/*
 * usbmidi.c - ALSA USB MIDI driver
 *
 * Copyright (c) 2002-2009 Clemens Ladisch
 * All rights reserved.
 *
 * Based on the OSS usb-midi driver by NAGANO Daisuke,
 *          NetBSD's umidi driver by Takuya SHIOZAKI,
 *          the "USB Device Class Definition for MIDI Devices" by Roland
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed and/or modified 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 SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/usb.h>
#include <linux/wait.h>
#include <linux/usb/audio.h>
#include <linux/module.h>

#include <sound/core.h>
#include <sound/control.h>
#include <sound/rawmidi.h>
#include <sound/asequencer.h>
#include "usbaudio.h"
#include "midi.h"
#include "power.h"
#include "helper.h"

/*
 * define this to log all USB packets
 */
/* #define DUMP_PACKETS */

/*
 * how long to wait after some USB errors, so that hub_wq can disconnect() us
 * without too many spurious errors
 */
#define ERROR_DELAY_JIFFIES (HZ / 10)

#define OUTPUT_URBS 7
#define INPUT_URBS 7


MODULE_AUTHOR("Clemens Ladisch <clemens@ladisch.de>");
MODULE_DESCRIPTION("USB Audio/MIDI helper module");
MODULE_LICENSE("Dual BSD/GPL");


struct usb_ms_header_descriptor {
        __u8  bLength;
        __u8  bDescriptorType;
        __u8  bDescriptorSubtype;
        __u8  bcdMSC[2];
        __le16 wTotalLength;
} __attribute__ ((packed));

struct usb_ms_endpoint_descriptor {
        __u8  bLength;
        __u8  bDescriptorType;
        __u8  bDescriptorSubtype;
        __u8  bNumEmbMIDIJack;
        __u8  baAssocJackID[0];
} __attribute__ ((packed));

struct snd_usb_midi_in_endpoint;
struct snd_usb_midi_out_endpoint;
struct snd_usb_midi_endpoint;

struct usb_protocol_ops {
        void (*input)(struct snd_usb_midi_in_endpoint*, uint8_t*, int);
        void (*output)(struct snd_usb_midi_out_endpoint *ep, struct urb *urb);
        void (*output_packet)(struct urb*, uint8_t, uint8_t, uint8_t, uint8_t);
        void (*init_out_endpoint)(struct snd_usb_midi_out_endpoint *);
        void (*finish_out_endpoint)(struct snd_usb_midi_out_endpoint *);
};

struct snd_usb_midi {
        struct usb_device *dev;
        struct snd_card *card;
        struct usb_interface *iface;
        const struct snd_usb_audio_quirk *quirk;
        struct snd_rawmidi *rmidi;
        const struct usb_protocol_ops *usb_protocol_ops;
        struct list_head list;
        struct timer_list error_timer;
        spinlock_t disc_lock;
        struct rw_semaphore disc_rwsem;
        struct mutex mutex;
        u32 usb_id;
        int next_midi_device;

        struct snd_usb_midi_endpoint {
                struct snd_usb_midi_out_endpoint *out;
                struct snd_usb_midi_in_endpoint *in;
        } endpoints[MIDI_MAX_ENDPOINTS];
        unsigned long input_triggered;
        unsigned int opened[2];
        unsigned char disconnected;
        unsigned char input_running;

        struct snd_kcontrol *roland_load_ctl;
};

struct snd_usb_midi_out_endpoint {
        struct snd_usb_midi *umidi;
        struct out_urb_context {
                struct urb *urb;
                struct snd_usb_midi_out_endpoint *ep;
        } urbs[OUTPUT_URBS];
        unsigned int active_urbs;
        unsigned int drain_urbs;
        int max_transfer;               /* size of urb buffer */
        struct tasklet_struct tasklet;
        unsigned int next_urb;
        spinlock_t buffer_lock;

        struct usbmidi_out_port {
                struct snd_usb_midi_out_endpoint *ep;
                struct snd_rawmidi_substream *substream;
                int active;
                uint8_t cable;          /* cable number << 4 */
                uint8_t state;
#define STATE_UNKNOWN   0
#define STATE_1PARAM    1
#define STATE_2PARAM_1  2
#define STATE_2PARAM_2  3
#define STATE_SYSEX_0   4
#define STATE_SYSEX_1   5
#define STATE_SYSEX_2   6
                uint8_t data[2];
        } ports[0x10];
        int current_port;

        wait_queue_head_t drain_wait;
};

struct snd_usb_midi_in_endpoint {
        struct snd_usb_midi *umidi;
        struct urb *urbs[INPUT_URBS];
        struct usbmidi_in_port {
                struct snd_rawmidi_substream *substream;
                u8 running_status_length;
        } ports[0x10];
        u8 seen_f5;
        bool in_sysex;
        u8 last_cin;
        u8 error_resubmit;
        int current_port;
};

static void snd_usbmidi_do_output(struct snd_usb_midi_out_endpoint *ep);

static const uint8_t snd_usbmidi_cin_length[] = {
        0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1
};

/*
 * Submits the URB, with error handling.
 */
static int snd_usbmidi_submit_urb(struct urb *urb, gfp_t flags)
{
        int err = usb_submit_urb(urb, flags);
        if (err < 0 && err != -ENODEV)
                dev_err(&urb->dev->dev, "usb_submit_urb: %d\n", err);
        return err;
}

/*
 * Error handling for URB completion functions.
 */
static int snd_usbmidi_urb_error(const struct urb *urb)
{
        switch (urb->status) {
        /* manually unlinked, or device gone */
        case -ENOENT:
        case -ECONNRESET:
        case -ESHUTDOWN:
        case -ENODEV:
                return -ENODEV;
        /* errors that might occur during unplugging */
        case -EPROTO:
        case -ETIME:
        case -EILSEQ:
                return -EIO;
        default:
                dev_err(&urb->dev->dev, "urb status %d\n", urb->status);
                return 0; /* continue */
        }
}

/*
 * Receives a chunk of MIDI data.
 */
static void snd_usbmidi_input_data(struct snd_usb_midi_in_endpoint *ep,
                                   int portidx, uint8_t *data, int length)
{
        struct usbmidi_in_port *port = &ep->ports[portidx];

        if (!port->substream) {
                dev_dbg(&ep->umidi->dev->dev, "unexpected port %d!\n", portidx);
                return;
        }
        if (!test_bit(port->substream->number, &ep->umidi->input_triggered))
                return;
        snd_rawmidi_receive(port->substream, data, length);
}

#ifdef DUMP_PACKETS
static void dump_urb(const char *type, const u8 *data, int length)
{
        snd_printk(KERN_DEBUG "%s packet: [", type);
        for (; length > 0; ++data, --length)
                printk(KERN_CONT " %02x", *data);
        printk(KERN_CONT " ]\n");
}
#else
#define dump_urb(type, data, length) /* nothing */
#endif

/*
 * Processes the data read from the device.
 */
static void snd_usbmidi_in_urb_complete(struct urb *urb)
{
        struct snd_usb_midi_in_endpoint *ep = urb->context;

        if (urb->status == 0) {
                dump_urb("received", urb->transfer_buffer, urb->actual_length);
                ep->umidi->usb_protocol_ops->input(ep, urb->transfer_buffer,
                                                   urb->actual_length);
        } else {
                int err = snd_usbmidi_urb_error(urb);
                if (err < 0) {
                        if (err != -ENODEV) {
                                ep->error_resubmit = 1;
                                mod_timer(&ep->umidi->error_timer,
                                          jiffies + ERROR_DELAY_JIFFIES);
                        }
                        return;
                }
        }

        urb->dev = ep->umidi->dev;
        snd_usbmidi_submit_urb(urb, GFP_ATOMIC);
}

static void snd_usbmidi_out_urb_complete(struct urb *urb)
{
        struct out_urb_context *context = urb->context;
        struct snd_usb_midi_out_endpoint *ep = context->ep;
        unsigned int urb_index;

        spin_lock(&ep->buffer_lock);
        urb_index = context - ep->urbs;
        ep->active_urbs &= ~(1 << urb_index);
        if (unlikely(ep->drain_urbs)) {
                ep->drain_urbs &= ~(1 << urb_index);
                wake_up(&ep->drain_wait);
        }
        spin_unlock(&ep->buffer_lock);
        if (urb->status < 0) {
                int err = snd_usbmidi_urb_error(urb);
                if (err < 0) {
                        if (err != -ENODEV)
                                mod_timer(&ep->umidi->error_timer,
                                          jiffies + ERROR_DELAY_JIFFIES);
                        return;
                }
        }
        snd_usbmidi_do_output(ep);
}

/*
 * This is called when some data should be transferred to the device
 * (from one or more substreams).
 */
static void snd_usbmidi_do_output(struct snd_usb_midi_out_endpoint *ep)
{
        unsigned int urb_index;
        struct urb *urb;
        unsigned long flags;

        spin_lock_irqsave(&ep->buffer_lock, flags);
        if (ep->umidi->disconnected) {
                spin_unlock_irqrestore(&ep->buffer_lock, flags);
                return;
        }

        urb_index = ep->next_urb;
        for (;;) {
                if (!(ep->active_urbs & (1 << urb_index))) {
                        urb = ep->urbs[urb_index].urb;
                        urb->transfer_buffer_length = 0;
                        ep->umidi->usb_protocol_ops->output(ep, urb);
                        if (urb->transfer_buffer_length == 0)
                                break;

                        dump_urb("sending", urb->transfer_buffer,
                                 urb->transfer_buffer_length);
                        urb->dev = ep->umidi->dev;
                        if (snd_usbmidi_submit_urb(urb, GFP_ATOMIC) < 0)
                                break;
                        ep->active_urbs |= 1 << urb_index;
                }
                if (++urb_index >= OUTPUT_URBS)
                        urb_index = 0;
                if (urb_index == ep->next_urb)
                        break;
        }
        ep->next_urb = urb_index;
        spin_unlock_irqrestore(&ep->buffer_lock, flags);
}

static void snd_usbmidi_out_tasklet(unsigned long data)
{
        struct snd_usb_midi_out_endpoint *ep =
                (struct snd_usb_midi_out_endpoint *) data;

        snd_usbmidi_do_output(ep);
}

/* called after transfers had been interrupted due to some USB error */
static void snd_usbmidi_error_timer(struct timer_list *t)
{
        struct snd_usb_midi *umidi = from_timer(umidi, t, error_timer);
        unsigned int i, j;

        spin_lock(&umidi->disc_lock);
        if (umidi->disconnected) {
                spin_unlock(&umidi->disc_lock);
                return;
        }
        for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
                struct snd_usb_midi_in_endpoint *in = umidi->endpoints[i].in;
                if (in && in->error_resubmit) {
                        in->error_resubmit = 0;
                        for (j = 0; j < INPUT_URBS; ++j) {
                                if (atomic_read(&in->urbs[j]->use_count))
                                        continue;
                                in->urbs[j]->dev = umidi->dev;
                                snd_usbmidi_submit_urb(in->urbs[j], GFP_ATOMIC);
                        }
                }
                if (umidi->endpoints[i].out)
                        snd_usbmidi_do_output(umidi->endpoints[i].out);
        }
        spin_unlock(&umidi->disc_lock);
}

/* helper function to send static data that may not DMA-able */
static int send_bulk_static_data(struct snd_usb_midi_out_endpoint *ep,
                                 const void *data, int len)
{
        int err = 0;
        void *buf = kmemdup(data, len, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;
        dump_urb("sending", buf, len);
        if (ep->urbs[0].urb)
                err = usb_bulk_msg(ep->umidi->dev, ep->urbs[0].urb->pipe,
                                   buf, len, NULL, 250);
        kfree(buf);
        return err;
}

