// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  HID driver for the Prodikeys PC-MIDI Keyboard
 *  providing midi & extra multimedia keys functionality
 *
 *  Copyright (c) 2009 Don Prince <dhprince.devel@yahoo.co.uk>
 *
 *  Controls for Octave Shift Up/Down, Channel, and
 *  Sustain Duration available via sysfs.
 */

/*
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/device.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/mutex.h>
#include <linux/hid.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/rawmidi.h>
#include "hid-ids.h"


#define pk_debug(format, arg...) \
        pr_debug("hid-prodikeys: " format "\n" , ## arg)
#define pk_error(format, arg...) \
        pr_err("hid-prodikeys: " format "\n" , ## arg)

struct pcmidi_snd;

struct pcmidi_sustain {
        unsigned long           in_use;
        struct pcmidi_snd       *pm;
        struct timer_list       timer;
        unsigned char           status;
        unsigned char           note;
        unsigned char           velocity;
};

#define PCMIDI_SUSTAINED_MAX    32
struct pcmidi_snd {
        struct hid_device               *hdev;
        unsigned short                  ifnum;
        struct hid_report               *pcmidi_report6;
        struct input_dev                *input_ep82;
        unsigned short                  midi_mode;
        unsigned short                  midi_sustain_mode;
        unsigned short                  midi_sustain;
        unsigned short                  midi_channel;
        short                           midi_octave;
        struct pcmidi_sustain           sustained_notes[PCMIDI_SUSTAINED_MAX];
        unsigned short                  fn_state;
        unsigned short                  last_key[24];
        spinlock_t                      rawmidi_in_lock;
        struct snd_card                 *card;
        struct snd_rawmidi              *rwmidi;
        struct snd_rawmidi_substream    *in_substream;
        unsigned long                   in_triggered;
};

#define PK_QUIRK_NOGET  0x00010000
#define PCMIDI_MIDDLE_C 60
#define PCMIDI_CHANNEL_MIN 0
#define PCMIDI_CHANNEL_MAX 15
#define PCMIDI_OCTAVE_MIN (-2)
#define PCMIDI_OCTAVE_MAX 2
#define PCMIDI_SUSTAIN_MIN 0
#define PCMIDI_SUSTAIN_MAX 5000

static const char shortname[] = "PC-MIDI";
static const char longname[] = "Prodikeys PC-MIDI Keyboard";

static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;

module_param_array(index, int, NULL, 0444);
module_param_array(id, charp, NULL, 0444);
module_param_array(enable, bool, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for the PC-MIDI virtual audio driver");
MODULE_PARM_DESC(id, "ID string for the PC-MIDI virtual audio driver");
MODULE_PARM_DESC(enable, "Enable for the PC-MIDI virtual audio driver");


/* Output routine for the sysfs channel file */
static ssize_t show_channel(struct device *dev,
        struct device_attribute *attr, char *buf)
{
        struct hid_device *hdev = to_hid_device(dev);
        struct pcmidi_snd *pm = hid_get_drvdata(hdev);

        dbg_hid("pcmidi sysfs read channel=%u\n", pm->midi_channel);

        return sprintf(buf, "%u (min:%u, max:%u)\n", pm->midi_channel,
                PCMIDI_CHANNEL_MIN, PCMIDI_CHANNEL_MAX);
}

/* Input routine for the sysfs channel file */
static ssize_t store_channel(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
        struct hid_device *hdev = to_hid_device(dev);
        struct pcmidi_snd *pm = hid_get_drvdata(hdev);

        unsigned channel = 0;

        if (sscanf(buf, "%u", &channel) > 0 && channel <= PCMIDI_CHANNEL_MAX) {
                dbg_hid("pcmidi sysfs write channel=%u\n", channel);
                pm->midi_channel = channel;
                return strlen(buf);
        }
        return -EINVAL;
}

static DEVICE_ATTR(channel, S_IRUGO | S_IWUSR | S_IWGRP , show_channel,
                store_channel);

static struct device_attribute *sysfs_device_attr_channel = {
                &dev_attr_channel,
                };

/* Output routine for the sysfs sustain file */
static ssize_t show_sustain(struct device *dev,
 struct device_attribute *attr, char *buf)
{
        struct hid_device *hdev = to_hid_device(dev);
        struct pcmidi_snd *pm = hid_get_drvdata(hdev);

        dbg_hid("pcmidi sysfs read sustain=%u\n", pm->midi_sustain);

        return sprintf(buf, "%u (off:%u, max:%u (ms))\n", pm->midi_sustain,
                PCMIDI_SUSTAIN_MIN, PCMIDI_SUSTAIN_MAX);
}

