/*
 * Copyright (c) 2007-2011 Atheros Communications Inc.
 * Copyright (c) 2011-2012 Qualcomm Atheros, 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/usb.h>

#include "debug.h"
#include "core.h"

/* constants */
#define TX_URB_COUNT            32
#define RX_URB_COUNT            32
#define ATH6KL_USB_RX_BUFFER_SIZE  4096

/* tx/rx pipes for usb */
enum ATH6KL_USB_PIPE_ID {
        ATH6KL_USB_PIPE_TX_CTRL = 0,
        ATH6KL_USB_PIPE_TX_DATA_LP,
        ATH6KL_USB_PIPE_TX_DATA_MP,
        ATH6KL_USB_PIPE_TX_DATA_HP,
        ATH6KL_USB_PIPE_RX_CTRL,
        ATH6KL_USB_PIPE_RX_DATA,
        ATH6KL_USB_PIPE_RX_DATA2,
        ATH6KL_USB_PIPE_RX_INT,
        ATH6KL_USB_PIPE_MAX
};

#define ATH6KL_USB_PIPE_INVALID ATH6KL_USB_PIPE_MAX

struct ath6kl_usb_pipe {
        struct list_head urb_list_head;
        struct usb_anchor urb_submitted;
        u32 urb_alloc;
        u32 urb_cnt;
        u32 urb_cnt_thresh;
        unsigned int usb_pipe_handle;
        u32 flags;
        u8 ep_address;
        u8 logical_pipe_num;
        struct ath6kl_usb *ar_usb;
        u16 max_packet_size;
        struct work_struct io_complete_work;
        struct sk_buff_head io_comp_queue;
        struct usb_endpoint_descriptor *ep_desc;
};

#define ATH6KL_USB_PIPE_FLAG_TX    (1 << 0)

/* usb device object */
struct ath6kl_usb {
        /* protects pipe->urb_list_head and  pipe->urb_cnt */
        spinlock_t cs_lock;

        struct usb_device *udev;
        struct usb_interface *interface;
        struct ath6kl_usb_pipe pipes[ATH6KL_USB_PIPE_MAX];
        u8 *diag_cmd_buffer;
        u8 *diag_resp_buffer;
        struct ath6kl *ar;
        struct workqueue_struct *wq;
};

/* usb urb object */
struct ath6kl_urb_context {
        struct list_head link;
        struct ath6kl_usb_pipe *pipe;
        struct sk_buff *skb;
        struct ath6kl *ar;
};

/* USB endpoint definitions */
#define ATH6KL_USB_EP_ADDR_APP_CTRL_IN          0x81
#define ATH6KL_USB_EP_ADDR_APP_DATA_IN          0x82
#define ATH6KL_USB_EP_ADDR_APP_DATA2_IN         0x83
#define ATH6KL_USB_EP_ADDR_APP_INT_IN           0x84

#define ATH6KL_USB_EP_ADDR_APP_CTRL_OUT         0x01
#define ATH6KL_USB_EP_ADDR_APP_DATA_LP_OUT      0x02
#define ATH6KL_USB_EP_ADDR_APP_DATA_MP_OUT      0x03
#define ATH6KL_USB_EP_ADDR_APP_DATA_HP_OUT      0x04

/* diagnostic command definitions */
#define ATH6KL_USB_CONTROL_REQ_SEND_BMI_CMD        1
#define ATH6KL_USB_CONTROL_REQ_RECV_BMI_RESP       2
#define ATH6KL_USB_CONTROL_REQ_DIAG_CMD            3
#define ATH6KL_USB_CONTROL_REQ_DIAG_RESP           4

#define ATH6KL_USB_CTRL_DIAG_CC_READ               0
#define ATH6KL_USB_CTRL_DIAG_CC_WRITE              1

struct ath6kl_usb_ctrl_diag_cmd_write {
        __le32 cmd;
        __le32 address;
        __le32 value;
        __le32 _pad[1];
} __packed;

struct ath6kl_usb_ctrl_diag_cmd_read {
        __le32 cmd;
        __le32 address;
} __packed;

struct ath6kl_usb_ctrl_diag_resp_read {
        __le32 value;
} __packed;

/* function declarations */
static void ath6kl_usb_recv_complete(struct urb *urb);

#define ATH6KL_USB_IS_BULK_EP(attr) (((attr) & 3) == 0x02)
#define ATH6KL_USB_IS_INT_EP(attr)  (((attr) & 3) == 0x03)
#define ATH6KL_USB_IS_ISOC_EP(attr)  (((attr) & 3) == 0x01)
#define ATH6KL_USB_IS_DIR_IN(addr)  ((addr) & 0x80)

/* pipe/urb operations */
static struct ath6kl_urb_context *
ath6kl_usb_alloc_urb_from_pipe(struct ath6kl_usb_pipe *pipe)
{
        struct ath6kl_urb_context *urb_context = NULL;
        unsigned long flags;

        /* bail if this pipe is not initialized */
        if (!pipe->ar_usb)
                return NULL;

        spin_lock_irqsave(&pipe->ar_usb->cs_lock, flags);
        if (!list_empty(&pipe->urb_list_head)) {
                urb_context =
                    list_first_entry(&pipe->urb_list_head,
                                     struct ath6kl_urb_context, link);
                list_del(&urb_context->link);
                pipe->urb_cnt--;
        }
        spin_unlock_irqrestore(&pipe->ar_usb->cs_lock, flags);

        return urb_context;
}

static void ath6kl_usb_free_urb_to_pipe(struct ath6kl_usb_pipe *pipe,
                                        struct ath6kl_urb_context *urb_context)
{
        unsigned long flags;

