODULE_DEFINE(usb),
+       D_SUBMODULE_DEFINE(fw),
+       D_SUBMODULE_DEFINE(notif),
+       D_SUBMODULE_DEFINE(rx),
+       D_SUBMODULE_DEFINE(tx),
+};
+size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
+
+
+#define __debugfs_register(prefix, name, parent)                       \
+do {                                                                   \
+       result = d_level_register_debugfs(prefix, name, parent);        \
+       if (result < 0)                                                 \
+               goto error;                                             \
+} while (0)
+
+
+static
+int i2400mu_debugfs_add(struct i2400mu *i2400mu)
+{
+       int result;
+       struct device *dev = &i2400mu->usb_iface->dev;
+       struct dentry *dentry = i2400mu->i2400m.wimax_dev.debugfs_dentry;
+       struct dentry *fd;
+
+       dentry = debugfs_create_dir("i2400m-usb", dentry);
+       result = PTR_ERR(dentry);
+       if (IS_ERR(dentry)) {
+               if (result == -ENODEV)
+                       result = 0;     /* No debugfs support */
+               goto error;
+       }
+       i2400mu->debugfs_dentry = dentry;
+       __debugfs_register("dl_", usb, dentry);
+       __debugfs_register("dl_", fw, dentry);
+       __debugfs_register("dl_", notif, dentry);
+       __debugfs_register("dl_", rx, dentry);
+       __debugfs_register("dl_", tx, dentry);
+
+       /* Don't touch these if you don't know what you are doing */
+       fd = debugfs_create_u8("rx_size_auto_shrink", 0600, dentry,
+                              &i2400mu->rx_size_auto_shrink);
+       result = PTR_ERR(fd);
+       if (IS_ERR(fd) && result != -ENODEV) {
+               dev_err(dev, "Can't create debugfs entry "
+                       "rx_size_auto_shrink: %d\n", result);
+               goto error;
+       }
+
+       fd = debugfs_create_size_t("rx_size", 0600, dentry,
+                                  &i2400mu->rx_size);
+       result = PTR_ERR(fd);
+       if (IS_ERR(fd) && result != -ENODEV) {
+               dev_err(dev, "Can't create debugfs entry "
+                       "rx_size: %d\n", result);
+               goto error;
+       }
+
+       return 0;
+
+error:
+       debugfs_remove_recursive(i2400mu->debugfs_dentry);
+       return result;
+}
+
+
+static struct device_type i2400mu_type = {
+       .name   = "wimax",
+};
+
+/*
+ * Probe a i2400m interface and register it
+ *
+ * @iface:   USB interface to link to
+ * @id:      USB class/subclass/protocol id
+ * @returns: 0 if ok, < 0 errno code on error.
+ *
+ * Alloc a net device, initialize the bus-specific details and then
+ * calls the bus-generic initialization routine. That will register
+ * the wimax and netdev devices, upload the firmware [using
+ * _bus_bm_*()], call _bus_dev_start() to finalize the setup of the
+ * communication with the device and then will start to talk to it to
+ * finnish setting it up.
+ */
+static
+int i2400mu_probe(struct usb_interface *iface,
+                 const struct usb_device_id *id)
+{
+       int result;
+       struct net_device *net_dev;
+       struct device *dev = &iface->dev;
+       struct i2400m *i2400m;
+       struct i2400mu *i2400mu;
+       struct usb_device *usb_dev = interface_to_usbdev(iface);
+
+       if (usb_dev->speed != USB_SPEED_HIGH)
+               dev_err(dev, "device not connected as high speed\n");
+
+       /* Allocate instance [calls i2400m_netdev_setup() on it]. */
+       result = -ENOMEM;
+       net_dev = alloc_netdev(sizeof(*i2400mu), "wmx%d", NET_NAME_UNKNOWN,
+                              i2400mu_netdev_setup);
+       if (net_dev == NULL) {
+               dev_err(dev, "no memory for network device instance\n");
+               goto error_alloc_netdev;
+       }
+       SET_NETDEV_DEV(net_dev, dev);
+       SET_NETDEV_DEVTYPE(net_dev, &i2400mu_type);
+       i2400m = net_dev_to_i2400m(net_dev);
+       i2400mu = container_of(i2400m, struct i2400mu, i2400m);
+       i2400m->wimax_dev.net_dev = net_dev;
+       i2400mu->usb_dev = usb_get_dev(usb_dev);
+       i2400mu->usb_iface = iface;
+       usb_set_intfdata(iface, i2400mu);
+
+       i2400m->bus_tx_block_size = I2400MU_BLK_SIZE;
+       /*
+        * Room required in the Tx queue for USB message to accommodate
+        * a smallest payload while allocating header space is 16 bytes.
