kernel/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 = min(line6_midibuf_bytes_free(mb), line6->max_packet_size);
  52                 done = snd_rawmidi_transmit_peek(substream, chunk, req);
  53
  54                 if (done == 0)
  55                         break;
  56
  57                 line6_midibuf_write(mb, chunk, done);
  58                 snd_rawmidi_transmit_ack(substream, done);
  59         }
  60
  61         for (;;) {
  62                 done = line6_midibuf_read(mb, chunk,
  63                                           LINE6_FALLBACK_MAXPACKETSIZE);
  64
  65                 if (done == 0)
  66                         break;
  67
  68                 send_midi_async(line6, chunk, done);
  69         }
  70 }
  71
  72 /*
  73         Notification of completion of MIDI transmission.
  74 */
  75 static void midi_sent(struct urb *urb)
  76 {
  77         unsigned long flags;
  78         int status;
  79         int num;
  80         struct usb_line6 *line6 = (struct usb_line6 *)urb->context;
  81
  82         status = urb->status;
  83         kfree(urb->transfer_buffer);
  84         usb_free_urb(urb);
  85
  86         if (status == -ESHUTDOWN)
  87                 return;
  88
  89         spin_lock_irqsave(&line6->line6midi->lock, flags);
  90         num = --line6->line6midi->num_active_send_urbs;
  91
  92         if (num == 0) {
  93                 line6_midi_transmit(line6->line6midi->substream_transmit);
  94                 num = line6->line6midi->num_active_send_urbs;
  95         }
  96
  97         if (num == 0)
  98                 wake_up(&line6->line6midi->send_wait);
  99
 100         spin_unlock_irqrestore(&line6->line6midi->lock, flags);
 101 }
 102
 103 /*
 104         Send an asynchronous MIDI message.
 105         Assumes that line6->line6midi->lock is held
 106         (i.e., this function is serialized).
 107 */
 108 static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
 109                            int length)
 110 {
 111         struct urb *urb;
 112         int retval;
 113         unsigned char *transfer_buffer;
 114
 115         urb = usb_alloc_urb(0, GFP_ATOMIC);
 116
 117         if (urb == NULL)
 118                 return -ENOMEM;
 119
 120         transfer_buffer = kmemdup(data, length, GFP_ATOMIC);
 121
 122         if (transfer_buffer == NULL) {
 123                 usb_free_urb(urb);
 124                 return -ENOMEM;
 125         }
 126
 127         usb_fill_int_urb(urb, line6->usbdev,
 128                          usb_sndbulkpipe(line6->usbdev,
 129                                          line6->properties->ep_ctrl_w),
 130                          transfer_buffer, length, midi_sent, line6,
 131                          line6->interval);
 132         urb->actual_length = 0;
 133         retval = usb_submit_urb(urb, GFP_ATOMIC);
 134
 135         if (retval < 0) {
 136                 dev_err(line6->ifcdev, "usb_submit_urb failed\n");
 137                 usb_free_urb(urb);
 138                 return retval;
 139         }
 140
 141         ++line6->line6midi->num_active_send_urbs;
 142         return 0;
 143 }
 144
 145 static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
 146 {
 147         return 0;
 148 }
 149
 150 static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
 151 {
 152         return 0;
 153 }
 154
 155 static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream,
 156                                       int up)
 157 {
 158         unsigned long flags;
 159         struct usb_line6 *line6 =
 160             line6_rawmidi_substream_midi(substream)->line6;
 161
 162         line6->line6midi->substream_transmit = substream;
 163         spin_lock_irqsave(&line6->line6midi->lock, flags);
 164
 165         if (line6->line6midi->num_active_send_urbs == 0)
 166                 line6_midi_transmit(substream);
 167
 168         spin_unlock_irqrestore(&line6->line6midi->lock, flags);
 169 }
 170
 171 static void line6_midi_output_drain(struct snd_rawmidi_substream *substream)
 172 {
