ClabureDB: Classified Bug-Reports Database

   /*
    * usbmidi.c - ALSA USB MIDI driver
    *
    * Copyright (c) 2002-2007 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 <sound/core.h>
  #include <sound/rawmidi.h>
  #include <sound/asequencer.h>
  #include "usbaudio.h"
  
  
  /*
   * define this to log all USB packets
   */
  /* #define DUMP_PACKETS */
  
  /*
   * how long to wait after some USB errors, so that khubd can disconnect() us
   * without too many spurious errors
   */
  #define ERROR_DELAY_JIFFIES (HZ / 10)
  
  
  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*);
          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 snd_usb_audio *chip;
         struct usb_interface *iface;
         const struct snd_usb_audio_quirk *quirk;
         struct snd_rawmidi *rmidi;
         struct usb_protocol_ops* usb_protocol_ops;
         struct list_head list;
         struct timer_list error_timer;
         spinlock_t disc_lock;
 
         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 char disconnected;
 };
 
 struct snd_usb_midi_out_endpoint {
         struct snd_usb_midi* umidi;
         struct urb* urb;
         int urb_active;
         int max_transfer;                /* size of urb buffer */
         struct tasklet_struct tasklet;
 
         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;
 };
 
 struct snd_usb_midi_in_endpoint {
         struct snd_usb_midi* umidi;
         struct urb* urb;
         struct usbmidi_in_port {
                 struct snd_rawmidi_substream *substream;
                 u8 running_status_length;
         } ports[0x10];
         u8 seen_f5;
         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)
                 snd_printk(KERN_ERR "usb_submit_urb: %d\n", err);
         return err;
 }
 
 /*
  * Error handling for URB completion functions.
  */
 static int snd_usbmidi_urb_error(int status)
 {
         switch (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:
                 snd_printk(KERN_ERR "urb status %d\n", 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) {
                 snd_printd("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(" %02x", *data);
         printk(" ]\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->status);
                 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->chip->dev;
         snd_usbmidi_submit_urb(urb, GFP_ATOMIC);
 }
 
 static void snd_usbmidi_out_urb_complete(struct urb* urb)
 {
         struct snd_usb_midi_out_endpoint* ep = urb->context;
 
         spin_lock(&ep->buffer_lock);
         ep->urb_active = 0;
         spin_unlock(&ep->buffer_lock);
         if (urb->status < 0) {
                 int err = snd_usbmidi_urb_error(urb->status);
                 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)
 {
         struct urb* urb = ep->urb;
         unsigned long flags;
 
         spin_lock_irqsave(&ep->buffer_lock, flags);
         if (ep->urb_active || ep->umidi->chip->shutdown) {
                 spin_unlock_irqrestore(&ep->buffer_lock, flags);
                 return;
         }
 
         urb->transfer_buffer_length = 0;
         ep->umidi->usb_protocol_ops->output(ep);
 
         if (urb->transfer_buffer_length > 0) {
                 dump_urb("sending", urb->transfer_buffer,
                          urb->transfer_buffer_length);
                 urb->dev = ep->umidi->chip->dev;
                 ep->urb_active = snd_usbmidi_submit_urb(urb, GFP_ATOMIC) >= 0;
         }
         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(unsigned long data)
 {
         struct snd_usb_midi *umidi = (struct snd_usb_midi *)data;
         int i;
 
         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;
                         in->urb->dev = umidi->chip->dev;
                         snd_usbmidi_submit_urb(in->urb, 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;
         void *buf = kmemdup(data, len, GFP_KERNEL);
         if (!buf)
                 return -ENOMEM;
         dump_urb("sending", buf, len);
         err = usb_bulk_msg(ep->umidi->chip->dev, ep->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);
                 }
 }
 
 /*
  * 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 = ep->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 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 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 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 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,
 };
 
 /*
  * 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)
 {
         uint8_t* transfer_buffer;
         int count;
 
         if (!ep->ports[0].active)
                 return;
         transfer_buffer = ep->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;
         ep->urb->transfer_buffer_length = 2 + count;
 }
 
 static struct usb_protocol_ops snd_usbmidi_novation_ops = {
         .input = snd_usbmidi_novation_input,
         .output = snd_usbmidi_novation_output,
 };
 
