/*
 * Atheros AR9170 driver
 *
 * USB - frontend
 *
 * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
 * Copyright 2009, Christian Lamparter <chunkeey@web.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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; see the file COPYING.  If not, see
 * http://www.gnu.org/licenses/.
 *
 * This file incorporates work covered by the following copyright and
 * permission notice:
 *    Copyright (c) 2007-2008 Atheros Communications, Inc.
 *
 *    Permission to use, copy, modify, and/or distribute this software for any
 *    purpose with or without fee is hereby granted, provided that the above
 *    copyright notice and this permission notice appear in all copies.
 *
 *    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 *    WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *    MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 *    ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 *    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 *    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 *    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/firmware.h>
#include <linux/etherdevice.h>
#include <linux/device.h>
#include <net/mac80211.h>
#include "ar9170.h"
#include "cmd.h"
#include "hw.h"
#include "usb.h"

MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
MODULE_AUTHOR("Christian Lamparter <chunkeey@web.de>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Atheros AR9170 802.11n USB wireless");
MODULE_FIRMWARE("ar9170.fw");

enum ar9170_requirements {
        AR9170_REQ_FW1_ONLY = 1,
};

static struct usb_device_id ar9170_usb_ids[] = {
        /* Atheros 9170 */
        { USB_DEVICE(0x0cf3, 0x9170) },
        /* Atheros TG121N */
        { USB_DEVICE(0x0cf3, 0x1001) },
        /* TP-Link TL-WN821N v2 */
        { USB_DEVICE(0x0cf3, 0x1002) },
        /* 3Com Dual Band 802.11n USB Adapter */
        { USB_DEVICE(0x0cf3, 0x1010) },
        /* H3C Dual Band 802.11n USB Adapter */
        { USB_DEVICE(0x0cf3, 0x1011) },
        /* Cace Airpcap NX */
        { USB_DEVICE(0xcace, 0x0300) },
        /* D-Link DWA 160 A1 */
        { USB_DEVICE(0x07d1, 0x3c10) },
        /* D-Link DWA 160 A2 */
        { USB_DEVICE(0x07d1, 0x3a09) },
        /* Netgear WNA1000 */
        { USB_DEVICE(0x0846, 0x9040) },
        /* Netgear WNDA3100 */
        { USB_DEVICE(0x0846, 0x9010) },
        /* Netgear WN111 v2 */
        { USB_DEVICE(0x0846, 0x9001) },
        /* Zydas ZD1221 */
        { USB_DEVICE(0x0ace, 0x1221) },
        /* Proxim ORiNOCO 802.11n USB */
        { USB_DEVICE(0x1435, 0x0804) },
        /* WNC Generic 11n USB Dongle */
        { USB_DEVICE(0x1435, 0x0326) },
        /* ZyXEL NWD271N */
        { USB_DEVICE(0x0586, 0x3417) },
        /* Z-Com UB81 BG */
        { USB_DEVICE(0x0cde, 0x0023) },
        /* Z-Com UB82 ABG */
        { USB_DEVICE(0x0cde, 0x0026) },
        /* Sphairon Homelink 1202 */
        { USB_DEVICE(0x0cde, 0x0027) },
        /* Arcadyan WN7512 */
        { USB_DEVICE(0x083a, 0xf522) },
        /* Planex GWUS300 */
        { USB_DEVICE(0x2019, 0x5304) },
        /* IO-Data WNGDNUS2 */
        { USB_DEVICE(0x04bb, 0x093f) },
        /* AVM FRITZ!WLAN USB Stick N */
        { USB_DEVICE(0x057C, 0x8401) },
        /* NEC WL300NU-G */
        { USB_DEVICE(0x0409, 0x0249) },
        /* AVM FRITZ!WLAN USB Stick N 2.4 */
        { USB_DEVICE(0x057C, 0x8402), .driver_info = AR9170_REQ_FW1_ONLY },
        /* Qwest/Actiontec 802AIN Wireless N USB Network Adapter */
        { USB_DEVICE(0x1668, 0x1200) },

