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459 lines
13 KiB
459 lines
13 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Generic MIDI synth driver for ALSA sequencer |
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* Copyright (c) 1998 by Frank van de Pol <[email protected]> |
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* Jaroslav Kysela <[email protected]> |
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*/ |
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|
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/* |
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Possible options for midisynth module: |
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- automatic opening of midi ports on first received event or subscription |
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(close will be performed when client leaves) |
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*/ |
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#include <linux/init.h> |
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#include <linux/slab.h> |
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#include <linux/errno.h> |
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#include <linux/string.h> |
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#include <linux/module.h> |
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#include <linux/mutex.h> |
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#include <sound/core.h> |
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#include <sound/rawmidi.h> |
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#include <sound/seq_kernel.h> |
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#include <sound/seq_device.h> |
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#include <sound/seq_midi_event.h> |
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#include <sound/initval.h> |
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MODULE_AUTHOR("Frank van de Pol <[email protected]>, Jaroslav Kysela <[email protected]>"); |
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MODULE_DESCRIPTION("Advanced Linux Sound Architecture sequencer MIDI synth."); |
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MODULE_LICENSE("GPL"); |
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static int output_buffer_size = PAGE_SIZE; |
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module_param(output_buffer_size, int, 0644); |
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MODULE_PARM_DESC(output_buffer_size, "Output buffer size in bytes."); |
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static int input_buffer_size = PAGE_SIZE; |
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module_param(input_buffer_size, int, 0644); |
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MODULE_PARM_DESC(input_buffer_size, "Input buffer size in bytes."); |
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|
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/* data for this midi synth driver */ |
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struct seq_midisynth { |
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struct snd_card *card; |
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int device; |
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int subdevice; |
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struct snd_rawmidi_file input_rfile; |
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struct snd_rawmidi_file output_rfile; |
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int seq_client; |
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int seq_port; |
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struct snd_midi_event *parser; |
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}; |
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struct seq_midisynth_client { |
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int seq_client; |
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int num_ports; |
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int ports_per_device[SNDRV_RAWMIDI_DEVICES]; |
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struct seq_midisynth *ports[SNDRV_RAWMIDI_DEVICES]; |
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}; |
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static struct seq_midisynth_client *synths[SNDRV_CARDS]; |
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static DEFINE_MUTEX(register_mutex); |
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/* handle rawmidi input event (MIDI v1.0 stream) */ |
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static void snd_midi_input_event(struct snd_rawmidi_substream *substream) |
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{ |
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struct snd_rawmidi_runtime *runtime; |
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struct seq_midisynth *msynth; |
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struct snd_seq_event ev; |
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char buf[16], *pbuf; |
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long res; |
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if (substream == NULL) |
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return; |
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runtime = substream->runtime; |
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msynth = runtime->private_data; |
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if (msynth == NULL) |
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return; |
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memset(&ev, 0, sizeof(ev)); |
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while (runtime->avail > 0) { |
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res = snd_rawmidi_kernel_read(substream, buf, sizeof(buf)); |
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if (res <= 0) |
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continue; |
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if (msynth->parser == NULL) |
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continue; |
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pbuf = buf; |
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while (res-- > 0) { |
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if (!snd_midi_event_encode_byte(msynth->parser, |
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*pbuf++, &ev)) |
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continue; |
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ev.source.port = msynth->seq_port; |
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ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS; |
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snd_seq_kernel_client_dispatch(msynth->seq_client, &ev, 1, 0); |
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/* clear event and reset header */ |
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memset(&ev, 0, sizeof(ev)); |
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} |
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} |
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} |
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static int dump_midi(struct snd_rawmidi_substream *substream, const char *buf, int count) |
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{ |
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struct snd_rawmidi_runtime *runtime; |
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int tmp; |
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if (snd_BUG_ON(!substream || !buf)) |
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return -EINVAL; |
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runtime = substream->runtime; |
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tmp = runtime->avail; |
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if (tmp < count) { |
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if (printk_ratelimit()) |
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pr_err("ALSA: seq_midi: MIDI output buffer overrun\n"); |
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return -ENOMEM; |
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} |
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if (snd_rawmidi_kernel_write(substream, buf, count) < count) |
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return -EINVAL; |
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return 0; |
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} |
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static int event_process_midi(struct snd_seq_event *ev, int direct, |
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void *private_data, int atomic, int hop) |
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{ |
