hid-prodikeys.c

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/*
 *  HID driver for the Prodikeys PC-MIDI Keyboard
 *  providing midi & extra multimedia keys functionality
 *
 *  Copyright (c) 2009 Don Prince <[email protected]>
 *
 *  Controls for Octave Shift Up/Down, Channel, and
 *  Sustain Duration available via sysfs.
 *
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

#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 "usbhid/usbhid.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 pk_device {
    unsigned long       quirks;

    struct hid_device   *hdev;
    struct pcmidi_snd   *pm; /* pcmidi device context */
};

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 pk_device        *pk;
    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;
    struct snd_rawmidi_substream    *out_substream;
    unsigned long           in_triggered;
    unsigned long           out_active;
};

#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 = container_of(dev, struct hid_device, dev);
    struct pk_device *pk = hid_get_drvdata(hdev);

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

    return sprintf(buf, "%u (min:%u, max:%u)\n", pk->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 = container_of(dev, struct hid_device, dev);
    struct pk_device *pk = 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);
        pk->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 = container_of(dev, struct hid_device, dev);
    struct pk_device *pk = hid_get_drvdata(hdev);

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

    return sprintf(buf, "%u (off:%u, max:%u (ms))\n", pk->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 = container_of(dev, struct hid_device, dev);
    struct pk_device *pk = 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);
        pk->pm->midi_sustain = sustain;
        pk->pm->midi_sustain_mode =
            (0 == sustain || !pk->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 = container_of(dev, struct hid_device, dev);
    struct pk_device *pk = hid_get_drvdata(hdev);

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

    return sprintf(buf, "%d (min:%d, max:%d)\n", pk->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 = container_of(dev, struct hid_device, dev);
    struct pk_device *pk = 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);
        pk->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(unsigned long data)
{
    struct pcmidi_sustain *pms = (struct pcmidi_sustain *)data;

    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;
        setup_timer(&pms->timer, pcmidi_sustained_note_release,
            (unsigned long)pms);
    }
}

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;
        del_timer_sync(&pms->timer);
    }
}

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

    usbhid_submit_report(hdev, report, USB_DIR_OUT);
}

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];

    /* break keys */
    for (bit_index = 0; bit_index < 24; bit_index++) {
        key = pm->last_key[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
    */
    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
    };

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

    pcmidi_get_output_report(pm);
    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 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_create(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;
    }

    strncpy(card->driver, shortname, sizeof(card->driver));
    strncpy(card->shortname, shortname, sizeof(card->shortname));
    strncpy(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;
    strncpy(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);

    snd_card_set_dev(card, &pm->pk->hdev->dev);

    /* create sysfs variables */
    err = device_create_file(&pm->pk->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->pk->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->pk->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);
    pcmidi_set_operational(pm);

    /* 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->pk->hdev->dev, sysfs_device_attr_octave);
fail_attr_octave:
    device_remove_file(&pm->pk->hdev->dev, sysfs_device_attr_sustain);
fail_attr_sustain:
    device_remove_file(&pm->pk->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->pk->hdev->dev,
            sysfs_device_attr_channel);
        device_remove_file(&pm->pk->hdev->dev,
            sysfs_device_attr_sustain);
        device_remove_file(&pm->pk->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 __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 pk_device *pk = hid_get_drvdata(hdev);
    struct pcmidi_snd *pm;

    pm = pk->pm;

    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 pk_device *pk = hid_get_drvdata(hdev);
    int ret = 0;

    if (1 == pk->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(pk->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 = to_usb_interface(hdev->dev.parent);
    unsigned short ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
    unsigned long quirks = id->driver_data;
    struct pk_device *pk;
    struct pcmidi_snd *pm = NULL;

    pk = kzalloc(sizeof(*pk), GFP_KERNEL);
    if (pk == NULL) {
        hid_err(hdev, "can't alloc descriptor\n");
        return -ENOMEM;
    }

    pk->hdev = hdev;

    pm = kzalloc(sizeof(*pm), GFP_KERNEL);
    if (pm == NULL) {
        hid_err(hdev, "can't alloc descriptor\n");
        ret = -ENOMEM;
        goto err_free_pk;
    }

    pm->pk = pk;
    pk->pm = pm;
    pm->ifnum = ifnum;

    hid_set_drvdata(hdev, pk);

    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);
err_free_pk:
    kfree(pk);

    return ret;
}

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

    pm = pk->pm;
    if (pm) {
        pcmidi_snd_terminate(pm);
        kfree(pm);
    }

    hid_hw_stop(hdev);

    kfree(pk);
}

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,
};

static int pk_init(void)
{
    int ret;

    ret = hid_register_driver(&pk_driver);
    if (ret)
        pr_err("can't register prodikeys driver\n");

    return ret;
}

static void pk_exit(void)
{
    hid_unregister_driver(&pk_driver);
}

module_init(pk_init);
module_exit(pk_exit);
MODULE_LICENSE("GPL");