        /* terminate */
        {}
};
MODULE_DEVICE_TABLE(usb, ar9170_usb_ids);

static void ar9170_usb_submit_urb(struct ar9170_usb *aru)
{
        struct urb *urb;
        unsigned long flags;
        int err;

        if (unlikely(!IS_STARTED(&aru->common)))
                return ;

        spin_lock_irqsave(&aru->tx_urb_lock, flags);
        if (atomic_read(&aru->tx_submitted_urbs) >= AR9170_NUM_TX_URBS) {
                spin_unlock_irqrestore(&aru->tx_urb_lock, flags);
                return ;
        }
        atomic_inc(&aru->tx_submitted_urbs);

        urb = usb_get_from_anchor(&aru->tx_pending);
        if (!urb) {
                atomic_dec(&aru->tx_submitted_urbs);
                spin_unlock_irqrestore(&aru->tx_urb_lock, flags);

                return ;
        }
        spin_unlock_irqrestore(&aru->tx_urb_lock, flags);

        aru->tx_pending_urbs--;
        usb_anchor_urb(urb, &aru->tx_submitted);

        err = usb_submit_urb(urb, GFP_ATOMIC);
        if (unlikely(err)) {
                if (ar9170_nag_limiter(&aru->common))
                        dev_err(&aru->udev->dev, "submit_urb failed (%d).\n",
                                err);

                usb_unanchor_urb(urb);
                atomic_dec(&aru->tx_submitted_urbs);
                ar9170_tx_callback(&aru->common, urb->context);
        }

        usb_free_urb(urb);
}

static void ar9170_usb_tx_urb_complete_frame(struct urb *urb)
{
        struct sk_buff *skb = urb->context;
        struct ar9170_usb *aru = usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));

        if (unlikely(!aru)) {
                dev_kfree_skb_irq(skb);
                return ;
        }

        atomic_dec(&aru->tx_submitted_urbs);

        ar9170_tx_callback(&aru->common, skb);

        ar9170_usb_submit_urb(aru);
}

static void ar9170_usb_tx_urb_complete(struct urb *urb)
{
}

static void ar9170_usb_irq_completed(struct urb *urb)
{
        struct ar9170_usb *aru = urb->context;

        switch (urb->status) {
        /* everything is fine */
        case 0:
                break;

        /* disconnect */
        case -ENOENT:
        case -ECONNRESET:
        case -ENODEV:
        case -ESHUTDOWN:
                goto free;

        default:
                goto resubmit;
        }

        ar9170_handle_command_response(&aru->common, urb->transfer_buffer,
                                       urb->actual_length);

resubmit:
        usb_anchor_urb(urb, &aru->rx_submitted);
        if (usb_submit_urb(urb, GFP_ATOMIC)) {
                usb_unanchor_urb(urb);
                goto free;
        }

        return;

free:
        usb_free_coherent(aru->udev, 64, urb->transfer_buffer, urb->transfer_dma);
}

static void ar9170_usb_rx_completed(struct urb *urb)
{
        struct sk_buff *skb = urb->context;
        struct ar9170_usb *aru = usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));
        int err;

        if (!aru)
                goto free;

        switch (urb->status) {
        /* everything is fine */
        case 0:
                break;

        /* disconnect */
        case -ENOENT:
        case -ECONNRESET:
        case -ENODEV:
        case -ESHUTDOWN:
                goto free;

        default:
                goto resubmit;
        }

        skb_put(skb, urb->actual_length);
        ar9170_rx(&aru->common, skb);

resubmit:
        skb_reset_tail_pointer(skb);
        skb_trim(skb, 0);

        usb_anchor_urb(urb, &aru->rx_submitted);
        err = usb_submit_urb(urb, GFP_ATOMIC);
        if (unlikely(err)) {
                usb_unanchor_urb(urb);
                goto free;
        }

        return ;

free:
        dev_kfree_skb_irq(skb);
}

static int ar9170_usb_prep_rx_urb(struct ar9170_usb *aru,
                                  struct urb *urb, gfp_t gfp)
{
        struct sk_buff *skb;

        skb = __dev_alloc_skb(AR9170_MAX_RX_BUFFER_SIZE + 32, gfp);
        if (!skb)
                return -ENOMEM;

        /* reserve some space for mac80211's radiotap */
        skb_reserve(skb, 32);

        usb_fill_bulk_urb(urb, aru->udev,
                          usb_rcvbulkpipe(aru->udev, AR9170_EP_RX),
                          skb->data, min(skb_tailroom(skb),
                          AR9170_MAX_RX_BUFFER_SIZE),
                          ar9170_usb_rx_completed, skb);

        return 0;
}

static int ar9170_usb_alloc_rx_irq_urb(struct ar9170_usb *aru)
{
        struct urb *urb = NULL;
        void *ibuf;
        int err = -ENOMEM;

