sound/pci/echoaudio/midi.c

   1 /****************************************************************************
   2
   3    Copyright Echo Digital Audio Corporation (c) 1998 - 2004
   4    All rights reserved
   5    www.echoaudio.com
   6
   7    This file is part of Echo Digital Audio's generic driver library.
   8
   9    Echo Digital Audio's generic driver library is free software;
  10    you can redistribute it and/or modify it under the terms of
  11    the GNU General Public License as published by the Free Software
  12    Foundation.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  22    MA  02111-1307, USA.
  23
  24    *************************************************************************
  25
  26  Translation from C++ and adaptation for use in ALSA-Driver
  27  were made by Giuliano Pochini <pochini@shiny.it>
  28
  29 ****************************************************************************/
  30
  31
  32 /******************************************************************************
  33         MIDI lowlevel code
  34 ******************************************************************************/
  35
  36 /* Start and stop Midi input */
  37 static int enable_midi_input(struct echoaudio *chip, char enable)
  38 {
  39         DE_MID(("enable_midi_input(%d)\n", enable));
  40
  41         if (wait_handshake(chip))
  42                 return -EIO;
  43
  44         if (enable) {
  45                 chip->mtc_state = MIDI_IN_STATE_NORMAL;
  46                 chip->comm_page->flags |=
  47                         cpu_to_le32(DSP_FLAG_MIDI_INPUT);
  48         } else
  49                 chip->comm_page->flags &=
  50                         ~cpu_to_le32(DSP_FLAG_MIDI_INPUT);
  51
  52         clear_handshake(chip);
  53         return send_vector(chip, DSP_VC_UPDATE_FLAGS);
  54 }
  55
  56
  57
  58 /* Send a buffer full of MIDI data to the DSP
  59 Returns how many actually written or < 0 on error */
  60 static int write_midi(struct echoaudio *chip, u8 *data, int bytes)
  61 {
  62         if (snd_BUG_ON(bytes <= 0 || bytes >= MIDI_OUT_BUFFER_SIZE))
  63                 return -EINVAL;
  64
  65         if (wait_handshake(chip))
  66                 return -EIO;
  67
  68         /* HF4 indicates that it is safe to write MIDI output data */
  69         if (! (get_dsp_register(chip, CHI32_STATUS_REG) & CHI32_STATUS_REG_HF4))
  70                 return 0;
  71
  72         chip->comm_page->midi_output[0] = bytes;
  73         memcpy(&chip->comm_page->midi_output[1], data, bytes);
  74         chip->comm_page->midi_out_free_count = 0;
  75         clear_handshake(chip);
  76         send_vector(chip, DSP_VC_MIDI_WRITE);
  77         DE_MID(("write_midi: %d\n", bytes));
  78         return bytes;
  79 }
  80
  81
  82
  83 /* Run the state machine for MIDI input data
  84 MIDI time code sync isn't supported by this code right now, but you still need
  85 this state machine to parse the incoming MIDI data stream.  Every time the DSP
  86 sees a 0xF1 byte come in, it adds the DSP sample position to the MIDI data
  87 stream. The DSP sample position is represented as a 32 bit unsigned value,
  88 with the high 16 bits first, followed by the low 16 bits. Since these aren't
  89 real MIDI bytes, the following logic is needed to skip them. */
  90 static inline int mtc_process_data(struct echoaudio *chip, short midi_byte)
  91 {
  92         switch (chip->mtc_state) {
  93         case MIDI_IN_STATE_NORMAL:
  94                 if (midi_byte == 0xF1)
  95                         chip->mtc_state = MIDI_IN_STATE_TS_HIGH;
  96                 break;
  97         case MIDI_IN_STATE_TS_HIGH:
  98                 chip->mtc_state = MIDI_IN_STATE_TS_LOW;
  99                 return MIDI_IN_SKIP_DATA;
 100                 break;
 101         case MIDI_IN_STATE_TS_LOW:
 102                 chip->mtc_state = MIDI_IN_STATE_F1_DATA;
 103                 return MIDI_IN_SKIP_DATA;
 104                 break;
 105         case MIDI_IN_STATE_F1_DATA:
 106                 chip->mtc_state = MIDI_IN_STATE_NORMAL;
 107                 break;
 108         }
 109         return 0;
 110 }
 111
 112
 113
 114 /* This function is called from the IRQ handler and it reads the midi data
 115 from the DSP's buffer.  It returns the number of bytes received. */
 116 static int midi_service_irq(struct echoaudio *chip)
 117 {