/*
 * Standard USB MIDI protocol: see the spec.
 * Midiman protocol: like the standard protocol, but the control byte is the
 * fourth byte in each packet, and uses length instead of CIN.
 */

static void snd_usbmidi_standard_input(struct snd_usb_midi_in_endpoint *ep,
                                       uint8_t *buffer, int buffer_length)
{
        int i;

        for (i = 0; i + 3 < buffer_length; i += 4)
                if (buffer[i] != 0) {
                        int cable = buffer[i] >> 4;
                        int length = snd_usbmidi_cin_length[buffer[i] & 0x0f];
                        snd_usbmidi_input_data(ep, cable, &buffer[i + 1],
                                               length);
                }
}

static void snd_usbmidi_midiman_input(struct snd_usb_midi_in_endpoint *ep,
                                      uint8_t *buffer, int buffer_length)
{
        int i;

        for (i = 0; i + 3 < buffer_length; i += 4)
                if (buffer[i + 3] != 0) {
                        int port = buffer[i + 3] >> 4;
                        int length = buffer[i + 3] & 3;
                        snd_usbmidi_input_data(ep, port, &buffer[i], length);
                }
}

/*
 * Buggy M-Audio device: running status on input results in a packet that has
 * the data bytes but not the status byte and that is marked with CIN 4.
 */
static void snd_usbmidi_maudio_broken_running_status_input(
                                        struct snd_usb_midi_in_endpoint *ep,
                                        uint8_t *buffer, int buffer_length)
{
        int i;

        for (i = 0; i + 3 < buffer_length; i += 4)
                if (buffer[i] != 0) {
                        int cable = buffer[i] >> 4;
                        u8 cin = buffer[i] & 0x0f;
                        struct usbmidi_in_port *port = &ep->ports[cable];
                        int length;

                        length = snd_usbmidi_cin_length[cin];
                        if (cin == 0xf && buffer[i + 1] >= 0xf8)
                                ; /* realtime msg: no running status change */
                        else if (cin >= 0x8 && cin <= 0xe)
                                /* channel msg */
                                port->running_status_length = length - 1;
                        else if (cin == 0x4 &&
                                 port->running_status_length != 0 &&
                                 buffer[i + 1] < 0x80)
                                /* CIN 4 that is not a SysEx */
                                length = port->running_status_length;
                        else
                                /*
                                 * All other msgs cannot begin running status.
                                 * (A channel msg sent as two or three CIN 0xF
                                 * packets could in theory, but this device
                                 * doesn't use this format.)
                                 */
                                port->running_status_length = 0;
                        snd_usbmidi_input_data(ep, cable, &buffer[i + 1],
                                               length);
                }
}

/*
 * QinHeng CH345 is buggy: every second packet inside a SysEx has not CIN 4
 * but the previously seen CIN, but still with three data bytes.
 */
static void ch345_broken_sysex_input(struct snd_usb_midi_in_endpoint *ep,
                                     uint8_t *buffer, int buffer_length)
{
        unsigned int i, cin, length;

        for (i = 0; i + 3 < buffer_length; i += 4) {
                if (buffer[i] == 0 && i > 0)
                        break;
                cin = buffer[i] & 0x0f;
                if (ep->in_sysex &&
                    cin == ep->last_cin &&
                    (buffer[i + 1 + (cin == 0x6)] & 0x80) == 0)
                        cin = 0x4;
#if 0
                if (buffer[i + 1] == 0x90) {
                        /*
                         * Either a corrupted running status or a real note-on
                         * message; impossible to detect reliably.
                         */
                }
#endif
                length = snd_usbmidi_cin_length[cin];
                snd_usbmidi_input_data(ep, 0, &buffer[i + 1], length);
                ep->in_sysex = cin == 0x4;
                if (!ep->in_sysex)
                        ep->last_cin = cin;
        }
}

/*
 * CME protocol: like the standard protocol, but SysEx commands are sent as a
 * single USB packet preceded by a 0x0F byte.
 */
static void snd_usbmidi_cme_input(struct snd_usb_midi_in_endpoint *ep,
                                  uint8_t *buffer, int buffer_length)
{
        if (buffer_length < 2 || (buffer[0] & 0x0f) != 0x0f)
                snd_usbmidi_standard_input(ep, buffer, buffer_length);
        else
                snd_usbmidi_input_data(ep, buffer[0] >> 4,
                                       &buffer[1], buffer_length - 1);
}

/*
 * Adds one USB MIDI packet to the output buffer.
 */
static void snd_usbmidi_output_standard_packet(struct urb *urb, uint8_t p0,
                                               uint8_t p1, uint8_t p2,
                                               uint8_t p3)
{

        uint8_t *buf =
                (uint8_t *)urb->transfer_buffer + urb->transfer_buffer_length;
        buf[0] = p0;
        buf[1] = p1;
        buf[2] = p2;
        buf[3] = p3;
        urb->transfer_buffer_length += 4;
}

/*
 * Adds one Midiman packet to the output buffer.
 */
static void snd_usbmidi_output_midiman_packet(struct urb *urb, uint8_t p0,
                                              uint8_t p1, uint8_t p2,
                                              uint8_t p3)
{

        uint8_t *buf =
                (uint8_t *)urb->transfer_buffer + urb->transfer_buffer_length;
        buf[0] = p1;
        buf[1] = p2;
        buf[2] = p3;
        buf[3] = (p0 & 0xf0) | snd_usbmidi_cin_length[p0 & 0x0f];
        urb->transfer_buffer_length += 4;
}

/*
 * Converts MIDI commands to USB MIDI packets.
 */
static void snd_usbmidi_transmit_byte(struct usbmidi_out_port *port,
                                      uint8_t b, struct urb *urb)
{
        uint8_t p0 = port->cable;
        void (*output_packet)(struct urb*, uint8_t, uint8_t, uint8_t, uint8_t) =
                port->ep->umidi->usb_protocol_ops->output_packet;

        if (b >= 0xf8) {
                output_packet(urb, p0 | 0x0f, b, 0, 0);
        } else if (b >= 0xf0) {
                switch (b) {
                case 0xf0:
                        port->data[0] = b;
                        port->state = STATE_SYSEX_1;
                        break;
                case 0xf1:
                case 0xf3:
                        port->data[0] = b;
                        port->state = STATE_1PARAM;
                        break;
                case 0xf2:
                        port->data[0] = b;
                        port->state = STATE_2PARAM_1;
                        break;
                case 0xf4:
                case 0xf5:
                        port->state = STATE_UNKNOWN;
                        break;
                case 0xf6:
                        output_packet(urb, p0 | 0x05, 0xf6, 0, 0);
                        port->state = STATE_UNKNOWN;
                        break;
                case 0xf7:
                        switch (port->state) {
                        case STATE_SYSEX_0:
                                output_packet(urb, p0 | 0x05, 0xf7, 0, 0);
                                break;
                        case STATE_SYSEX_1:
                                output_packet(urb, p0 | 0x06, port->data[0],
                                              0xf7, 0);
                                break;
                        case STATE_SYSEX_2:
                                output_packet(urb, p0 | 0x07, port->data[0],
                                              port->data[1], 0xf7);
                                break;
                        }
                        port->state = STATE_UNKNOWN;
                        break;
                }
        } else if (b >= 0x80) {
                port->data[0] = b;
                if (b >= 0xc0 && b <= 0xdf)
                        port->state = STATE_1PARAM;
                else
                        port->state = STATE_2PARAM_1;
        } else { /* b < 0x80 */
                switch (port->state) {
                case STATE_1PARAM:
                        if (port->data[0] < 0xf0) {
                                p0 |= port->data[0] >> 4;
                        } else {
                                p0 |= 0x02;
                                port->state = STATE_UNKNOWN;
                        }
                        output_packet(urb, p0, port->data[0], b, 0);
                        break;
                case STATE_2PARAM_1:
                        port->data[1] = b;
                        port->state = STATE_2PARAM_2;
                        break;
                case STATE_2PARAM_2:
                        if (port->data[0] < 0xf0) {
                                p0 |= port->data[0] >> 4;
                                port->state = STATE_2PARAM_1;
                        } else {
                                p0 |= 0x03;
                                port->state = STATE_UNKNOWN;
                        }
                        output_packet(urb, p0, port->data[0], port->data[1], b);
                        break;
                case STATE_SYSEX_0:
                        port->data[0] = b;
                        port->state = STATE_SYSEX_1;
                        break;
                case STATE_SYSEX_1:
                        port->data[1] = b;
                        port->state = STATE_SYSEX_2;
                        break;
                case STATE_SYSEX_2:
                        output_packet(urb, p0 | 0x04, port->data[0],
                                      port->data[1], b);
                        port->state = STATE_SYSEX_0;
                        break;
                }
        }
}

static void snd_usbmidi_standard_output(struct snd_usb_midi_out_endpoint *ep,
                                        struct urb *urb)
{
        int p;

        /* FIXME: lower-numbered ports can starve higher-numbered ports */
        for (p = 0; p < 0x10; ++p) {
                struct usbmidi_out_port *port = &ep->ports[p];
                if (!port->active)
                        continue;
                while (urb->transfer_buffer_length + 3 < ep->max_transfer) {
                        uint8_t b;
                        if (snd_rawmidi_transmit(port->substream, &b, 1) != 1) {
                                port->active = 0;
                                break;
                        }
                        snd_usbmidi_transmit_byte(port, b, urb);
                }
        }
}

static const struct usb_protocol_ops snd_usbmidi_standard_ops = {
        .input = snd_usbmidi_standard_input,
        .output = snd_usbmidi_standard_output,
        .output_packet = snd_usbmidi_output_standard_packet,
};

static const struct usb_protocol_ops snd_usbmidi_midiman_ops = {
        .input = snd_usbmidi_midiman_input,
        .output = snd_usbmidi_standard_output,
        .output_packet = snd_usbmidi_output_midiman_packet,
};

static const
struct usb_protocol_ops snd_usbmidi_maudio_broken_running_status_ops = {
        .input = snd_usbmidi_maudio_broken_running_status_input,
        .output = snd_usbmidi_standard_output,
        .output_packet = snd_usbmidi_output_standard_packet,
};

static const struct usb_protocol_ops snd_usbmidi_cme_ops = {
        .input = snd_usbmidi_cme_input,
        .output = snd_usbmidi_standard_output,
        .output_packet = snd_usbmidi_output_standard_packet,
};

static const struct usb_protocol_ops snd_usbmidi_ch345_broken_sysex_ops = {
        .input = ch345_broken_sysex_input,
        .output = snd_usbmidi_standard_output,
        .output_packet = snd_usbmidi_output_standard_packet,
};

/*
 * AKAI MPD16 protocol:
 *
 * For control port (endpoint 1):
 * ==============================
 * One or more chunks consisting of first byte of (0x10 | msg_len) and then a
 * SysEx message (msg_len=9 bytes long).
 *
 * For data port (endpoint 2):
 * ===========================
 * One or more chunks consisting of first byte of (0x20 | msg_len) and then a
 * MIDI message (msg_len bytes long)
 *
 * Messages sent: Active Sense, Note On, Poly Pressure, Control Change.
 */
static void snd_usbmidi_akai_input(struct snd_usb_midi_in_endpoint *ep,
                                   uint8_t *buffer, int buffer_length)
{
        unsigned int pos = 0;
        unsigned int len = (unsigned int)buffer_length;
        while (pos < len) {
                unsigned int port = (buffer[pos] >> 4) - 1;
                unsigned int msg_len = buffer[pos] & 0x0f;
                pos++;
                if (pos + msg_len <= len && port < 2)
                        snd_usbmidi_input_data(ep, 0, &buffer[pos], msg_len);
                pos += msg_len;
        }
}

