diff options
Diffstat (limited to 'kernel/sound/pci/echoaudio/midi.c')
| -rw-r--r-- | kernel/sound/pci/echoaudio/midi.c | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/kernel/sound/pci/echoaudio/midi.c b/kernel/sound/pci/echoaudio/midi.c new file mode 100644 index 000000000..a8fe58335 --- /dev/null +++ b/kernel/sound/pci/echoaudio/midi.c @@ -0,0 +1,326 @@ +/**************************************************************************** + + Copyright Echo Digital Audio Corporation (c) 1998 - 2004 + All rights reserved + www.echoaudio.com + + This file is part of Echo Digital Audio's generic driver library. + + Echo Digital Audio's generic driver library is free software; + you can redistribute it and/or modify it under the terms of + the GNU General Public License as published by the Free Software + Foundation. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, + MA 02111-1307, USA. + + ************************************************************************* + + Translation from C++ and adaptation for use in ALSA-Driver + were made by Giuliano Pochini <pochini@shiny.it> + +****************************************************************************/ + + +/****************************************************************************** + MIDI lowlevel code +******************************************************************************/ + +/* Start and stop Midi input */ +static int enable_midi_input(struct echoaudio *chip, char enable) +{ + dev_dbg(chip->card->dev, "enable_midi_input(%d)\n", enable); + + if (wait_handshake(chip)) + return -EIO; + + if (enable) { + chip->mtc_state = MIDI_IN_STATE_NORMAL; + chip->comm_page->flags |= + cpu_to_le32(DSP_FLAG_MIDI_INPUT); + } else + chip->comm_page->flags &= + ~cpu_to_le32(DSP_FLAG_MIDI_INPUT); + + clear_handshake(chip); + return send_vector(chip, DSP_VC_UPDATE_FLAGS); +} + + + +/* Send a buffer full of MIDI data to the DSP +Returns how many actually written or < 0 on error */ +static int write_midi(struct echoaudio *chip, u8 *data, int bytes) +{ + if (snd_BUG_ON(bytes <= 0 || bytes >= MIDI_OUT_BUFFER_SIZE)) + return -EINVAL; + + if (wait_handshake(chip)) + return -EIO; + + /* HF4 indicates that it is safe to write MIDI output data */ + if (! (get_dsp_register(chip, CHI32_STATUS_REG) & CHI32_STATUS_REG_HF4)) + return 0; + + chip->comm_page->midi_output[0] = bytes; + memcpy(&chip->comm_page->midi_output[1], data, bytes); + chip->comm_page->midi_out_free_count = 0; + clear_handshake(chip); + send_vector(chip, DSP_VC_MIDI_WRITE); + dev_dbg(chip->card->dev, "write_midi: %d\n", bytes); + return bytes; +} + + + +/* Run the state machine for MIDI input data +MIDI time code sync isn't supported by this code right now, but you still need +this state machine to parse the incoming MIDI data stream. Every time the DSP +sees a 0xF1 byte come in, it adds the DSP sample position to the MIDI data +stream. The DSP sample position is represented as a 32 bit unsigned value, +with the high 16 bits first, followed by the low 16 bits. Since these aren't +real MIDI bytes, the following logic is needed to skip them. */ +static inline int mtc_process_data(struct echoaudio *chip, short midi_byte) +{ + switch (chip->mtc_state) { + case MIDI_IN_STATE_NORMAL: + if (midi_byte == 0xF1) + chip->mtc_state = MIDI_IN_STATE_TS_HIGH; + break; + case MIDI_IN_STATE_TS_HIGH: + chip->mtc_state = MIDI_IN_STATE_TS_LOW; + return MIDI_IN_SKIP_DATA; + break; + case MIDI_IN_STATE_TS_LOW: + chip->mtc_state = MIDI_IN_STATE_F1_DATA; + return MIDI_IN_SKIP_DATA; + break; + case MIDI_IN_STATE_F1_DATA: + chip->mtc_state = MIDI_IN_STATE_NORMAL; + break; + } + return 0; +} + + + +/* This function is called from the IRQ handler and it reads the midi data +from the DSP's buffer. It returns the number of bytes received. */ +static int midi_service_irq(struct echoaudio *chip) +{ + short int count, midi_byte, i, received; + + /* The count is at index 0, followed by actual data */ + count = le16_to_cpu(chip->comm_page->midi_input[0]); + + if (snd_BUG_ON(count >= MIDI_IN_BUFFER_SIZE)) + return 0; + + /* Get the MIDI data from the comm page */ + i = 1; + received = 0; + for (i = 1; i <= count; i++) { + /* Get the MIDI byte */ + midi_byte = le16_to_cpu(chip->comm_page->midi_input[i]); + + /* Parse the incoming MIDI stream. The incoming MIDI data + consists of MIDI bytes and timestamps for the MIDI time code + 0xF1 bytes. mtc_process_data() is a little state machine that + parses the stream. If you get MIDI_IN_SKIP_DATA back, then + this is a timestamp byte, not a MIDI byte, so don't store it + in the MIDI input buffer. */ + if (mtc_process_data(chip, midi_byte) == MIDI_IN_SKIP_DATA) + continue; + + chip->midi_buffer[received++] = (u8)midi_byte; + } + + return