/*
 * tascam.c - a part of driver for TASCAM FireWire series
 *
 * Copyright (c) 2015 Takashi Sakamoto
 *
 * Licensed under the terms of the GNU General Public License, version 2.
 */

#include "tascam.h"

MODULE_DESCRIPTION("TASCAM FireWire series Driver");
MODULE_AUTHOR("Takashi Sakamoto <o-takashi@sakamocchi.jp>");
MODULE_LICENSE("GPL v2");

static struct snd_tscm_spec model_specs[] = {
        {
                .name = "FW-1884",
                .has_adat = true,
                .has_spdif = true,
                .pcm_capture_analog_channels = 8,
                .pcm_playback_analog_channels = 8,
                .midi_capture_ports = 4,
                .midi_playback_ports = 4,
        },
        {
                .name = "FW-1082",
                .has_adat = false,
                .has_spdif = true,
                .pcm_capture_analog_channels = 8,
                .pcm_playback_analog_channels = 2,
                .midi_capture_ports = 2,
                .midi_playback_ports = 2,
        },
        {
                .name = "FW-1804",
                .has_adat = true,
                .has_spdif = true,
                .pcm_capture_analog_channels = 8,
                .pcm_playback_analog_channels = 2,
                .midi_capture_ports = 2,
                .midi_playback_ports = 4,
        },
};

static int identify_model(struct snd_tscm *tscm)
{
        struct fw_device *fw_dev = fw_parent_device(tscm->unit);
        const u32 *config_rom = fw_dev->config_rom;
        char model[9];
        unsigned int i;
        u8 c;

        if (fw_dev->config_rom_length < 30) {
                dev_err(&tscm->unit->device,
                        "Configuration ROM is too short.\n");
                return -ENODEV;
        }

        /* Pick up model name from certain addresses. */
        for (i = 0; i < 8; i++) {
                c = config_rom[28 + i / 4] >> (24 - 8 * (i % 4));
                if (c == '\0')
                        break;
                model[i] = c;
        }
        model[i] = '\0';

        for (i = 0; i < ARRAY_SIZE(model_specs); i++) {
                if (strcmp(model, model_specs[i].name) == 0) {
                        tscm->spec = &model_specs[i];
                        break;
                }
        }
        if (tscm->spec == NULL)
                return -ENODEV;

        strcpy(tscm->card->driver, "FW-TASCAM");
        strcpy(tscm->card->shortname, model);
        strcpy(tscm->card->mixername, model);
        snprintf(tscm->card->longname, sizeof(tscm->card->longname),
                 "TASCAM %s, GUID %08x%08x at %s, S%d", model,
                 fw_dev->config_rom[3], fw_dev->config_rom[4],
                 dev_name(&tscm->unit->device), 100 << fw_dev->max_speed);

        return 0;
}

static void tscm_free(struct snd_tscm *tscm)
{
        snd_tscm_transaction_unregister(tscm);
        snd_tscm_stream_destroy_duplex(tscm);

        fw_unit_put(tscm->unit);

        mutex_destroy(&tscm->mutex);
}

static void tscm_card_free(struct snd_card *card)
{
        tscm_free(card->private_data);
}

static void do_registration(struct work_struct *work)
{
        struct snd_tscm *tscm = container_of(work, struct snd_tscm, dwork.work);
        int err;

        err = snd_card_new(&tscm->unit->device, -1, NULL, THIS_MODULE, 0,
                           &tscm->card);
        if (err < 0)
                return;

        err = identify_model(tscm);
        if (err < 0)
                goto error;

        err = snd_tscm_transaction_register(tscm);
        if (err < 0)
                goto error;

        err = snd_tscm_stream_init_duplex(tscm);
        if (err < 0)
                goto error;

        snd_tscm_proc_init(tscm);

        err = snd_tscm_create_pcm_devices(tscm);
        if (err < 0)
                goto error;

        err = snd_tscm_create_midi_devices(tscm);
        if (err < 0)
                goto error;

        err = snd_tscm_create_hwdep_device(tscm);
        if (err < 0)
                goto error;

        err = snd_card_register(tscm->card);
        if (err < 0)
                goto error;

