// SPDX-License-Identifier: GPL-2.0-only
/*
 * Line 6 Linux USB driver
 *
 * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/usb.h>

#include <sound/core.h>
#include <sound/initval.h>
#include <sound/hwdep.h>

#include "capture.h"
#include "driver.h"
#include "midi.h"
#include "playback.h"

#define DRIVER_AUTHOR  "Markus Grabner <grabner@icg.tugraz.at>"
#define DRIVER_DESC    "Line 6 USB Driver"

/*
        This is Line 6's MIDI manufacturer ID.
*/
const unsigned char line6_midi_id[3] = {
        0x00, 0x01, 0x0c
};
EXPORT_SYMBOL_GPL(line6_midi_id);

/*
        Code to request version of POD, Variax interface
        (and maybe other devices).
*/
static const char line6_request_version[] = {
        0xf0, 0x7e, 0x7f, 0x06, 0x01, 0xf7
};

/*
         Class for asynchronous messages.
*/
struct message {
        struct usb_line6 *line6;
        const char *buffer;
        int size;
        int done;
};

/*
        Forward declarations.
*/
static void line6_data_received(struct urb *urb);
static int line6_send_raw_message_async_part(struct message *msg,
                                             struct urb *urb);

/*
        Start to listen on endpoint.
*/
static int line6_start_listen(struct usb_line6 *line6)
{
        int err;

        if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
                usb_fill_int_urb(line6->urb_listen, line6->usbdev,
                        usb_rcvintpipe(line6->usbdev, line6->properties->ep_ctrl_r),
                        line6->buffer_listen, LINE6_BUFSIZE_LISTEN,
                        line6_data_received, line6, line6->interval);
        } else {
                usb_fill_bulk_urb(line6->urb_listen, line6->usbdev,
                        usb_rcvbulkpipe(line6->usbdev, line6->properties->ep_ctrl_r),
                        line6->buffer_listen, LINE6_BUFSIZE_LISTEN,
                        line6_data_received, line6);
        }

        /* sanity checks of EP before actually submitting */
        if (usb_urb_ep_type_check(line6->urb_listen)) {
                dev_err(line6->ifcdev, "invalid control EP\n");
                return -EINVAL;
        }

        line6->urb_listen->actual_length = 0;
        err = usb_submit_urb(line6->urb_listen, GFP_ATOMIC);
        return err;
}

/*
        Stop listening on endpoint.
*/
static void line6_stop_listen(struct usb_line6 *line6)
{
        usb_kill_urb(line6->urb_listen);
}

/*
        Send raw message in pieces of wMaxPacketSize bytes.
*/
int line6_send_raw_message(struct usb_line6 *line6, const char *buffer,
                                  int size)
{
        int i, done = 0;
        const struct line6_properties *properties = line6->properties;

        for (i = 0; i < size; i += line6->max_packet_size) {
                int partial;
                const char *frag_buf = buffer + i;
                int frag_size = min(line6->max_packet_size, size - i);
                int retval;

                if (properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
                        retval = usb_interrupt_msg(line6->usbdev,
                                                usb_sndintpipe(line6->usbdev, properties->ep_ctrl_w),
                                                (char *)frag_buf, frag_size,
                                                &partial, LINE6_TIMEOUT * HZ);
                } else {
                        retval = usb_bulk_msg(line6->usbdev,
                                                usb_sndbulkpipe(line6->usbdev, properties->ep_ctrl_w),
                                                (char *)frag_buf, frag_size,
                                                &partial, LINE6_TIMEOUT * HZ);
                }

                if (retval) {
                        dev_err(line6->ifcdev,
                                "usb_bulk_msg failed (%d)\n", retval);
                        break;
                }

                done += frag_size;
        }

        return done;
}
EXPORT_SYMBOL_GPL(line6_send_raw_message);

/*
        Notification of completion of asynchronous request transmission.
*/
static void line6_async_request_sent(struct urb *urb)
{
        struct message *msg = (struct message *)urb->context;

        if (msg->done >= msg->size) {
                usb_free_urb(urb);
                kfree(msg);
        } else
                line6_send_raw_message_async_part(msg, urb);
}

