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1/****************************************************************************2 3 Copyright Echo Digital Audio Corporation (c) 1998 - 20044 All rights reserved5 www.echoaudio.com6 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 of11 the GNU General Public License as published by the Free Software12 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 of16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the17 GNU General Public License for more details.18 19 You should have received a copy of the GNU General Public License20 along with this program; if not, write to the Free Software21 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-Driver27 were made by Giuliano Pochini <pochini@shiny.it>28 29****************************************************************************/30 31 32/******************************************************************************33 MIDI lowlevel code34******************************************************************************/35 36/* Start and stop Midi input */37static int enable_midi_input(struct echoaudio *chip, char enable)38{39 dev_dbg(chip->card->dev, "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 } else49 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 DSP59Returns how many actually written or < 0 on error */60static 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 dev_dbg(chip->card->dev, "write_midi: %d\n", bytes);78 return bytes;79}80 81 82 83/* Run the state machine for MIDI input data84MIDI time code sync isn't supported by this code right now, but you still need85this state machine to parse the incoming MIDI data stream. Every time the DSP86sees a 0xF1 byte come in, it adds the DSP sample position to the MIDI data87stream. The DSP sample position is represented as a 32 bit unsigned value,88with the high 16 bits first, followed by the low 16 bits. Since these aren't89real MIDI bytes, the following logic is needed to skip them. */90static 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 data115from the DSP's buffer. It returns the number of bytes received. */116static 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 received = 0;128 for (i = 1; i <= count; i++) {129 /* Get the MIDI byte */130 midi_byte = le16_to_cpu(chip->comm_page->midi_input[i]);131 132 /* Parse the incoming MIDI stream. The incoming MIDI data133 consists of MIDI bytes and timestamps for the MIDI time code134 0xF1 bytes. mtc_process_data() is a little state machine that135 parses the stream. If you get MIDI_IN_SKIP_DATA back, then136 this is a timestamp byte, not a MIDI byte, so don't store it137 in the MIDI input buffer. */138 if (mtc_process_data(chip, midi_byte) == MIDI_IN_SKIP_DATA)139 continue;140 141 chip->midi_buffer[received++] = (u8)midi_byte;142 }143 144 return received;145}146 147 148 149 150/******************************************************************************151 MIDI interface152******************************************************************************/153 154static int snd_echo_midi_input_open(struct snd_rawmidi_substream *substream)155{156 struct echoaudio *chip = substream->rmidi->private_data;157 158 chip->midi_in = substream;159 return 0;160}161 162 163 164static void snd_echo_midi_input_trigger(struct snd_rawmidi_substream *substream,165 int up)166{167 struct echoaudio *chip = substream->rmidi->private_data;168 169 if (up != chip->midi_input_enabled) {170 spin_lock_irq(&chip->lock);171 enable_midi_input(chip, up);172 spin_unlock_irq(&chip->lock);173 chip->midi_input_enabled = up;174 }175}176 177 178 179static int snd_echo_midi_input_close(struct snd_rawmidi_substream *substream)180{181 struct echoaudio *chip = substream->rmidi->private_data;182 183 chip->midi_in = NULL;184 return 0;185}186 187 188 189static int snd_echo_midi_output_open(struct