emux_seq.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Midi Sequencer interface routines.
 *
 *  Copyright (C) 1999 Steve Ratcliffe
 *  Copyright (c) 1999-2000 Takashi Iwai <[email protected]>
 */

#include "emux_voice.h"
#include <linux/slab.h>
#include <linux/module.h>

/* Prototypes for static functions */
static void free_port(void *private);
static void snd_emux_init_port(struct snd_emux_port *p);
static int snd_emux_use(void *private_data, struct snd_seq_port_subscribe *info);
static int snd_emux_unuse(void *private_data, struct snd_seq_port_subscribe *info);

/*
 * MIDI emulation operators
 */
static const struct snd_midi_op emux_ops = {
	.note_on = snd_emux_note_on,
	.note_off = snd_emux_note_off,
	.key_press = snd_emux_key_press,
	.note_terminate = snd_emux_terminate_note,
	.control = snd_emux_control,
	.nrpn = snd_emux_nrpn,
	.sysex = snd_emux_sysex,
};


/*
 * number of MIDI channels
 */
#define MIDI_CHANNELS		16

/*
 * type flags for MIDI sequencer port
 */
#define DEFAULT_MIDI_TYPE	(SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |\
				 SNDRV_SEQ_PORT_TYPE_MIDI_GM |\
				 SNDRV_SEQ_PORT_TYPE_MIDI_GS |\
				 SNDRV_SEQ_PORT_TYPE_MIDI_XG |\
				 SNDRV_SEQ_PORT_TYPE_HARDWARE |\
				 SNDRV_SEQ_PORT_TYPE_SYNTHESIZER)

/*
 * Initialise the EMUX Synth by creating a client and registering
 * a series of ports.
 * Each of the ports will contain the 16 midi channels.  Applications
 * can connect to these ports to play midi data.
 */
int
snd_emux_init_seq(struct snd_emux *emu, struct snd_card *card, int index)
{
	int  i;
	struct snd_seq_port_callback pinfo;
	char tmpname[64];

	emu->client = snd_seq_create_kernel_client(card, index,
						   "%s WaveTable", emu->name);
	if (emu->client < 0) {
		dev_err(card->dev, "can't create client\n");
		return -ENODEV;
	}

	if (emu->num_ports <= 0) {
		dev_warn(card->dev, "seqports must be greater than zero\n");
		emu->num_ports = 1;
	} else if (emu->num_ports > SNDRV_EMUX_MAX_PORTS) {
		dev_warn(card->dev,
			 "too many ports. limited max. ports %d\n",
			 SNDRV_EMUX_MAX_PORTS);
		emu->num_ports = SNDRV_EMUX_MAX_PORTS;
	}

	memset(&pinfo, 0, sizeof(pinfo));
	pinfo.owner = THIS_MODULE;
	pinfo.use = snd_emux_use;
	pinfo.unuse = snd_emux_unuse;
	pinfo.event_input = snd_emux_event_input;

	for (i = 0; i < emu->num_ports; i++) {
		struct snd_emux_port *p;

		sprintf(tmpname, "%s Port %d", emu->name, i);
		p = snd_emux_create_port(emu, tmpname, MIDI_CHANNELS,
					 0, &pinfo);
		if (!p) {
			dev_err(card->dev, "can't create port\n");
			return -ENOMEM;
		}

		p->port_mode =  SNDRV_EMUX_PORT_MODE_MIDI;
		snd_emux_init_port(p);
		emu->ports[i] = p->chset.port;
		emu->portptrs[i] = p;
	}

	return 0;
}


/*
 * Detach from the ports that were set up for this synthesizer and
 * destroy the kernel client.
 */
void
snd_emux_detach_seq(struct snd_emux *emu)
{
	if (emu->voices)
		snd_emux_terminate_all(emu);
		
	if (emu->client >= 0) {
		snd_seq_delete_kernel_client(emu->client);
		emu->client = -1;
	}
}


/*
 * create a sequencer port and channel_set
 */

struct snd_emux_port *
snd_emux_create_port(struct snd_emux *emu, char *name,
		     int max_channels, int oss_port,
		     struct snd_seq_port_callback *callback)
{
	struct snd_emux_port *p;
	int i, type, cap;

	/* Allocate structures for this channel */
	p = kzalloc(sizeof(*p), GFP_KERNEL);
	if (!p)
		return NULL;

	p->chset.channels = kcalloc(max_channels, sizeof(*p->chset.channels),
				    GFP_KERNEL);
	if (!p->chset.channels) {
		kfree(p);
		return NULL;
	}
	for (i = 0; i < max_channels; i++)
		p->chset.channels[i].number = i;
	p->chset.private_data = p;
	p->chset.max_channels = max_channels;
	p->emu = emu;
	p->chset.client = emu->client;
#ifdef SNDRV_EMUX_USE_RAW_EFFECT
	snd_emux_create_effect(p);
#endif
	callback->private_free = free_port;
	callback->private_data = p;

	cap = SNDRV_SEQ_PORT_CAP_WRITE;
	if (oss_port) {
		type = SNDRV_SEQ_PORT_TYPE_SPECIFIC;
	} else {
		type = DEFAULT_MIDI_TYPE;
		cap |= SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
	}

	p->chset.port = snd_seq_event_port_attach(emu->client, callback,
						  cap, type, max_channels,
						  emu->max_voices, name);

	return p;
}


/*
 * release memory block for port
 */
static void
free_port(void *private_data)
{
	struct snd_emux_port *p;

	p = private_data;
	if (p) {
#ifdef SNDRV_EMUX_USE_RAW_EFFECT
		snd_emux_delete_effect(p);
#endif
		kfree(p->chset.channels);
		kfree(p);
	}
}