/*
        Asynchronously send part of a raw message.
*/
static int line6_send_raw_message_async_part(struct message *msg,
                                             struct urb *urb)
{
        int retval;
        struct usb_line6 *line6 = msg->line6;
        int done = msg->done;
        int bytes = min(msg->size - done, line6->max_packet_size);

        if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
                usb_fill_int_urb(urb, line6->usbdev,
                        usb_sndintpipe(line6->usbdev, line6->properties->ep_ctrl_w),
                        (char *)msg->buffer + done, bytes,
                        line6_async_request_sent, msg, line6->interval);
        } else {
                usb_fill_bulk_urb(urb, line6->usbdev,
                        usb_sndbulkpipe(line6->usbdev, line6->properties->ep_ctrl_w),
                        (char *)msg->buffer + done, bytes,
                        line6_async_request_sent, msg);
        }

        msg->done += bytes;

        /* sanity checks of EP before actually submitting */
        retval = usb_urb_ep_type_check(urb);
        if (retval < 0)
                goto error;

        retval = usb_submit_urb(urb, GFP_ATOMIC);
        if (retval < 0)
                goto error;

        return 0;

 error:
        dev_err(line6->ifcdev, "%s: usb_submit_urb failed (%d)\n",
                __func__, retval);
        usb_free_urb(urb);
        kfree(msg);
        return retval;
}

/*
        Asynchronously send raw message.
*/
int line6_send_raw_message_async(struct usb_line6 *line6, const char *buffer,
                                 int size)
{
        struct message *msg;
        struct urb *urb;

        /* create message: */
        msg = kmalloc(sizeof(struct message), GFP_ATOMIC);
        if (msg == NULL)
                return -ENOMEM;

        /* create URB: */
        urb = usb_alloc_urb(0, GFP_ATOMIC);

        if (urb == NULL) {
                kfree(msg);
                return -ENOMEM;
        }

        /* set message data: */
        msg->line6 = line6;
        msg->buffer = buffer;
        msg->size = size;
        msg->done = 0;

        /* start sending: */
        return line6_send_raw_message_async_part(msg, urb);
}
EXPORT_SYMBOL_GPL(line6_send_raw_message_async);

/*
        Send asynchronous device version request.
*/
int line6_version_request_async(struct usb_line6 *line6)
{
        char *buffer;
        int retval;

        buffer = kmemdup(line6_request_version,
                        sizeof(line6_request_version), GFP_ATOMIC);
        if (buffer == NULL)
                return -ENOMEM;

        retval = line6_send_raw_message_async(line6, buffer,
                                              sizeof(line6_request_version));
        kfree(buffer);
        return retval;
}
EXPORT_SYMBOL_GPL(line6_version_request_async);

/*
        Send sysex message in pieces of wMaxPacketSize bytes.
*/
int line6_send_sysex_message(struct usb_line6 *line6, const char *buffer,
                             int size)
{
        return line6_send_raw_message(line6, buffer,
                                      size + SYSEX_EXTRA_SIZE) -
            SYSEX_EXTRA_SIZE;
}
EXPORT_SYMBOL_GPL(line6_send_sysex_message);

/*
        Allocate buffer for sysex message and prepare header.
        @param code sysex message code
        @param size number of bytes between code and sysex end
*/
char *line6_alloc_sysex_buffer(struct usb_line6 *line6, int code1, int code2,
                               int size)
{
        char *buffer = kmalloc(size + SYSEX_EXTRA_SIZE, GFP_ATOMIC);

        if (!buffer)
                return NULL;

        buffer[0] = LINE6_SYSEX_BEGIN;
        memcpy(buffer + 1, line6_midi_id, sizeof(line6_midi_id));
        buffer[sizeof(line6_midi_id) + 1] = code1;
        buffer[sizeof(line6_midi_id) + 2] = code2;
        buffer[sizeof(line6_midi_id) + 3 + size] = LINE6_SYSEX_END;
        return buffer;
}
EXPORT_SYMBOL_GPL(line6_alloc_sysex_buffer);

/*
        Notification of data received from the Line 6 device.
*/
static void line6_data_received(struct urb *urb)
{
        struct usb_line6 *line6 = (struct usb_line6 *)urb->context;
        struct midi_buffer *mb = &line6->line6midi->midibuf_in;
        int done;

        if (urb->status == -ESHUTDOWN)
                return;

        if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
                done =
                        line6_midibuf_write(mb, urb->transfer_buffer, urb->actual_length);

                if (done < urb->actual_length) {
                        line6_midibuf_ignore(mb, done);
                        dev_dbg(line6->ifcdev, "%d %d buffer overflow - message skipped\n",
                                done, urb->actual_length);
                }

                for (;;) {
                        done =
                                line6_midibuf_read(mb, line6->buffer_message,
                                                LINE6_MIDI_MESSAGE_MAXLEN);