        /* bail if this pipe is not initialized */
        if (!pipe->ar_usb)
                return;

        spin_lock_irqsave(&pipe->ar_usb->cs_lock, flags);
        pipe->urb_cnt++;

        list_add(&urb_context->link, &pipe->urb_list_head);
        spin_unlock_irqrestore(&pipe->ar_usb->cs_lock, flags);
}

static void ath6kl_usb_cleanup_recv_urb(struct ath6kl_urb_context *urb_context)
{
        dev_kfree_skb(urb_context->skb);
        urb_context->skb = NULL;

        ath6kl_usb_free_urb_to_pipe(urb_context->pipe, urb_context);
}

static inline struct ath6kl_usb *ath6kl_usb_priv(struct ath6kl *ar)
{
        return ar->hif_priv;
}

/* pipe resource allocation/cleanup */
static int ath6kl_usb_alloc_pipe_resources(struct ath6kl_usb_pipe *pipe,
                                           int urb_cnt)
{
        struct ath6kl_urb_context *urb_context;
        int status = 0, i;

        INIT_LIST_HEAD(&pipe->urb_list_head);
        init_usb_anchor(&pipe->urb_submitted);

        for (i = 0; i < urb_cnt; i++) {
                urb_context = kzalloc_obj(struct ath6kl_urb_context);
                if (urb_context == NULL) {
                        status = -ENOMEM;
                        goto fail_alloc_pipe_resources;
                }

                urb_context->pipe = pipe;

                /*
                 * we are only allocate the urb contexts here, the actual URB
                 * is allocated from the kernel as needed to do a transaction
                 */
                pipe->urb_alloc++;
                ath6kl_usb_free_urb_to_pipe(pipe, urb_context);
        }

        ath6kl_dbg(ATH6KL_DBG_USB,
                   "ath6kl usb: alloc resources lpipe:%d hpipe:0x%X urbs:%d\n",
                   pipe->logical_pipe_num, pipe->usb_pipe_handle,
                   pipe->urb_alloc);

fail_alloc_pipe_resources:
        return status;
}

static void ath6kl_usb_free_pipe_resources(struct ath6kl_usb_pipe *pipe)
{
        struct ath6kl_urb_context *urb_context;

        if (pipe->ar_usb == NULL) {
                /* nothing allocated for this pipe */
                return;
        }

        ath6kl_dbg(ATH6KL_DBG_USB,
                   "ath6kl usb: free resources lpipe:%d"
                   "hpipe:0x%X urbs:%d avail:%d\n",
                   pipe->logical_pipe_num, pipe->usb_pipe_handle,
                   pipe->urb_alloc, pipe->urb_cnt);

        if (pipe->urb_alloc != pipe->urb_cnt) {
                ath6kl_dbg(ATH6KL_DBG_USB,
                           "ath6kl usb: urb leak! lpipe:%d"
                           "hpipe:0x%X urbs:%d avail:%d\n",
                           pipe->logical_pipe_num, pipe->usb_pipe_handle,
                           pipe->urb_alloc, pipe->urb_cnt);
        }

        while (true) {
                urb_context = ath6kl_usb_alloc_urb_from_pipe(pipe);
                if (urb_context == NULL)
                        break;
                kfree(urb_context);
        }
}

static void ath6kl_usb_cleanup_pipe_resources(struct ath6kl_usb *ar_usb)
{
        int i;

        for (i = 0; i < ATH6KL_USB_PIPE_MAX; i++)
                ath6kl_usb_free_pipe_resources(&ar_usb->pipes[i]);
}

static u8 ath6kl_usb_get_logical_pipe_num(struct ath6kl_usb *ar_usb,
                                          u8 ep_address, int *urb_count)
{
        u8 pipe_num = ATH6KL_USB_PIPE_INVALID;

        switch (ep_address) {
        case ATH6KL_USB_EP_ADDR_APP_CTRL_IN:
                pipe_num = ATH6KL_USB_PIPE_RX_CTRL;
                *urb_count = RX_URB_COUNT;
                break;
        case ATH6KL_USB_EP_ADDR_APP_DATA_IN:
                pipe_num = ATH6KL_USB_PIPE_RX_DATA;
                *urb_count = RX_URB_COUNT;
                break;
        case ATH6KL_USB_EP_ADDR_APP_INT_IN:
                pipe_num = ATH6KL_USB_PIPE_RX_INT;
                *urb_count = RX_URB_COUNT;
                break;
        case ATH6KL_USB_EP_ADDR_APP_DATA2_IN:
                pipe_num = ATH6KL_USB_PIPE_RX_DATA2;
                *urb_count = RX_URB_COUNT;
                break;
        case ATH6KL_USB_EP_ADDR_APP_CTRL_OUT:
                pipe_num = ATH6KL_USB_PIPE_TX_CTRL;
                *urb_count = TX_URB_COUNT;
                break;
        case ATH6KL_USB_EP_ADDR_APP_DATA_LP_OUT:
                pipe_num = ATH6KL_USB_PIPE_TX_DATA_LP;
                *urb_count = TX_URB_COUNT;
                break;
        case ATH6KL_USB_EP_ADDR_APP_DATA_MP_OUT:
                pipe_num = ATH6KL_USB_PIPE_TX_DATA_MP;
                *urb_count = TX_URB_COUNT;
                break;
        case ATH6KL_USB_EP_ADDR_APP_DATA_HP_OUT:
                pipe_num = ATH6KL_USB_PIPE_TX_DATA_HP;
                *urb_count = TX_URB_COUNT;
                break;
        default:
                /* note: there may be endpoints not currently used */
                break;
        }

        return pipe_num;
}

static int ath6kl_usb_setup_pipe_resources(struct ath6kl_usb *ar_usb)
{
        struct usb_interface *interface = ar_usb->interface;
        struct usb_host_interface *iface_desc = interface->cur_altsetting;
        struct usb_endpoint_descriptor *endpoint;
        struct ath6kl_usb_pipe *pipe;
        int i, urbcount, status = 0;
        u8 pipe_num;

        ath6kl_dbg(ATH6KL_DBG_USB, "setting up USB Pipes using interface\n");