 /*
  * "raw" protocol: used by the MOTU FastLane.
  */
 
 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)
 {
         int count;
 
         if (!ep->ports[0].active)
                 return;
         count = snd_rawmidi_transmit(ep->ports[0].substream,
                                      ep->urb->transfer_buffer,
                                      ep->max_transfer);
         if (count < 1) {
                 ep->ports[0].active = 0;
                 return;
         }
         ep->urb->transfer_buffer_length = count;
 }
 
 static struct usb_protocol_ops snd_usbmidi_raw_ops = {
         .input = snd_usbmidi_raw_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)
 {
         int count;
 
         if (!ep->ports[0].active)
                 return;
         count = ep->urb->dev->speed == USB_SPEED_HIGH ? 1 : 2;
         count = snd_rawmidi_transmit(ep->ports[0].substream,
                                      ep->urb->transfer_buffer,
                                      count);
         if (count < 1) {
                 ep->ports[0].active = 0;
                 return;
         }
 
         memset(ep->urb->transfer_buffer + count, 0xFD, 9 - count);
         ep->urb->transfer_buffer_length = count;
 }
 
 static 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)
 {
         int port0 = ep->current_port;
         uint8_t* buf = ep->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;
         }
         ep->urb->transfer_buffer_length = ep->max_transfer - buf_free;
 }
 
 static 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 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 0;
 }
 
 static int snd_usbmidi_output_close(struct snd_rawmidi_substream *substream)
 {
         return 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->chip->shutdown) {
                         /* 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_hi_schedule(&port->ep->tasklet);
         }
 }
 
 static int snd_usbmidi_input_open(struct snd_rawmidi_substream *substream)
 {
         return 0;
 }
 
 static int snd_usbmidi_input_close(struct snd_rawmidi_substream *substream)
 {
         return 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 struct snd_rawmidi_ops snd_usbmidi_output_ops = {
         .open = snd_usbmidi_output_open,
         .close = snd_usbmidi_output_close,
         .trigger = snd_usbmidi_output_trigger,
 };
 
 static struct snd_rawmidi_ops snd_usbmidi_input_ops = {
         .open = snd_usbmidi_input_open,
         .close = snd_usbmidi_input_close,
         .trigger = snd_usbmidi_input_trigger
 };
 
 /*
  * 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)
 {
         if (ep->urb) {
                 usb_buffer_free(ep->umidi->chip->dev,
                                 ep->urb->transfer_buffer_length,
                                 ep->urb->transfer_buffer,
                                 ep->urb->transfer_dma);
                 usb_free_urb(ep->urb);
         }
         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;
 
         rep->in = NULL;
         ep = kzalloc(sizeof(*ep), GFP_KERNEL);
         if (!ep)
                 return -ENOMEM;
         ep->umidi = umidi;
 
         ep->urb = usb_alloc_urb(0, GFP_KERNEL);
         if (!ep->urb) {
                 snd_usbmidi_in_endpoint_delete(ep);
                 return -ENOMEM;
         }
         if (ep_info->in_interval)
                 pipe = usb_rcvintpipe(umidi->chip->dev, ep_info->in_ep);
         else
                 pipe = usb_rcvbulkpipe(umidi->chip->dev, ep_info->in_ep);
         length = usb_maxpacket(umidi->chip->dev, pipe, 0);
         buffer = usb_buffer_alloc(umidi->chip->dev, length, GFP_KERNEL,
                                   &ep->urb->transfer_dma);
         if (!buffer) {
                 snd_usbmidi_in_endpoint_delete(ep);
                 return -ENOMEM;
         }
         if (ep_info->in_interval)
                 usb_fill_int_urb(ep->urb, umidi->chip->dev, pipe, buffer,
                                  length, snd_usbmidi_in_urb_complete, ep,
                                  ep_info->in_interval);
         else
                 usb_fill_bulk_urb(ep->urb, umidi->chip->dev, pipe, buffer,
                                   length, snd_usbmidi_in_urb_complete, ep);
         ep->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
 
         rep->in = ep;
         return 0;
 }
 
 static unsigned int snd_usbmidi_count_bits(unsigned int x)
 {
         unsigned int bits;
 
         for (bits = 0; x; ++bits)
                 x &= x - 1;
         return bits;
 }
 
 /*
  * Frees an output endpoint.
  * May be called when ep hasn't been initialized completely.
  */
 static void snd_usbmidi_out_endpoint_delete(struct snd_usb_midi_out_endpoint* ep)
 {
         if (ep->urb) {
                 usb_buffer_free(ep->umidi->chip->dev, ep->max_transfer,
                                 ep->urb->transfer_buffer,
                                ep->urb->transfer_dma);
                usb_free_urb(ep->urb);
        }
        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;
        int i;
        unsigned int pipe;
        void* buffer;