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struct seq_midisynth *msynth = private_data; |
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unsigned char msg[10]; /* buffer for constructing midi messages */ |
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struct snd_rawmidi_substream *substream; |
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int len; |
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if (snd_BUG_ON(!msynth)) |
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return -EINVAL; |
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substream = msynth->output_rfile.output; |
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if (substream == NULL) |
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return -ENODEV; |
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if (ev->type == SNDRV_SEQ_EVENT_SYSEX) { /* special case, to save space */ |
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if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE) { |
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/* invalid event */ |
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pr_debug("ALSA: seq_midi: invalid sysex event flags = 0x%x\n", ev->flags); |
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return 0; |
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} |
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snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)dump_midi, substream); |
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snd_midi_event_reset_decode(msynth->parser); |
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} else { |
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if (msynth->parser == NULL) |
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return -EIO; |
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len = snd_midi_event_decode(msynth->parser, msg, sizeof(msg), ev); |
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if (len < 0) |
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return 0; |
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if (dump_midi(substream, msg, len) < 0) |
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snd_midi_event_reset_decode(msynth->parser); |
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} |
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return 0; |
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} |
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static int snd_seq_midisynth_new(struct seq_midisynth *msynth, |
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struct snd_card *card, |
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int device, |
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int subdevice) |
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{ |
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if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &msynth->parser) < 0) |
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return -ENOMEM; |
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msynth->card = card; |
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msynth->device = device; |
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msynth->subdevice = subdevice; |
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return 0; |
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} |
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/* open associated midi device for input */ |
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static int midisynth_subscribe(void *private_data, struct snd_seq_port_subscribe *info) |
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{ |
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int err; |
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struct seq_midisynth *msynth = private_data; |
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struct snd_rawmidi_runtime *runtime; |
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struct snd_rawmidi_params params; |
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/* open midi port */ |
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err = snd_rawmidi_kernel_open(msynth->card, msynth->device, |
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msynth->subdevice, |
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SNDRV_RAWMIDI_LFLG_INPUT, |
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&msynth->input_rfile); |
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if (err < 0) { |
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pr_debug("ALSA: seq_midi: midi input open failed!!!\n"); |
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return err; |
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} |
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runtime = msynth->input_rfile.input->runtime; |
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memset(¶ms, 0, sizeof(params)); |
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params.avail_min = 1; |
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params.buffer_size = input_buffer_size; |
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err = snd_rawmidi_input_params(msynth->input_rfile.input, ¶ms); |
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if (err < 0) { |
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snd_rawmidi_kernel_release(&msynth->input_rfile); |
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return err; |
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} |
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snd_midi_event_reset_encode(msynth->parser); |
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runtime->event = snd_midi_input_event; |
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runtime->private_data = msynth; |
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snd_rawmidi_kernel_read(msynth->input_rfile.input, NULL, 0); |
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return 0; |
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} |
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/* close associated midi device for input */ |
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static int midisynth_unsubscribe(void *private_data, struct snd_seq_port_subscribe *info) |
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{ |
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int err; |
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struct seq_midisynth *msynth = private_data; |
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if (snd_BUG_ON(!msynth->input_rfile.input)) |
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return -EINVAL; |
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err = snd_rawmidi_kernel_release(&msynth->input_rfile); |
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return err; |
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} |
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/* open associated midi device for output */ |
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static int midisynth_use(void *private_data, struct snd_seq_port_subscribe *info) |
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{ |
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int err; |
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struct seq_midisynth *msynth = private_data; |
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struct snd_rawmidi_params params; |
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/* open midi port */ |
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err = snd_rawmidi_kernel_open(msynth->card, msynth->device, |
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msynth->subdevice, |
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SNDRV_RAWMIDI_LFLG_OUTPUT, |
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&msynth->output_rfile); |
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if (err < 0) { |
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pr_debug("ALSA: seq_midi: midi output open failed!!!\n"); |
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return err; |
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} |
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memset(¶ms, 0, sizeof(params)); |
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params.avail_min = 1; |
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params.buffer_size = output_buffer_size; |
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params.no_active_sensing = 1; |
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err = snd_rawmidi_output_params(msynth->output_rfile.output, ¶ms); |
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if (err < 0) { |
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snd_rawmidi_kernel_release(&msynth->output_rfile); |
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return err; |
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} |