        /* initialize interrupt endpoint */
        urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!urb)
                goto out;

        ibuf = usb_alloc_coherent(aru->udev, 64, GFP_KERNEL, &urb->transfer_dma);
        if (!ibuf)
                goto out;

        usb_fill_int_urb(urb, aru->udev,
                         usb_rcvintpipe(aru->udev, AR9170_EP_IRQ), ibuf,
                         64, ar9170_usb_irq_completed, aru, 1);
        urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

        usb_anchor_urb(urb, &aru->rx_submitted);
        err = usb_submit_urb(urb, GFP_KERNEL);
        if (err) {
                usb_unanchor_urb(urb);
                usb_free_coherent(aru->udev, 64, urb->transfer_buffer,
                                  urb->transfer_dma);
        }

out:
        usb_free_urb(urb);
        return err;
}

static int ar9170_usb_alloc_rx_bulk_urbs(struct ar9170_usb *aru)
{
        struct urb *urb;
        int i;
        int err = -EINVAL;

        for (i = 0; i < AR9170_NUM_RX_URBS; i++) {
                err = -ENOMEM;
                urb = usb_alloc_urb(0, GFP_KERNEL);
                if (!urb)
                        goto err_out;

                err = ar9170_usb_prep_rx_urb(aru, urb, GFP_KERNEL);
                if (err) {
                        usb_free_urb(urb);
                        goto err_out;
                }

                usb_anchor_urb(urb, &aru->rx_submitted);
                err = usb_submit_urb(urb, GFP_KERNEL);
                if (err) {
                        usb_unanchor_urb(urb);
                        dev_kfree_skb_any((void *) urb->transfer_buffer);
                        usb_free_urb(urb);
                        goto err_out;
                }
                usb_free_urb(urb);
        }

        /* the device now waiting for a firmware. */
        aru->common.state = AR9170_IDLE;
        return 0;

err_out:

        usb_kill_anchored_urbs(&aru->rx_submitted);
        return err;
}

static int ar9170_usb_flush(struct ar9170 *ar)
{
        struct ar9170_usb *aru = (void *) ar;
        struct urb *urb;
        int ret, err = 0;

        if (IS_STARTED(ar))
                aru->common.state = AR9170_IDLE;

        usb_wait_anchor_empty_timeout(&aru->tx_pending,
                                            msecs_to_jiffies(800));
        while ((urb = usb_get_from_anchor(&aru->tx_pending))) {
                ar9170_tx_callback(&aru->common, (void *) urb->context);
                usb_free_urb(urb);
        }

        /* lets wait a while until the tx - queues are dried out */
        ret = usb_wait_anchor_empty_timeout(&aru->tx_submitted,
                                            msecs_to_jiffies(100));
        if (ret == 0)
                err = -ETIMEDOUT;

        usb_kill_anchored_urbs(&aru->tx_submitted);

        if (IS_ACCEPTING_CMD(ar))
                aru->common.state = AR9170_STARTED;

        return err;
}

static void ar9170_usb_cancel_urbs(struct ar9170_usb *aru)
{
        int err;

        aru->common.state = AR9170_UNKNOWN_STATE;

        err = ar9170_usb_flush(&aru->common);
        if (err)
                dev_err(&aru->udev->dev, "stuck tx urbs!\n");

        usb_poison_anchored_urbs(&aru->tx_submitted);
        usb_poison_anchored_urbs(&aru->rx_submitted);
}

static int ar9170_usb_exec_cmd(struct ar9170 *ar, enum ar9170_cmd cmd,
                               unsigned int plen, void *payload,
                               unsigned int outlen, void *out)
{
        struct ar9170_usb *aru = (void *) ar;
        struct urb *urb = NULL;
        unsigned long flags;
        int err = -ENOMEM;

        if (unlikely(!IS_ACCEPTING_CMD(ar)))
                return -EPERM;

        if (WARN_ON(plen > AR9170_MAX_CMD_LEN - 4))
                return -EINVAL;

        urb = usb_alloc_urb(0, GFP_ATOMIC);
        if (unlikely(!urb))
                goto err_free;

