sound/usb/line6/midi.c

   1 /*
   2  * Line 6 Linux USB driver
   3  *
   4  * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License as
   8  *      published by the Free Software Foundation, version 2.
   9  *
  10  */
  11
  12 #include <linux/slab.h>
  13 #include <linux/usb.h>
  14 #include <linux/export.h>
  15 #include <sound/core.h>
  16 #include <sound/rawmidi.h>
  17
  18 #include "driver.h"
  19 #include "midi.h"
  20
  21 #define line6_rawmidi_substream_midi(substream) \
  22         ((struct snd_line6_midi *)((substream)->rmidi->private_data))
  23
  24 static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
  25                            int length);
  26
  27 /*
  28         Pass data received via USB to MIDI.
  29 */
  30 void line6_midi_receive(struct usb_line6 *line6, unsigned char *data,
  31                         int length)
  32 {
  33         if (line6->line6midi->substream_receive)
  34                 snd_rawmidi_receive(line6->line6midi->substream_receive,
  35                                     data, length);
  36 }
  37
  38 /*
  39         Read data from MIDI buffer and transmit them via USB.
  40 */
  41 static void line6_midi_transmit(struct snd_rawmidi_substream *substream)
  42 {
  43         struct usb_line6 *line6 =
  44             line6_rawmidi_substream_midi(substream)->line6;
  45         struct snd_line6_midi *line6midi = line6->line6midi;
  46         struct midi_buffer *mb = &line6midi->midibuf_out;
  47         unsigned char chunk[LINE6_FALLBACK_MAXPACKETSIZE];
  48         int req, done;
  49
  50         for (;;) {
  51                 req = min3(line6_midibuf_bytes_free(mb), line6->max_packet_size,
  52                            LINE6_FALLBACK_MAXPACKETSIZE);
  53                 done = snd_rawmidi_transmit_peek(substream, chunk, req);
  54
  55                 if (done == 0)
  56                         break;
  57
  58                 line6_midibuf_write(mb, chunk, done);
  59                 snd_rawmidi_transmit_ack(substream, done);
  60         }
  61
  62         for (;;) {
  63                 done = line6_midibuf_read(mb, chunk,
  64                                           LINE6_FALLBACK_MAXPACKETSIZE,
  65                                           LINE6_MIDIBUF_READ_TX);
  66
  67                 if (done == 0)
  68                         break;
  69
  70                 send_midi_async(line6, chunk, done);
  71         }
  72 }
  73
  74 /*
  75         Notification of completion of MIDI transmission.
  76 */
  77 static void midi_sent(struct urb *urb)
  78 {
  79         unsigned long flags;
  80         int status;
  81         int num;
  82         struct usb_line6 *line6 = (struct usb_line6 *)urb->context;
  83
  84         status = urb->status;
  85         kfree(urb->transfer_buffer);
  86         usb_free_urb(urb);
  87
  88         if (status == -ESHUTDOWN)
  89                 return;
  90
  91         spin_lock_irqsave(&line6->line6midi->lock, flags);
  92         num = --line6->line6midi->num_active_send_urbs;
  93
  94         if (num == 0) {
  95                 line6_midi_transmit(line6->line6midi->substream_transmit);
  96                 num = line6->line6midi->num_active_send_urbs;
  97         }
  98
  99         if (num == 0)
 100                 wake_up(&line6->line6midi->send_wait);
 101
 102         spin_unlock_irqrestore(&line6->line6midi->lock, flags);
 103 }
 104
 105 /*
 106         Send an asynchronous MIDI message.
 107         Assumes that line6->line6midi->lock is held
 108         (i.e., this function is serialized).