 118         short int count, midi_byte, i, received;
 119
 120         /* The count is at index 0, followed by actual data */
 121         count = le16_to_cpu(chip->comm_page->midi_input[0]);
 122
 123         if (snd_BUG_ON(count >= MIDI_IN_BUFFER_SIZE))
 124                 return 0;
 125
 126         /* Get the MIDI data from the comm page */
 127         i = 1;
 128         received = 0;
 129         for (i = 1; i <= count; i++) {
 130                 /* Get the MIDI byte */
 131                 midi_byte = le16_to_cpu(chip->comm_page->midi_input[i]);
 132
 133                 /* Parse the incoming MIDI stream. The incoming MIDI data
 134                 consists of MIDI bytes and timestamps for the MIDI time code
 135                 0xF1 bytes. mtc_process_data() is a little state machine that
 136                 parses the stream. If you get MIDI_IN_SKIP_DATA back, then
 137                 this is a timestamp byte, not a MIDI byte, so don't store it
 138                 in the MIDI input buffer. */
 139                 if (mtc_process_data(chip, midi_byte) == MIDI_IN_SKIP_DATA)
 140                         continue;
 141
 142                 chip->midi_buffer[received++] = (u8)midi_byte;
 143         }
 144
 145         return received;
 146 }
 147
 148
 149
 150
 151 /******************************************************************************
 152         MIDI interface
 153 ******************************************************************************/
 154
 155 static int snd_echo_midi_input_open(struct snd_rawmidi_substream *substream)
 156 {
 157         struct echoaudio *chip = substream->rmidi->private_data;
 158
 159         chip->midi_in = substream;
 160         DE_MID(("rawmidi_iopen\n"));
 161         return 0;
 162 }
 163
 164
 165
 166 static void snd_echo_midi_input_trigger(struct snd_rawmidi_substream *substream,
 167                                         int up)
 168 {
 169         struct echoaudio *chip = substream->rmidi->private_data;
 170
 171         if (up != chip->midi_input_enabled) {
 172                 spin_lock_irq(&chip->lock);
 173                 enable_midi_input(chip, up);
 174                 spin_unlock_irq(&chip->lock);
 175                 chip->midi_input_enabled = up;
 176         }
 177 }
 178
 179
 180
 181 static int snd_echo_midi_input_close(struct snd_rawmidi_substream *substream)
 182 {
 183         struct echoaudio *chip = substream->rmidi->private_data;
 184
 185         chip->midi_in = NULL;
 186         DE_MID(("rawmidi_iclose\n"));
 187         return 0;
 188 }
 189
 190
 191
 192 static int snd_echo_midi_output_open(struct snd_rawmidi_substream *substream)
 193 {
 194         struct echoaudio *chip = substream->rmidi->private_data;
 195
 196         chip->tinuse = 0;
 197         chip->midi_full = 0;
 198         chip->midi_out = substream;
 199         DE_MID(("rawmidi_oopen\n"));
 200         return 0;
 201 }
 202
 203
 204
 205 static void snd_echo_midi_output_write(unsigned long data)
 206 {
 207         struct echoaudio *chip = (struct echoaudio *)data;
 208         unsigned long flags;
 209         int bytes, sent, time;
 210         unsigned char buf[MIDI_OUT_BUFFER_SIZE - 1];
 211
 212         DE_MID(("snd_echo_midi_output_write\n"));
 213         /* No interrupts are involved: we have to check at regular intervals
 214         if the card's output buffer has room for new data. */
 215         sent = bytes = 0;
 216         spin_lock_irqsave(&chip->lock, flags);
 217         chip->midi_full = 0;
 218         if (!snd_rawmidi_transmit_empty(chip->midi_out)) {
 219                 bytes = snd_rawmidi_transmit_peek(chip->midi_out, buf,
 220                                                   MIDI_OUT_BUFFER_SIZE - 1);
 221                 DE_MID(("Try to send %d bytes...\n", bytes));
 222                 sent = write_midi(chip, buf, bytes);
 223                 if (sent < 0) {
 224                         snd_printk(KERN_ERR "write_midi() error %d\n", sent);
 225                         /* retry later */
 226                         sent = 9000;
 227                         chip->midi_full = 1;
 228                 } else if (sent > 0) {
 229                         DE_MID(("%d bytes sent\n", sent));
 230                         snd_rawmidi_transmit_ack(chip->midi_out, sent);
 231                 } else {
 232                         /* Buffer is full. DSP's internal buffer is 64 (128 ?)