        ar->cmdbuf[0] = cpu_to_le32(plen);
        ar->cmdbuf[0] |= cpu_to_le32(cmd << 8);
        /* writing multiple regs fills this buffer already */
        if (plen && payload != (u8 *)(&ar->cmdbuf[1]))
                memcpy(&ar->cmdbuf[1], payload, plen);

        spin_lock_irqsave(&aru->common.cmdlock, flags);
        aru->readbuf = (u8 *)out;
        aru->readlen = outlen;
        spin_unlock_irqrestore(&aru->common.cmdlock, flags);

        usb_fill_int_urb(urb, aru->udev,
                         usb_sndintpipe(aru->udev, AR9170_EP_CMD),
                         aru->common.cmdbuf, plen + 4,
                         ar9170_usb_tx_urb_complete, NULL, 1);

        usb_anchor_urb(urb, &aru->tx_submitted);
        err = usb_submit_urb(urb, GFP_ATOMIC);
        if (unlikely(err)) {
                usb_unanchor_urb(urb);
                usb_free_urb(urb);
                goto err_unbuf;
        }
        usb_free_urb(urb);

        err = wait_for_completion_timeout(&aru->cmd_wait, HZ);
        if (err == 0) {
                err = -ETIMEDOUT;
                goto err_unbuf;
        }

        if (aru->readlen != outlen) {
                err = -EMSGSIZE;
                goto err_unbuf;
        }

        return 0;

err_unbuf:
        /* Maybe the device was removed in the second we were waiting? */
        if (IS_STARTED(ar)) {
                dev_err(&aru->udev->dev, "no command feedback "
                                         "received (%d).\n", err);

                /* provide some maybe useful debug information */
                print_hex_dump_bytes("ar9170 cmd: ", DUMP_PREFIX_NONE,
                                     aru->common.cmdbuf, plen + 4);
                dump_stack();
        }

        /* invalidate to avoid completing the next prematurely */
        spin_lock_irqsave(&aru->common.cmdlock, flags);
        aru->readbuf = NULL;
        aru->readlen = 0;
        spin_unlock_irqrestore(&aru->common.cmdlock, flags);

err_free:

        return err;
}

static int ar9170_usb_tx(struct ar9170 *ar, struct sk_buff *skb)
{
        struct ar9170_usb *aru = (struct ar9170_usb *) ar;
        struct urb *urb;

        if (unlikely(!IS_STARTED(ar))) {
                /* Seriously, what were you drink... err... thinking!? */
                return -EPERM;
        }

        urb = usb_alloc_urb(0, GFP_ATOMIC);
        if (unlikely(!urb))
                return -ENOMEM;

        usb_fill_bulk_urb(urb, aru->udev,
                          usb_sndbulkpipe(aru->udev, AR9170_EP_TX),
                          skb->data, skb->len,
                          ar9170_usb_tx_urb_complete_frame, skb);
        urb->transfer_flags |= URB_ZERO_PACKET;

        usb_anchor_urb(urb, &aru->tx_pending);
        aru->tx_pending_urbs++;

        usb_free_urb(urb);

        ar9170_usb_submit_urb(aru);
        return 0;
}

static void ar9170_usb_callback_cmd(struct ar9170 *ar, u32 len , void *buffer)
{
        struct ar9170_usb *aru = (void *) ar;
        unsigned long flags;
        u32 in, out;

        if (unlikely(!buffer))
                return ;

        in = le32_to_cpup((__le32 *)buffer);
        out = le32_to_cpu(ar->cmdbuf[0]);

        /* mask off length byte */
        out &= ~0xFF;

        if (aru->readlen >= 0) {
                /* add expected length */
                out |= aru->readlen;
        } else {
                /* add obtained length */
                out |= in & 0xFF;
        }

        /*
         * Some commands (e.g: AR9170_CMD_FREQUENCY) have a variable response
         * length and we cannot predict the correct length in advance.
         * So we only check if we provided enough space for the data.
         */
        if (unlikely(out < in)) {
                dev_warn(&aru->udev->dev, "received invalid command response "
                                          "got %d bytes, instead of %d bytes "
                                          "and the resp length is %d bytes\n",
                         in, out, len);
                print_hex_dump_bytes("ar9170 invalid resp: ",
                                     DUMP_PREFIX_OFFSET, buffer, len);
                /*
                 * Do not complete, then the command times out,
                 * and we get a stack trace from there.
                 */
                return ;
        }