+        * Adding this room  for the new tx message increases the
+        * possibilities of including any payload with size <= 16 bytes.
+        */
+       i2400m->bus_tx_room_min = I2400MU_BLK_SIZE;
+       i2400m->bus_pl_size_max = I2400MU_PL_SIZE_MAX;
+       i2400m->bus_setup = NULL;
+       i2400m->bus_dev_start = i2400mu_bus_dev_start;
+       i2400m->bus_dev_stop = i2400mu_bus_dev_stop;
+       i2400m->bus_release = NULL;
+       i2400m->bus_tx_kick = i2400mu_bus_tx_kick;
+       i2400m->bus_reset = i2400mu_bus_reset;
+       i2400m->bus_bm_retries = I2400M_USB_BOOT_RETRIES;
+       i2400m->bus_bm_cmd_send = i2400mu_bus_bm_cmd_send;
+       i2400m->bus_bm_wait_for_ack = i2400mu_bus_bm_wait_for_ack;
+       i2400m->bus_bm_mac_addr_impaired = 0;
+
+       switch (id->idProduct) {
+       case USB_DEVICE_ID_I6050:
+       case USB_DEVICE_ID_I6050_2:
+       case USB_DEVICE_ID_I6150:
+       case USB_DEVICE_ID_I6150_2:
+       case USB_DEVICE_ID_I6150_3:
+       case USB_DEVICE_ID_I6250:
+               i2400mu->i6050 = 1;
+               break;
+       default:
+               break;
+       }
+
+       if (i2400mu->i6050) {
+               i2400m->bus_fw_names = i2400mu_bus_fw_names_6050;
+               i2400mu->endpoint_cfg.bulk_out = 0;
+               i2400mu->endpoint_cfg.notification = 3;
+               i2400mu->endpoint_cfg.reset_cold = 2;
+               i2400mu->endpoint_cfg.bulk_in = 1;
+       } else {
+               i2400m->bus_fw_names = i2400mu_bus_fw_names_5x50;
+               i2400mu->endpoint_cfg.bulk_out = 0;
+               i2400mu->endpoint_cfg.notification = 1;
+               i2400mu->endpoint_cfg.reset_cold = 2;
+               i2400mu->endpoint_cfg.bulk_in = 3;
+       }
+#ifdef CONFIG_PM
+       iface->needs_remote_wakeup = 1;         /* autosuspend (15s delay) */
+       device_init_wakeup(dev, 1);
+       pm_runtime_set_autosuspend_delay(&usb_dev->dev, 15000);
+       usb_enable_autosuspend(usb_dev);
+#endif
+
+       result = i2400m_setup(i2400m, I2400M_BRI_MAC_REINIT);
+       if (result < 0) {
+               dev_err(dev, "cannot setup device: %d\n", result);
+               goto error_setup;
+       }
+       result = i2400mu_debugfs_add(i2400mu);
+       if (result < 0) {
+               dev_err(dev, "Can't register i2400mu's debugfs: %d\n", result);
+               goto error_debugfs_add;
+       }
+       return 0;
+
+error_debugfs_add:
+       i2400m_release(i2400m);
+error_setup:
+       usb_set_intfdata(iface, NULL);
+       usb_put_dev(i2400mu->usb_dev);
+       free_netdev(net_dev);
+error_alloc_netdev:
+       return result;
+}
+
+
+/*
+ * Disconect a i2400m from the system.
+ *
+ * i2400m_stop() has been called before, so al the rx and tx contexts
+ * have been taken down already. Make sure the queue is stopped,
+ * unregister netdev and i2400m, free and kill.
+ */
+static
+void i2400mu_disconnect(struct usb_interface *iface)
+{
+       struct i2400mu *i2400mu = usb_get_intfdata(iface);
+       struct i2400m *i2400m = &i2400mu->i2400m;
+       struct net_device *net_dev = i2400m->wimax_dev.net_dev;
+       struct device *dev = &iface->dev;
+
+       d_fnstart(3, dev, "(iface %p i2400m %p)\n", iface, i2400m);
+
+       debugfs_remove_recursive(i2400mu->debugfs_dentry);
+       i2400m_release(i2400m);
+       usb_set_intfdata(iface, NULL);
+       usb_put_dev(i2400mu->usb_dev);
+       free_netdev(net_dev);
+       d_fnend(3, dev, "(iface %p i2400m %p) = void\n", iface, i2400m);
+}
+
+
+/*
+ * Get the device ready for USB port or system standby and hibernation
+ *
+ * USB port and system standby are handled the same.