        /* walk descriptors and setup pipes */
        for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
                endpoint = &iface_desc->endpoint[i].desc;

                if (ATH6KL_USB_IS_BULK_EP(endpoint->bmAttributes)) {
                        ath6kl_dbg(ATH6KL_DBG_USB,
                                   "%s Bulk Ep:0x%2.2X maxpktsz:%d\n",
                                   ATH6KL_USB_IS_DIR_IN
                                   (endpoint->bEndpointAddress) ?
                                   "RX" : "TX", endpoint->bEndpointAddress,
                                   le16_to_cpu(endpoint->wMaxPacketSize));
                } else if (ATH6KL_USB_IS_INT_EP(endpoint->bmAttributes)) {
                        ath6kl_dbg(ATH6KL_DBG_USB,
                                   "%s Int Ep:0x%2.2X maxpktsz:%d interval:%d\n",
                                   ATH6KL_USB_IS_DIR_IN
                                   (endpoint->bEndpointAddress) ?
                                   "RX" : "TX", endpoint->bEndpointAddress,
                                   le16_to_cpu(endpoint->wMaxPacketSize),
                                   endpoint->bInterval);
                } else if (ATH6KL_USB_IS_ISOC_EP(endpoint->bmAttributes)) {
                        /* TODO for ISO */
                        ath6kl_dbg(ATH6KL_DBG_USB,
                                   "%s ISOC Ep:0x%2.2X maxpktsz:%d interval:%d\n",
                                   ATH6KL_USB_IS_DIR_IN
                                   (endpoint->bEndpointAddress) ?
                                   "RX" : "TX", endpoint->bEndpointAddress,
                                   le16_to_cpu(endpoint->wMaxPacketSize),
                                   endpoint->bInterval);
                }

                /* Ignore broken descriptors. */
                if (usb_endpoint_maxp(endpoint) == 0)
                        continue;

                urbcount = 0;

                pipe_num =
                    ath6kl_usb_get_logical_pipe_num(ar_usb,
                                                    endpoint->bEndpointAddress,
                                                    &urbcount);
                if (pipe_num == ATH6KL_USB_PIPE_INVALID)
                        continue;

                pipe = &ar_usb->pipes[pipe_num];
                if (pipe->ar_usb != NULL) {
                        /* hmmm..pipe was already setup */
                        continue;
                }

                pipe->ar_usb = ar_usb;
                pipe->logical_pipe_num = pipe_num;
                pipe->ep_address = endpoint->bEndpointAddress;
                pipe->max_packet_size = le16_to_cpu(endpoint->wMaxPacketSize);

                if (ATH6KL_USB_IS_BULK_EP(endpoint->bmAttributes)) {
                        if (ATH6KL_USB_IS_DIR_IN(pipe->ep_address)) {
                                pipe->usb_pipe_handle =
                                    usb_rcvbulkpipe(ar_usb->udev,
                                                    pipe->ep_address);
                        } else {
                                pipe->usb_pipe_handle =
                                    usb_sndbulkpipe(ar_usb->udev,
                                                    pipe->ep_address);
                        }
                } else if (ATH6KL_USB_IS_INT_EP(endpoint->bmAttributes)) {
                        if (ATH6KL_USB_IS_DIR_IN(pipe->ep_address)) {
                                pipe->usb_pipe_handle =
                                    usb_rcvintpipe(ar_usb->udev,
                                                   pipe->ep_address);
                        } else {
                                pipe->usb_pipe_handle =
                                    usb_sndintpipe(ar_usb->udev,
                                                   pipe->ep_address);
                        }
                } else if (ATH6KL_USB_IS_ISOC_EP(endpoint->bmAttributes)) {
                        /* TODO for ISO */
                        if (ATH6KL_USB_IS_DIR_IN(pipe->ep_address)) {
                                pipe->usb_pipe_handle =
                                    usb_rcvisocpipe(ar_usb->udev,
                                                    pipe->ep_address);
                        } else {
                                pipe->usb_pipe_handle =
                                    usb_sndisocpipe(ar_usb->udev,
                                                    pipe->ep_address);
                        }
                }

                pipe->ep_desc = endpoint;

                if (!ATH6KL_USB_IS_DIR_IN(pipe->ep_address))
                        pipe->flags |= ATH6KL_USB_PIPE_FLAG_TX;

                status = ath6kl_usb_alloc_pipe_resources(pipe, urbcount);
                if (status != 0)
                        break;
        }

        return status;
}

/* pipe operations */
static void ath6kl_usb_post_recv_transfers(struct ath6kl_usb_pipe *recv_pipe,
                                           int buffer_length)
{
        struct ath6kl_urb_context *urb_context;
        struct urb *urb;
        int usb_status;

        while (true) {
                urb_context = ath6kl_usb_alloc_urb_from_pipe(recv_pipe);
                if (urb_context == NULL)
                        break;

                urb_context->skb = dev_alloc_skb(buffer_length);
                if (urb_context->skb == NULL)
                        goto err_cleanup_urb;

                urb = usb_alloc_urb(0, GFP_ATOMIC);
                if (urb == NULL)
                        goto err_cleanup_urb;

                usb_fill_bulk_urb(urb,
                                  recv_pipe->ar_usb->udev,
                                  recv_pipe->usb_pipe_handle,
                                  urb_context->skb->data,
                                  buffer_length,
                                  ath6kl_usb_recv_complete, urb_context);

                ath6kl_dbg(ATH6KL_DBG_USB_BULK,
                           "ath6kl usb: bulk recv submit:%d, 0x%X (ep:0x%2.2X), %d bytes buf:0x%p\n",
                           recv_pipe->logical_pipe_num,
                           recv_pipe->usb_pipe_handle, recv_pipe->ep_address,
                           buffer_length, urb_context->skb);

                usb_anchor_urb(urb, &recv_pipe->urb_submitted);
                usb_status = usb_submit_urb(urb, GFP_ATOMIC);