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

        ep->urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!ep->urb) {
                snd_usbmidi_out_endpoint_delete(ep);
                return -ENOMEM;
        }
        if (ep_info->out_interval)
                pipe = usb_sndintpipe(umidi->chip->dev, ep_info->out_ep);
        else
                pipe = usb_sndbulkpipe(umidi->chip->dev, ep_info->out_ep);
        if (umidi->chip->usb_id == USB_ID(0x0a92, 0x1020)) /* ESI M4U */
                /* FIXME: we need more URBs to get reasonable bandwidth here: */
                ep->max_transfer = 4;
        else
                ep->max_transfer = usb_maxpacket(umidi->chip->dev, pipe, 1);
        buffer = usb_buffer_alloc(umidi->chip->dev, ep->max_transfer,
                                  GFP_KERNEL, &ep->urb->transfer_dma);
        if (!buffer) {
                snd_usbmidi_out_endpoint_delete(ep);
                return -ENOMEM;
        }
        if (ep_info->out_interval)
                usb_fill_int_urb(ep->urb, umidi->chip->dev, pipe, buffer,
                                 ep->max_transfer, snd_usbmidi_out_urb_complete,
                                 ep, ep_info->out_interval);
        else
                usb_fill_bulk_urb(ep->urb, umidi->chip->dev,
                                  pipe, buffer, ep->max_transfer,
                                  snd_usbmidi_out_urb_complete, ep);
        ep->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);

        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;
}

/*
 * 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);
        }
        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;
        int i;

        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
         */
        spin_lock_irq(&umidi->disc_lock);
        umidi->disconnected = 1;
        spin_unlock_irq(&umidi->disc_lock);
        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 && ep->out->urb) {
                        usb_kill_urb(ep->out->urb);
                        if (umidi->usb_protocol_ops->finish_out_endpoint)
                                umidi->usb_protocol_ops->finish_out_endpoint(ep->out);
                }
                if (ep->in)
                        usb_kill_urb(ep->in->urb);
                /* free endpoints here; later call can result in Oops */
                if (ep->out) {
                        snd_usbmidi_out_endpoint_delete(ep->out);
                        ep->out = NULL;
                }
                if (ep->in) {
                        snd_usbmidi_in_endpoint_delete(ep->in);
                        ep->in = NULL;
                }
        }
        del_timer_sync(&umidi->error_timer);
}

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 list_head* list;

        list_for_each(list, &umidi->rmidi->streams[stream].substreams) {
                struct snd_rawmidi_substream *substream = list_entry(list, struct snd_rawmidi_substream, 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 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)
        /* 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"),
        /* Edirol UM-3EX */
        CONTROL_PORT(0x0582, 0x009a, 3, "%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"),
};

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->chip->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) {
                snd_printd(KERN_ERR "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->chip->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;
                        }
                }
        }
        snd_printdd(KERN_INFO "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 == HEADER)
                snd_printdd(KERN_INFO "MIDIStreaming version %02x.%02x\n",
                            ms_header->bcdMSC[1], ms_header->bcdMSC[0]);
        else
                snd_printk(KERN_WARNING "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 ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_BULK &&
                    (ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_INT)
                        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 != MS_GENERAL)
                        continue;
                if ((ep->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT) {
                        if (endpoints[epidx].out_ep) {
                                if (++epidx >= MIDI_MAX_ENDPOINTS) {
                                        snd_printk(KERN_WARNING "too many endpoints\n");
                                        break;
                                }
                        }
                        endpoints[epidx].out_ep = ep->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
                        if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)
                                endpoints[epidx].out_interval = ep->bInterval;
                        else if (snd_usb_get_speed(umidi->chip->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;
                        snd_printdd(KERN_INFO "EP %02X: %d jack(s)\n",
                                    ep->bEndpointAddress, ms_ep->bNumEmbMIDIJack);
                } else {
                        if (endpoints[epidx].in_ep) {
                                if (++epidx >= MIDI_MAX_ENDPOINTS) {
                                        snd_printk(KERN_WARNING "too many endpoints\n");
                                        break;
                                }
                        }
                        endpoints[epidx].in_ep = ep->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
                        if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)
                                endpoints[epidx].in_interval = ep->bInterval;
                        else if (snd_usb_get_speed(umidi->chip->dev) == USB_SPEED_LOW)
                                endpoints[epidx].in_interval = 1;
                        endpoints[epidx].in_cables = (1 << ms_ep->bNumEmbMIDIJack) - 1;
                        snd_printdd(KERN_INFO "EP %02X: %d jack(s)\n",
                                    ep->bEndpointAddress, ms_ep->bNumEmbMIDIJack);
                }
        }
        return 0;
}

