// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Midi Sequencer interface routines.
 *
 *  Copyright (C) 1999 Steve Ratcliffe
 *  Copyright (c) 1999-2000 Takashi Iwai <tiwai@suse.de>
 */

#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_obj(*p);
        if (!p)
                return NULL;

        p->chset.channels = kzalloc_objs(*p->chset.channels, max_channels);
        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 = kzalloc_objs(*emu->vmidi, emu->midi_ports);
        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;
}