received; +} + + + + +/****************************************************************************** + MIDI interface +******************************************************************************/ + +static int snd_echo_midi_input_open(struct snd_rawmidi_substream *substream) +{ + struct echoaudio *chip = substream->rmidi->private_data; + + chip->midi_in = substream; + return 0; +} + + + +static void snd_echo_midi_input_trigger(struct snd_rawmidi_substream *substream, + int up) +{ + struct echoaudio *chip = substream->rmidi->private_data; + + if (up != chip->midi_input_enabled) { + spin_lock_irq(&chip->lock); + enable_midi_input(chip, up); + spin_unlock_irq(&chip->lock); + chip->midi_input_enabled = up; + } +} + + + +static int snd_echo_midi_input_close(struct snd_rawmidi_substream *substream) +{ + struct echoaudio *chip = substream->rmidi->private_data; + + chip->midi_in = NULL; + return 0; +} + + + +static int snd_echo_midi_output_open(struct snd_rawmidi_substream *substream) +{ + struct echoaudio *chip = substream->rmidi->private_data; + + chip->tinuse = 0; + chip->midi_full = 0; + chip->midi_out = substream; + return 0; +} + + + +static void snd_echo_midi_output_write(unsigned long data) +{ + struct echoaudio *chip = (struct echoaudio *)data; + unsigned long flags; + int bytes, sent, time; + unsigned char buf[MIDI_OUT_BUFFER_SIZE - 1]; + + /* No interrupts are involved: we have to check at regular intervals + if the card's output buffer has room for new data. */ + sent = bytes = 0; + spin_lock_irqsave(&chip->lock, flags); + chip->midi_full = 0; + if (!snd_rawmidi_transmit_empty(chip->midi_out)) { + bytes = snd_rawmidi_transmit_peek(chip->midi_out, buf, + MIDI_OUT_BUFFER_SIZE - 1); + dev_dbg(chip->card->dev, "Try to send %d bytes...\n", bytes); + sent = write_midi(chip, buf, bytes); + if (sent < 0) { + dev_err(chip->card->dev, + "write_midi() error %d\n", sent); + /* retry later */ + sent = 9000; + chip->midi_full = 1; + } else if (sent > 0) { + dev_dbg(chip->card->dev, "%d bytes sent\n", sent); + snd_rawmidi_transmit_ack(chip->midi_out, sent); + } else { + /* Buffer is full. DSP's internal buffer is 64 (128 ?) + bytes long. Let's wait until half of them are sent */ + dev_dbg(chip->card->dev, "Full\n"); + sent = 32; + chip->midi_full = 1; + } + } + + /* We restart the timer only if there is some data left to send */ + if (!snd_rawmidi_transmit_empty(chip->midi_out) && chip->tinuse) { + /* The timer will expire slightly after the data has been + sent */ + time = (sent << 3) / 25 + 1; /* 8/25=0.32ms to send a byte */ + mod_timer(&chip->timer, jiffies + (time * HZ + 999) / 1000); + dev_dbg(chip->card->dev, + "Timer armed(%d)\n", ((time * HZ + 999) / 1000)); + } + spin_unlock_irqrestore(&chip->lock, flags); +} + + + +static void snd_echo_midi_output_trigger(struct snd_rawmidi_substream *substream, + int up) +{ + struct echoaudio *chip = substream->rmidi->private_data; + + dev_dbg(chip->card->dev, "snd_echo_midi_output_trigger(%d)\n", up); + spin_lock_irq(&chip->lock); + if (up) { + if (!chip->tinuse) { + setup_timer(&chip->timer, snd_echo_midi_output_write, + (unsigned long)chip); + chip->tinuse = 1; + } + } else { + if (chip->tinuse) { + chip->tinuse = 0; + spin_unlock_irq(&chip->lock); + del_timer_sync(&chip->timer); + dev_dbg(chip->card->dev, "Timer removed\n"); + return; + } + } + spin_unlock_irq(&chip->lock); + + if (up && !chip->midi_full) + snd_echo_midi_output_write((unsigned long)chip); +} + + + +static int snd_echo_midi_output_close(struct snd_rawmidi_substream *substream) +{ + struct echoaudio *chip = substream->rmidi->private_data; + + chip->midi_out = NULL; + return 0; +} + + + +static struct snd_rawmidi_ops snd_echo_midi_input = { + .open = snd_echo_midi_input_open, + .close = snd_echo_midi_input_close, + .trigger = snd_echo_midi_input_trigger, +}; + +static struct snd_rawmidi_ops snd_echo_midi_output = { + .open = snd_echo_midi_output_open, + .close = snd_echo_midi_output_close, + .trigger = snd_echo_midi_output_trigger, +}; + + + +/* <--snd_echo_probe() */ +static int snd_echo_midi_create(struct snd_card *card, + struct echoaudio *chip) +{ + int err; + + if ((err = snd_rawmidi_new(card, card->shortname, 0, 1, 1, + &chip->rmidi)) < 0) + return err; + + strcpy(chip->rmidi->name, card->shortname); + chip->rmidi->private_data = chip; + + snd_rawmidi_set_ops(chip->rmidi, SNDRV_RAWMIDI_STREAM_INPUT, + &snd_echo_midi_input); + snd_rawmidi_set_ops(chip->rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, + &snd_echo_midi_output); + + chip->rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT | + SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX; + return 0; +} |