        spin_lock_irqsave(&aru->common.cmdlock, flags);
        if (aru->readbuf && len > 0) {
                memcpy(aru->readbuf, buffer + 4, len - 4);
                aru->readbuf = NULL;
        }
        complete(&aru->cmd_wait);
        spin_unlock_irqrestore(&aru->common.cmdlock, flags);
}

static int ar9170_usb_upload(struct ar9170_usb *aru, const void *data,
                             size_t len, u32 addr, bool complete)
{
        int transfer, err;
        u8 *buf = kmalloc(4096, GFP_KERNEL);

        if (!buf)
                return -ENOMEM;

        while (len) {
                transfer = min_t(int, len, 4096);
                memcpy(buf, data, transfer);

                err = usb_control_msg(aru->udev, usb_sndctrlpipe(aru->udev, 0),
                                      0x30 /* FW DL */, 0x40 | USB_DIR_OUT,
                                      addr >> 8, 0, buf, transfer, 1000);

                if (err < 0) {
                        kfree(buf);
                        return err;
                }

                len -= transfer;
                data += transfer;
                addr += transfer;
        }
        kfree(buf);

        if (complete) {
                err = usb_control_msg(aru->udev, usb_sndctrlpipe(aru->udev, 0),
                                      0x31 /* FW DL COMPLETE */,
                                      0x40 | USB_DIR_OUT, 0, 0, NULL, 0, 5000);
        }

        return 0;
}

static int ar9170_usb_reset(struct ar9170_usb *aru)
{
        int ret, lock = (aru->intf->condition != USB_INTERFACE_BINDING);

        if (lock) {
                ret = usb_lock_device_for_reset(aru->udev, aru->intf);
                if (ret < 0) {
                        dev_err(&aru->udev->dev, "unable to lock device "
                                "for reset (%d).\n", ret);
                        return ret;
                }
        }

        ret = usb_reset_device(aru->udev);
        if (lock)
                usb_unlock_device(aru->udev);

        /* let it rest - for a second - */
        msleep(1000);

        return ret;
}

static int ar9170_usb_upload_firmware(struct ar9170_usb *aru)
{
        int err;

        if (!aru->init_values)
                goto upload_fw_start;

        /* First, upload initial values to device RAM */
        err = ar9170_usb_upload(aru, aru->init_values->data,
                                aru->init_values->size, 0x102800, false);
        if (err) {
                dev_err(&aru->udev->dev, "firmware part 1 "
                        "upload failed (%d).\n", err);
                return err;
        }

upload_fw_start:

        /* Then, upload the firmware itself and start it */
        return ar9170_usb_upload(aru, aru->firmware->data, aru->firmware->size,
                                0x200000, true);
}

static int ar9170_usb_init_transport(struct ar9170_usb *aru)
{
        struct ar9170 *ar = (void *) &aru->common;
        int err;

        ar9170_regwrite_begin(ar);

        /* Set USB Rx stream mode MAX packet number to 2 */
        ar9170_regwrite(AR9170_USB_REG_MAX_AGG_UPLOAD, 0x4);

        /* Set USB Rx stream mode timeout to 10us */
        ar9170_regwrite(AR9170_USB_REG_UPLOAD_TIME_CTL, 0x80);

        ar9170_regwrite_finish();

        err = ar9170_regwrite_result();
        if (err)
                dev_err(&aru->udev->dev, "USB setup failed (%d).\n", err);

        return err;
}

static void ar9170_usb_stop(struct ar9170 *ar)
{
        struct ar9170_usb *aru = (void *) ar;
        int ret;

        if (IS_ACCEPTING_CMD(ar))
                aru->common.state = AR9170_STOPPED;

        ret = ar9170_usb_flush(ar);
        if (ret)
                dev_err(&aru->udev->dev, "kill pending tx urbs.\n");

        usb_poison_anchored_urbs(&aru->tx_submitted);