+ *
+ * When the system hibernates, the USB device is powered down and then
+ * up, so we don't really have to do much here, as it will be seen as
+ * a reconnect. Still for simplicity we consider this case the same as
+ * suspend, so that the device has a chance to do notify the base
+ * station (if connected).
+ *
+ * So at the end, the three cases require common handling.
+ *
+ * If at the time of this call the device's firmware is not loaded,
+ * nothing has to be done. Note we can be "loose" about not reading
+ * i2400m->updown under i2400m->init_mutex. If it happens to change
+ * inmediately, other parts of the call flow will fail and effectively
+ * catch it.
+ *
+ * If the firmware is loaded, we need to:
+ *
+ *  - tell the device to go into host interface power save mode, wait
+ *    for it to ack
+ *
+ *    This is quite more interesting than it is; we need to execute a
+ *    command, but this time, we don't want the code in usb-{tx,rx}.c
+ *    to call the usb_autopm_get/put_interface() barriers as it'd
+ *    deadlock, so we need to decrement i2400mu->do_autopm, that acts
+ *    as a poor man's semaphore. Ugly, but it works.
+ *
+ *    As well, the device might refuse going to sleep for whichever
+ *    reason. In this case we just fail. For system suspend/hibernate,
+ *    we *can't* fail. We check PMSG_IS_AUTO to see if the
+ *    suspend call comes from the USB stack or from the system and act
+ *    in consequence.
+ *
+ *  - stop the notification endpoint polling
+ */
+static
+int i2400mu_suspend(struct usb_interface *iface, pm_message_t pm_msg)
+{
+       int result = 0;
+       struct device *dev = &iface->dev;
+       struct i2400mu *i2400mu = usb_get_intfdata(iface);
+       unsigned is_autosuspend = 0;
+       struct i2400m *i2400m = &i2400mu->i2400m;
+
+#ifdef CONFIG_PM
+       if (PMSG_IS_AUTO(pm_msg))
+               is_autosuspend = 1;
+#endif
+
+       d_fnstart(3, dev, "(iface %p pm_msg %u)\n", iface, pm_msg.event);
+       rmb();          /* see i2400m->updown's documentation  */
+       if (i2400m->updown == 0)
+               goto no_firmware;
+       if (i2400m->state == I2400M_SS_DATA_PATH_CONNECTED && is_autosuspend) {
+               /* ugh -- the device is connected and this suspend
+                * request is an autosuspend one (not a system standby
+                * / hibernate).
+                *
+                * The only way the device can go to standby is if the
+                * link with the base station is in IDLE mode; that
+                * were the case, we'd be in status
+                * I2400M_SS_CONNECTED_IDLE. But we are not.
+                *
+                * If we *tell* him to go power save now, it'll reset
+                * as a precautionary measure, so if this is an
+                * autosuspend thing, say no and it'll come back
+                * later, when the link is IDLE
+                */
+               result = -EBADF;
+               d_printf(1, dev, "fw up, link up, not-idle, autosuspend: "
+                        "not entering powersave\n");
+               goto error_not_now;
+       }
+       d_printf(1, dev, "fw up: entering powersave\n");
+       atomic_dec(&i2400mu->do_autopm);
+       result = i2400m_cmd_enter_powersave(i2400m);
+       atomic_inc(&i2400mu->do_autopm);
+       if (result < 0 && !is_autosuspend) {
+               /* System suspend, can't fail */
+               dev_err(dev, "failed to suspend, will reset on resume\n");
+               result = 0;
+       }
+       if (result < 0)
+               goto error_enter_powersave;
+       i2400mu_notification_release(i2400mu);
+       d_printf(1, dev, "powersave requested\n");
+error_enter_powersave:
+error_not_now:
+no_firmware:
+       d_fnend(3, dev, "(iface %p pm_msg %u) = %d\n",
+               iface, pm_msg.event, result);
+       return result;
+}
+
+
+static
+int i2400mu_resume(struct usb_interface *iface)
+{
+       int ret = 0;
+       struct device *dev = &iface->dev;
+       struct i2400mu *i2400mu = usb_get_intfdata(iface);
+       struct i2400m *i2400m = &i2400mu->i2400m;
+
+       d_fnstart(3, dev, "(iface %p)\n", iface);
+       rmb();          /* see i2400m->updown's documentation  */
+       if (i2400m->updown == 0) {
+               d_printf(1, dev, "fw was down, no resume needed\n");
+               goto out;
+       }
+       d_printf(1, dev, "fw was up, resuming\n");
+       i2400mu_notification_setup(i2400mu);
+       /* USB has flow control, so we don't need to give it time to
+        * come back; otherwise, we'd use something like a get-state
+        * command... */
+out:
+       d_fnend(3, dev, "(iface %p) = %d\n", iface, ret);
+       return ret;
+}
+
+
+static
+int i2400mu_reset_resume(struct usb_interface *iface)
+{
+       int result;
+       struct device *dev = &iface->dev;
+       struct i2400mu *i2400mu = usb_get_intfdata(iface);
+       struct i2400m *i2400m = &i2400mu->i2400m;
+
+       d_fnstart(3, dev, "(iface %p)\n", iface);
+       result = i2400m_dev_reset_handle(i2400m, "device reset on resume");
+       d_fnend(3, dev, "(iface %p) = %d\n", iface, result);
+       return result < 0 ? result : 0;
+}
+
+
+/*
+ * Another driver or user space is triggering a reset on the device
+ * which contains the interface passed as an argument. Cease IO and
+ * save any device state you need to restore.