                        if (done <= 0)
                                break;

                        line6->message_length = done;
                        line6_midi_receive(line6, line6->buffer_message, done);

                        if (line6->process_message)
                                line6->process_message(line6);
                }
        } else {
                line6->buffer_message = urb->transfer_buffer;
                line6->message_length = urb->actual_length;
                if (line6->process_message)
                        line6->process_message(line6);
                line6->buffer_message = NULL;
        }

        line6_start_listen(line6);
}

#define LINE6_READ_WRITE_STATUS_DELAY 2  /* milliseconds */
#define LINE6_READ_WRITE_MAX_RETRIES 50

/*
        Read data from device.
*/
int line6_read_data(struct usb_line6 *line6, unsigned address, void *data,
                    unsigned datalen)
{
        struct usb_device *usbdev = line6->usbdev;
        int ret;
        u8 len;
        unsigned count;

        if (address > 0xffff || datalen > 0xff)
                return -EINVAL;

        /* query the serial number: */
        ret = usb_control_msg_send(usbdev, 0, 0x67,
                                   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
                                   (datalen << 8) | 0x21, address, NULL, 0,
                                   LINE6_TIMEOUT * HZ, GFP_KERNEL);
        if (ret) {
                dev_err(line6->ifcdev, "read request failed (error %d)\n", ret);
                goto exit;
        }

        /* Wait for data length. We'll get 0xff until length arrives. */
        for (count = 0; count < LINE6_READ_WRITE_MAX_RETRIES; count++) {
                mdelay(LINE6_READ_WRITE_STATUS_DELAY);

                ret = usb_control_msg_recv(usbdev, 0, 0x67,
                                           USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
                                           0x0012, 0x0000, &len, 1,
                                           LINE6_TIMEOUT * HZ, GFP_KERNEL);
                if (ret) {
                        dev_err(line6->ifcdev,
                                "receive length failed (error %d)\n", ret);
                        goto exit;
                }

                if (len != 0xff)
                        break;
        }

        ret = -EIO;
        if (len == 0xff) {
                dev_err(line6->ifcdev, "read failed after %d retries\n",
                        count);
                goto exit;
        } else if (len != datalen) {
                /* should be equal or something went wrong */
                dev_err(line6->ifcdev,
                        "length mismatch (expected %d, got %d)\n",
                        (int)datalen, len);
                goto exit;
        }

        /* receive the result: */
        ret = usb_control_msg_recv(usbdev, 0, 0x67,
                                   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
                                   0x0013, 0x0000, data, datalen, LINE6_TIMEOUT * HZ,
                                   GFP_KERNEL);
        if (ret)
                dev_err(line6->ifcdev, "read failed (error %d)\n", ret);

exit:
        return ret;
}
EXPORT_SYMBOL_GPL(line6_read_data);

/*
        Write data to device.
*/
int line6_write_data(struct usb_line6 *line6, unsigned address, void *data,
                     unsigned datalen)
{
        struct usb_device *usbdev = line6->usbdev;
        int ret;
        unsigned char *status;
        int count;

        if (address > 0xffff || datalen > 0xffff)
                return -EINVAL;

        status = kmalloc(1, GFP_KERNEL);
        if (!status)
                return -ENOMEM;

        ret = usb_control_msg_send(usbdev, 0, 0x67,
                                   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
                                   0x0022, address, data, datalen, LINE6_TIMEOUT * HZ,
                                   GFP_KERNEL);
        if (ret) {
                dev_err(line6->ifcdev,
                        "write request failed (error %d)\n", ret);
                goto exit;
        }

        for (count = 0; count < LINE6_READ_WRITE_MAX_RETRIES; count++) {
                mdelay(LINE6_READ_WRITE_STATUS_DELAY);

                ret = usb_control_msg_recv(usbdev, 0, 0x67,
                                           USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
                                           0x0012, 0x0000, status, 1, LINE6_TIMEOUT * HZ,
                                           GFP_KERNEL);
                if (ret) {
                        dev_err(line6->ifcdev,
                                "receiving status failed (error %d)\n", ret);
                        goto exit;
                }

                if (*status != 0xff)
                        break;
        }

        if (*status == 0xff) {
                dev_err(line6->ifcdev, "write failed after %d retries\n",
                        count);
                ret = -EIO;
        } else if (*status != 0) {
                dev_err(line6->ifcdev, "write failed (error %d)\n", ret);
                ret = -EIO;
        }
exit:
        kfree(status);
        return ret;
}
EXPORT_SYMBOL_GPL(line6_write_data);