#define MAX_AKAI_SYSEX_LEN 9

static void snd_usbmidi_akai_output(struct snd_usb_midi_out_endpoint *ep,
                                    struct urb *urb)
{
        uint8_t *msg;
        int pos, end, count, buf_end;
        uint8_t tmp[MAX_AKAI_SYSEX_LEN];
        struct snd_rawmidi_substream *substream = ep->ports[0].substream;

        if (!ep->ports[0].active)
                return;

        msg = urb->transfer_buffer + urb->transfer_buffer_length;
        buf_end = ep->max_transfer - MAX_AKAI_SYSEX_LEN - 1;

        /* only try adding more data when there's space for at least 1 SysEx */
        while (urb->transfer_buffer_length < buf_end) {
                count = snd_rawmidi_transmit_peek(substream,
                                                  tmp, MAX_AKAI_SYSEX_LEN);
                if (!count) {
                        ep->ports[0].active = 0;
                        return;
                }
                /* try to skip non-SysEx data */
                for (pos = 0; pos < count && tmp[pos] != 0xF0; pos++)
                        ;

                if (pos > 0) {
                        snd_rawmidi_transmit_ack(substream, pos);
                        continue;
                }

                /* look for the start or end marker */
                for (end = 1; end < count && tmp[end] < 0xF0; end++)
                        ;

                /* next SysEx started before the end of current one */
                if (end < count && tmp[end] == 0xF0) {
                        /* it's incomplete - drop it */
                        snd_rawmidi_transmit_ack(substream, end);
                        continue;
                }
                /* SysEx complete */
                if (end < count && tmp[end] == 0xF7) {
                        /* queue it, ack it, and get the next one */
                        count = end + 1;
                        msg[0] = 0x10 | count;
                        memcpy(&msg[1], tmp, count);
                        snd_rawmidi_transmit_ack(substream, count);
                        urb->transfer_buffer_length += count + 1;
                        msg += count + 1;
                        continue;
                }
                /* less than 9 bytes and no end byte - wait for more */
                if (count < MAX_AKAI_SYSEX_LEN) {
                        ep->ports[0].active = 0;
                        return;
                }
                /* 9 bytes and no end marker in sight - malformed, skip it */
                snd_rawmidi_transmit_ack(substream, count);
        }
}

static const struct usb_protocol_ops snd_usbmidi_akai_ops = {
        .input = snd_usbmidi_akai_input,
        .output = snd_usbmidi_akai_output,
};

/*
 * Novation USB MIDI protocol: number of data bytes is in the first byte
 * (when receiving) (+1!) or in the second byte (when sending); data begins
 * at the third byte.
 */

static void snd_usbmidi_novation_input(struct snd_usb_midi_in_endpoint *ep,
                                       uint8_t *buffer, int buffer_length)
{
        if (buffer_length < 2 || !buffer[0] || buffer_length < buffer[0] + 1)
                return;
        snd_usbmidi_input_data(ep, 0, &buffer[2], buffer[0] - 1);
}

static void snd_usbmidi_novation_output(struct snd_usb_midi_out_endpoint *ep,
                                        struct urb *urb)
{
        uint8_t *transfer_buffer;
        int count;

        if (!ep->ports[0].active)
                return;
        transfer_buffer = urb->transfer_buffer;
        count = snd_rawmidi_transmit(ep->ports[0].substream,
                                     &transfer_buffer[2],
                                     ep->max_transfer - 2);
        if (count < 1) {
                ep->ports[0].active = 0;
                return;
        }
        transfer_buffer[0] = 0;
        transfer_buffer[1] = count;
        urb->transfer_buffer_length = 2 + count;
}

static const struct usb_protocol_ops snd_usbmidi_novation_ops = {
        .input = snd_usbmidi_novation_input,
        .output = snd_usbmidi_novation_output,
};

/*
 * "raw" protocol: just move raw MIDI bytes from/to the endpoint
 */

static void snd_usbmidi_raw_input(struct snd_usb_midi_in_endpoint *ep,
                                  uint8_t *buffer, int buffer_length)
{
        snd_usbmidi_input_data(ep, 0, buffer, buffer_length);
}

static void snd_usbmidi_raw_output(struct snd_usb_midi_out_endpoint *ep,
                                   struct urb *urb)
{
        int count;

        if (!ep->ports[0].active)
                return;
        count = snd_rawmidi_transmit(ep->ports[0].substream,
                                     urb->transfer_buffer,
                                     ep->max_transfer);
        if (count < 1) {
                ep->ports[0].active = 0;
                return;
        }
        urb->transfer_buffer_length = count;
}

static const struct usb_protocol_ops snd_usbmidi_raw_ops = {
        .input = snd_usbmidi_raw_input,
        .output = snd_usbmidi_raw_output,
};

/*
 * FTDI protocol: raw MIDI bytes, but input packets have two modem status bytes.
 */

static void snd_usbmidi_ftdi_input(struct snd_usb_midi_in_endpoint *ep,
                                   uint8_t *buffer, int buffer_length)
{
        if (buffer_length > 2)
                snd_usbmidi_input_data(ep, 0, buffer + 2, buffer_length - 2);
}

static const struct usb_protocol_ops snd_usbmidi_ftdi_ops = {
        .input = snd_usbmidi_ftdi_input,
        .output = snd_usbmidi_raw_output,
};

static void snd_usbmidi_us122l_input(struct snd_usb_midi_in_endpoint *ep,
                                     uint8_t *buffer, int buffer_length)
{
        if (buffer_length != 9)
                return;
        buffer_length = 8;
        while (buffer_length && buffer[buffer_length - 1] == 0xFD)
                buffer_length--;
        if (buffer_length)
                snd_usbmidi_input_data(ep, 0, buffer, buffer_length);
}

static void snd_usbmidi_us122l_output(struct snd_usb_midi_out_endpoint *ep,
                                      struct urb *urb)
{
        int count;

        if (!ep->ports[0].active)
                return;
        switch (snd_usb_get_speed(ep->umidi->dev)) {
        case USB_SPEED_HIGH:
        case USB_SPEED_SUPER:
        case USB_SPEED_SUPER_PLUS:
                count = 1;
                break;
        default:
                count = 2;
        }
        count = snd_rawmidi_transmit(ep->ports[0].substream,
                                     urb->transfer_buffer,
                                     count);
        if (count < 1) {
                ep->ports[0].active = 0;
                return;
        }

        memset(urb->transfer_buffer + count, 0xFD, ep->max_transfer - count);
        urb->transfer_buffer_length = ep->max_transfer;
}

static const struct usb_protocol_ops snd_usbmidi_122l_ops = {
        .input = snd_usbmidi_us122l_input,
        .output = snd_usbmidi_us122l_output,
};

/*
 * Emagic USB MIDI protocol: raw MIDI with "F5 xx" port switching.
 */

static void snd_usbmidi_emagic_init_out(struct snd_usb_midi_out_endpoint *ep)
{
        static const u8 init_data[] = {
                /* initialization magic: "get version" */
                0xf0,
                0x00, 0x20, 0x31,       /* Emagic */
                0x64,                   /* Unitor8 */
                0x0b,                   /* version number request */
                0x00,                   /* command version */
                0x00,                   /* EEPROM, box 0 */
                0xf7
        };
        send_bulk_static_data(ep, init_data, sizeof(init_data));
        /* while we're at it, pour on more magic */
        send_bulk_static_data(ep, init_data, sizeof(init_data));
}

static void snd_usbmidi_emagic_finish_out(struct snd_usb_midi_out_endpoint *ep)
{
        static const u8 finish_data[] = {
                /* switch to patch mode with last preset */
                0xf0,
                0x00, 0x20, 0x31,       /* Emagic */
                0x64,                   /* Unitor8 */
                0x10,                   /* patch switch command */
                0x00,                   /* command version */
                0x7f,                   /* to all boxes */
                0x40,                   /* last preset in EEPROM */
                0xf7
        };
        send_bulk_static_data(ep, finish_data, sizeof(finish_data));
}

static void snd_usbmidi_emagic_input(struct snd_usb_midi_in_endpoint *ep,
                                     uint8_t *buffer, int buffer_length)
{
        int i;

        /* FF indicates end of valid data */
        for (i = 0; i < buffer_length; ++i)
                if (buffer[i] == 0xff) {
                        buffer_length = i;
                        break;
                }

        /* handle F5 at end of last buffer */
        if (ep->seen_f5)
                goto switch_port;

        while (buffer_length > 0) {
                /* determine size of data until next F5 */
                for (i = 0; i < buffer_length; ++i)
                        if (buffer[i] == 0xf5)
                                break;
                snd_usbmidi_input_data(ep, ep->current_port, buffer, i);
                buffer += i;
                buffer_length -= i;

                if (buffer_length <= 0)
                        break;

                /* assert(buffer[0] == 0xf5); */
                ep->seen_f5 = 1;
                ++buffer;
                --buffer_length;

        switch_port:
                if (buffer_length <= 0)
                        break;
                if (buffer[0] < 0x80) {
                        ep->current_port = (buffer[0] - 1) & 15;
                        ++buffer;
                        --buffer_length;
                }
                ep->seen_f5 = 0;
        }
}

static void snd_usbmidi_emagic_output(struct snd_usb_midi_out_endpoint *ep,
                                      struct urb *urb)
{
        int port0 = ep->current_port;
        uint8_t *buf = urb->transfer_buffer;
        int buf_free = ep->max_transfer;
        int length, i;

        for (i = 0; i < 0x10; ++i) {
                /* round-robin, starting at the last current port */
                int portnum = (port0 + i) & 15;
                struct usbmidi_out_port *port = &ep->ports[portnum];

                if (!port->active)
                        continue;
                if (snd_rawmidi_transmit_peek(port->substream, buf, 1) != 1) {
                        port->active = 0;
                        continue;
                }

                if (portnum != ep->current_port) {
                        if (buf_free < 2)
                                break;
                        ep->current_port = portnum;
                        buf[0] = 0xf5;
                        buf[1] = (portnum + 1) & 15;
                        buf += 2;
                        buf_free -= 2;
                }

                if (buf_free < 1)
                        break;
                length = snd_rawmidi_transmit(port->substream, buf, buf_free);
                if (length > 0) {
                        buf += length;
                        buf_free -= length;
                        if (buf_free < 1)
                                break;
                }
        }
        if (buf_free < ep->max_transfer && buf_free > 0) {
                *buf = 0xff;
                --buf_free;
        }
        urb->transfer_buffer_length = ep->max_transfer - buf_free;
}

static const struct usb_protocol_ops snd_usbmidi_emagic_ops = {
        .input = snd_usbmidi_emagic_input,
        .output = snd_usbmidi_emagic_output,
        .init_out_endpoint = snd_usbmidi_emagic_init_out,
        .finish_out_endpoint = snd_usbmidi_emagic_finish_out,
};


static void update_roland_altsetting(struct snd_usb_midi *umidi)
{
        struct usb_interface *intf;
        struct usb_host_interface *hostif;
        struct usb_interface_descriptor *intfd;
        int is_light_load;