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snd_midi_event_reset_decode(msynth->parser); |
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return 0; |
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} |
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/* close associated midi device for output */ |
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static int midisynth_unuse(void *private_data, struct snd_seq_port_subscribe *info) |
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{ |
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struct seq_midisynth *msynth = private_data; |
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if (snd_BUG_ON(!msynth->output_rfile.output)) |
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return -EINVAL; |
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snd_rawmidi_drain_output(msynth->output_rfile.output); |
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return snd_rawmidi_kernel_release(&msynth->output_rfile); |
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} |
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/* delete given midi synth port */ |
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static void snd_seq_midisynth_delete(struct seq_midisynth *msynth) |
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{ |
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if (msynth == NULL) |
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return; |
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if (msynth->seq_client > 0) { |
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/* delete port */ |
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snd_seq_event_port_detach(msynth->seq_client, msynth->seq_port); |
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} |
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snd_midi_event_free(msynth->parser); |
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} |
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/* register new midi synth port */ |
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static int |
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snd_seq_midisynth_probe(struct device *_dev) |
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{ |
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struct snd_seq_device *dev = to_seq_dev(_dev); |
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struct seq_midisynth_client *client; |
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struct seq_midisynth *msynth, *ms; |
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struct snd_seq_port_info *port; |
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struct snd_rawmidi_info *info; |
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struct snd_rawmidi *rmidi = dev->private_data; |
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int newclient = 0; |
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unsigned int p, ports; |
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struct snd_seq_port_callback pcallbacks; |
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struct snd_card *card = dev->card; |
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int device = dev->device; |
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unsigned int input_count = 0, output_count = 0; |
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if (snd_BUG_ON(!card || device < 0 || device >= SNDRV_RAWMIDI_DEVICES)) |
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return -EINVAL; |
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info = kmalloc(sizeof(*info), GFP_KERNEL); |
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if (! info) |
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return -ENOMEM; |
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info->device = device; |
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info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT; |
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info->subdevice = 0; |
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if (snd_rawmidi_info_select(card, info) >= 0) |
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output_count = info->subdevices_count; |
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info->stream = SNDRV_RAWMIDI_STREAM_INPUT; |
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if (snd_rawmidi_info_select(card, info) >= 0) { |
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input_count = info->subdevices_count; |
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} |
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ports = output_count; |
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if (ports < input_count) |
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ports = input_count; |
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if (ports == 0) { |
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kfree(info); |
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return -ENODEV; |
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} |
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if (ports > (256 / SNDRV_RAWMIDI_DEVICES)) |
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ports = 256 / SNDRV_RAWMIDI_DEVICES; |
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mutex_lock(®ister_mutex); |
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client = synths[card->number]; |
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if (client == NULL) { |
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newclient = 1; |
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client = kzalloc(sizeof(*client), GFP_KERNEL); |
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if (client == NULL) { |
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mutex_unlock(®ister_mutex); |
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kfree(info); |
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return -ENOMEM; |
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} |
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client->seq_client = |
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snd_seq_create_kernel_client( |
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card, 0, "%s", card->shortname[0] ? |
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(const char *)card->shortname : "External MIDI"); |
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if (client->seq_client < 0) { |
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kfree(client); |
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mutex_unlock(®ister_mutex); |
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kfree(info); |
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return -ENOMEM; |
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} |
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} |
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msynth = kcalloc(ports, sizeof(struct seq_midisynth), GFP_KERNEL); |
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port = kmalloc(sizeof(*port), GFP_KERNEL); |
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if (msynth == NULL || port == NULL) |
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goto __nomem; |
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for (p = 0; p < ports; p++) { |
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ms = &msynth[p]; |
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if (snd_seq_midisynth_new(ms, card, device, p) < 0) |
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goto __nomem; |
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/* declare port */ |
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memset(port, 0, sizeof(*port)); |
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port->addr.client = client->seq_client; |
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port->addr.port = device * (256 / SNDRV_RAWMIDI_DEVICES) + p; |
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port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT; |
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memset(info, 0, sizeof(*info)); |
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info->device = device; |
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if (p < output_count) |
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info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT; |
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else |
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info->stream = SNDRV_RAWMIDI_STREAM_INPUT; |
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info->subdevice = p; |
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if (snd_rawmidi_info_select(card, info) >= 0) |
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strcpy(port->name, info->subname); |
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if (! port->name[0]) { |