 109 */
 110 static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
 111                            int length)
 112 {
 113         struct urb *urb;
 114         int retval;
 115         unsigned char *transfer_buffer;
 116
 117         urb = usb_alloc_urb(0, GFP_ATOMIC);
 118
 119         if (urb == NULL)
 120                 return -ENOMEM;
 121
 122         transfer_buffer = kmemdup(data, length, GFP_ATOMIC);
 123
 124         if (transfer_buffer == NULL) {
 125                 usb_free_urb(urb);
 126                 return -ENOMEM;
 127         }
 128
 129         usb_fill_int_urb(urb, line6->usbdev,
 130                          usb_sndintpipe(line6->usbdev,
 131                                          line6->properties->ep_ctrl_w),
 132                          transfer_buffer, length, midi_sent, line6,
 133                          line6->interval);
 134         urb->actual_length = 0;
 135         retval = usb_urb_ep_type_check(urb);
 136         if (retval < 0)
 137                 goto error;
 138
 139         retval = usb_submit_urb(urb, GFP_ATOMIC);
 140         if (retval < 0)
 141                 goto error;
 142
 143         ++line6->line6midi->num_active_send_urbs;
 144         return 0;
 145
 146  error:
 147         dev_err(line6->ifcdev, "usb_submit_urb failed\n");
 148         usb_free_urb(urb);
 149         return retval;
 150 }
 151
 152 static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
 153 {
 154         return 0;
 155 }
 156
 157 static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
 158 {
 159         return 0;
 160 }
 161
 162 static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream,
 163                                       int up)
 164 {
 165         unsigned long flags;
 166         struct usb_line6 *line6 =
 167             line6_rawmidi_substream_midi(substream)->line6;
 168
 169         line6->line6midi->substream_transmit = substream;
 170         spin_lock_irqsave(&line6->line6midi->lock, flags);
 171
 172         if (line6->line6midi->num_active_send_urbs == 0)
 173                 line6_midi_transmit(substream);
 174
 175         spin_unlock_irqrestore(&line6->line6midi->lock, flags);
 176 }
 177
 178 static void line6_midi_output_drain(struct snd_rawmidi_substream *substream)
 179 {
 180         struct usb_line6 *line6 =
 181             line6_rawmidi_substream_midi(substream)->line6;
 182         struct snd_line6_midi *midi = line6->line6midi;
 183
 184         wait_event_interruptible(midi->send_wait,
 185                                  midi->num_active_send_urbs == 0);
 186 }
 187
 188 static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
 189 {
 190         return 0;
 191 }
 192
 193 static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
 194 {
 195         return 0;
 196 }
 197
 198 static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream,
 199                                      int up)
 200 {
 201         struct usb_line6 *line6 =
 202             line6_rawmidi_substream_midi(substream)->line6;
 203
 204         if (up)
 205                 line6->line6midi->substream_receive = substream;
 206         else
 207                 line6->line6midi->substream_receive = NULL;
 208 }
 209
 210 static const struct snd_rawmidi_ops line6_midi_output_ops = {
 211         .open = line6_midi_output_open,
 212         .close = line6_midi_output_close,
 213         .trigger = line6_midi_output_trigger,
 214         .drain = line6_midi_output_drain,
 215 };
 216
 217 static const struct snd_rawmidi_ops line6_midi_input_ops = {
 218         .open = line6_midi_input_open,
 219         .close = line6_midi_input_close,
 220         .trigger = line6_midi_input_trigger,
 221 };
 222
 223 /* Create a MIDI device */
 224 static int snd_line6_new_midi(struct usb_line6 *line6,
 225                               struct snd_rawmidi **rmidi_ret)
 226 {
 227         struct snd_rawmidi *rmidi;
 228         int err;
 229
 230         err = snd_rawmidi_new(line6->card, "Line 6 MIDI", 0, 1, 1, rmidi_ret);
 231         if (err < 0)
 232                 return err;
 233
 234         rmidi = *rmidi_ret;
 235         strcpy(rmidi->id, line6->properties->id);
 236         strcpy(rmidi->name, line6->properties->name);
 237
 238         rmidi->info_flags =
 239             SNDRV_RAWMIDI_INFO_OUTPUT |
 240             SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
 241
 242         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 243                             &line6_midi_output_ops);
 244         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 245                             &line6_midi_input_ops);
 246         return 0;
 247 }
 248
 249 /* MIDI device destructor */
 250 static void snd_line6_midi_free(struct snd_rawmidi *rmidi)
 251 {
 252         struct snd_line6_midi *line6midi = rmidi->private_data;
 253
 254         line6_midibuf_destroy(&line6midi->midibuf_in);
 255         line6_midibuf_destroy(&line6midi->midibuf_out);
 256         kfree(line6midi);
 257 }
 258
 259 /*
 260         Initialize the Line 6 MIDI subsystem.
 261 */
 262 int line6_init_midi(struct usb_line6 *line6)
 263 {
 264         int err;
 265         struct snd_rawmidi *rmidi;
 266         struct snd_line6_midi *line6midi;
 267
 268         if (!(line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI)) {
 269                 /* skip MIDI initialization and report success */
 270                 return 0;
 271         }
 272
 273         err = snd_line6_new_midi(line6, &rmidi);
 274         if (err < 0)
 275                 return err;
 276
 277         line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL);
 278         if (!line6midi)
 279                 return -ENOMEM;
 280
 281         rmidi->private_data = line6midi;
 282         rmidi->private_free = snd_line6_midi_free;
 283
 284         init_waitqueue_head(&line6midi->send_wait);
 285         spin_lock_init(&line6midi->lock);
 286         line6midi->line6 = line6;
 287
 288         err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0);
 289         if (err < 0)
 290                 return err;
 291
 292         err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1);
 293         if (err < 0)
 294                 return err;
 295
 296         line6->line6midi = line6midi;
 297         return 0;
 298 }
 299 EXPORT_SYMBOL_GPL(line6_init_midi);