                if (usb_status) {
                        ath6kl_dbg(ATH6KL_DBG_USB_BULK,
                                   "ath6kl usb : usb bulk recv failed %d\n",
                                   usb_status);
                        usb_unanchor_urb(urb);
                        usb_free_urb(urb);
                        goto err_cleanup_urb;
                }
                usb_free_urb(urb);
        }
        return;

err_cleanup_urb:
        ath6kl_usb_cleanup_recv_urb(urb_context);
        return;
}

static void ath6kl_usb_flush_all(struct ath6kl_usb *ar_usb)
{
        int i;

        for (i = 0; i < ATH6KL_USB_PIPE_MAX; i++) {
                if (ar_usb->pipes[i].ar_usb != NULL)
                        usb_kill_anchored_urbs(&ar_usb->pipes[i].urb_submitted);
        }

        /*
         * Flushing any pending I/O may schedule work this call will block
         * until all scheduled work runs to completion.
         */
        flush_workqueue(ar_usb->wq);
}

static void ath6kl_usb_start_recv_pipes(struct ath6kl_usb *ar_usb)
{
        /*
         * note: control pipe is no longer used
         * ar_usb->pipes[ATH6KL_USB_PIPE_RX_CTRL].urb_cnt_thresh =
         *      ar_usb->pipes[ATH6KL_USB_PIPE_RX_CTRL].urb_alloc/2;
         * ath6kl_usb_post_recv_transfers(&ar_usb->
         *              pipes[ATH6KL_USB_PIPE_RX_CTRL],
         *              ATH6KL_USB_RX_BUFFER_SIZE);
         */

        ar_usb->pipes[ATH6KL_USB_PIPE_RX_DATA].urb_cnt_thresh = 1;

        ath6kl_usb_post_recv_transfers(&ar_usb->pipes[ATH6KL_USB_PIPE_RX_DATA],
                                       ATH6KL_USB_RX_BUFFER_SIZE);
}

/* hif usb rx/tx completion functions */
static void ath6kl_usb_recv_complete(struct urb *urb)
{
        struct ath6kl_urb_context *urb_context = urb->context;
        struct ath6kl_usb_pipe *pipe = urb_context->pipe;
        struct sk_buff *skb = NULL;
        int status = 0;

        ath6kl_dbg(ATH6KL_DBG_USB_BULK,
                   "%s: recv pipe: %d, stat:%d, len:%d urb:0x%p\n", __func__,
                   pipe->logical_pipe_num, urb->status, urb->actual_length,
                   urb);

        if (urb->status != 0) {
                status = -EIO;
                switch (urb->status) {
                case -ECONNRESET:
                case -ENOENT:
                case -ESHUTDOWN:
                        /*
                         * no need to spew these errors when device
                         * removed or urb killed due to driver shutdown
                         */
                        status = -ECANCELED;
                        break;
                default:
                        ath6kl_dbg(ATH6KL_DBG_USB_BULK,
                                   "%s recv pipe: %d (ep:0x%2.2X), failed:%d\n",
                                   __func__, pipe->logical_pipe_num,
                                   pipe->ep_address, urb->status);
                        break;
                }
                goto cleanup_recv_urb;
        }

        if (urb->actual_length == 0)
                goto cleanup_recv_urb;

        skb = urb_context->skb;

        /* we are going to pass it up */
        urb_context->skb = NULL;
        skb_put(skb, urb->actual_length);

        /* note: queue implements a lock */
        skb_queue_tail(&pipe->io_comp_queue, skb);
        queue_work(pipe->ar_usb->wq, &pipe->io_complete_work);

cleanup_recv_urb:
        ath6kl_usb_cleanup_recv_urb(urb_context);

        if (status == 0 &&
            pipe->urb_cnt >= pipe->urb_cnt_thresh) {
                /* our free urbs are piling up, post more transfers */
                ath6kl_usb_post_recv_transfers(pipe, ATH6KL_USB_RX_BUFFER_SIZE);
        }
}

static void ath6kl_usb_usb_transmit_complete(struct urb *urb)
{
        struct ath6kl_urb_context *urb_context = urb->context;
        struct ath6kl_usb_pipe *pipe = urb_context->pipe;
        struct sk_buff *skb;

        ath6kl_dbg(ATH6KL_DBG_USB_BULK,
                   "%s: pipe: %d, stat:%d, len:%d\n",
                   __func__, pipe->logical_pipe_num, urb->status,
                   urb->actual_length);

        if (urb->status != 0) {
                ath6kl_dbg(ATH6KL_DBG_USB_BULK,
                           "%s:  pipe: %d, failed:%d\n",
                           __func__, pipe->logical_pipe_num, urb->status);
        }

        skb = urb_context->skb;
        urb_context->skb = NULL;
        ath6kl_usb_free_urb_to_pipe(urb_context->pipe, urb_context);

        /* note: queue implements a lock */
        skb_queue_tail(&pipe->io_comp_queue, skb);
        queue_work(pipe->ar_usb->wq, &pipe->io_complete_work);
}

static void ath6kl_usb_io_comp_work(struct work_struct *work)
{
        struct ath6kl_usb_pipe *pipe = container_of(work,
                                                    struct ath6kl_usb_pipe,
                                                    io_complete_work);
        struct ath6kl_usb *ar_usb;
        struct sk_buff *skb;

        ar_usb = pipe->ar_usb;

        while ((skb = skb_dequeue(&pipe->io_comp_queue))) {
                if (pipe->flags & ATH6KL_USB_PIPE_FLAG_TX) {
                        ath6kl_dbg(ATH6KL_DBG_USB_BULK,
                                   "ath6kl usb xmit callback buf:0x%p\n", skb);
                        ath6kl_core_tx_complete(ar_usb->ar, skb);
                } else {
                        ath6kl_dbg(ATH6KL_DBG_USB_BULK,
                                   "ath6kl usb recv callback buf:0x%p\n", skb);
                        ath6kl_core_rx_complete(ar_usb->ar, skb,
                                                pipe->logical_pipe_num);
                }
        }
}