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if (info->name[0]) { |
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if (ports > 1) |
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snprintf(port->name, sizeof(port->name), "%s-%u", info->name, p); |
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else |
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snprintf(port->name, sizeof(port->name), "%s", info->name); |
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} else { |
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/* last resort */ |
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if (ports > 1) |
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sprintf(port->name, "MIDI %d-%d-%u", card->number, device, p); |
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else |
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sprintf(port->name, "MIDI %d-%d", card->number, device); |
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} |
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} |
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if ((info->flags & SNDRV_RAWMIDI_INFO_OUTPUT) && p < output_count) |
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port->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE; |
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if ((info->flags & SNDRV_RAWMIDI_INFO_INPUT) && p < input_count) |
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port->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ; |
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if ((port->capability & (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ)) == (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ) && |
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info->flags & SNDRV_RAWMIDI_INFO_DUPLEX) |
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port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX; |
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port->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |
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| SNDRV_SEQ_PORT_TYPE_HARDWARE |
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| SNDRV_SEQ_PORT_TYPE_PORT; |
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port->midi_channels = 16; |
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memset(&pcallbacks, 0, sizeof(pcallbacks)); |
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pcallbacks.owner = THIS_MODULE; |
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pcallbacks.private_data = ms; |
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pcallbacks.subscribe = midisynth_subscribe; |
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pcallbacks.unsubscribe = midisynth_unsubscribe; |
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pcallbacks.use = midisynth_use; |
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pcallbacks.unuse = midisynth_unuse; |
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pcallbacks.event_input = event_process_midi; |
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port->kernel = &pcallbacks; |
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if (rmidi->ops && rmidi->ops->get_port_info) |
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rmidi->ops->get_port_info(rmidi, p, port); |
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if (snd_seq_kernel_client_ctl(client->seq_client, SNDRV_SEQ_IOCTL_CREATE_PORT, port)<0) |
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goto __nomem; |
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ms->seq_client = client->seq_client; |
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ms->seq_port = port->addr.port; |
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} |
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client->ports_per_device[device] = ports; |
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client->ports[device] = msynth; |
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client->num_ports++; |
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if (newclient) |
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synths[card->number] = client; |
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mutex_unlock(®ister_mutex); |
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kfree(info); |
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kfree(port); |
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return 0; /* success */ |
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__nomem: |
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if (msynth != NULL) { |
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for (p = 0; p < ports; p++) |
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snd_seq_midisynth_delete(&msynth[p]); |
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kfree(msynth); |
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} |
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if (newclient) { |
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snd_seq_delete_kernel_client(client->seq_client); |
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kfree(client); |
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} |
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kfree(info); |
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kfree(port); |
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mutex_unlock(®ister_mutex); |
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return -ENOMEM; |
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} |
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/* release midi synth port */ |
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static int |
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snd_seq_midisynth_remove(struct device *_dev) |
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{ |
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struct snd_seq_device *dev = to_seq_dev(_dev); |
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struct seq_midisynth_client *client; |
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struct seq_midisynth *msynth; |
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struct snd_card *card = dev->card; |
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int device = dev->device, p, ports; |
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mutex_lock(®ister_mutex); |
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client = synths[card->number]; |
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if (client == NULL || client->ports[device] == NULL) { |
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mutex_unlock(®ister_mutex); |
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return -ENODEV; |
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} |
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ports = client->ports_per_device[device]; |
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client->ports_per_device[device] = 0; |
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msynth = client->ports[device]; |
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client->ports[device] = NULL; |
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for (p = 0; p < ports; p++) |
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snd_seq_midisynth_delete(&msynth[p]); |
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kfree(msynth); |
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client->num_ports--; |
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if (client->num_ports <= 0) { |
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snd_seq_delete_kernel_client(client->seq_client); |
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synths[card->number] = NULL; |
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kfree(client); |
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} |
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mutex_unlock(®ister_mutex); |
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return 0; |
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} |
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static struct snd_seq_driver seq_midisynth_driver = { |
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.driver = { |
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.name = KBUILD_MODNAME, |
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.probe = snd_seq_midisynth_probe, |
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.remove = snd_seq_midisynth_remove, |
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}, |
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.id = SNDRV_SEQ_DEV_ID_MIDISYNTH, |
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.argsize = 0, |
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}; |
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module_snd_seq_driver(seq_midisynth_driver);
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