        intf = umidi->iface;
        is_light_load = intf->cur_altsetting != intf->altsetting;
        if (umidi->roland_load_ctl->private_value == is_light_load)
                return;
        hostif = &intf->altsetting[umidi->roland_load_ctl->private_value];
        intfd = get_iface_desc(hostif);
        snd_usbmidi_input_stop(&umidi->list);
        usb_set_interface(umidi->dev, intfd->bInterfaceNumber,
                          intfd->bAlternateSetting);
        snd_usbmidi_input_start(&umidi->list);
}

static int substream_open(struct snd_rawmidi_substream *substream, int dir,
                          int open)
{
        struct snd_usb_midi *umidi = substream->rmidi->private_data;
        struct snd_kcontrol *ctl;

        down_read(&umidi->disc_rwsem);
        if (umidi->disconnected) {
                up_read(&umidi->disc_rwsem);
                return open ? -ENODEV : 0;
        }

        mutex_lock(&umidi->mutex);
        if (open) {
                if (!umidi->opened[0] && !umidi->opened[1]) {
                        if (umidi->roland_load_ctl) {
                                ctl = umidi->roland_load_ctl;
                                ctl->vd[0].access |=
                                        SNDRV_CTL_ELEM_ACCESS_INACTIVE;
                                snd_ctl_notify(umidi->card,
                                       SNDRV_CTL_EVENT_MASK_INFO, &ctl->id);
                                update_roland_altsetting(umidi);
                        }
                }
                umidi->opened[dir]++;
                if (umidi->opened[1])
                        snd_usbmidi_input_start(&umidi->list);
        } else {
                umidi->opened[dir]--;
                if (!umidi->opened[1])
                        snd_usbmidi_input_stop(&umidi->list);
                if (!umidi->opened[0] && !umidi->opened[1]) {
                        if (umidi->roland_load_ctl) {
                                ctl = umidi->roland_load_ctl;
                                ctl->vd[0].access &=
                                        ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
                                snd_ctl_notify(umidi->card,
                                       SNDRV_CTL_EVENT_MASK_INFO, &ctl->id);
                        }
                }
        }
        mutex_unlock(&umidi->mutex);
        up_read(&umidi->disc_rwsem);
        return 0;
}

static int snd_usbmidi_output_open(struct snd_rawmidi_substream *substream)
{
        struct snd_usb_midi *umidi = substream->rmidi->private_data;
        struct usbmidi_out_port *port = NULL;
        int i, j;

        for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i)
                if (umidi->endpoints[i].out)
                        for (j = 0; j < 0x10; ++j)
                                if (umidi->endpoints[i].out->ports[j].substream == substream) {
                                        port = &umidi->endpoints[i].out->ports[j];
                                        break;
                                }
        if (!port) {
                snd_BUG();
                return -ENXIO;
        }

        substream->runtime->private_data = port;
        port->state = STATE_UNKNOWN;
        return substream_open(substream, 0, 1);
}

static int snd_usbmidi_output_close(struct snd_rawmidi_substream *substream)
{
        return substream_open(substream, 0, 0);
}

static void snd_usbmidi_output_trigger(struct snd_rawmidi_substream *substream,
                                       int up)
{
        struct usbmidi_out_port *port =
                (struct usbmidi_out_port *)substream->runtime->private_data;

        port->active = up;
        if (up) {
                if (port->ep->umidi->disconnected) {
                        /* gobble up remaining bytes to prevent wait in
                         * snd_rawmidi_drain_output */
                        while (!snd_rawmidi_transmit_empty(substream))
                                snd_rawmidi_transmit_ack(substream, 1);
                        return;
                }
                tasklet_schedule(&port->ep->tasklet);
        }
}

static void snd_usbmidi_output_drain(struct snd_rawmidi_substream *substream)
{
        struct usbmidi_out_port *port = substream->runtime->private_data;
        struct snd_usb_midi_out_endpoint *ep = port->ep;
        unsigned int drain_urbs;
        DEFINE_WAIT(wait);
        long timeout = msecs_to_jiffies(50);

        if (ep->umidi->disconnected)
                return;
        /*
         * The substream buffer is empty, but some data might still be in the
         * currently active URBs, so we have to wait for those to complete.
         */
        spin_lock_irq(&ep->buffer_lock);
        drain_urbs = ep->active_urbs;
        if (drain_urbs) {
                ep->drain_urbs |= drain_urbs;
                do {
                        prepare_to_wait(&ep->drain_wait, &wait,
                                        TASK_UNINTERRUPTIBLE);
                        spin_unlock_irq(&ep->buffer_lock);
                        timeout = schedule_timeout(timeout);
                        spin_lock_irq(&ep->buffer_lock);
                        drain_urbs &= ep->drain_urbs;
                } while (drain_urbs && timeout);
                finish_wait(&ep->drain_wait, &wait);
        }
        spin_unlock_irq(&ep->buffer_lock);
}

static int snd_usbmidi_input_open(struct snd_rawmidi_substream *substream)
{
        return substream_open(substream, 1, 1);
}

static int snd_usbmidi_input_close(struct snd_rawmidi_substream *substream)
{
        return substream_open(substream, 1, 0);
}

static void snd_usbmidi_input_trigger(struct snd_rawmidi_substream *substream,
                                      int up)
{
        struct snd_usb_midi *umidi = substream->rmidi->private_data;

        if (up)
                set_bit(substream->number, &umidi->input_triggered);
        else
                clear_bit(substream->number, &umidi->input_triggered);
}

static const struct snd_rawmidi_ops snd_usbmidi_output_ops = {
        .open = snd_usbmidi_output_open,
        .close = snd_usbmidi_output_close,
        .trigger = snd_usbmidi_output_trigger,
        .drain = snd_usbmidi_output_drain,
};

static const struct snd_rawmidi_ops snd_usbmidi_input_ops = {
        .open = snd_usbmidi_input_open,
        .close = snd_usbmidi_input_close,
        .trigger = snd_usbmidi_input_trigger
};

static void free_urb_and_buffer(struct snd_usb_midi *umidi, struct urb *urb,
                                unsigned int buffer_length)
{
        usb_free_coherent(umidi->dev, buffer_length,
                          urb->transfer_buffer, urb->transfer_dma);
        usb_free_urb(urb);
}

/*
 * Frees an input endpoint.
 * May be called when ep hasn't been initialized completely.
 */
static void snd_usbmidi_in_endpoint_delete(struct snd_usb_midi_in_endpoint *ep)
{
        unsigned int i;

        for (i = 0; i < INPUT_URBS; ++i)
                if (ep->urbs[i])
                        free_urb_and_buffer(ep->umidi, ep->urbs[i],
                                            ep->urbs[i]->transfer_buffer_length);
        kfree(ep);
}

/*
 * Creates an input endpoint.
 */
static int snd_usbmidi_in_endpoint_create(struct snd_usb_midi *umidi,
                                          struct snd_usb_midi_endpoint_info *ep_info,
                                          struct snd_usb_midi_endpoint *rep)
{
        struct snd_usb_midi_in_endpoint *ep;
        void *buffer;
        unsigned int pipe;
        int length;
        unsigned int i;
        int err;

        rep->in = NULL;
        ep = kzalloc(sizeof(*ep), GFP_KERNEL);
        if (!ep)
                return -ENOMEM;
        ep->umidi = umidi;

        for (i = 0; i < INPUT_URBS; ++i) {
                ep->urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
                if (!ep->urbs[i]) {
                        err = -ENOMEM;
                        goto error;
                }
        }
        if (ep_info->in_interval)
                pipe = usb_rcvintpipe(umidi->dev, ep_info->in_ep);
        else
                pipe = usb_rcvbulkpipe(umidi->dev, ep_info->in_ep);
        length = usb_maxpacket(umidi->dev, pipe, 0);
        for (i = 0; i < INPUT_URBS; ++i) {
                buffer = usb_alloc_coherent(umidi->dev, length, GFP_KERNEL,
                                            &ep->urbs[i]->transfer_dma);
                if (!buffer) {
                        err = -ENOMEM;
                        goto error;
                }
                if (ep_info->in_interval)
                        usb_fill_int_urb(ep->urbs[i], umidi->dev,
                                         pipe, buffer, length,
                                         snd_usbmidi_in_urb_complete,
                                         ep, ep_info->in_interval);
                else
                        usb_fill_bulk_urb(ep->urbs[i], umidi->dev,
                                          pipe, buffer, length,
                                          snd_usbmidi_in_urb_complete, ep);
                ep->urbs[i]->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
                err = usb_urb_ep_type_check(ep->urbs[i]);
                if (err < 0) {
                        dev_err(&umidi->dev->dev, "invalid MIDI in EP %x\n",
                                ep_info->in_ep);
                        goto error;
                }
        }

        rep->in = ep;
        return 0;

 error:
        snd_usbmidi_in_endpoint_delete(ep);
        return -ENOMEM;
}

/*
 * Frees an output endpoint.
 * May be called when ep hasn't been initialized completely.
 */
static void snd_usbmidi_out_endpoint_clear(struct snd_usb_midi_out_endpoint *ep)
{
        unsigned int i;

        for (i = 0; i < OUTPUT_URBS; ++i)
                if (ep->urbs[i].urb) {
                        free_urb_and_buffer(ep->umidi, ep->urbs[i].urb,
                                            ep->max_transfer);
                        ep->urbs[i].urb = NULL;
                }
}

static void snd_usbmidi_out_endpoint_delete(struct snd_usb_midi_out_endpoint *ep)
{
        snd_usbmidi_out_endpoint_clear(ep);
        kfree(ep);
}

/*
 * Creates an output endpoint, and initializes output ports.
 */
static int snd_usbmidi_out_endpoint_create(struct snd_usb_midi *umidi,
                                           struct snd_usb_midi_endpoint_info *ep_info,
                                           struct snd_usb_midi_endpoint *rep)
{
        struct snd_usb_midi_out_endpoint *ep;
        unsigned int i;
        unsigned int pipe;
        void *buffer;
        int err;

        rep->out = NULL;
        ep = kzalloc(sizeof(*ep), GFP_KERNEL);
        if (!ep)
                return -ENOMEM;
        ep->umidi = umidi;

        for (i = 0; i < OUTPUT_URBS; ++i) {
                ep->urbs[i].urb = usb_alloc_urb(0, GFP_KERNEL);
                if (!ep->urbs[i].urb) {
                        err = -ENOMEM;
                        goto error;
                }
                ep->urbs[i].ep = ep;
        }
        if (ep_info->out_interval)
                pipe = usb_sndintpipe(umidi->dev, ep_info->out_ep);
        else
                pipe = usb_sndbulkpipe(umidi->dev, ep_info->out_ep);
        switch (umidi->usb_id) {
        default:
                ep->max_transfer = usb_maxpacket(umidi->dev, pipe, 1);
                break;
                /*
                 * Various chips declare a packet size larger than 4 bytes, but
                 * do not actually work with larger packets:
                 */
        case USB_ID(0x0a67, 0x5011): /* Medeli DD305 */
        case USB_ID(0x0a92, 0x1020): /* ESI M4U */
        case USB_ID(0x1430, 0x474b): /* RedOctane GH MIDI INTERFACE */
        case USB_ID(0x15ca, 0x0101): /* Textech USB Midi Cable */
        case USB_ID(0x15ca, 0x1806): /* Textech USB Midi Cable */
        case USB_ID(0x1a86, 0x752d): /* QinHeng CH345 "USB2.0-MIDI" */
        case USB_ID(0xfc08, 0x0101): /* Unknown vendor Cable */
                ep->max_transfer = 4;
                break;
                /*
                 * Some devices only work with 9 bytes packet size:
                 */
        case USB_ID(0x0644, 0x800E): /* Tascam US-122L */
        case USB_ID(0x0644, 0x800F): /* Tascam US-144 */
                ep->max_transfer = 9;
                break;
        }
        for (i = 0; i < OUTPUT_URBS; ++i) {
                buffer = usb_alloc_coherent(umidi->dev,
                                            ep->max_transfer, GFP_KERNEL,
                                            &ep->urbs[i].urb->transfer_dma);
                if (!buffer) {
                        err = -ENOMEM;
                        goto error;
                }
                if (ep_info->out_interval)
                        usb_fill_int_urb(ep->urbs[i].urb, umidi->dev,
                                         pipe, buffer, ep->max_transfer,
                                         snd_usbmidi_out_urb_complete,
                                         &ep->urbs[i], ep_info->out_interval);
                else
                        usb_fill_bulk_urb(ep->urbs[i].urb, umidi->dev,
                                          pipe, buffer, ep->max_transfer,
                                          snd_usbmidi_out_urb_complete,
                                          &ep->urbs[i]);
                err = usb_urb_ep_type_check(ep->urbs[i].urb);
                if (err < 0) {
                        dev_err(&umidi->dev->dev, "invalid MIDI out EP %x\n",
                                ep_info->out_ep);
                        goto error;
                }
                ep->urbs[i].urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
        }