/*
        Read Line 6 device serial number.
        (POD, TonePort, GuitarPort)
*/
int line6_read_serial_number(struct usb_line6 *line6, u32 *serial_number)
{
        return line6_read_data(line6, 0x80d0, serial_number,
                               sizeof(*serial_number));
}
EXPORT_SYMBOL_GPL(line6_read_serial_number);

/*
        Card destructor.
*/
static void line6_destruct(struct snd_card *card)
{
        struct usb_line6 *line6 = card->private_data;
        struct usb_device *usbdev = line6->usbdev;

        /* Free buffer memory first. We cannot depend on the existence of private
         * data from the (podhd) module, it may be gone already during this call
         */
        kfree(line6->buffer_message);

        kfree(line6->buffer_listen);

        /* then free URBs: */
        usb_free_urb(line6->urb_listen);
        line6->urb_listen = NULL;

        /* decrement reference counters: */
        usb_put_dev(usbdev);
}

static void line6_get_usb_properties(struct usb_line6 *line6)
{
        struct usb_device *usbdev = line6->usbdev;
        const struct line6_properties *properties = line6->properties;
        int pipe;
        struct usb_host_endpoint *ep = NULL;

        if (properties->capabilities & LINE6_CAP_CONTROL) {
                if (properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
                        pipe = usb_rcvintpipe(line6->usbdev,
                                line6->properties->ep_ctrl_r);
                } else {
                        pipe = usb_rcvbulkpipe(line6->usbdev,
                                line6->properties->ep_ctrl_r);
                }
                ep = usbdev->ep_in[usb_pipeendpoint(pipe)];
        }

        /* Control data transfer properties */
        if (ep) {
                line6->interval = ep->desc.bInterval;
                line6->max_packet_size = le16_to_cpu(ep->desc.wMaxPacketSize);
        } else {
                if (properties->capabilities & LINE6_CAP_CONTROL) {
                        dev_err(line6->ifcdev,
                                "endpoint not available, using fallback values");
                }
                line6->interval = LINE6_FALLBACK_INTERVAL;
                line6->max_packet_size = LINE6_FALLBACK_MAXPACKETSIZE;
        }

        /* Isochronous transfer properties */
        if (usbdev->speed == USB_SPEED_LOW) {
                line6->intervals_per_second = USB_LOW_INTERVALS_PER_SECOND;
                line6->iso_buffers = USB_LOW_ISO_BUFFERS;
        } else {
                line6->intervals_per_second = USB_HIGH_INTERVALS_PER_SECOND;
                line6->iso_buffers = USB_HIGH_ISO_BUFFERS;
        }
}

/* Enable buffering of incoming messages, flush the buffer */
static int line6_hwdep_open(struct snd_hwdep *hw, struct file *file)
{
        struct usb_line6 *line6 = hw->private_data;

        /* NOTE: hwdep layer provides atomicity here */

        line6->messages.active = 1;
        line6->messages.nonblock = file->f_flags & O_NONBLOCK ? 1 : 0;

        return 0;
}

/* Stop buffering */
static int line6_hwdep_release(struct snd_hwdep *hw, struct file *file)
{
        struct usb_line6 *line6 = hw->private_data;

        line6->messages.active = 0;

        return 0;
}

/* Read from circular buffer, return to user */
static long
line6_hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
                                        loff_t *offset)
{
        struct usb_line6 *line6 = hwdep->private_data;
        long rv = 0;
        unsigned int out_count;

        if (mutex_lock_interruptible(&line6->messages.read_lock))
                return -ERESTARTSYS;

        while (kfifo_len(&line6->messages.fifo) == 0) {
                mutex_unlock(&line6->messages.read_lock);

                if (line6->messages.nonblock)
                        return -EAGAIN;

                rv = wait_event_interruptible(
                        line6->messages.wait_queue,
                        kfifo_len(&line6->messages.fifo) != 0);
                if (rv < 0)
                        return rv;

                if (mutex_lock_interruptible(&line6->messages.read_lock))
                        return -ERESTARTSYS;
        }

        if (kfifo_peek_len(&line6->messages.fifo) > count) {
                /* Buffer too small; allow re-read of the current item... */
                rv = -EINVAL;
        } else {
                rv = kfifo_to_user(&line6->messages.fifo, buf, count, &out_count);
                if (rv == 0)
                        rv = out_count;
        }

