/*
 * TC Applied Technologies Digital Interface Communications Engine driver
 *
 * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
 * Licensed under the terms of the GNU General Public License, version 2.
 */

#include "dice.h"

MODULE_DESCRIPTION("DICE driver");
MODULE_AUTHOR("Clemens Ladisch <clemens@ladisch.de>");
MODULE_LICENSE("GPL v2");

#define OUI_WEISS               0x001c6a
#define OUI_LOUD                0x000ff2
#define OUI_FOCUSRITE           0x00130e
#define OUI_TCELECTRONIC        0x000166

#define DICE_CATEGORY_ID        0x04
#define WEISS_CATEGORY_ID       0x00
#define LOUD_CATEGORY_ID        0x10

/*
 * Some models support several isochronous channels, while these streams are not
 * always available. In this case, add the model name to this list.
 */
static bool force_two_pcm_support(struct fw_unit *unit)
{
        static const char *const models[] = {
                /* TC Electronic models. */
                "StudioKonnekt48",
                /* Focusrite models. */
                "SAFFIRE_PRO_40",
                "LIQUID_SAFFIRE_56",
                "SAFFIRE_PRO_40_1",
        };
        char model[32];
        unsigned int i;
        int err;

        err = fw_csr_string(unit->directory, CSR_MODEL, model, sizeof(model));
        if (err < 0)
                return false;

        for (i = 0; i < ARRAY_SIZE(models); i++) {
                if (strcmp(models[i], model) == 0)
                        break;
        }

        return i < ARRAY_SIZE(models);
}

static int check_dice_category(struct fw_unit *unit)
{
        struct fw_device *device = fw_parent_device(unit);
        struct fw_csr_iterator it;
        int key, val, vendor = -1, model = -1;
        unsigned int category;

        /*
         * Check that GUID and unit directory are constructed according to DICE
         * rules, i.e., that the specifier ID is the GUID's OUI, and that the
         * GUID chip ID consists of the 8-bit category ID, the 10-bit product
         * ID, and a 22-bit serial number.
         */
        fw_csr_iterator_init(&it, unit->directory);
        while (fw_csr_iterator_next(&it, &key, &val)) {
                switch (key) {
                case CSR_SPECIFIER_ID:
                        vendor = val;
                        break;
                case CSR_MODEL:
                        model = val;
                        break;
                }
        }

        if (vendor == OUI_FOCUSRITE || vendor == OUI_TCELECTRONIC) {
                if (force_two_pcm_support(unit))
                        return 0;
        }

        if (vendor == OUI_WEISS)
                category = WEISS_CATEGORY_ID;
        else if (vendor == OUI_LOUD)
                category = LOUD_CATEGORY_ID;
        else
                category = DICE_CATEGORY_ID;
        if (device->config_rom[3] != ((vendor << 8) | category) ||
            device->config_rom[4] >> 22 != model)
                return -ENODEV;

        return 0;
}

static int check_clock_caps(struct snd_dice *dice)
{
        __be32 value;
        int err;

        /* some very old firmwares don't tell about their clock support */
        if (dice->clock_caps > 0) {
                err = snd_dice_transaction_read_global(dice,
                                                GLOBAL_CLOCK_CAPABILITIES,
                                                &value, 4);
                if (err < 0)
                        return err;
                dice->clock_caps = be32_to_cpu(value);
        } else {
                /* this should be supported by any device */
                dice->clock_caps = CLOCK_CAP_RATE_44100 |
                                   CLOCK_CAP_RATE_48000 |
                                   CLOCK_CAP_SOURCE_ARX1 |
                                   CLOCK_CAP_SOURCE_INTERNAL;
        }

        return 0;
}

static void dice_card_strings(struct snd_dice *dice)
{
        struct snd_card *card = dice->card;
        struct fw_device *dev = fw_parent_device(dice->unit);
        char vendor[32], model[32];
        unsigned int i;
        int err;

        strcpy(card->driver, "DICE");

        strcpy(card->shortname, "DICE");
        BUILD_BUG_ON(NICK_NAME_SIZE < sizeof(card->shortname));
        err = snd_dice_transaction_read_global(dice, GLOBAL_NICK_NAME,
                                               card->shortname,
                                               sizeof(card->shortname));
        if (err >= 0) {
                /* DICE strings are returned in "always-wrong" endianness */
                BUILD_BUG_ON(sizeof(card->shortname) % 4 != 0);
                for (i = 0; i < sizeof(card->shortname); i += 4)
                        swab32s((u32 *)&card->shortname[i]);
                card->shortname[sizeof(card->shortname) - 1] = '\0';
        }