#define ATH6KL_USB_MAX_DIAG_CMD (sizeof(struct ath6kl_usb_ctrl_diag_cmd_write))
#define ATH6KL_USB_MAX_DIAG_RESP (sizeof(struct ath6kl_usb_ctrl_diag_resp_read))

static void ath6kl_usb_destroy(struct ath6kl_usb *ar_usb)
{
        ath6kl_usb_flush_all(ar_usb);

        ath6kl_usb_cleanup_pipe_resources(ar_usb);

        usb_set_intfdata(ar_usb->interface, NULL);

        kfree(ar_usb->diag_cmd_buffer);
        kfree(ar_usb->diag_resp_buffer);
        destroy_workqueue(ar_usb->wq);

        kfree(ar_usb);
}

static struct ath6kl_usb *ath6kl_usb_create(struct usb_interface *interface)
{
        struct usb_device *dev = interface_to_usbdev(interface);
        struct ath6kl_usb *ar_usb;
        struct ath6kl_usb_pipe *pipe;
        int status = 0;
        int i;

        /* ath6kl_usb_destroy() needs ar_usb != NULL && ar_usb->wq != NULL. */
        ar_usb = kzalloc_obj(struct ath6kl_usb);
        if (ar_usb == NULL)
                return NULL;
        ar_usb->wq = alloc_workqueue("ath6kl_wq", WQ_PERCPU, 0);
        if (!ar_usb->wq) {
                kfree(ar_usb);
                return NULL;
        }

        usb_set_intfdata(interface, ar_usb);
        spin_lock_init(&(ar_usb->cs_lock));
        ar_usb->udev = dev;
        ar_usb->interface = interface;

        for (i = 0; i < ATH6KL_USB_PIPE_MAX; i++) {
                pipe = &ar_usb->pipes[i];
                INIT_WORK(&pipe->io_complete_work,
                          ath6kl_usb_io_comp_work);
                skb_queue_head_init(&pipe->io_comp_queue);
        }

        ar_usb->diag_cmd_buffer = kzalloc(ATH6KL_USB_MAX_DIAG_CMD, GFP_KERNEL);
        if (ar_usb->diag_cmd_buffer == NULL) {
                status = -ENOMEM;
                goto fail_ath6kl_usb_create;
        }

        ar_usb->diag_resp_buffer = kzalloc(ATH6KL_USB_MAX_DIAG_RESP,
                                           GFP_KERNEL);
        if (ar_usb->diag_resp_buffer == NULL) {
                status = -ENOMEM;
                goto fail_ath6kl_usb_create;
        }

        status = ath6kl_usb_setup_pipe_resources(ar_usb);

fail_ath6kl_usb_create:
        if (status != 0) {
                ath6kl_usb_destroy(ar_usb);
                ar_usb = NULL;
        }
        return ar_usb;
}

static void ath6kl_usb_device_detached(struct usb_interface *interface)
{
        struct ath6kl_usb *ar_usb;

        ar_usb = usb_get_intfdata(interface);
        if (ar_usb == NULL)
                return;

        ath6kl_stop_txrx(ar_usb->ar);

        /* Delay to wait for the target to reboot */
        mdelay(20);
        ath6kl_core_cleanup(ar_usb->ar);
        ath6kl_usb_destroy(ar_usb);
}

/* exported hif usb APIs for htc pipe */
static void hif_start(struct ath6kl *ar)
{
        struct ath6kl_usb *device = ath6kl_usb_priv(ar);
        int i;

        ath6kl_usb_start_recv_pipes(device);

        /* set the TX resource avail threshold for each TX pipe */
        for (i = ATH6KL_USB_PIPE_TX_CTRL;
             i <= ATH6KL_USB_PIPE_TX_DATA_HP; i++) {
                device->pipes[i].urb_cnt_thresh =
                    device->pipes[i].urb_alloc / 2;
        }
}

static int ath6kl_usb_send(struct ath6kl *ar, u8 PipeID,
                           struct sk_buff *hdr_skb, struct sk_buff *skb)
{
        struct ath6kl_usb *device = ath6kl_usb_priv(ar);
        struct ath6kl_usb_pipe *pipe = &device->pipes[PipeID];
        struct ath6kl_urb_context *urb_context;
        int usb_status, status = 0;
        struct urb *urb;
        u8 *data;
        u32 len;

        ath6kl_dbg(ATH6KL_DBG_USB_BULK, "+%s pipe : %d, buf:0x%p\n",
                   __func__, PipeID, skb);

        urb_context = ath6kl_usb_alloc_urb_from_pipe(pipe);

        if (urb_context == NULL) {
                /*
                 * TODO: it is possible to run out of urbs if
                 * 2 endpoints map to the same pipe ID
                 */
                ath6kl_dbg(ATH6KL_DBG_USB_BULK,
                           "%s pipe:%d no urbs left. URB Cnt : %d\n",
                           __func__, PipeID, pipe->urb_cnt);
                status = -ENOMEM;
                goto fail_hif_send;
        }

        urb_context->skb = skb;

        data = skb->data;
        len = skb->len;

        urb = usb_alloc_urb(0, GFP_ATOMIC);
        if (urb == NULL) {
                status = -ENOMEM;
                ath6kl_usb_free_urb_to_pipe(urb_context->pipe,
                                            urb_context);
                goto fail_hif_send;
        }

        usb_fill_bulk_urb(urb,
                          device->udev,
                          pipe->usb_pipe_handle,
                          data,
                          len,
                          ath6kl_usb_usb_transmit_complete, urb_context);

        if ((len % pipe->max_packet_size) == 0) {
                /* hit a max packet boundary on this pipe */
                urb->transfer_flags |= URB_ZERO_PACKET;
        }