/*
 * 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 (intfd->bNumEndpoints != 2 ||
            (get_endpoint(hostif, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_BULK ||
            (get_endpoint(hostif, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_INT)
                return;

        snd_printdd(KERN_INFO "switching to altsetting %d with int ep\n",
                    intfd->bAlternateSetting);
        usb_set_interface(umidi->chip->dev, intfd->bInterfaceNumber,
                          intfd->bAlternateSetting);
}

/*
 * 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->chip->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 ((epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_BULK &&
                    (epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_INT)
                        continue;
                if (out_eps < max_endpoints &&
                    (epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT) {
                        endpoint[out_eps].out_ep = epd->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
                        if ((epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)
                                endpoint[out_eps].out_interval = epd->bInterval;
                        ++out_eps;
                }
                if (in_eps < max_endpoints &&
                    (epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN) {
                        endpoint[in_eps].in_ep = epd->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
                        if ((epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)
                                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] == MIDI_IN_JACK)
                                endpoint->in_cables = (endpoint->in_cables << 1) | 1;
                        else if (cs_desc[2] == 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);
}

/*
 * 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)) {
                snd_printdd(KERN_ERR "not enough endpoints\n");
                return -ENOENT;
        }

        epd = get_endpoint(hostif, 0);
        if ((epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK) != USB_DIR_IN ||
            (epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_INT) {
                snd_printdd(KERN_ERR "endpoint[0] isn't interrupt\n");
                return -ENXIO;
        }
        epd = get_endpoint(hostif, 2);
        if ((epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK) != USB_DIR_OUT ||
            (epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_BULK) {
                snd_printdd(KERN_ERR "endpoint[2] isn't bulk output\n");
                return -ENXIO;
        }
        if (endpoint->out_cables > 0x0001) {
                epd = get_endpoint(hostif, 4);
                if ((epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK) != USB_DIR_OUT ||
                    (epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_BULK) {
                        snd_printdd(KERN_ERR "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_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 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->chip->card, "USB MIDI",
                              umidi->chip->next_midi_device++,
                              out_ports, in_ports, &rmidi);
        if (err < 0)
                return err;
        strcpy(rmidi->name, umidi->chip->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;
        int i;

        umidi = list_entry(p, struct snd_usb_midi, list);
        for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
                struct snd_usb_midi_endpoint* ep = &umidi->endpoints[i];
                if (ep->in)
                        usb_kill_urb(ep->in->urb);
        }
}

static void snd_usbmidi_input_start_ep(struct snd_usb_midi_in_endpoint* ep)
{
        if (ep) {
                struct urb* urb = ep->urb;
                urb->dev = ep->umidi->chip->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);
        for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i)
                snd_usbmidi_input_start_ep(umidi->endpoints[i].in);
}

/*
 * Creates and registers everything needed for a MIDI streaming interface.
 */
int snd_usb_create_midi_interface(struct snd_usb_audio* chip,
                                  struct usb_interface* iface,
                                  const struct snd_usb_audio_quirk* quirk)
{
        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->chip = chip;
        umidi->iface = iface;
        umidi->quirk = quirk;
        umidi->usb_protocol_ops = &snd_usbmidi_standard_ops;
        init_timer(&umidi->error_timer);
        spin_lock_init(&umidi->disc_lock);
        umidi->error_timer.function = snd_usbmidi_error_timer;
        umidi->error_timer.data = (unsigned long)umidi;

        /* 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 (chip->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_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:
                umidi->usb_protocol_ops = &snd_usbmidi_raw_ops;
                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;
        default:
                snd_printd(KERN_ERR "invalid quirk type %d\n", quirk->type);
                err = -ENXIO;
                break;
        }
        if (err < 0) {
                kfree(umidi);
                return err;
        }

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

        /* 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) {
                snd_usbmidi_free(umidi);
                return err;
        }

        list_add(&umidi->list, &umidi->chip->midi_list);

        for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i)
                snd_usbmidi_input_start_ep(umidi->endpoints[i].in);
        return 0;
}

EXPORT_SYMBOL(snd_usb_create_midi_interface);
EXPORT_SYMBOL(snd_usbmidi_input_stop);
EXPORT_SYMBOL(snd_usbmidi_input_start);
EXPORT_SYMBOL(snd_usbmidi_disconnect);