        strcpy(vendor, "?");
        fw_csr_string(dev->config_rom + 5, CSR_VENDOR, vendor, sizeof(vendor));
        strcpy(model, "?");
        fw_csr_string(dice->unit->directory, CSR_MODEL, model, sizeof(model));
        snprintf(card->longname, sizeof(card->longname),
                 "%s %s (serial %u) at %s, S%d",
                 vendor, model, dev->config_rom[4] & 0x3fffff,
                 dev_name(&dice->unit->device), 100 << dev->max_speed);

        strcpy(card->mixername, "DICE");
}

static void dice_free(struct snd_dice *dice)
{
        snd_dice_stream_destroy_duplex(dice);
        snd_dice_transaction_destroy(dice);
        fw_unit_put(dice->unit);

        mutex_destroy(&dice->mutex);
        kfree(dice);
}

/*
 * This module releases the FireWire unit data after all ALSA character devices
 * are released by applications. This is for releasing stream data or finishing
 * transactions safely. Thus at returning from .remove(), this module still keep
 * references for the unit.
 */
static void dice_card_free(struct snd_card *card)
{
        dice_free(card->private_data);
}

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

        if (dice->registered)
                return;

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

        if (force_two_pcm_support(dice->unit))
                dice->force_two_pcms = true;

        err = snd_dice_transaction_init(dice);
        if (err < 0)
                goto error;

        err = check_clock_caps(dice);
        if (err < 0)
                goto error;

        dice_card_strings(dice);

        err = snd_dice_stream_init_duplex(dice);
        if (err < 0)
                goto error;

        snd_dice_create_proc(dice);

        err = snd_dice_create_pcm(dice);
        if (err < 0)
                goto error;

        err = snd_dice_create_midi(dice);
        if (err < 0)
                goto error;

        err = snd_dice_create_hwdep(dice);
        if (err < 0)
                goto error;

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

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

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

static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
{
        struct snd_dice *dice;
        int err;

        err = check_dice_category(unit);
        if (err < 0)
                return -ENODEV;

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

        dice->unit = fw_unit_get(unit);
        dev_set_drvdata(&unit->device, dice);

        spin_lock_init(&dice->lock);
        mutex_init(&dice->mutex);
        init_completion(&dice->clock_accepted);
        init_waitqueue_head(&dice->hwdep_wait);

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

        return 0;
}

static void dice_remove(struct fw_unit *unit)
{
        struct snd_dice *dice = 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(&dice->dwork);

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

static void dice_bus_reset(struct fw_unit *unit)
{
        struct snd_dice *dice = dev_get_drvdata(&unit->device);

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

        /* The handler address register becomes initialized. */
        snd_dice_transaction_reinit(dice);

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

#define DICE_INTERFACE  0x000001

static const struct ieee1394_device_id dice_id_table[] = {
        {
                .match_flags = IEEE1394_MATCH_VERSION,
                .version     = DICE_INTERFACE,
        },
        /* M-Audio Profire 610/2626 has a different value in version field. */
        {
                .match_flags    = IEEE1394_MATCH_VENDOR_ID |
                                  IEEE1394_MATCH_SPECIFIER_ID,
                .vendor_id      = 0x000d6c,
                .specifier_id   = 0x000d6c,
        },
        { }
};
MODULE_DEVICE_TABLE(ieee1394, dice_id_table);

static struct fw_driver dice_driver = {
        .driver   = {
                .owner  = THIS_MODULE,
                .name   = KBUILD_MODNAME,
                .bus    = &fw_bus_type,
        },
        .probe    = dice_probe,
        .update   = dice_bus_reset,
        .remove   = dice_remove,
        .id_table = dice_id_table,
};

static int __init alsa_dice_init(void)
{
        return driver_register(&dice_driver.driver);
}

static void __exit alsa_dice_exit(void)
{
        driver_unregister(&dice_driver.driver);
}

module_init(alsa_dice_init);
module_exit(alsa_dice_exit);