        spin_lock_init(&ep->buffer_lock);
        tasklet_init(&ep->tasklet, snd_usbmidi_out_tasklet, (unsigned long)ep);
        init_waitqueue_head(&ep->drain_wait);

        for (i = 0; i < 0x10; ++i)
                if (ep_info->out_cables & (1 << i)) {
                        ep->ports[i].ep = ep;
                        ep->ports[i].cable = i << 4;
                }

        if (umidi->usb_protocol_ops->init_out_endpoint)
                umidi->usb_protocol_ops->init_out_endpoint(ep);

        rep->out = ep;
        return 0;

 error:
        snd_usbmidi_out_endpoint_delete(ep);
        return err;
}

/*
 * Frees everything.
 */
static void snd_usbmidi_free(struct snd_usb_midi *umidi)
{
        int i;

        for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
                struct snd_usb_midi_endpoint *ep = &umidi->endpoints[i];
                if (ep->out)
                        snd_usbmidi_out_endpoint_delete(ep->out);
                if (ep->in)
                        snd_usbmidi_in_endpoint_delete(ep->in);
        }
        mutex_destroy(&umidi->mutex);
        kfree(umidi);
}

/*
 * Unlinks all URBs (must be done before the usb_device is deleted).
 */
void snd_usbmidi_disconnect(struct list_head *p)
{
        struct snd_usb_midi *umidi;
        unsigned int i, j;

        umidi = list_entry(p, struct snd_usb_midi, list);
        /*
         * an URB's completion handler may start the timer and
         * a timer may submit an URB. To reliably break the cycle
         * a flag under lock must be used
         */
        down_write(&umidi->disc_rwsem);
        spin_lock_irq(&umidi->disc_lock);
        umidi->disconnected = 1;
        spin_unlock_irq(&umidi->disc_lock);
        up_write(&umidi->disc_rwsem);

        for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
                struct snd_usb_midi_endpoint *ep = &umidi->endpoints[i];
                if (ep->out)
                        tasklet_kill(&ep->out->tasklet);
                if (ep->out) {
                        for (j = 0; j < OUTPUT_URBS; ++j)
                                usb_kill_urb(ep->out->urbs[j].urb);
                        if (umidi->usb_protocol_ops->finish_out_endpoint)
                                umidi->usb_protocol_ops->finish_out_endpoint(ep->out);
                        ep->out->active_urbs = 0;
                        if (ep->out->drain_urbs) {
                                ep->out->drain_urbs = 0;
                                wake_up(&ep->out->drain_wait);
                        }
                }
                if (ep->in)
                        for (j = 0; j < INPUT_URBS; ++j)
                                usb_kill_urb(ep->in->urbs[j]);
                /* free endpoints here; later call can result in Oops */
                if (ep->out)
                        snd_usbmidi_out_endpoint_clear(ep->out);
                if (ep->in) {
                        snd_usbmidi_in_endpoint_delete(ep->in);
                        ep->in = NULL;
                }
        }
        del_timer_sync(&umidi->error_timer);
}
EXPORT_SYMBOL(snd_usbmidi_disconnect);

static void snd_usbmidi_rawmidi_free(struct snd_rawmidi *rmidi)
{
        struct snd_usb_midi *umidi = rmidi->private_data;
        snd_usbmidi_free(umidi);
}

static struct snd_rawmidi_substream *snd_usbmidi_find_substream(struct snd_usb_midi *umidi,
                                                                int stream,
                                                                int number)
{
        struct snd_rawmidi_substream *substream;

        list_for_each_entry(substream, &umidi->rmidi->streams[stream].substreams,
                            list) {
                if (substream->number == number)
                        return substream;
        }
        return NULL;
}

/*
 * This list specifies names for ports that do not fit into the standard
 * "(product) MIDI (n)" schema because they aren't external MIDI ports,
 * such as internal control or synthesizer ports.
 */
static struct port_info {
        u32 id;
        short int port;
        short int voices;
        const char *name;
        unsigned int seq_flags;
} snd_usbmidi_port_info[] = {
#define PORT_INFO(vendor, product, num, name_, voices_, flags) \
        { .id = USB_ID(vendor, product), \
          .port = num, .voices = voices_, \
          .name = name_, .seq_flags = flags }
#define EXTERNAL_PORT(vendor, product, num, name) \
        PORT_INFO(vendor, product, num, name, 0, \
                  SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC | \
                  SNDRV_SEQ_PORT_TYPE_HARDWARE | \
                  SNDRV_SEQ_PORT_TYPE_PORT)
#define CONTROL_PORT(vendor, product, num, name) \
        PORT_INFO(vendor, product, num, name, 0, \
                  SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC | \
                  SNDRV_SEQ_PORT_TYPE_HARDWARE)
#define GM_SYNTH_PORT(vendor, product, num, name, voices) \
        PORT_INFO(vendor, product, num, name, voices, \
                  SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC | \
                  SNDRV_SEQ_PORT_TYPE_MIDI_GM | \
                  SNDRV_SEQ_PORT_TYPE_HARDWARE | \
                  SNDRV_SEQ_PORT_TYPE_SYNTHESIZER)
#define ROLAND_SYNTH_PORT(vendor, product, num, name, voices) \
        PORT_INFO(vendor, product, num, name, voices, \
                  SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC | \
                  SNDRV_SEQ_PORT_TYPE_MIDI_GM | \
                  SNDRV_SEQ_PORT_TYPE_MIDI_GM2 | \
                  SNDRV_SEQ_PORT_TYPE_MIDI_GS | \
                  SNDRV_SEQ_PORT_TYPE_MIDI_XG | \
                  SNDRV_SEQ_PORT_TYPE_HARDWARE | \
                  SNDRV_SEQ_PORT_TYPE_SYNTHESIZER)
#define SOUNDCANVAS_PORT(vendor, product, num, name, voices) \
        PORT_INFO(vendor, product, num, name, voices, \
                  SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC | \
                  SNDRV_SEQ_PORT_TYPE_MIDI_GM | \
                  SNDRV_SEQ_PORT_TYPE_MIDI_GM2 | \
                  SNDRV_SEQ_PORT_TYPE_MIDI_GS | \
                  SNDRV_SEQ_PORT_TYPE_MIDI_XG | \
                  SNDRV_SEQ_PORT_TYPE_MIDI_MT32 | \
                  SNDRV_SEQ_PORT_TYPE_HARDWARE | \
                  SNDRV_SEQ_PORT_TYPE_SYNTHESIZER)
        /* Yamaha MOTIF XF */
        GM_SYNTH_PORT(0x0499, 0x105c, 0, "%s Tone Generator", 128),
        CONTROL_PORT(0x0499, 0x105c, 1, "%s Remote Control"),
        EXTERNAL_PORT(0x0499, 0x105c, 2, "%s Thru"),
        CONTROL_PORT(0x0499, 0x105c, 3, "%s Editor"),
        /* Roland UA-100 */
        CONTROL_PORT(0x0582, 0x0000, 2, "%s Control"),
        /* Roland SC-8850 */
        SOUNDCANVAS_PORT(0x0582, 0x0003, 0, "%s Part A", 128),
        SOUNDCANVAS_PORT(0x0582, 0x0003, 1, "%s Part B", 128),
        SOUNDCANVAS_PORT(0x0582, 0x0003, 2, "%s Part C", 128),
        SOUNDCANVAS_PORT(0x0582, 0x0003, 3, "%s Part D", 128),
        EXTERNAL_PORT(0x0582, 0x0003, 4, "%s MIDI 1"),
        EXTERNAL_PORT(0x0582, 0x0003, 5, "%s MIDI 2"),
        /* Roland U-8 */
        EXTERNAL_PORT(0x0582, 0x0004, 0, "%s MIDI"),
        CONTROL_PORT(0x0582, 0x0004, 1, "%s Control"),
        /* Roland SC-8820 */
        SOUNDCANVAS_PORT(0x0582, 0x0007, 0, "%s Part A", 64),
        SOUNDCANVAS_PORT(0x0582, 0x0007, 1, "%s Part B", 64),
        EXTERNAL_PORT(0x0582, 0x0007, 2, "%s MIDI"),
        /* Roland SK-500 */
        SOUNDCANVAS_PORT(0x0582, 0x000b, 0, "%s Part A", 64),
        SOUNDCANVAS_PORT(0x0582, 0x000b, 1, "%s Part B", 64),
        EXTERNAL_PORT(0x0582, 0x000b, 2, "%s MIDI"),
        /* Roland SC-D70 */
        SOUNDCANVAS_PORT(0x0582, 0x000c, 0, "%s Part A", 64),
        SOUNDCANVAS_PORT(0x0582, 0x000c, 1, "%s Part B", 64),
        EXTERNAL_PORT(0x0582, 0x000c, 2, "%s MIDI"),
        /* Edirol UM-880 */
        CONTROL_PORT(0x0582, 0x0014, 8, "%s Control"),
        /* Edirol SD-90 */
        ROLAND_SYNTH_PORT(0x0582, 0x0016, 0, "%s Part A", 128),
        ROLAND_SYNTH_PORT(0x0582, 0x0016, 1, "%s Part B", 128),
        EXTERNAL_PORT(0x0582, 0x0016, 2, "%s MIDI 1"),
        EXTERNAL_PORT(0x0582, 0x0016, 3, "%s MIDI 2"),
        /* Edirol UM-550 */
        CONTROL_PORT(0x0582, 0x0023, 5, "%s Control"),
        /* Edirol SD-20 */
        ROLAND_SYNTH_PORT(0x0582, 0x0027, 0, "%s Part A", 64),
        ROLAND_SYNTH_PORT(0x0582, 0x0027, 1, "%s Part B", 64),
        EXTERNAL_PORT(0x0582, 0x0027, 2, "%s MIDI"),
        /* Edirol SD-80 */
        ROLAND_SYNTH_PORT(0x0582, 0x0029, 0, "%s Part A", 128),
        ROLAND_SYNTH_PORT(0x0582, 0x0029, 1, "%s Part B", 128),
        EXTERNAL_PORT(0x0582, 0x0029, 2, "%s MIDI 1"),
        EXTERNAL_PORT(0x0582, 0x0029, 3, "%s MIDI 2"),
        /* Edirol UA-700 */
        EXTERNAL_PORT(0x0582, 0x002b, 0, "%s MIDI"),
        CONTROL_PORT(0x0582, 0x002b, 1, "%s Control"),
        /* Roland VariOS */
        EXTERNAL_PORT(0x0582, 0x002f, 0, "%s MIDI"),
        EXTERNAL_PORT(0x0582, 0x002f, 1, "%s External MIDI"),
        EXTERNAL_PORT(0x0582, 0x002f, 2, "%s Sync"),
        /* Edirol PCR */
        EXTERNAL_PORT(0x0582, 0x0033, 0, "%s MIDI"),
        EXTERNAL_PORT(0x0582, 0x0033, 1, "%s 1"),
        EXTERNAL_PORT(0x0582, 0x0033, 2, "%s 2"),
        /* BOSS GS-10 */
        EXTERNAL_PORT(0x0582, 0x003b, 0, "%s MIDI"),
        CONTROL_PORT(0x0582, 0x003b, 1, "%s Control"),
        /* Edirol UA-1000 */
        EXTERNAL_PORT(0x0582, 0x0044, 0, "%s MIDI"),
        CONTROL_PORT(0x0582, 0x0044, 1, "%s Control"),
        /* Edirol UR-80 */
        EXTERNAL_PORT(0x0582, 0x0048, 0, "%s MIDI"),
        EXTERNAL_PORT(0x0582, 0x0048, 1, "%s 1"),
        EXTERNAL_PORT(0x0582, 0x0048, 2, "%s 2"),
        /* Edirol PCR-A */
        EXTERNAL_PORT(0x0582, 0x004d, 0, "%s MIDI"),
        EXTERNAL_PORT(0x0582, 0x004d, 1, "%s 1"),
        EXTERNAL_PORT(0x0582, 0x004d, 2, "%s 2"),
        /* BOSS GT-PRO */
        CONTROL_PORT(0x0582, 0x0089, 0, "%s Control"),
        /* Edirol UM-3EX */
        CONTROL_PORT(0x0582, 0x009a, 3, "%s Control"),
        /* Roland VG-99 */
        CONTROL_PORT(0x0582, 0x00b2, 0, "%s Control"),
        EXTERNAL_PORT(0x0582, 0x00b2, 1, "%s MIDI"),
        /* Cakewalk Sonar V-Studio 100 */
        EXTERNAL_PORT(0x0582, 0x00eb, 0, "%s MIDI"),
        CONTROL_PORT(0x0582, 0x00eb, 1, "%s Control"),
        /* Roland VB-99 */
        CONTROL_PORT(0x0582, 0x0102, 0, "%s Control"),
        EXTERNAL_PORT(0x0582, 0x0102, 1, "%s MIDI"),
        /* Roland A-PRO */
        EXTERNAL_PORT(0x0582, 0x010f, 0, "%s MIDI"),
        CONTROL_PORT(0x0582, 0x010f, 1, "%s 1"),
        CONTROL_PORT(0x0582, 0x010f, 2, "%s 2"),
        /* Roland SD-50 */
        ROLAND_SYNTH_PORT(0x0582, 0x0114, 0, "%s Synth", 128),
        EXTERNAL_PORT(0x0582, 0x0114, 1, "%s MIDI"),
        CONTROL_PORT(0x0582, 0x0114, 2, "%s Control"),
        /* Roland OCTA-CAPTURE */
        EXTERNAL_PORT(0x0582, 0x0120, 0, "%s MIDI"),
        CONTROL_PORT(0x0582, 0x0120, 1, "%s Control"),
        EXTERNAL_PORT(0x0582, 0x0121, 0, "%s MIDI"),
        CONTROL_PORT(0x0582, 0x0121, 1, "%s Control"),
        /* Roland SPD-SX */
        CONTROL_PORT(0x0582, 0x0145, 0, "%s Control"),
        EXTERNAL_PORT(0x0582, 0x0145, 1, "%s MIDI"),
        /* Roland A-Series */
        CONTROL_PORT(0x0582, 0x0156, 0, "%s Keyboard"),
        EXTERNAL_PORT(0x0582, 0x0156, 1, "%s MIDI"),
        /* Roland INTEGRA-7 */
        ROLAND_SYNTH_PORT(0x0582, 0x015b, 0, "%s Synth", 128),
        CONTROL_PORT(0x0582, 0x015b, 1, "%s Control"),
        /* M-Audio MidiSport 8x8 */
        CONTROL_PORT(0x0763, 0x1031, 8, "%s Control"),
        CONTROL_PORT(0x0763, 0x1033, 8, "%s Control"),
        /* MOTU Fastlane */
        EXTERNAL_PORT(0x07fd, 0x0001, 0, "%s MIDI A"),
        EXTERNAL_PORT(0x07fd, 0x0001, 1, "%s MIDI B"),
        /* Emagic Unitor8/AMT8/MT4 */
        EXTERNAL_PORT(0x086a, 0x0001, 8, "%s Broadcast"),
        EXTERNAL_PORT(0x086a, 0x0002, 8, "%s Broadcast"),
        EXTERNAL_PORT(0x086a, 0x0003, 4, "%s Broadcast"),
        /* Akai MPD16 */
        CONTROL_PORT(0x09e8, 0x0062, 0, "%s Control"),
        PORT_INFO(0x09e8, 0x0062, 1, "%s MIDI", 0,
                SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |
                SNDRV_SEQ_PORT_TYPE_HARDWARE),
        /* Access Music Virus TI */
        EXTERNAL_PORT(0x133e, 0x0815, 0, "%s MIDI"),
        PORT_INFO(0x133e, 0x0815, 1, "%s Synth", 0,
                SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |
                SNDRV_SEQ_PORT_TYPE_HARDWARE |
                SNDRV_SEQ_PORT_TYPE_SYNTHESIZER),
};