 173         struct usb_line6 *line6 =
 174             line6_rawmidi_substream_midi(substream)->line6;
 175         struct snd_line6_midi *midi = line6->line6midi;
 176
 177         wait_event_interruptible(midi->send_wait,
 178                                  midi->num_active_send_urbs == 0);
 179 }
 180
 181 static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
 182 {
 183         return 0;
 184 }
 185
 186 static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
 187 {
 188         return 0;
 189 }
 190
 191 static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream,
 192                                      int up)
 193 {
 194         struct usb_line6 *line6 =
 195             line6_rawmidi_substream_midi(substream)->line6;
 196
 197         if (up)
 198                 line6->line6midi->substream_receive = substream;
 199         else
 200                 line6->line6midi->substream_receive = NULL;
 201 }
 202
 203 static struct snd_rawmidi_ops line6_midi_output_ops = {
 204         .open = line6_midi_output_open,
 205         .close = line6_midi_output_close,
 206         .trigger = line6_midi_output_trigger,
 207         .drain = line6_midi_output_drain,
 208 };
 209
 210 static struct snd_rawmidi_ops line6_midi_input_ops = {
 211         .open = line6_midi_input_open,
 212         .close = line6_midi_input_close,
 213         .trigger = line6_midi_input_trigger,
 214 };
 215
 216 /* Create a MIDI device */
 217 static int snd_line6_new_midi(struct usb_line6 *line6,
 218                               struct snd_rawmidi **rmidi_ret)
 219 {
 220         struct snd_rawmidi *rmidi;
 221         int err;
 222
 223         err = snd_rawmidi_new(line6->card, "Line 6 MIDI", 0, 1, 1, rmidi_ret);
 224         if (err < 0)
 225                 return err;
 226
 227         rmidi = *rmidi_ret;
 228         strcpy(rmidi->id, line6->properties->id);
 229         strcpy(rmidi->name, line6->properties->name);
 230
 231         rmidi->info_flags =
 232             SNDRV_RAWMIDI_INFO_OUTPUT |
 233             SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
 234
 235         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 236                             &line6_midi_output_ops);
 237         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 238                             &line6_midi_input_ops);
 239         return 0;
 240 }
 241
 242 /* MIDI device destructor */
 243 static void snd_line6_midi_free(struct snd_rawmidi *rmidi)
 244 {
 245         struct snd_line6_midi *line6midi = rmidi->private_data;
 246
 247         line6_midibuf_destroy(&line6midi->midibuf_in);
 248         line6_midibuf_destroy(&line6midi->midibuf_out);
 249         kfree(line6midi);
 250 }
 251
 252 /*
 253         Initialize the Line 6 MIDI subsystem.
 254 */
 255 int line6_init_midi(struct usb_line6 *line6)
 256 {
 257         int err;
 258         struct snd_rawmidi *rmidi;
 259         struct snd_line6_midi *line6midi;
 260
 261         if (!(line6->properties->capabilities & LINE6_CAP_CONTROL)) {
 262                 /* skip MIDI initialization and report success */
 263                 return 0;
 264         }
 265
 266         err = snd_line6_new_midi(line6, &rmidi);
 267         if (err < 0)
 268                 return err;
 269
 270         line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL);
 271         if (!line6midi)
 272                 return -ENOMEM;
 273
 274         rmidi->private_data = line6midi;
 275         rmidi->private_free = snd_line6_midi_free;
 276
 277         init_waitqueue_head(&line6midi->send_wait);
 278         spin_lock_init(&line6midi->lock);
 279         line6midi->line6 = line6;
 280
 281         err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0);
 282         if (err < 0)
 283                 return err;
 284
 285         err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1);
 286         if (err < 0)
 287                 return err;
 288
 289         line6->line6midi = line6midi;
 290         return 0;
 291 }
 292 EXPORT_SYMBOL_GPL(line6_init_midi);