/* Input routine for the sysfs sustain file */
static ssize_t store_sustain(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
        struct hid_device *hdev = to_hid_device(dev);
        struct pcmidi_snd *pm = hid_get_drvdata(hdev);

        unsigned sustain = 0;

        if (sscanf(buf, "%u", &sustain) > 0 && sustain <= PCMIDI_SUSTAIN_MAX) {
                dbg_hid("pcmidi sysfs write sustain=%u\n", sustain);
                pm->midi_sustain = sustain;
                pm->midi_sustain_mode = (0 == sustain || !pm->midi_mode) ? 0 : 1;
                return strlen(buf);
        }
        return -EINVAL;
}

static DEVICE_ATTR(sustain, S_IRUGO | S_IWUSR | S_IWGRP, show_sustain,
                store_sustain);

static struct device_attribute *sysfs_device_attr_sustain = {
                &dev_attr_sustain,
                };

/* Output routine for the sysfs octave file */
static ssize_t show_octave(struct device *dev,
        struct device_attribute *attr, char *buf)
{
        struct hid_device *hdev = to_hid_device(dev);
        struct pcmidi_snd *pm = hid_get_drvdata(hdev);

        dbg_hid("pcmidi sysfs read octave=%d\n", pm->midi_octave);

        return sprintf(buf, "%d (min:%d, max:%d)\n", pm->midi_octave,
                PCMIDI_OCTAVE_MIN, PCMIDI_OCTAVE_MAX);
}

/* Input routine for the sysfs octave file */
static ssize_t store_octave(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
        struct hid_device *hdev = to_hid_device(dev);
        struct pcmidi_snd *pm = hid_get_drvdata(hdev);

        int octave = 0;

        if (sscanf(buf, "%d", &octave) > 0 &&
                octave >= PCMIDI_OCTAVE_MIN && octave <= PCMIDI_OCTAVE_MAX) {
                dbg_hid("pcmidi sysfs write octave=%d\n", octave);
                pm->midi_octave = octave;
                return strlen(buf);
        }
        return -EINVAL;
}

static DEVICE_ATTR(octave, S_IRUGO | S_IWUSR | S_IWGRP, show_octave,
                store_octave);

static struct device_attribute *sysfs_device_attr_octave = {
                &dev_attr_octave,
                };


static void pcmidi_send_note(struct pcmidi_snd *pm,
        unsigned char status, unsigned char note, unsigned char velocity)
{
        unsigned long flags;
        unsigned char buffer[3];

        buffer[0] = status;
        buffer[1] = note;
        buffer[2] = velocity;

        spin_lock_irqsave(&pm->rawmidi_in_lock, flags);

        if (!pm->in_substream)
                goto drop_note;
        if (!test_bit(pm->in_substream->number, &pm->in_triggered))
                goto drop_note;

        snd_rawmidi_receive(pm->in_substream, buffer, 3);

drop_note:
        spin_unlock_irqrestore(&pm->rawmidi_in_lock, flags);

        return;
}

static void pcmidi_sustained_note_release(struct timer_list *t)
{
        struct pcmidi_sustain *pms = timer_container_of(pms, t, timer);

        pcmidi_send_note(pms->pm, pms->status, pms->note, pms->velocity);
        pms->in_use = 0;
}

static void init_sustain_timers(struct pcmidi_snd *pm)
{
        struct pcmidi_sustain *pms;
        unsigned i;

        for (i = 0; i < PCMIDI_SUSTAINED_MAX; i++) {
                pms = &pm->sustained_notes[i];
                pms->in_use = 0;
                pms->pm = pm;
                timer_setup(&pms->timer, pcmidi_sustained_note_release, 0);
        }
}

static void stop_sustain_timers(struct pcmidi_snd *pm)
{
        struct pcmidi_sustain *pms;
        unsigned i;

        for (i = 0; i < PCMIDI_SUSTAINED_MAX; i++) {
                pms = &pm->sustained_notes[i];
                pms->in_use = 1;
                timer_delete_sync(&pms->timer);
        }
}

static int pcmidi_get_output_report(struct pcmidi_snd *pm)
{
        struct hid_device *hdev = pm->hdev;
        struct hid_report *report;

        list_for_each_entry(report,
                &hdev->report_enum[HID_OUTPUT_REPORT].report_list, list) {
                if (!(6 == report->id))
                        continue;