        ath6kl_dbg(ATH6KL_DBG_USB_BULK,
                   "athusb bulk send submit:%d, 0x%X (ep:0x%2.2X), %d bytes\n",
                   pipe->logical_pipe_num, pipe->usb_pipe_handle,
                   pipe->ep_address, len);

        usb_anchor_urb(urb, &pipe->urb_submitted);
        usb_status = usb_submit_urb(urb, GFP_ATOMIC);

        if (usb_status) {
                ath6kl_dbg(ATH6KL_DBG_USB_BULK,
                           "ath6kl usb : usb bulk transmit failed %d\n",
                           usb_status);
                usb_unanchor_urb(urb);
                ath6kl_usb_free_urb_to_pipe(urb_context->pipe,
                                            urb_context);
                status = -EINVAL;
        }
        usb_free_urb(urb);

fail_hif_send:
        return status;
}

static void hif_stop(struct ath6kl *ar)
{
        struct ath6kl_usb *device = ath6kl_usb_priv(ar);

        ath6kl_usb_flush_all(device);
}

static void ath6kl_usb_get_default_pipe(struct ath6kl *ar,
                                        u8 *ul_pipe, u8 *dl_pipe)
{
        *ul_pipe = ATH6KL_USB_PIPE_TX_CTRL;
        *dl_pipe = ATH6KL_USB_PIPE_RX_CTRL;
}

static int ath6kl_usb_map_service_pipe(struct ath6kl *ar, u16 svc_id,
                                       u8 *ul_pipe, u8 *dl_pipe)
{
        int status = 0;

        switch (svc_id) {
        case HTC_CTRL_RSVD_SVC:
        case WMI_CONTROL_SVC:
                *ul_pipe = ATH6KL_USB_PIPE_TX_CTRL;
                /* due to large control packets, shift to data pipe */
                *dl_pipe = ATH6KL_USB_PIPE_RX_DATA;
                break;
        case WMI_DATA_BE_SVC:
        case WMI_DATA_BK_SVC:
                *ul_pipe = ATH6KL_USB_PIPE_TX_DATA_LP;
                /*
                * Disable rxdata2 directly, it will be enabled
                * if FW enable rxdata2
                */
                *dl_pipe = ATH6KL_USB_PIPE_RX_DATA;
                break;
        case WMI_DATA_VI_SVC:

                if (test_bit(ATH6KL_FW_CAPABILITY_MAP_LP_ENDPOINT,
                             ar->fw_capabilities))
                        *ul_pipe = ATH6KL_USB_PIPE_TX_DATA_LP;
                else
                        *ul_pipe = ATH6KL_USB_PIPE_TX_DATA_MP;
                /*
                * Disable rxdata2 directly, it will be enabled
                * if FW enable rxdata2
                */
                *dl_pipe = ATH6KL_USB_PIPE_RX_DATA;
                break;
        case WMI_DATA_VO_SVC:

                if (test_bit(ATH6KL_FW_CAPABILITY_MAP_LP_ENDPOINT,
                             ar->fw_capabilities))
                        *ul_pipe = ATH6KL_USB_PIPE_TX_DATA_LP;
                else
                        *ul_pipe = ATH6KL_USB_PIPE_TX_DATA_MP;
                /*
                * Disable rxdata2 directly, it will be enabled
                * if FW enable rxdata2
                */
                *dl_pipe = ATH6KL_USB_PIPE_RX_DATA;
                break;
        default:
                status = -EPERM;
                break;
        }

        return status;
}

static u16 ath6kl_usb_get_free_queue_number(struct ath6kl *ar, u8 pipe_id)
{
        struct ath6kl_usb *device = ath6kl_usb_priv(ar);

        return device->pipes[pipe_id].urb_cnt;
}

static void hif_detach_htc(struct ath6kl *ar)
{
        struct ath6kl_usb *device = ath6kl_usb_priv(ar);

        ath6kl_usb_flush_all(device);
}

static int ath6kl_usb_submit_ctrl_out(struct ath6kl_usb *ar_usb,
                                   u8 req, u16 value, u16 index, void *data,
                                   u32 size)
{
        u8 *buf = NULL;
        int ret;

        if (size > 0) {
                buf = kmemdup(data, size, GFP_KERNEL);
                if (buf == NULL)
                        return -ENOMEM;
        }

        /* note: if successful returns number of bytes transferred */
        ret = usb_control_msg(ar_usb->udev,
                              usb_sndctrlpipe(ar_usb->udev, 0),
                              req,
                              USB_DIR_OUT | USB_TYPE_VENDOR |
                              USB_RECIP_DEVICE, value, index, buf,
                              size, 1000);

        if (ret < 0) {
                ath6kl_warn("Failed to submit usb control message: %d\n", ret);
                kfree(buf);
                return ret;
        }

        kfree(buf);

        return 0;
}

static int ath6kl_usb_submit_ctrl_in(struct ath6kl_usb *ar_usb,
                                  u8 req, u16 value, u16 index, void *data,
                                  u32 size)
{
        u8 *buf = NULL;
        int ret;

        if (size > 0) {
                buf = kmalloc(size, GFP_KERNEL);
                if (buf == NULL)
                        return -ENOMEM;
        }

        /* note: if successful returns number of bytes transferred */
        ret = usb_control_msg(ar_usb->udev,
                                 usb_rcvctrlpipe(ar_usb->udev, 0),
                                 req,
                                 USB_DIR_IN | USB_TYPE_VENDOR |
                                 USB_RECIP_DEVICE, value, index, buf,
                                 size, 2000);

        if (ret < 0) {
                ath6kl_warn("Failed to read usb control message: %d\n", ret);
                kfree(buf);
                return ret;
        }

        memcpy((u8 *) data, buf, size);

        kfree(buf);

        return 0;
}

static int ath6kl_usb_ctrl_msg_exchange(struct ath6kl_usb *ar_usb,
                                     u8 req_val, u8 *req_buf, u32 req_len,
                                     u8 resp_val, u8 *resp_buf, u32 *resp_len)
{
        int ret;