        mutex_unlock(&line6->messages.read_lock);
        return rv;
}

/* Write directly (no buffering) to device by user*/
static long
line6_hwdep_write(struct snd_hwdep *hwdep, const char __user *data, long count,
                                        loff_t *offset)
{
        struct usb_line6 *line6 = hwdep->private_data;
        int rv;
        char *data_copy;

        if (count > line6->max_packet_size * LINE6_RAW_MESSAGES_MAXCOUNT) {
                /* This is an arbitrary limit - still better than nothing... */
                return -EINVAL;
        }

        data_copy = memdup_user(data, count);
        if (IS_ERR(data_copy))
                return PTR_ERR(data_copy);

        rv = line6_send_raw_message(line6, data_copy, count);

        kfree(data_copy);
        return rv;
}

static __poll_t
line6_hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
{
        __poll_t rv;
        struct usb_line6 *line6 = hwdep->private_data;

        poll_wait(file, &line6->messages.wait_queue, wait);

        mutex_lock(&line6->messages.read_lock);
        rv = kfifo_len(&line6->messages.fifo) == 0 ? 0 : EPOLLIN | EPOLLRDNORM;
        mutex_unlock(&line6->messages.read_lock);

        return rv;
}

static const struct snd_hwdep_ops hwdep_ops = {
        .open    = line6_hwdep_open,
        .release = line6_hwdep_release,
        .read    = line6_hwdep_read,
        .write   = line6_hwdep_write,
        .poll    = line6_hwdep_poll,
};

/* Insert into circular buffer */
static void line6_hwdep_push_message(struct usb_line6 *line6)
{
        if (!line6->messages.active)
                return;

        if (kfifo_avail(&line6->messages.fifo) >= line6->message_length) {
                /* No race condition here, there's only one writer */
                kfifo_in(&line6->messages.fifo,
                        line6->buffer_message, line6->message_length);
        } /* else TODO: signal overflow */

        wake_up_interruptible(&line6->messages.wait_queue);
}

static int line6_hwdep_init(struct usb_line6 *line6)
{
        int err;
        struct snd_hwdep *hwdep;

        /* TODO: usb_driver_claim_interface(); */
        line6->process_message = line6_hwdep_push_message;
        line6->messages.active = 0;
        init_waitqueue_head(&line6->messages.wait_queue);
        mutex_init(&line6->messages.read_lock);
        INIT_KFIFO(line6->messages.fifo);

        err = snd_hwdep_new(line6->card, "config", 0, &hwdep);
        if (err < 0)
                goto end;
        strcpy(hwdep->name, "config");
        hwdep->iface = SNDRV_HWDEP_IFACE_LINE6;
        hwdep->ops = hwdep_ops;
        hwdep->private_data = line6;
        hwdep->exclusive = true;

end:
        return err;
}

static int line6_init_cap_control(struct usb_line6 *line6)
{
        int ret;

        /* initialize USB buffers: */
        line6->buffer_listen = kmalloc(LINE6_BUFSIZE_LISTEN, GFP_KERNEL);
        if (!line6->buffer_listen)
                return -ENOMEM;

        line6->urb_listen = usb_alloc_urb(0, GFP_KERNEL);
        if (!line6->urb_listen)
                return -ENOMEM;

        if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
                line6->buffer_message = kmalloc(LINE6_MIDI_MESSAGE_MAXLEN, GFP_KERNEL);
                if (!line6->buffer_message)
                        return -ENOMEM;

                ret = line6_init_midi(line6);
                if (ret < 0)
                        return ret;
        } else {
                ret = line6_hwdep_init(line6);
                if (ret < 0)
                        return ret;
        }

        ret = line6_start_listen(line6);
        if (ret < 0) {
                dev_err(line6->ifcdev, "cannot start listening: %d\n", ret);
                return ret;
        }

        return 0;
}

static void line6_startup_work(struct work_struct *work)
{
        struct usb_line6 *line6 =
                container_of(work, struct usb_line6, startup_work.work);

        if (line6->startup)
                line6->startup(line6);
}

/*
        Probe USB device.
*/
int line6_probe(struct usb_interface *interface,
                const struct usb_device_id *id,
                const char *driver_name,
                const struct line6_properties *properties,
                int (*private_init)(struct usb_line6 *, const struct usb_device_id *id),
                size_t data_size)
{
        struct usb_device *usbdev = interface_to_usbdev(interface);
        struct snd_card *card;
        struct usb_line6 *line6;
        int interface_number;
        int ret;

        if (WARN_ON(data_size < sizeof(*line6)))
                return -EINVAL;