                if (report->maxfield < 1) {
                        hid_err(hdev, "output report is empty\n");
                        break;
                }
                if (report->field[0]->report_count != 2) {
                        hid_err(hdev, "field count too low\n");
                        break;
                }
                pm->pcmidi_report6 = report;
                return 0;
        }
        /* should never get here */
        return -ENODEV;
}

static void pcmidi_submit_output_report(struct pcmidi_snd *pm, int state)
{
        struct hid_device *hdev = pm->hdev;
        struct hid_report *report = pm->pcmidi_report6;
        report->field[0]->value[0] = 0x01;
        report->field[0]->value[1] = state;

        hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
}

static int pcmidi_handle_report1(struct pcmidi_snd *pm, u8 *data)
{
        u32 bit_mask;

        bit_mask = data[1];
        bit_mask = (bit_mask << 8) | data[2];
        bit_mask = (bit_mask << 8) | data[3];

        dbg_hid("pcmidi mode: %d\n", pm->midi_mode);

        /*KEY_MAIL or octave down*/
        if (pm->midi_mode && bit_mask == 0x004000) {
                /* octave down */
                pm->midi_octave--;
                if (pm->midi_octave < -2)
                        pm->midi_octave = -2;
                dbg_hid("pcmidi mode: %d octave: %d\n",
                        pm->midi_mode, pm->midi_octave);
                return 1;
        }
        /*KEY_WWW or sustain*/
        else if (pm->midi_mode && bit_mask == 0x000004) {
                /* sustain on/off*/
                pm->midi_sustain_mode ^= 0x1;
                return 1;
        }

        return 0; /* continue key processing */
}

static int pcmidi_handle_report3(struct pcmidi_snd *pm, u8 *data, int size)
{
        struct pcmidi_sustain *pms;
        unsigned i, j;
        unsigned char status, note, velocity;

        unsigned num_notes = (size-1)/2;
        for (j = 0; j < num_notes; j++) {
                note = data[j*2+1];
                velocity = data[j*2+2];

                if (note < 0x81) { /* note on */
                        status = 128 + 16 + pm->midi_channel; /* 1001nnnn */
                        note = note - 0x54 + PCMIDI_MIDDLE_C +
                                (pm->midi_octave * 12);
                        if (0 == velocity)
                                velocity = 1; /* force note on */
                } else { /* note off */
                        status = 128 + pm->midi_channel; /* 1000nnnn */
                        note = note - 0x94 + PCMIDI_MIDDLE_C +
                                (pm->midi_octave*12);

                        if (pm->midi_sustain_mode) {
                                for (i = 0; i < PCMIDI_SUSTAINED_MAX; i++) {
                                        pms = &pm->sustained_notes[i];
                                        if (!pms->in_use) {
                                                pms->status = status;
                                                pms->note = note;
                                                pms->velocity = velocity;
                                                pms->in_use = 1;

                                                mod_timer(&pms->timer,
                                                        jiffies +
                                        msecs_to_jiffies(pm->midi_sustain));
                                                return 1;
                                        }
                                }
                        }
                }
                pcmidi_send_note(pm, status, note, velocity);
        }

        return 1;
}

static int pcmidi_handle_report4(struct pcmidi_snd *pm, u8 *data)
{
        unsigned        key;
        u32             bit_mask;
        u32             bit_index;

        bit_mask = data[1];
        bit_mask = (bit_mask << 8) | data[2];
        bit_mask = (bit_mask << 8) | data[3];

        /* robustness in case input_mapping hook does not get called */
        if (!pm->input_ep82)
                return 0;

        /* break keys */
        for (bit_index = 0; bit_index < 24; bit_index++) {
                if (!((0x01 << bit_index) & bit_mask)) {
                        input_event(pm->input_ep82, EV_KEY,
                                pm->last_key[bit_index], 0);
                        pm->last_key[bit_index] = 0;
                }
        }

        /* make keys */
        for (bit_index = 0; bit_index < 24; bit_index++) {
                key = 0;
                switch ((0x01 << bit_index) & bit_mask) {
                case 0x000010: /* Fn lock*/
                        pm->fn_state ^= 0x000010;
                        if (pm->fn_state)
                                pcmidi_submit_output_report(pm, 0xc5);
                        else
                                pcmidi_submit_output_report(pm, 0xc6);
                        continue;
                case 0x020000: /* midi launcher..send a key (qwerty) or not? */
                        pcmidi_submit_output_report(pm, 0xc1);
                        pm->midi_mode ^= 0x01;