        /* send command */
        ret = ath6kl_usb_submit_ctrl_out(ar_usb, req_val, 0, 0,
                                         req_buf, req_len);

        if (ret != 0)
                return ret;

        if (resp_buf == NULL) {
                /* no expected response */
                return ret;
        }

        /* get response */
        ret = ath6kl_usb_submit_ctrl_in(ar_usb, resp_val, 0, 0,
                                        resp_buf, *resp_len);

        return ret;
}

static int ath6kl_usb_diag_read32(struct ath6kl *ar, u32 address, u32 *data)
{
        struct ath6kl_usb *ar_usb = ar->hif_priv;
        struct ath6kl_usb_ctrl_diag_resp_read *resp;
        struct ath6kl_usb_ctrl_diag_cmd_read *cmd;
        u32 resp_len;
        int ret;

        cmd = (struct ath6kl_usb_ctrl_diag_cmd_read *) ar_usb->diag_cmd_buffer;

        memset(cmd, 0, sizeof(*cmd));
        cmd->cmd = ATH6KL_USB_CTRL_DIAG_CC_READ;
        cmd->address = cpu_to_le32(address);
        resp_len = sizeof(*resp);

        ret = ath6kl_usb_ctrl_msg_exchange(ar_usb,
                                ATH6KL_USB_CONTROL_REQ_DIAG_CMD,
                                (u8 *) cmd,
                                sizeof(struct ath6kl_usb_ctrl_diag_cmd_write),
                                ATH6KL_USB_CONTROL_REQ_DIAG_RESP,
                                ar_usb->diag_resp_buffer, &resp_len);

        if (ret) {
                ath6kl_warn("diag read32 failed: %d\n", ret);
                return ret;
        }

        resp = (struct ath6kl_usb_ctrl_diag_resp_read *)
                ar_usb->diag_resp_buffer;

        *data = le32_to_cpu(resp->value);

        return ret;
}

static int ath6kl_usb_diag_write32(struct ath6kl *ar, u32 address, __le32 data)
{
        struct ath6kl_usb *ar_usb = ar->hif_priv;
        struct ath6kl_usb_ctrl_diag_cmd_write *cmd;
        int ret;

        cmd = (struct ath6kl_usb_ctrl_diag_cmd_write *) ar_usb->diag_cmd_buffer;

        memset(cmd, 0, sizeof(struct ath6kl_usb_ctrl_diag_cmd_write));
        cmd->cmd = cpu_to_le32(ATH6KL_USB_CTRL_DIAG_CC_WRITE);
        cmd->address = cpu_to_le32(address);
        cmd->value = data;

        ret = ath6kl_usb_ctrl_msg_exchange(ar_usb,
                                           ATH6KL_USB_CONTROL_REQ_DIAG_CMD,
                                           (u8 *) cmd,
                                           sizeof(*cmd),
                                           0, NULL, NULL);
        if (ret) {
                ath6kl_warn("diag_write32 failed: %d\n", ret);
                return ret;
        }

        return 0;
}

static int ath6kl_usb_bmi_read(struct ath6kl *ar, u8 *buf, u32 len)
{
        struct ath6kl_usb *ar_usb = ar->hif_priv;
        int ret;

        /* get response */
        ret = ath6kl_usb_submit_ctrl_in(ar_usb,
                                        ATH6KL_USB_CONTROL_REQ_RECV_BMI_RESP,
                                        0, 0, buf, len);
        if (ret) {
                ath6kl_err("Unable to read the bmi data from the device: %d\n",
                           ret);
                return ret;
        }

        return 0;
}

static int ath6kl_usb_bmi_write(struct ath6kl *ar, u8 *buf, u32 len)
{
        struct ath6kl_usb *ar_usb = ar->hif_priv;
        int ret;

        /* send command */
        ret = ath6kl_usb_submit_ctrl_out(ar_usb,
                                         ATH6KL_USB_CONTROL_REQ_SEND_BMI_CMD,
                                         0, 0, buf, len);
        if (ret) {
                ath6kl_err("unable to send the bmi data to the device: %d\n",
                           ret);
                return ret;
        }

        return 0;
}

static int ath6kl_usb_power_on(struct ath6kl *ar)
{
        hif_start(ar);
        return 0;
}

static int ath6kl_usb_power_off(struct ath6kl *ar)
{
        hif_detach_htc(ar);
        return 0;
}

static void ath6kl_usb_stop(struct ath6kl *ar)
{
        hif_stop(ar);
}

static void ath6kl_usb_cleanup_scatter(struct ath6kl *ar)
{
        /*
         * USB doesn't support it. Just return.
         */
        return;
}

static int ath6kl_usb_suspend(struct ath6kl *ar, struct cfg80211_wowlan *wow)
{
        /*
         * cfg80211 suspend/WOW currently not supported for USB.
         */
        return 0;
}

static int ath6kl_usb_resume(struct ath6kl *ar)
{
        /*
         * cfg80211 resume currently not supported for USB.
         */
        return 0;
}

static const struct ath6kl_hif_ops ath6kl_usb_ops = {
        .diag_read32 = ath6kl_usb_diag_read32,
        .diag_write32 = ath6kl_usb_diag_write32,
        .bmi_read = ath6kl_usb_bmi_read,
        .bmi_write = ath6kl_usb_bmi_write,
        .power_on = ath6kl_usb_power_on,
        .power_off = ath6kl_usb_power_off,
        .stop = ath6kl_usb_stop,
        .pipe_send = ath6kl_usb_send,
        .pipe_get_default = ath6kl_usb_get_default_pipe,
        .pipe_map_service = ath6kl_usb_map_service_pipe,
        .pipe_get_free_queue_number = ath6kl_usb_get_free_queue_number,
        .cleanup_scatter = ath6kl_usb_cleanup_scatter,
        .suspend = ath6kl_usb_suspend,
        .resume = ath6kl_usb_resume,
};