        /*
         * Note:
         * So far we freed all tx urbs, but we won't dare to touch any rx urbs.
         * Else we would end up with a unresponsive device...
         */
}

static int ar9170_usb_open(struct ar9170 *ar)
{
        struct ar9170_usb *aru = (void *) ar;
        int err;

        usb_unpoison_anchored_urbs(&aru->tx_submitted);
        err = ar9170_usb_init_transport(aru);
        if (err) {
                usb_poison_anchored_urbs(&aru->tx_submitted);
                return err;
        }

        aru->common.state = AR9170_IDLE;
        return 0;
}

static int ar9170_usb_init_device(struct ar9170_usb *aru)
{
        int err;

        err = ar9170_usb_alloc_rx_irq_urb(aru);
        if (err)
                goto err_out;

        err = ar9170_usb_alloc_rx_bulk_urbs(aru);
        if (err)
                goto err_unrx;

        err = ar9170_usb_upload_firmware(aru);
        if (err) {
                err = ar9170_echo_test(&aru->common, 0x60d43110);
                if (err) {
                        /* force user invention, by disabling the device */
                        err = usb_driver_set_configuration(aru->udev, -1);
                        dev_err(&aru->udev->dev, "device is in a bad state. "
                                                 "please reconnect it!\n");
                        goto err_unrx;
                }
        }

        return 0;

err_unrx:
        ar9170_usb_cancel_urbs(aru);

err_out:
        return err;
}

static void ar9170_usb_firmware_failed(struct ar9170_usb *aru)
{
        struct device *parent = aru->udev->dev.parent;
        struct usb_device *udev;

        /*
         * Store a copy of the usb_device pointer locally.
         * This is because device_release_driver initiates
         * ar9170_usb_disconnect, which in turn frees our
         * driver context (aru).
         */
        udev = aru->udev;

        complete(&aru->firmware_loading_complete);

        /* unbind anything failed */
        if (parent)
                device_lock(parent);

        device_release_driver(&udev->dev);
        if (parent)
                device_unlock(parent);

        usb_put_dev(udev);
}

static void ar9170_usb_firmware_finish(const struct firmware *fw, void *context)
{
        struct ar9170_usb *aru = context;
        int err;

        aru->firmware = fw;

        if (!fw) {
                dev_err(&aru->udev->dev, "firmware file not found.\n");
                goto err_freefw;
        }

        err = ar9170_usb_init_device(aru);
        if (err)
                goto err_freefw;

        err = ar9170_usb_open(&aru->common);
        if (err)
                goto err_unrx;

        err = ar9170_register(&aru->common, &aru->udev->dev);

        ar9170_usb_stop(&aru->common);
        if (err)
                goto err_unrx;

        complete(&aru->firmware_loading_complete);
        usb_put_dev(aru->udev);
        return;

 err_unrx:
        ar9170_usb_cancel_urbs(aru);

 err_freefw:
        ar9170_usb_firmware_failed(aru);
}

static void ar9170_usb_firmware_inits(const struct firmware *fw,
                                      void *context)
{
        struct ar9170_usb *aru = context;
        int err;

        if (!fw) {
                dev_err(&aru->udev->dev, "file with init values not found.\n");
                ar9170_usb_firmware_failed(aru);
                return;
        }

        aru->init_values = fw;

        /* ok so we have the init values -- get code for two-stage */

        err = request_firmware_nowait(THIS_MODULE, 1, "ar9170-2.fw",
                                      &aru->udev->dev, GFP_KERNEL, aru,
                                      ar9170_usb_firmware_finish);
        if (err)
                ar9170_usb_firmware_failed(aru);
}

static void ar9170_usb_firmware_step2(const struct firmware *fw, void *context)
{
        struct ar9170_usb *aru = context;
        int err;

        if (fw) {
                ar9170_usb_firmware_finish(fw, context);
                return;
        }

        if (aru->req_one_stage_fw) {
                dev_err(&aru->udev->dev, "ar9170.fw firmware file "
                        "not found and is required for this device\n");
                ar9170_usb_firmware_failed(aru);
                return;
        }

        dev_err(&aru->udev->dev, "ar9170.fw firmware file "
                "not found, trying old firmware...\n");

        err = request_firmware_nowait(THIS_MODULE, 1, "ar9170-1.fw",
                                      &aru->udev->dev, GFP_KERNEL, aru,
                                      ar9170_usb_firmware_inits);
        if (err)
                ar9170_usb_firmware_failed(aru);
}

static bool ar9170_requires_one_stage(const struct usb_device_id *id)
{
        if (!id->driver_info)
                return false;
        if (id->driver_info == AR9170_REQ_FW1_ONLY)
                return true;
        return false;
}

static int ar9170_usb_probe(struct usb_interface *intf,
                        const struct usb_device_id *id)
{
        struct ar9170_usb *aru;
        struct ar9170 *ar;
        struct usb_device *udev;
        int err;