                        dbg_hid("pcmidi mode: %d\n", pm->midi_mode);
                        continue;
                case 0x100000: /* KEY_MESSENGER or octave up */
                        dbg_hid("pcmidi mode: %d\n", pm->midi_mode);
                        if (pm->midi_mode) {
                                pm->midi_octave++;
                                if (pm->midi_octave > 2)
                                        pm->midi_octave = 2;
                                dbg_hid("pcmidi mode: %d octave: %d\n",
                                        pm->midi_mode, pm->midi_octave);
                                continue;
                        } else
                                key = KEY_MESSENGER;
                        break;
                case 0x400000:
                        key = KEY_CALENDAR;
                        break;
                case 0x080000:
                        key = KEY_ADDRESSBOOK;
                        break;
                case 0x040000:
                        key = KEY_DOCUMENTS;
                        break;
                case 0x800000:
                        key = KEY_WORDPROCESSOR;
                        break;
                case 0x200000:
                        key = KEY_SPREADSHEET;
                        break;
                case 0x010000:
                        key = KEY_COFFEE;
                        break;
                case 0x000100:
                        key = KEY_HELP;
                        break;
                case 0x000200:
                        key = KEY_SEND;
                        break;
                case 0x000400:
                        key = KEY_REPLY;
                        break;
                case 0x000800:
                        key = KEY_FORWARDMAIL;
                        break;
                case 0x001000:
                        key = KEY_NEW;
                        break;
                case 0x002000:
                        key = KEY_OPEN;
                        break;
                case 0x004000:
                        key = KEY_CLOSE;
                        break;
                case 0x008000:
                        key = KEY_SAVE;
                        break;
                case 0x000001:
                        key = KEY_UNDO;
                        break;
                case 0x000002:
                        key = KEY_REDO;
                        break;
                case 0x000004:
                        key = KEY_SPELLCHECK;
                        break;
                case 0x000008:
                        key = KEY_PRINT;
                        break;
                }
                if (key) {
                        input_event(pm->input_ep82, EV_KEY, key, 1);
                        pm->last_key[bit_index] = key;
                }
        }

        return 1;
}

static int pcmidi_handle_report(
        struct pcmidi_snd *pm, unsigned report_id, u8 *data, int size)
{
        int ret = 0;

        switch (report_id) {
        case 0x01: /* midi keys (qwerty)*/
                ret = pcmidi_handle_report1(pm, data);
                break;
        case 0x03: /* midi keyboard (musical)*/
                ret = pcmidi_handle_report3(pm, data, size);
                break;
        case 0x04: /* multimedia/midi keys (qwerty)*/
                ret = pcmidi_handle_report4(pm, data);
                break;
        }
        return ret;
}

static void pcmidi_setup_extra_keys(
        struct pcmidi_snd *pm, struct input_dev *input)
{
        /* reassigned functionality for N/A keys
                MY PICTURES =>  KEY_WORDPROCESSOR
                MY MUSIC=>      KEY_SPREADSHEET
        */
        static const unsigned int keys[] = {
                KEY_FN,
                KEY_MESSENGER, KEY_CALENDAR,
                KEY_ADDRESSBOOK, KEY_DOCUMENTS,
                KEY_WORDPROCESSOR,
                KEY_SPREADSHEET,
                KEY_COFFEE,
                KEY_HELP, KEY_SEND,
                KEY_REPLY, KEY_FORWARDMAIL,
                KEY_NEW, KEY_OPEN,
                KEY_CLOSE, KEY_SAVE,
                KEY_UNDO, KEY_REDO,
                KEY_SPELLCHECK, KEY_PRINT,
                0
        };

        const unsigned int *pkeys = &keys[0];
        unsigned short i;

        if (pm->ifnum != 1)  /* only set up ONCE for interace 1 */
                return;

        pm->input_ep82 = input;

        for (i = 0; i < 24; i++)
                pm->last_key[i] = 0;

        while (*pkeys != 0) {
                set_bit(*pkeys, pm->input_ep82->keybit);
                ++pkeys;
        }
}

static int pcmidi_set_operational(struct pcmidi_snd *pm)
{
        int rc;

        if (pm->ifnum != 1)
                return 0; /* only set up ONCE for interace 1 */

        rc = pcmidi_get_output_report(pm);
        if (rc < 0)
                return rc;
        pcmidi_submit_output_report(pm, 0xc1);
        return 0;
}