        /*
         * After registered, tscm instance can be released corresponding to
         * releasing the sound card instance.
         */
        tscm->card->private_free = tscm_card_free;
        tscm->card->private_data = tscm;
        tscm->registered = true;

        return;
error:
        snd_tscm_transaction_unregister(tscm);
        snd_tscm_stream_destroy_duplex(tscm);
        snd_card_free(tscm->card);
        dev_info(&tscm->unit->device,
                 "Sound card registration failed: %d\n", err);
}

static int snd_tscm_probe(struct fw_unit *unit,
                           const struct ieee1394_device_id *entry)
{
        struct snd_tscm *tscm;

        /* Allocate this independent of sound card instance. */
        tscm = kzalloc(sizeof(struct snd_tscm), GFP_KERNEL);
        if (tscm == NULL)
                return -ENOMEM;

        /* initialize myself */
        tscm->unit = fw_unit_get(unit);
        dev_set_drvdata(&unit->device, tscm);

        mutex_init(&tscm->mutex);
        spin_lock_init(&tscm->lock);
        init_waitqueue_head(&tscm->hwdep_wait);

        /* Allocate and register this sound card later. */
        INIT_DEFERRABLE_WORK(&tscm->dwork, do_registration);
        snd_fw_schedule_registration(unit, &tscm->dwork);

        return 0;
}

static void snd_tscm_update(struct fw_unit *unit)
{
        struct snd_tscm *tscm = dev_get_drvdata(&unit->device);

        /* Postpone a workqueue for deferred registration. */
        if (!tscm->registered)
                snd_fw_schedule_registration(unit, &tscm->dwork);

        snd_tscm_transaction_reregister(tscm);

        /*
         * After registration, userspace can start packet streaming, then this
         * code block works fine.
         */
        if (tscm->registered) {
                mutex_lock(&tscm->mutex);
                snd_tscm_stream_update_duplex(tscm);
                mutex_unlock(&tscm->mutex);
        }
}

static void snd_tscm_remove(struct fw_unit *unit)
{
        struct snd_tscm *tscm = dev_get_drvdata(&unit->device);

        /*
         * Confirm to stop the work for registration before the sound card is
         * going to be released. The work is not scheduled again because bus
         * reset handler is not called anymore.
         */
        cancel_delayed_work_sync(&tscm->dwork);

        if (tscm->registered) {
                /* No need to wait for releasing card object in this context. */
                snd_card_free_when_closed(tscm->card);
        } else {
                /* Don't forget this case. */
                tscm_free(tscm);
        }
}

static const struct ieee1394_device_id snd_tscm_id_table[] = {
        {
                .match_flags = IEEE1394_MATCH_VENDOR_ID |
                               IEEE1394_MATCH_SPECIFIER_ID,
                .vendor_id = 0x00022e,
                .specifier_id = 0x00022e,
        },
        /* FE-08 requires reverse-engineering because it just has faders. */
        {}
};
MODULE_DEVICE_TABLE(ieee1394, snd_tscm_id_table);

static struct fw_driver tscm_driver = {
        .driver = {
                .owner = THIS_MODULE,
                .name = "snd-firewire-tascam",
                .bus = &fw_bus_type,
        },
        .probe    = snd_tscm_probe,
        .update   = snd_tscm_update,
        .remove   = snd_tscm_remove,
        .id_table = snd_tscm_id_table,
};

static int __init snd_tscm_init(void)
{
        return driver_register(&tscm_driver.driver);
}

static void __exit snd_tscm_exit(void)
{
        driver_unregister(&tscm_driver.driver);
}

module_init(snd_tscm_init);
module_exit(snd_tscm_exit);