static struct port_info *find_port_info(struct snd_usb_midi *umidi, int number)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(snd_usbmidi_port_info); ++i) {
                if (snd_usbmidi_port_info[i].id == umidi->usb_id &&
                    snd_usbmidi_port_info[i].port == number)
                        return &snd_usbmidi_port_info[i];
        }
        return NULL;
}

static void snd_usbmidi_get_port_info(struct snd_rawmidi *rmidi, int number,
                                      struct snd_seq_port_info *seq_port_info)
{
        struct snd_usb_midi *umidi = rmidi->private_data;
        struct port_info *port_info;

        /* TODO: read port flags from descriptors */
        port_info = find_port_info(umidi, number);
        if (port_info) {
                seq_port_info->type = port_info->seq_flags;
                seq_port_info->midi_voices = port_info->voices;
        }
}

static void snd_usbmidi_init_substream(struct snd_usb_midi *umidi,
                                       int stream, int number,
                                       struct snd_rawmidi_substream **rsubstream)
{
        struct port_info *port_info;
        const char *name_format;

        struct snd_rawmidi_substream *substream =
                snd_usbmidi_find_substream(umidi, stream, number);
        if (!substream) {
                dev_err(&umidi->dev->dev, "substream %d:%d not found\n", stream,
                        number);
                return;
        }

        /* TODO: read port name from jack descriptor */
        port_info = find_port_info(umidi, number);
        name_format = port_info ? port_info->name : "%s MIDI %d";
        snprintf(substream->name, sizeof(substream->name),
                 name_format, umidi->card->shortname, number + 1);

        *rsubstream = substream;
}

/*
 * Creates the endpoints and their ports.
 */
static int snd_usbmidi_create_endpoints(struct snd_usb_midi *umidi,
                                        struct snd_usb_midi_endpoint_info *endpoints)
{
        int i, j, err;
        int out_ports = 0, in_ports = 0;

        for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
                if (endpoints[i].out_cables) {
                        err = snd_usbmidi_out_endpoint_create(umidi,
                                                              &endpoints[i],
                                                              &umidi->endpoints[i]);
                        if (err < 0)
                                return err;
                }
                if (endpoints[i].in_cables) {
                        err = snd_usbmidi_in_endpoint_create(umidi,
                                                             &endpoints[i],
                                                             &umidi->endpoints[i]);
                        if (err < 0)
                                return err;
                }

                for (j = 0; j < 0x10; ++j) {
                        if (endpoints[i].out_cables & (1 << j)) {
                                snd_usbmidi_init_substream(umidi,
                                                           SNDRV_RAWMIDI_STREAM_OUTPUT,
                                                           out_ports,
                                                           &umidi->endpoints[i].out->ports[j].substream);
                                ++out_ports;
                        }
                        if (endpoints[i].in_cables & (1 << j)) {
                                snd_usbmidi_init_substream(umidi,
                                                           SNDRV_RAWMIDI_STREAM_INPUT,
                                                           in_ports,
                                                           &umidi->endpoints[i].in->ports[j].substream);
                                ++in_ports;
                        }
                }
        }
        dev_dbg(&umidi->dev->dev, "created %d output and %d input ports\n",
                    out_ports, in_ports);
        return 0;
}

/*
 * Returns MIDIStreaming device capabilities.
 */
static int snd_usbmidi_get_ms_info(struct snd_usb_midi *umidi,
                                   struct snd_usb_midi_endpoint_info *endpoints)
{
        struct usb_interface *intf;
        struct usb_host_interface *hostif;
        struct usb_interface_descriptor *intfd;
        struct usb_ms_header_descriptor *ms_header;
        struct usb_host_endpoint *hostep;
        struct usb_endpoint_descriptor *ep;
        struct usb_ms_endpoint_descriptor *ms_ep;
        int i, epidx;

        intf = umidi->iface;
        if (!intf)
                return -ENXIO;
        hostif = &intf->altsetting[0];
        intfd = get_iface_desc(hostif);
        ms_header = (struct usb_ms_header_descriptor *)hostif->extra;
        if (hostif->extralen >= 7 &&
            ms_header->bLength >= 7 &&
            ms_header->bDescriptorType == USB_DT_CS_INTERFACE &&
            ms_header->bDescriptorSubtype == UAC_HEADER)
                dev_dbg(&umidi->dev->dev, "MIDIStreaming version %02x.%02x\n",
                            ms_header->bcdMSC[1], ms_header->bcdMSC[0]);
        else
                dev_warn(&umidi->dev->dev,
                         "MIDIStreaming interface descriptor not found\n");

        epidx = 0;
        for (i = 0; i < intfd->bNumEndpoints; ++i) {
                hostep = &hostif->endpoint[i];
                ep = get_ep_desc(hostep);
                if (!usb_endpoint_xfer_bulk(ep) && !usb_endpoint_xfer_int(ep))
                        continue;
                ms_ep = (struct usb_ms_endpoint_descriptor *)hostep->extra;
                if (hostep->extralen < 4 ||
                    ms_ep->bLength < 4 ||
                    ms_ep->bDescriptorType != USB_DT_CS_ENDPOINT ||
                    ms_ep->bDescriptorSubtype != UAC_MS_GENERAL)
                        continue;
                if (usb_endpoint_dir_out(ep)) {
                        if (endpoints[epidx].out_ep) {
                                if (++epidx >= MIDI_MAX_ENDPOINTS) {
                                        dev_warn(&umidi->dev->dev,
                                                 "too many endpoints\n");
                                        break;
                                }
                        }
                        endpoints[epidx].out_ep = usb_endpoint_num(ep);
                        if (usb_endpoint_xfer_int(ep))
                                endpoints[epidx].out_interval = ep->bInterval;
                        else if (snd_usb_get_speed(umidi->dev) == USB_SPEED_LOW)
                                /*
                                 * Low speed bulk transfers don't exist, so
                                 * force interrupt transfers for devices like
                                 * ESI MIDI Mate that try to use them anyway.
                                 */
                                endpoints[epidx].out_interval = 1;
                        endpoints[epidx].out_cables =
                                (1 << ms_ep->bNumEmbMIDIJack) - 1;
                        dev_dbg(&umidi->dev->dev, "EP %02X: %d jack(s)\n",
                                ep->bEndpointAddress, ms_ep->bNumEmbMIDIJack);
                } else {
                        if (endpoints[epidx].in_ep) {
                                if (++epidx >= MIDI_MAX_ENDPOINTS) {
                                        dev_warn(&umidi->dev->dev,
                                                 "too many endpoints\n");
                                        break;
                                }
                        }
                        endpoints[epidx].in_ep = usb_endpoint_num(ep);
                        if (usb_endpoint_xfer_int(ep))
                                endpoints[epidx].in_interval = ep->bInterval;
                        else if (snd_usb_get_speed(umidi->dev) == USB_SPEED_LOW)
                                endpoints[epidx].in_interval = 1;
                        endpoints[epidx].in_cables =
                                (1 << ms_ep->bNumEmbMIDIJack) - 1;
                        dev_dbg(&umidi->dev->dev, "EP %02X: %d jack(s)\n",
                                ep->bEndpointAddress, ms_ep->bNumEmbMIDIJack);
                }
        }
        return 0;
}