static int pcmidi_snd_free(struct snd_device *dev)
{
        return 0;
}

static int pcmidi_in_open(struct snd_rawmidi_substream *substream)
{
        struct pcmidi_snd *pm = substream->rmidi->private_data;

        dbg_hid("pcmidi in open\n");
        pm->in_substream = substream;
        return 0;
}

static int pcmidi_in_close(struct snd_rawmidi_substream *substream)
{
        dbg_hid("pcmidi in close\n");
        return 0;
}

static void pcmidi_in_trigger(struct snd_rawmidi_substream *substream, int up)
{
        struct pcmidi_snd *pm = substream->rmidi->private_data;

        dbg_hid("pcmidi in trigger %d\n", up);

        pm->in_triggered = up;
}

static const struct snd_rawmidi_ops pcmidi_in_ops = {
        .open = pcmidi_in_open,
        .close = pcmidi_in_close,
        .trigger = pcmidi_in_trigger
};

static int pcmidi_snd_initialise(struct pcmidi_snd *pm)
{
        static int dev;
        struct snd_card *card;
        struct snd_rawmidi *rwmidi;
        int err;

        static struct snd_device_ops ops = {
                .dev_free = pcmidi_snd_free,
        };

        if (pm->ifnum != 1)
                return 0; /* only set up midi device ONCE for interace 1 */

        if (dev >= SNDRV_CARDS)
                return -ENODEV;

        if (!enable[dev]) {
                dev++;
                return -ENOENT;
        }

        /* Setup sound card */

        err = snd_card_new(&pm->hdev->dev, index[dev], id[dev],
                           THIS_MODULE, 0, &card);
        if (err < 0) {
                pk_error("failed to create pc-midi sound card\n");
                err = -ENOMEM;
                goto fail;
        }
        pm->card = card;

        /* Setup sound device */
        err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, pm, &ops);
        if (err < 0) {
                pk_error("failed to create pc-midi sound device: error %d\n",
                        err);
                goto fail;
        }

        strscpy(card->driver, shortname, sizeof(card->driver));
        strscpy(card->shortname, shortname, sizeof(card->shortname));
        strscpy(card->longname, longname, sizeof(card->longname));

        /* Set up rawmidi */
        err = snd_rawmidi_new(card, card->shortname, 0,
                              0, 1, &rwmidi);
        if (err < 0) {
                pk_error("failed to create pc-midi rawmidi device: error %d\n",
                        err);
                goto fail;
        }
        pm->rwmidi = rwmidi;
        strscpy(rwmidi->name, card->shortname, sizeof(rwmidi->name));
        rwmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT;
        rwmidi->private_data = pm;

        snd_rawmidi_set_ops(rwmidi, SNDRV_RAWMIDI_STREAM_INPUT,
                &pcmidi_in_ops);

        /* create sysfs variables */
        err = device_create_file(&pm->hdev->dev,
                                 sysfs_device_attr_channel);
        if (err < 0) {
                pk_error("failed to create sysfs attribute channel: error %d\n",
                        err);
                goto fail;
        }

        err = device_create_file(&pm->hdev->dev,
                                sysfs_device_attr_sustain);
        if (err < 0) {
                pk_error("failed to create sysfs attribute sustain: error %d\n",
                        err);
                goto fail_attr_sustain;
        }

        err = device_create_file(&pm->hdev->dev,
                         sysfs_device_attr_octave);
        if (err < 0) {
                pk_error("failed to create sysfs attribute octave: error %d\n",
                        err);
                goto fail_attr_octave;
        }

        spin_lock_init(&pm->rawmidi_in_lock);

        init_sustain_timers(pm);
        err = pcmidi_set_operational(pm);
        if (err < 0) {
                pk_error("failed to find output report\n");
                goto fail_register;
        }

        /* register it */
        err = snd_card_register(card);
        if (err < 0) {
                pk_error("failed to register pc-midi sound card: error %d\n",
                         err);
                goto fail_register;
        }

        dbg_hid("pcmidi_snd_initialise finished ok\n");
        return 0;

fail_register:
        stop_sustain_timers(pm);
        device_remove_file(&pm->hdev->dev, sysfs_device_attr_octave);
fail_attr_octave:
        device_remove_file(&pm->hdev->dev, sysfs_device_attr_sustain);
fail_attr_sustain:
        device_remove_file(&pm->hdev->dev, sysfs_device_attr_channel);
fail:
        if (pm->card) {
                snd_card_free(pm->card);
                pm->card = NULL;
        }
        return err;
}