        aru = ar9170_alloc(sizeof(*aru));
        if (IS_ERR(aru)) {
                err = PTR_ERR(aru);
                goto out;
        }

        udev = interface_to_usbdev(intf);
        usb_get_dev(udev);
        aru->udev = udev;
        aru->intf = intf;
        ar = &aru->common;

        aru->req_one_stage_fw = ar9170_requires_one_stage(id);

        usb_set_intfdata(intf, aru);
        SET_IEEE80211_DEV(ar->hw, &intf->dev);

        init_usb_anchor(&aru->rx_submitted);
        init_usb_anchor(&aru->tx_pending);
        init_usb_anchor(&aru->tx_submitted);
        init_completion(&aru->cmd_wait);
        init_completion(&aru->firmware_loading_complete);
        spin_lock_init(&aru->tx_urb_lock);

        aru->tx_pending_urbs = 0;
        atomic_set(&aru->tx_submitted_urbs, 0);

        aru->common.stop = ar9170_usb_stop;
        aru->common.flush = ar9170_usb_flush;
        aru->common.open = ar9170_usb_open;
        aru->common.tx = ar9170_usb_tx;
        aru->common.exec_cmd = ar9170_usb_exec_cmd;
        aru->common.callback_cmd = ar9170_usb_callback_cmd;

#ifdef CONFIG_PM
        udev->reset_resume = 1;
#endif /* CONFIG_PM */
        err = ar9170_usb_reset(aru);
        if (err)
                goto err_freehw;

        usb_get_dev(aru->udev);
        return request_firmware_nowait(THIS_MODULE, 1, "ar9170.fw",
                                       &aru->udev->dev, GFP_KERNEL, aru,
                                       ar9170_usb_firmware_step2);
err_freehw:
        usb_set_intfdata(intf, NULL);
        usb_put_dev(udev);
        ieee80211_free_hw(ar->hw);
out:
        return err;
}

static void ar9170_usb_disconnect(struct usb_interface *intf)
{
        struct ar9170_usb *aru = usb_get_intfdata(intf);

        if (!aru)
                return;

        aru->common.state = AR9170_IDLE;

        wait_for_completion(&aru->firmware_loading_complete);

        ar9170_unregister(&aru->common);
        ar9170_usb_cancel_urbs(aru);

        usb_put_dev(aru->udev);
        usb_set_intfdata(intf, NULL);
        ieee80211_free_hw(aru->common.hw);

        release_firmware(aru->init_values);
        release_firmware(aru->firmware);
}

#ifdef CONFIG_PM
static int ar9170_suspend(struct usb_interface *intf,
                          pm_message_t  message)
{
        struct ar9170_usb *aru = usb_get_intfdata(intf);

        if (!aru)
                return -ENODEV;

        aru->common.state = AR9170_IDLE;
        ar9170_usb_cancel_urbs(aru);

        return 0;
}

static int ar9170_resume(struct usb_interface *intf)
{
        struct ar9170_usb *aru = usb_get_intfdata(intf);
        int err;

        if (!aru)
                return -ENODEV;

        usb_unpoison_anchored_urbs(&aru->rx_submitted);
        usb_unpoison_anchored_urbs(&aru->tx_submitted);

        err = ar9170_usb_init_device(aru);
        if (err)
                goto err_unrx;

        err = ar9170_usb_open(&aru->common);
        if (err)
                goto err_unrx;

        return 0;

err_unrx:
        aru->common.state = AR9170_IDLE;
        ar9170_usb_cancel_urbs(aru);

        return err;
}
#endif /* CONFIG_PM */

static struct usb_driver ar9170_driver = {
        .name = "ar9170usb",
        .probe = ar9170_usb_probe,
        .disconnect = ar9170_usb_disconnect,
        .id_table = ar9170_usb_ids,
        .soft_unbind = 1,
#ifdef CONFIG_PM
        .suspend = ar9170_suspend,
        .resume = ar9170_resume,
        .reset_resume = ar9170_resume,
#endif /* CONFIG_PM */
};

static int __init ar9170_init(void)
{
        return usb_register(&ar9170_driver);
}

static void __exit ar9170_exit(void)
{
        usb_deregister(&ar9170_driver);
}

module_init(ar9170_init);
module_exit(ar9170_exit);