+ *
+ * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if
+ * you are in atomic context.
+ */
+static
+int i2400mu_pre_reset(struct usb_interface *iface)
+{
+       struct i2400mu *i2400mu = usb_get_intfdata(iface);
+       return i2400m_pre_reset(&i2400mu->i2400m);
+}
+
+
+/*
+ * The reset has completed.  Restore any saved device state and begin
+ * using the device again.
+ *
+ * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if
+ * you are in atomic context.
+ */
+static
+int i2400mu_post_reset(struct usb_interface *iface)
+{
+       struct i2400mu *i2400mu = usb_get_intfdata(iface);
+       return i2400m_post_reset(&i2400mu->i2400m);
+}
+
+
+static
+struct usb_device_id i2400mu_id_table[] = {
+       { USB_DEVICE(0x8086, USB_DEVICE_ID_I6050) },
+       { USB_DEVICE(0x8086, USB_DEVICE_ID_I6050_2) },
+       { USB_DEVICE(0x8087, USB_DEVICE_ID_I6150) },
+       { USB_DEVICE(0x8087, USB_DEVICE_ID_I6150_2) },
+       { USB_DEVICE(0x8087, USB_DEVICE_ID_I6150_3) },
+       { USB_DEVICE(0x8086, USB_DEVICE_ID_I6250) },
+       { USB_DEVICE(0x8086, 0x0181) },
+       { USB_DEVICE(0x8086, 0x1403) },
+       { USB_DEVICE(0x8086, 0x1405) },
+       { USB_DEVICE(0x8086, 0x0180) },
+       { USB_DEVICE(0x8086, 0x0182) },
+       { USB_DEVICE(0x8086, 0x1406) },
+       { USB_DEVICE(0x8086, 0x1403) },
+       { },
+};
+MODULE_DEVICE_TABLE(usb, i2400mu_id_table);
+
+
+static
+struct usb_driver i2400mu_driver = {
+       .name = KBUILD_MODNAME,
+       .suspend = i2400mu_suspend,
+       .resume = i2400mu_resume,
+       .reset_resume = i2400mu_reset_resume,
+       .probe = i2400mu_probe,
+       .disconnect = i2400mu_disconnect,
+       .pre_reset = i2400mu_pre_reset,
+       .post_reset = i2400mu_post_reset,
+       .id_table = i2400mu_id_table,
+       .supports_autosuspend = 1,
+};
+
+static
+int __init i2400mu_driver_init(void)
+{
+       d_parse_params(D_LEVEL, D_LEVEL_SIZE, i2400mu_debug_params,
+                      "i2400m_usb.debug");
+       return usb_register(&i2400mu_driver);
+}
+module_init(i2400mu_driver_init);
+
+
+static
+void __exit i2400mu_driver_exit(void)
+{
+       usb_deregister(&i2400mu_driver);
+}
+module_exit(i2400mu_driver_exit);
+
+MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
+MODULE_DESCRIPTION("Driver for USB based Intel Wireless WiMAX Connection 2400M "
+                  "(5x50 & 6050)");
+MODULE_LICENSE("GPL");
+MODULE_FIRMWARE(I2400MU_FW_FILE_NAME_v1_5);
+MODULE_FIRMWARE(I6050U_FW_FILE_NAME_v1_5);