static int pcmidi_snd_terminate(struct pcmidi_snd *pm)
{
        if (pm->card) {
                stop_sustain_timers(pm);

                device_remove_file(&pm->hdev->dev, sysfs_device_attr_channel);
                device_remove_file(&pm->hdev->dev, sysfs_device_attr_sustain);
                device_remove_file(&pm->hdev->dev, sysfs_device_attr_octave);

                snd_card_disconnect(pm->card);
                snd_card_free_when_closed(pm->card);
        }

        return 0;
}

/*
 * PC-MIDI report descriptor for report id is wrong.
 */
static const __u8 *pk_report_fixup(struct hid_device *hdev, __u8 *rdesc,
                unsigned int *rsize)
{
        if (*rsize == 178 &&
              rdesc[111] == 0x06 && rdesc[112] == 0x00 &&
              rdesc[113] == 0xff) {
                hid_info(hdev,
                         "fixing up pc-midi keyboard report descriptor\n");

                rdesc[144] = 0x18; /* report 4: was 0x10 report count */
        }
        return rdesc;
}

static int pk_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                struct hid_field *field, struct hid_usage *usage,
                unsigned long **bit, int *max)
{
        struct pcmidi_snd *pm = hid_get_drvdata(hdev);

        if (HID_UP_MSVENDOR == (usage->hid & HID_USAGE_PAGE) &&
                1 == pm->ifnum) {
                pcmidi_setup_extra_keys(pm, hi->input);
                return 0;
        }

        return 0;
}


static int pk_raw_event(struct hid_device *hdev, struct hid_report *report,
        u8 *data, int size)
{
        struct pcmidi_snd *pm = hid_get_drvdata(hdev);
        int ret = 0;

        if (1 == pm->ifnum) {
                if (report->id == data[0])
                        switch (report->id) {
                        case 0x01: /* midi keys (qwerty)*/
                        case 0x03: /* midi keyboard (musical)*/
                        case 0x04: /* extra/midi keys (qwerty)*/
                                ret = pcmidi_handle_report(pm,
                                                report->id, data, size);
                                break;
                        }
        }

        return ret;
}

static int pk_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
        int ret;
        struct usb_interface *intf;
        unsigned short ifnum;
        unsigned long quirks = id->driver_data;
        struct pcmidi_snd *pm;

        if (!hid_is_usb(hdev))
                return -EINVAL;

        intf = to_usb_interface(hdev->dev.parent);
        ifnum = intf->cur_altsetting->desc.bInterfaceNumber;

        pm = kzalloc_obj(*pm);
        if (pm == NULL) {
                hid_err(hdev, "can't alloc descriptor\n");
                return -ENOMEM;
        }

        pm->hdev = hdev;
        pm->ifnum = ifnum;

        hid_set_drvdata(hdev, pm);

        ret = hid_parse(hdev);
        if (ret) {
                hid_err(hdev, "hid parse failed\n");
                goto err_free;
        }

        if (quirks & PK_QUIRK_NOGET) { /* hid_parse cleared all the quirks */
                hdev->quirks |= HID_QUIRK_NOGET;
        }

        ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
        if (ret) {
                hid_err(hdev, "hw start failed\n");
                goto err_free;
        }

        ret = pcmidi_snd_initialise(pm);
        if (ret < 0)
                goto err_stop;

        return 0;
err_stop:
        hid_hw_stop(hdev);
err_free:
        kfree(pm);

        return ret;
}

static void pk_remove(struct hid_device *hdev)
{
        struct pcmidi_snd *pm = hid_get_drvdata(hdev);

        pcmidi_snd_terminate(pm);
        hid_hw_stop(hdev);

        kfree(pm);
}

static const struct hid_device_id pk_devices[] = {
        {HID_USB_DEVICE(USB_VENDOR_ID_CREATIVELABS,
                USB_DEVICE_ID_PRODIKEYS_PCMIDI),
            .driver_data = PK_QUIRK_NOGET},
        { }
};
MODULE_DEVICE_TABLE(hid, pk_devices);

static struct hid_driver pk_driver = {
        .name = "prodikeys",
        .id_table = pk_devices,
        .report_fixup = pk_report_fixup,
        .input_mapping = pk_input_mapping,
        .raw_event = pk_raw_event,
        .probe = pk_probe,
        .remove = pk_remove,
};
module_hid_driver(pk_driver);

MODULE_DESCRIPTION("HID driver for the Prodikeys PC-MIDI Keyboard");
MODULE_LICENSE("GPL");