/* ath6kl usb driver registered functions */
static int ath6kl_usb_probe(struct usb_interface *interface,
                            const struct usb_device_id *id)
{
        struct usb_device *dev = interface_to_usbdev(interface);
        struct ath6kl *ar;
        struct ath6kl_usb *ar_usb = NULL;
        int vendor_id, product_id;
        int ret = 0;

        vendor_id = le16_to_cpu(dev->descriptor.idVendor);
        product_id = le16_to_cpu(dev->descriptor.idProduct);

        ath6kl_dbg(ATH6KL_DBG_USB, "vendor_id = %04x\n", vendor_id);
        ath6kl_dbg(ATH6KL_DBG_USB, "product_id = %04x\n", product_id);

        if (interface->cur_altsetting)
                ath6kl_dbg(ATH6KL_DBG_USB, "USB Interface %d\n",
                           interface->cur_altsetting->desc.bInterfaceNumber);


        if (dev->speed == USB_SPEED_HIGH)
                ath6kl_dbg(ATH6KL_DBG_USB, "USB 2.0 Host\n");
        else
                ath6kl_dbg(ATH6KL_DBG_USB, "USB 1.1 Host\n");

        ar_usb = ath6kl_usb_create(interface);
        if (ar_usb == NULL)
                return -ENOMEM;

        ar = ath6kl_core_create(&ar_usb->udev->dev);
        if (ar == NULL) {
                ath6kl_err("Failed to alloc ath6kl core\n");
                ret = -ENOMEM;
                goto err_usb_destroy;
        }

        ar->hif_priv = ar_usb;
        ar->hif_type = ATH6KL_HIF_TYPE_USB;
        ar->hif_ops = &ath6kl_usb_ops;
        ar->mbox_info.block_size = 16;
        ar->bmi.max_data_size = 252;

        ar_usb->ar = ar;

        ret = ath6kl_core_init(ar, ATH6KL_HTC_TYPE_PIPE);
        if (ret) {
                ath6kl_err("Failed to init ath6kl core: %d\n", ret);
                goto err_core_free;
        }

        return ret;

err_core_free:
        ath6kl_core_destroy(ar);
err_usb_destroy:
        ath6kl_usb_destroy(ar_usb);

        return ret;
}

static void ath6kl_usb_disconnect(struct usb_interface *interface)
{
        ath6kl_usb_device_detached(interface);
}

#ifdef CONFIG_PM

static int ath6kl_usb_pm_suspend(struct usb_interface *interface,
                              pm_message_t message)
{
        struct ath6kl_usb *device;
        device = usb_get_intfdata(interface);

        ath6kl_usb_flush_all(device);
        return 0;
}

static int ath6kl_usb_pm_resume(struct usb_interface *interface)
{
        struct ath6kl_usb *device;
        device = usb_get_intfdata(interface);

        ath6kl_usb_post_recv_transfers(&device->pipes[ATH6KL_USB_PIPE_RX_DATA],
                                       ATH6KL_USB_RX_BUFFER_SIZE);
        ath6kl_usb_post_recv_transfers(&device->pipes[ATH6KL_USB_PIPE_RX_DATA2],
                                       ATH6KL_USB_RX_BUFFER_SIZE);

        return 0;
}

#else

#define ath6kl_usb_pm_suspend NULL
#define ath6kl_usb_pm_resume NULL

#endif

/* table of devices that work with this driver */
static const struct usb_device_id ath6kl_usb_ids[] = {
        {USB_DEVICE(0x0cf3, 0x9375)},
        {USB_DEVICE(0x0cf3, 0x9374)},
        {USB_DEVICE(0x04da, 0x390d)},
        { /* Terminating entry */ },
};

MODULE_DEVICE_TABLE(usb, ath6kl_usb_ids);

static struct usb_driver ath6kl_usb_driver = {
        .name = "ath6kl_usb",
        .probe = ath6kl_usb_probe,
        .suspend = ath6kl_usb_pm_suspend,
        .resume = ath6kl_usb_pm_resume,
        .disconnect = ath6kl_usb_disconnect,
        .id_table = ath6kl_usb_ids,
        .supports_autosuspend = true,
        .disable_hub_initiated_lpm = 1,
};

module_usb_driver(ath6kl_usb_driver);

MODULE_AUTHOR("Atheros Communications, Inc.");
MODULE_DESCRIPTION("Driver support for Atheros AR600x USB devices");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_FIRMWARE(AR6004_HW_1_0_FIRMWARE_FILE);
MODULE_FIRMWARE(AR6004_HW_1_0_BOARD_DATA_FILE);
MODULE_FIRMWARE(AR6004_HW_1_0_DEFAULT_BOARD_DATA_FILE);
MODULE_FIRMWARE(AR6004_HW_1_1_FIRMWARE_FILE);
MODULE_FIRMWARE(AR6004_HW_1_1_BOARD_DATA_FILE);
MODULE_FIRMWARE(AR6004_HW_1_1_DEFAULT_BOARD_DATA_FILE);
MODULE_FIRMWARE(AR6004_HW_1_2_FIRMWARE_FILE);
MODULE_FIRMWARE(AR6004_HW_1_2_BOARD_DATA_FILE);
MODULE_FIRMWARE(AR6004_HW_1_2_DEFAULT_BOARD_DATA_FILE);
MODULE_FIRMWARE(AR6004_HW_1_3_FW_DIR "/" AR6004_HW_1_3_FIRMWARE_FILE);
MODULE_FIRMWARE(AR6004_HW_1_3_BOARD_DATA_FILE);
MODULE_FIRMWARE(AR6004_HW_1_3_DEFAULT_BOARD_DATA_FILE);