static int roland_load_info(struct snd_kcontrol *kcontrol,
                            struct snd_ctl_elem_info *info)
{
        static const char *const names[] = { "High Load", "Light Load" };

        return snd_ctl_enum_info(info, 1, 2, names);
}

static int roland_load_get(struct snd_kcontrol *kcontrol,
                           struct snd_ctl_elem_value *value)
{
        value->value.enumerated.item[0] = kcontrol->private_value;
        return 0;
}

static int roland_load_put(struct snd_kcontrol *kcontrol,
                           struct snd_ctl_elem_value *value)
{
        struct snd_usb_midi *umidi = kcontrol->private_data;
        int changed;

        if (value->value.enumerated.item[0] > 1)
                return -EINVAL;
        mutex_lock(&umidi->mutex);
        changed = value->value.enumerated.item[0] != kcontrol->private_value;
        if (changed)
                kcontrol->private_value = value->value.enumerated.item[0];
        mutex_unlock(&umidi->mutex);
        return changed;
}

static const struct snd_kcontrol_new roland_load_ctl = {
        .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
        .name = "MIDI Input Mode",
        .info = roland_load_info,
        .get = roland_load_get,
        .put = roland_load_put,
        .private_value = 1,
};

/*
 * On Roland devices, use the second alternate setting to be able to use
 * the interrupt input endpoint.
 */
static void snd_usbmidi_switch_roland_altsetting(struct snd_usb_midi *umidi)
{
        struct usb_interface *intf;
        struct usb_host_interface *hostif;
        struct usb_interface_descriptor *intfd;

        intf = umidi->iface;
        if (!intf || intf->num_altsetting != 2)
                return;

        hostif = &intf->altsetting[1];
        intfd = get_iface_desc(hostif);
       /* If either or both of the endpoints support interrupt transfer,
        * then use the alternate setting
        */
        if (intfd->bNumEndpoints != 2 ||
            !((get_endpoint(hostif, 0)->bmAttributes &
               USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT ||
              (get_endpoint(hostif, 1)->bmAttributes &
               USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT))
                return;

        dev_dbg(&umidi->dev->dev, "switching to altsetting %d with int ep\n",
                    intfd->bAlternateSetting);
        usb_set_interface(umidi->dev, intfd->bInterfaceNumber,
                          intfd->bAlternateSetting);

        umidi->roland_load_ctl = snd_ctl_new1(&roland_load_ctl, umidi);
        if (snd_ctl_add(umidi->card, umidi->roland_load_ctl) < 0)
                umidi->roland_load_ctl = NULL;
}

/*
 * Try to find any usable endpoints in the interface.
 */
static int snd_usbmidi_detect_endpoints(struct snd_usb_midi *umidi,
                                        struct snd_usb_midi_endpoint_info *endpoint,
                                        int max_endpoints)
{
        struct usb_interface *intf;
        struct usb_host_interface *hostif;

        struct usb_interface_descriptor *intfd;
        struct usb_endpoint_descriptor *epd;
        int i, out_eps = 0, in_eps = 0;

        if (USB_ID_VENDOR(umidi->usb_id) == 0x0582)
                snd_usbmidi_switch_roland_altsetting(umidi);

        if (endpoint[0].out_ep || endpoint[0].in_ep)
                return 0;

        intf = umidi->iface;
        if (!intf || intf->num_altsetting < 1)
                return -ENOENT;
        hostif = intf->cur_altsetting;
        intfd = get_iface_desc(hostif);

        for (i = 0; i < intfd->bNumEndpoints; ++i) {
                epd = get_endpoint(hostif, i);
                if (!usb_endpoint_xfer_bulk(epd) &&
                    !usb_endpoint_xfer_int(epd))
                        continue;
                if (out_eps < max_endpoints &&
                    usb_endpoint_dir_out(epd)) {
                        endpoint[out_eps].out_ep = usb_endpoint_num(epd);
                        if (usb_endpoint_xfer_int(epd))
                                endpoint[out_eps].out_interval = epd->bInterval;
                        ++out_eps;
                }
                if (in_eps < max_endpoints &&
                    usb_endpoint_dir_in(epd)) {
                        endpoint[in_eps].in_ep = usb_endpoint_num(epd);
                        if (usb_endpoint_xfer_int(epd))
                                endpoint[in_eps].in_interval = epd->bInterval;
                        ++in_eps;
                }
        }
        return (out_eps || in_eps) ? 0 : -ENOENT;
}

/*
 * Detects the endpoints for one-port-per-endpoint protocols.
 */
static int snd_usbmidi_detect_per_port_endpoints(struct snd_usb_midi *umidi,
                                                 struct snd_usb_midi_endpoint_info *endpoints)
{
        int err, i;

        err = snd_usbmidi_detect_endpoints(umidi, endpoints, MIDI_MAX_ENDPOINTS);
        for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
                if (endpoints[i].out_ep)
                        endpoints[i].out_cables = 0x0001;
                if (endpoints[i].in_ep)
                        endpoints[i].in_cables = 0x0001;
        }
        return err;
}

/*
 * Detects the endpoints and ports of Yamaha devices.
 */
static int snd_usbmidi_detect_yamaha(struct snd_usb_midi *umidi,
                                     struct snd_usb_midi_endpoint_info *endpoint)
{
        struct usb_interface *intf;
        struct usb_host_interface *hostif;
        struct usb_interface_descriptor *intfd;
        uint8_t *cs_desc;

        intf = umidi->iface;
        if (!intf)
                return -ENOENT;
        hostif = intf->altsetting;
        intfd = get_iface_desc(hostif);
        if (intfd->bNumEndpoints < 1)
                return -ENOENT;

        /*
         * For each port there is one MIDI_IN/OUT_JACK descriptor, not
         * necessarily with any useful contents.  So simply count 'em.
         */
        for (cs_desc = hostif->extra;
             cs_desc < hostif->extra + hostif->extralen && cs_desc[0] >= 2;
             cs_desc += cs_desc[0]) {
                if (cs_desc[1] == USB_DT_CS_INTERFACE) {
                        if (cs_desc[2] == UAC_MIDI_IN_JACK)
                                endpoint->in_cables =
                                        (endpoint->in_cables << 1) | 1;
                        else if (cs_desc[2] == UAC_MIDI_OUT_JACK)
                                endpoint->out_cables =
                                        (endpoint->out_cables << 1) | 1;
                }
        }
        if (!endpoint->in_cables && !endpoint->out_cables)
                return -ENOENT;

        return snd_usbmidi_detect_endpoints(umidi, endpoint, 1);
}

/*
 * Detects the endpoints and ports of Roland devices.
 */
static int snd_usbmidi_detect_roland(struct snd_usb_midi *umidi,
                                     struct snd_usb_midi_endpoint_info *endpoint)
{
        struct usb_interface *intf;
        struct usb_host_interface *hostif;
        u8 *cs_desc;

        intf = umidi->iface;
        if (!intf)
                return -ENOENT;
        hostif = intf->altsetting;
        /*
         * Some devices have a descriptor <06 24 F1 02 <inputs> <outputs>>,
         * some have standard class descriptors, or both kinds, or neither.
         */
        for (cs_desc = hostif->extra;
             cs_desc < hostif->extra + hostif->extralen && cs_desc[0] >= 2;
             cs_desc += cs_desc[0]) {
                if (cs_desc[0] >= 6 &&
                    cs_desc[1] == USB_DT_CS_INTERFACE &&
                    cs_desc[2] == 0xf1 &&
                    cs_desc[3] == 0x02) {
                        endpoint->in_cables  = (1 << cs_desc[4]) - 1;
                        endpoint->out_cables = (1 << cs_desc[5]) - 1;
                        return snd_usbmidi_detect_endpoints(umidi, endpoint, 1);
                } else if (cs_desc[0] >= 7 &&
                           cs_desc[1] == USB_DT_CS_INTERFACE &&
                           cs_desc[2] == UAC_HEADER) {
                        return snd_usbmidi_get_ms_info(umidi, endpoint);
                }
        }

        return -ENODEV;
}

/*
 * Creates the endpoints and their ports for Midiman devices.
 */
static int snd_usbmidi_create_endpoints_midiman(struct snd_usb_midi *umidi,
                                                struct snd_usb_midi_endpoint_info *endpoint)
{
        struct snd_usb_midi_endpoint_info ep_info;
        struct usb_interface *intf;
        struct usb_host_interface *hostif;
        struct usb_interface_descriptor *intfd;
        struct usb_endpoint_descriptor *epd;
        int cable, err;

        intf = umidi->iface;
        if (!intf)
                return -ENOENT;
        hostif = intf->altsetting;
        intfd = get_iface_desc(hostif);
        /*
         * The various MidiSport devices have more or less random endpoint
         * numbers, so we have to identify the endpoints by their index in
         * the descriptor array, like the driver for that other OS does.
         *
         * There is one interrupt input endpoint for all input ports, one
         * bulk output endpoint for even-numbered ports, and one for odd-
         * numbered ports.  Both bulk output endpoints have corresponding
         * input bulk endpoints (at indices 1 and 3) which aren't used.
         */
        if (intfd->bNumEndpoints < (endpoint->out_cables > 0x0001 ? 5 : 3)) {
                dev_dbg(&umidi->dev->dev, "not enough endpoints\n");
                return -ENOENT;
        }

        epd = get_endpoint(hostif, 0);
        if (!usb_endpoint_dir_in(epd) || !usb_endpoint_xfer_int(epd)) {
                dev_dbg(&umidi->dev->dev, "endpoint[0] isn't interrupt\n");
                return -ENXIO;
        }
        epd = get_endpoint(hostif, 2);
        if (!usb_endpoint_dir_out(epd) || !usb_endpoint_xfer_bulk(epd)) {
                dev_dbg(&umidi->dev->dev, "endpoint[2] isn't bulk output\n");
                return -ENXIO;
        }
        if (endpoint->out_cables > 0x0001) {
                epd = get_endpoint(hostif, 4);
                if (!usb_endpoint_dir_out(epd) ||
                    !usb_endpoint_xfer_bulk(epd)) {
                        dev_dbg(&umidi->dev->dev,
                                "endpoint[4] isn't bulk output\n");
                        return -ENXIO;
                }
        }