#define DEFAULT_DRUM_FLAGS	(1<<9)

/*
 * initialize the port specific parameters
 */
static void
snd_emux_init_port(struct snd_emux_port *p)
{
	p->drum_flags = DEFAULT_DRUM_FLAGS;
	p->volume_atten = 0;

	snd_emux_reset_port(p);
}


/*
 * reset port
 */
void
snd_emux_reset_port(struct snd_emux_port *port)
{
	int i;

	/* stop all sounds */
	snd_emux_sounds_off_all(port);

	snd_midi_channel_set_clear(&port->chset);

#ifdef SNDRV_EMUX_USE_RAW_EFFECT
	snd_emux_clear_effect(port);
#endif

	/* set port specific control parameters */
	port->ctrls[EMUX_MD_DEF_BANK] = 0;
	port->ctrls[EMUX_MD_DEF_DRUM] = 0;
	port->ctrls[EMUX_MD_REALTIME_PAN] = 1;

	for (i = 0; i < port->chset.max_channels; i++) {
		struct snd_midi_channel *chan = port->chset.channels + i;
		chan->drum_channel = ((port->drum_flags >> i) & 1) ? 1 : 0;
	}
}


/*
 * input sequencer event
 */
int
snd_emux_event_input(struct snd_seq_event *ev, int direct, void *private_data,
		     int atomic, int hop)
{
	struct snd_emux_port *port;

	port = private_data;
	if (snd_BUG_ON(!port || !ev))
		return -EINVAL;

	snd_midi_process_event(&emux_ops, ev, &port->chset);

	return 0;
}


/*
 * increment usage count
 */
static int
__snd_emux_inc_count(struct snd_emux *emu)
{
	emu->used++;
	if (!try_module_get(emu->ops.owner))
		goto __error;
	if (!try_module_get(emu->card->module)) {
		module_put(emu->ops.owner);
	      __error:
		emu->used--;
		return 0;
	}
	return 1;
}

int snd_emux_inc_count(struct snd_emux *emu)
{
	guard(mutex)(&emu->register_mutex);
	return __snd_emux_inc_count(emu);
}

/*
 * decrease usage count
 */
static void
__snd_emux_dec_count(struct snd_emux *emu)
{
	module_put(emu->card->module);
	emu->used--;
	if (emu->used <= 0)
		snd_emux_terminate_all(emu);
	module_put(emu->ops.owner);
}

void snd_emux_dec_count(struct snd_emux *emu)
{
	guard(mutex)(&emu->register_mutex);
	__snd_emux_dec_count(emu);
}

/*
 * Routine that is called upon a first use of a particular port
 */
static int
snd_emux_use(void *private_data, struct snd_seq_port_subscribe *info)
{
	struct snd_emux_port *p;
	struct snd_emux *emu;

	p = private_data;
	if (snd_BUG_ON(!p))
		return -EINVAL;
	emu = p->emu;
	if (snd_BUG_ON(!emu))
		return -EINVAL;

	guard(mutex)(&emu->register_mutex);
	snd_emux_init_port(p);
	__snd_emux_inc_count(emu);
	return 0;
}

/*
 * Routine that is called upon the last unuse() of a particular port.
 */
static int
snd_emux_unuse(void *private_data, struct snd_seq_port_subscribe *info)
{
	struct snd_emux_port *p;
	struct snd_emux *emu;

	p = private_data;
	if (snd_BUG_ON(!p))
		return -EINVAL;
	emu = p->emu;
	if (snd_BUG_ON(!emu))
		return -EINVAL;

	guard(mutex)(&emu->register_mutex);
	snd_emux_sounds_off_all(p);
	__snd_emux_dec_count(emu);
	return 0;
}


/*
 * attach virtual rawmidi devices
 */
int snd_emux_init_virmidi(struct snd_emux *emu, struct snd_card *card)
{
	int i;

	emu->vmidi = NULL;
	if (emu->midi_ports <= 0)
		return 0;

	emu->vmidi = kcalloc(emu->midi_ports, sizeof(*emu->vmidi), GFP_KERNEL);
	if (!emu->vmidi)
		return -ENOMEM;

	for (i = 0; i < emu->midi_ports; i++) {
		struct snd_rawmidi *rmidi;
		struct snd_virmidi_dev *rdev;
		if (snd_virmidi_new(card, emu->midi_devidx + i, &rmidi) < 0)
			goto __error;
		rdev = rmidi->private_data;
		sprintf(rmidi->name, "%s Synth MIDI", emu->name);
		rdev->seq_mode = SNDRV_VIRMIDI_SEQ_ATTACH;
		rdev->client = emu->client;
		rdev->port = emu->ports[i];
		if (snd_device_register(card, rmidi) < 0) {
			snd_device_free(card, rmidi);
			goto __error;
		}
		emu->vmidi[i] = rmidi;
	}
	return 0;

__error:
	snd_emux_delete_virmidi(emu);
	return -ENOMEM;
}

int snd_emux_delete_virmidi(struct snd_emux *emu)
{
	int i;

	if (!emu->vmidi)
		return 0;

	for (i = 0; i < emu->midi_ports; i++) {
		if (emu->vmidi[i])
			snd_device_free(emu->card, emu->vmidi[i]);
	}
	kfree(emu->vmidi);
	emu->vmidi = NULL;
	return 0;
}