        /* we don't handle multiple configurations */
        if (usbdev->descriptor.bNumConfigurations != 1)
                return -ENODEV;

        ret = snd_card_new(&interface->dev,
                           SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
                           THIS_MODULE, data_size, &card);
        if (ret < 0)
                return ret;

        /* store basic data: */
        line6 = card->private_data;
        line6->card = card;
        line6->properties = properties;
        line6->usbdev = usbdev;
        line6->ifcdev = &interface->dev;
        INIT_DELAYED_WORK(&line6->startup_work, line6_startup_work);

        strcpy(card->id, properties->id);
        strcpy(card->driver, driver_name);
        strcpy(card->shortname, properties->name);
        sprintf(card->longname, "Line 6 %s at USB %s", properties->name,
                dev_name(line6->ifcdev));
        card->private_free = line6_destruct;

        usb_set_intfdata(interface, line6);

        /* increment reference counters: */
        usb_get_dev(usbdev);

        /* initialize device info: */
        dev_info(&interface->dev, "Line 6 %s found\n", properties->name);

        /* query interface number */
        interface_number = interface->cur_altsetting->desc.bInterfaceNumber;

        /* TODO reserves the bus bandwidth even without actual transfer */
        ret = usb_set_interface(usbdev, interface_number,
                                properties->altsetting);
        if (ret < 0) {
                dev_err(&interface->dev, "set_interface failed\n");
                goto error;
        }

        line6_get_usb_properties(line6);

        if (properties->capabilities & LINE6_CAP_CONTROL) {
                ret = line6_init_cap_control(line6);
                if (ret < 0)
                        goto error;
        }

        /* initialize device data based on device: */
        ret = private_init(line6, id);
        if (ret < 0)
                goto error;

        /* creation of additional special files should go here */

        dev_info(&interface->dev, "Line 6 %s now attached\n",
                 properties->name);

        return 0;

 error:
        /* we can call disconnect callback here because no close-sync is
         * needed yet at this point
         */
        line6_disconnect(interface);
        return ret;
}
EXPORT_SYMBOL_GPL(line6_probe);

/*
        Line 6 device disconnected.
*/
void line6_disconnect(struct usb_interface *interface)
{
        struct usb_line6 *line6 = usb_get_intfdata(interface);
        struct usb_device *usbdev = interface_to_usbdev(interface);

        if (!line6)
                return;

        if (WARN_ON(usbdev != line6->usbdev))
                return;

        cancel_delayed_work_sync(&line6->startup_work);

        if (line6->urb_listen != NULL)
                line6_stop_listen(line6);

        snd_card_disconnect(line6->card);
        if (line6->line6pcm)
                line6_pcm_disconnect(line6->line6pcm);
        if (line6->disconnect)
                line6->disconnect(line6);

        dev_info(&interface->dev, "Line 6 %s now disconnected\n",
                 line6->properties->name);

        /* make sure the device isn't destructed twice: */
        usb_set_intfdata(interface, NULL);

        snd_card_free_when_closed(line6->card);
}
EXPORT_SYMBOL_GPL(line6_disconnect);

#ifdef CONFIG_PM

/*
        Suspend Line 6 device.
*/
int line6_suspend(struct usb_interface *interface, pm_message_t message)
{
        struct usb_line6 *line6 = usb_get_intfdata(interface);
        struct snd_line6_pcm *line6pcm = line6->line6pcm;

        snd_power_change_state(line6->card, SNDRV_CTL_POWER_D3hot);

        if (line6->properties->capabilities & LINE6_CAP_CONTROL)
                line6_stop_listen(line6);

        if (line6pcm != NULL)
                line6pcm->flags = 0;

        return 0;
}
EXPORT_SYMBOL_GPL(line6_suspend);

/*
        Resume Line 6 device.
*/
int line6_resume(struct usb_interface *interface)
{
        struct usb_line6 *line6 = usb_get_intfdata(interface);

        if (line6->properties->capabilities & LINE6_CAP_CONTROL)
                line6_start_listen(line6);

        snd_power_change_state(line6->card, SNDRV_CTL_POWER_D0);
        return 0;
}
EXPORT_SYMBOL_GPL(line6_resume);

#endif /* CONFIG_PM */

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");