 233                         bytes long. Let's wait until half of them are sent */
 234                         DE_MID(("Full\n"));
 235                         sent = 32;
 236                         chip->midi_full = 1;
 237                 }
 238         }
 239
 240         /* We restart the timer only if there is some data left to send */
 241         if (!snd_rawmidi_transmit_empty(chip->midi_out) && chip->tinuse) {
 242                 /* The timer will expire slightly after the data has been
 243                    sent */
 244                 time = (sent << 3) / 25 + 1;    /* 8/25=0.32ms to send a byte */
 245                 mod_timer(&chip->timer, jiffies + (time * HZ + 999) / 1000);
 246                 DE_MID(("Timer armed(%d)\n", ((time * HZ + 999) / 1000)));
 247         }
 248         spin_unlock_irqrestore(&chip->lock, flags);
 249 }
 250
 251
 252
 253 static void snd_echo_midi_output_trigger(struct snd_rawmidi_substream *substream,
 254                                          int up)
 255 {
 256         struct echoaudio *chip = substream->rmidi->private_data;
 257
 258         DE_MID(("snd_echo_midi_output_trigger(%d)\n", up));
 259         spin_lock_irq(&chip->lock);
 260         if (up) {
 261                 if (!chip->tinuse) {
 262                         init_timer(&chip->timer);
 263                         chip->timer.function = snd_echo_midi_output_write;
 264                         chip->timer.data = (unsigned long)chip;
 265                         chip->tinuse = 1;
 266                 }
 267         } else {
 268                 if (chip->tinuse) {
 269                         chip->tinuse = 0;
 270                         spin_unlock_irq(&chip->lock);
 271                         del_timer_sync(&chip->timer);
 272                         DE_MID(("Timer removed\n"));
 273                         return;
 274                 }
 275         }
 276         spin_unlock_irq(&chip->lock);
 277
 278         if (up && !chip->midi_full)
 279                 snd_echo_midi_output_write((unsigned long)chip);
 280 }
 281
 282
 283
 284 static int snd_echo_midi_output_close(struct snd_rawmidi_substream *substream)
 285 {
 286         struct echoaudio *chip = substream->rmidi->private_data;
 287
 288         chip->midi_out = NULL;
 289         DE_MID(("rawmidi_oclose\n"));
 290         return 0;
 291 }
 292
 293
 294
 295 static struct snd_rawmidi_ops snd_echo_midi_input = {
 296         .open = snd_echo_midi_input_open,
 297         .close = snd_echo_midi_input_close,
 298         .trigger = snd_echo_midi_input_trigger,
 299 };
 300
 301 static struct snd_rawmidi_ops snd_echo_midi_output = {
 302         .open = snd_echo_midi_output_open,
 303         .close = snd_echo_midi_output_close,
 304         .trigger = snd_echo_midi_output_trigger,
 305 };
 306
 307
 308
 309 /* <--snd_echo_probe() */
 310 static int __devinit snd_echo_midi_create(struct snd_card *card,
 311                                           struct echoaudio *chip)
 312 {
 313         int err;
 314
 315         if ((err = snd_rawmidi_new(card, card->shortname, 0, 1, 1,
 316                                    &chip->rmidi)) < 0)
 317                 return err;
 318
 319         strcpy(chip->rmidi->name, card->shortname);
 320         chip->rmidi->private_data = chip;
 321
 322         snd_rawmidi_set_ops(chip->rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 323                             &snd_echo_midi_input);
 324         snd_rawmidi_set_ops(chip->rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 325                             &snd_echo_midi_output);
 326
 327         chip->rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT |
 328                 SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
 329         DE_INIT(("MIDI ok\n"));
 330         return 0;
 331 }