        ep_info.out_ep = get_endpoint(hostif, 2)->bEndpointAddress &
                USB_ENDPOINT_NUMBER_MASK;
        ep_info.out_interval = 0;
        ep_info.out_cables = endpoint->out_cables & 0x5555;
        err = snd_usbmidi_out_endpoint_create(umidi, &ep_info,
                                              &umidi->endpoints[0]);
        if (err < 0)
                return err;

        ep_info.in_ep = get_endpoint(hostif, 0)->bEndpointAddress &
                USB_ENDPOINT_NUMBER_MASK;
        ep_info.in_interval = get_endpoint(hostif, 0)->bInterval;
        ep_info.in_cables = endpoint->in_cables;
        err = snd_usbmidi_in_endpoint_create(umidi, &ep_info,
                                             &umidi->endpoints[0]);
        if (err < 0)
                return err;

        if (endpoint->out_cables > 0x0001) {
                ep_info.out_ep = get_endpoint(hostif, 4)->bEndpointAddress &
                        USB_ENDPOINT_NUMBER_MASK;
                ep_info.out_cables = endpoint->out_cables & 0xaaaa;
                err = snd_usbmidi_out_endpoint_create(umidi, &ep_info,
                                                      &umidi->endpoints[1]);
                if (err < 0)
                        return err;
        }

        for (cable = 0; cable < 0x10; ++cable) {
                if (endpoint->out_cables & (1 << cable))
                        snd_usbmidi_init_substream(umidi,
                                                   SNDRV_RAWMIDI_STREAM_OUTPUT,
                                                   cable,
                                                   &umidi->endpoints[cable & 1].out->ports[cable].substream);
                if (endpoint->in_cables & (1 << cable))
                        snd_usbmidi_init_substream(umidi,
                                                   SNDRV_RAWMIDI_STREAM_INPUT,
                                                   cable,
                                                   &umidi->endpoints[0].in->ports[cable].substream);
        }
        return 0;
}

static const struct snd_rawmidi_global_ops snd_usbmidi_ops = {
        .get_port_info = snd_usbmidi_get_port_info,
};

static int snd_usbmidi_create_rawmidi(struct snd_usb_midi *umidi,
                                      int out_ports, int in_ports)
{
        struct snd_rawmidi *rmidi;
        int err;

        err = snd_rawmidi_new(umidi->card, "USB MIDI",
                              umidi->next_midi_device++,
                              out_ports, in_ports, &rmidi);
        if (err < 0)
                return err;
        strcpy(rmidi->name, umidi->card->shortname);
        rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
                            SNDRV_RAWMIDI_INFO_INPUT |
                            SNDRV_RAWMIDI_INFO_DUPLEX;
        rmidi->ops = &snd_usbmidi_ops;
        rmidi->private_data = umidi;
        rmidi->private_free = snd_usbmidi_rawmidi_free;
        snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
                            &snd_usbmidi_output_ops);
        snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
                            &snd_usbmidi_input_ops);

        umidi->rmidi = rmidi;
        return 0;
}

/*
 * Temporarily stop input.
 */
void snd_usbmidi_input_stop(struct list_head *p)
{
        struct snd_usb_midi *umidi;
        unsigned int i, j;

        umidi = list_entry(p, struct snd_usb_midi, list);
        if (!umidi->input_running)
                return;
        for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
                struct snd_usb_midi_endpoint *ep = &umidi->endpoints[i];
                if (ep->in)
                        for (j = 0; j < INPUT_URBS; ++j)
                                usb_kill_urb(ep->in->urbs[j]);
        }
        umidi->input_running = 0;
}
EXPORT_SYMBOL(snd_usbmidi_input_stop);

static void snd_usbmidi_input_start_ep(struct snd_usb_midi_in_endpoint *ep)
{
        unsigned int i;

        if (!ep)
                return;
        for (i = 0; i < INPUT_URBS; ++i) {
                struct urb *urb = ep->urbs[i];
                urb->dev = ep->umidi->dev;
                snd_usbmidi_submit_urb(urb, GFP_KERNEL);
        }
}

/*
 * Resume input after a call to snd_usbmidi_input_stop().
 */
void snd_usbmidi_input_start(struct list_head *p)
{
        struct snd_usb_midi *umidi;
        int i;

        umidi = list_entry(p, struct snd_usb_midi, list);
        if (umidi->input_running || !umidi->opened[1])
                return;
        for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i)
                snd_usbmidi_input_start_ep(umidi->endpoints[i].in);
        umidi->input_running = 1;
}
EXPORT_SYMBOL(snd_usbmidi_input_start);

/*
 * Prepare for suspend. Typically called from the USB suspend callback.
 */
void snd_usbmidi_suspend(struct list_head *p)
{
        struct snd_usb_midi *umidi;

        umidi = list_entry(p, struct snd_usb_midi, list);
        mutex_lock(&umidi->mutex);
        snd_usbmidi_input_stop(p);
        mutex_unlock(&umidi->mutex);
}
EXPORT_SYMBOL(snd_usbmidi_suspend);

/*
 * Resume. Typically called from the USB resume callback.
 */
void snd_usbmidi_resume(struct list_head *p)
{
        struct snd_usb_midi *umidi;

        umidi = list_entry(p, struct snd_usb_midi, list);
        mutex_lock(&umidi->mutex);
        snd_usbmidi_input_start(p);
        mutex_unlock(&umidi->mutex);
}
EXPORT_SYMBOL(snd_usbmidi_resume);

/*
 * Creates and registers everything needed for a MIDI streaming interface.
 */
int __snd_usbmidi_create(struct snd_card *card,
                         struct usb_interface *iface,
                         struct list_head *midi_list,
                         const struct snd_usb_audio_quirk *quirk,
                         unsigned int usb_id)
{
        struct snd_usb_midi *umidi;
        struct snd_usb_midi_endpoint_info endpoints[MIDI_MAX_ENDPOINTS];
        int out_ports, in_ports;
        int i, err;

        umidi = kzalloc(sizeof(*umidi), GFP_KERNEL);
        if (!umidi)
                return -ENOMEM;
        umidi->dev = interface_to_usbdev(iface);
        umidi->card = card;
        umidi->iface = iface;
        umidi->quirk = quirk;
        umidi->usb_protocol_ops = &snd_usbmidi_standard_ops;
        spin_lock_init(&umidi->disc_lock);
        init_rwsem(&umidi->disc_rwsem);
        mutex_init(&umidi->mutex);
        if (!usb_id)
                usb_id = USB_ID(le16_to_cpu(umidi->dev->descriptor.idVendor),
                               le16_to_cpu(umidi->dev->descriptor.idProduct));
        umidi->usb_id = usb_id;
        timer_setup(&umidi->error_timer, snd_usbmidi_error_timer, 0);

        /* detect the endpoint(s) to use */
        memset(endpoints, 0, sizeof(endpoints));
        switch (quirk ? quirk->type : QUIRK_MIDI_STANDARD_INTERFACE) {
        case QUIRK_MIDI_STANDARD_INTERFACE:
                err = snd_usbmidi_get_ms_info(umidi, endpoints);
                if (umidi->usb_id == USB_ID(0x0763, 0x0150)) /* M-Audio Uno */
                        umidi->usb_protocol_ops =
                                &snd_usbmidi_maudio_broken_running_status_ops;
                break;
        case QUIRK_MIDI_US122L:
                umidi->usb_protocol_ops = &snd_usbmidi_122l_ops;
                /* fall through */
        case QUIRK_MIDI_FIXED_ENDPOINT:
                memcpy(&endpoints[0], quirk->data,
                       sizeof(struct snd_usb_midi_endpoint_info));
                err = snd_usbmidi_detect_endpoints(umidi, &endpoints[0], 1);
                break;
        case QUIRK_MIDI_YAMAHA:
                err = snd_usbmidi_detect_yamaha(umidi, &endpoints[0]);
                break;
        case QUIRK_MIDI_ROLAND:
                err = snd_usbmidi_detect_roland(umidi, &endpoints[0]);
                break;
        case QUIRK_MIDI_MIDIMAN:
                umidi->usb_protocol_ops = &snd_usbmidi_midiman_ops;
                memcpy(&endpoints[0], quirk->data,
                       sizeof(struct snd_usb_midi_endpoint_info));
                err = 0;
                break;
        case QUIRK_MIDI_NOVATION:
                umidi->usb_protocol_ops = &snd_usbmidi_novation_ops;
                err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
                break;
        case QUIRK_MIDI_RAW_BYTES:
                umidi->usb_protocol_ops = &snd_usbmidi_raw_ops;
                /*
                 * Interface 1 contains isochronous endpoints, but with the same
                 * numbers as in interface 0.  Since it is interface 1 that the
                 * USB core has most recently seen, these descriptors are now
                 * associated with the endpoint numbers.  This will foul up our
                 * attempts to submit bulk/interrupt URBs to the endpoints in
                 * interface 0, so we have to make sure that the USB core looks
                 * again at interface 0 by calling usb_set_interface() on it.
                 */
                if (umidi->usb_id == USB_ID(0x07fd, 0x0001)) /* MOTU Fastlane */
                        usb_set_interface(umidi->dev, 0, 0);
                err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
                break;
        case QUIRK_MIDI_EMAGIC:
                umidi->usb_protocol_ops = &snd_usbmidi_emagic_ops;
                memcpy(&endpoints[0], quirk->data,
                       sizeof(struct snd_usb_midi_endpoint_info));
                err = snd_usbmidi_detect_endpoints(umidi, &endpoints[0], 1);
                break;
        case QUIRK_MIDI_CME:
                umidi->usb_protocol_ops = &snd_usbmidi_cme_ops;
                err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
                break;
        case QUIRK_MIDI_AKAI:
                umidi->usb_protocol_ops = &snd_usbmidi_akai_ops;
                err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
                /* endpoint 1 is input-only */
                endpoints[1].out_cables = 0;
                break;
        case QUIRK_MIDI_FTDI:
                umidi->usb_protocol_ops = &snd_usbmidi_ftdi_ops;

                /* set baud rate to 31250 (48 MHz / 16 / 96) */
                err = usb_control_msg(umidi->dev, usb_sndctrlpipe(umidi->dev, 0),
                                      3, 0x40, 0x60, 0, NULL, 0, 1000);
                if (err < 0)
                        break;

                err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
                break;
        case QUIRK_MIDI_CH345:
                umidi->usb_protocol_ops = &snd_usbmidi_ch345_broken_sysex_ops;
                err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
                break;
        default:
                dev_err(&umidi->dev->dev, "invalid quirk type %d\n",
                        quirk->type);
                err = -ENXIO;
                break;
        }
        if (err < 0)
                goto free_midi;

        /* create rawmidi device */
        out_ports = 0;
        in_ports = 0;
        for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
                out_ports += hweight16(endpoints[i].out_cables);
                in_ports += hweight16(endpoints[i].in_cables);
        }
        err = snd_usbmidi_create_rawmidi(umidi, out_ports, in_ports);
        if (err < 0)
                goto free_midi;

        /* create endpoint/port structures */
        if (quirk && quirk->type == QUIRK_MIDI_MIDIMAN)
                err = snd_usbmidi_create_endpoints_midiman(umidi, &endpoints[0]);
        else
                err = snd_usbmidi_create_endpoints(umidi, endpoints);
        if (err < 0)
                goto exit;

        usb_autopm_get_interface_no_resume(umidi->iface);

        list_add_tail(&umidi->list, midi_list);
        return 0;

free_midi:
        kfree(umidi);
exit:
        return err;
}
EXPORT_SYMBOL(__snd_usbmidi_create);