snd_rawmidi_substream *substream)190{191 struct echoaudio *chip = substream->rmidi->private_data;192 193 chip->tinuse = 0;194 chip->midi_full = 0;195 chip->midi_out = substream;196 return 0;197}198 199 200 201static void snd_echo_midi_output_write(struct timer_list *t)202{203 struct echoaudio *chip = from_timer(chip, t, timer);204 unsigned long flags;205 int bytes, sent, time;206 unsigned char buf[MIDI_OUT_BUFFER_SIZE - 1];207 208 /* No interrupts are involved: we have to check at regular intervals209 if the card's output buffer has room for new data. */210 sent = 0;211 spin_lock_irqsave(&chip->lock, flags);212 chip->midi_full = 0;213 if (!snd_rawmidi_transmit_empty(chip->midi_out)) {214 bytes = snd_rawmidi_transmit_peek(chip->midi_out, buf,215 MIDI_OUT_BUFFER_SIZE - 1);216 dev_dbg(chip->card->dev, "Try to send %d bytes...\n", bytes);217 sent = write_midi(chip, buf, bytes);218 if (sent < 0) {219 dev_err(chip->card->dev,220 "write_midi() error %d\n", sent);221 /* retry later */222 sent = 9000;223 chip->midi_full = 1;224 } else if (sent > 0) {225 dev_dbg(chip->card->dev, "%d bytes sent\n", sent);226 snd_rawmidi_transmit_ack(chip->midi_out, sent);227 } else {228 /* Buffer is full. DSP's internal buffer is 64 (128 ?)229 bytes long. Let's wait until half of them are sent */230 dev_dbg(chip->card->dev, "Full\n");231 sent = 32;232 chip->midi_full = 1;233 }234 }235 236 /* We restart the timer only if there is some data left to send */237 if (!snd_rawmidi_transmit_empty(chip->midi_out) && chip->tinuse) {238 /* The timer will expire slightly after the data has been239 sent */240 time = (sent << 3) / 25 + 1; /* 8/25=0.32ms to send a byte */241 mod_timer(&chip->timer, jiffies + (time * HZ + 999) / 1000);242 dev_dbg(chip->card->dev,243 "Timer armed(%d)\n", ((time * HZ + 999) / 1000));244 }245 spin_unlock_irqrestore(&chip->lock, flags);246}247 248 249 250static void snd_echo_midi_output_trigger(struct snd_rawmidi_substream *substream,251 int up)252{253 struct echoaudio *chip = substream->rmidi->private_data;254 255 dev_dbg(chip->card->dev, "snd_echo_midi_output_trigger(%d)\n", up);256 spin_lock_irq(&chip->lock);257 if (up) {258 if (!chip->tinuse) {259 timer_setup(&chip->timer, snd_echo_midi_output_write,260 0);261 chip->tinuse = 1;262 }263 } else {264 if (chip->tinuse) {265 chip->tinuse = 0;266 spin_unlock_irq(&chip->lock);267 del_timer_sync(&chip->timer);268 dev_dbg(chip->card->dev, "Timer removed\n");269 return;270 }271 }272 spin_unlock_irq(&chip->lock);273 274 if (up && !chip->midi_full)275 snd_echo_midi_output_write(&chip->timer);276}277 278 279 280static int snd_echo_midi_output_close(struct snd_rawmidi_substream *substream)281{282 struct echoaudio *chip = substream->rmidi->private_data;283 284 chip->midi_out = NULL;285 return 0;286}287 288 289 290static const struct snd_rawmidi_ops snd_echo_midi_input = {291 .open = snd_echo_midi_input_open,292 .close = snd_echo_midi_input_close,293 .trigger = snd_echo_midi_input_trigger,294};295 296static const struct snd_rawmidi_ops snd_echo_midi_output = {297 .open = snd_echo_midi_output_open,298 .close = snd_echo_midi_output_close,299 .trigger = snd_echo_midi_output_trigger,300};301 302 303 304/* <--snd_echo_probe() */305static int snd_echo_midi_create(struct snd_card *card,306 struct echoaudio *chip)307{308 int err;309 310 err = snd_rawmidi_new(card, card->shortname, 0, 1, 1, &chip->rmidi);311 if (err < 0)312 return err;313 314 strcpy(chip->rmidi->name, card->shortname);315 chip->rmidi->private_data = chip;316 317 snd_rawmidi_set_ops(chip->rmidi, SNDRV_RAWMIDI_STREAM_INPUT,318 &snd_echo_midi_input);319 snd_rawmidi_set_ops(chip->rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,320 &snd_echo_midi_output);321 322 chip->rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT |323 SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;324 return 0;325}326