gmidi.c

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/*
 * gmidi.c -- USB MIDI Gadget Driver
 *
 * Copyright (C) 2006 Thumtronics Pty Ltd.
 * Developed for Thumtronics by Grey Innovation
 * Ben Williamson <[email protected]>
 *
 * This software is distributed under the terms of the GNU General Public
 * License ("GPL") version 2, as published by the Free Software Foundation.
 *
 * This code is based in part on:
 *
 * Gadget Zero driver, Copyright (C) 2003-2004 David Brownell.
 * USB Audio driver, Copyright (C) 2002 by Takashi Iwai.
 * USB MIDI driver, Copyright (C) 2002-2005 Clemens Ladisch.
 *
 * Refer to the USB Device Class Definition for MIDI Devices:
 * http://www.usb.org/developers/devclass_docs/midi10.pdf
 */

/* #define VERBOSE_DEBUG */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/device.h>

#include <sound/core.h>
#include <sound/initval.h>
#include <sound/rawmidi.h>

#include <linux/usb/ch9.h>
#include <linux/usb/composite.h>
#include <linux/usb/gadget.h>
#include <linux/usb/audio.h>
#include <linux/usb/midi.h>

#include "gadget_chips.h"

#include "f_midi.c"

/*-------------------------------------------------------------------------*/

MODULE_AUTHOR("Ben Williamson");
MODULE_LICENSE("GPL v2");

static const char shortname[] = "g_midi";
static const char longname[] = "MIDI Gadget";

USB_GADGET_COMPOSITE_OPTIONS();

static int index = SNDRV_DEFAULT_IDX1;
module_param(index, int, S_IRUGO);
MODULE_PARM_DESC(index, "Index value for the USB MIDI Gadget adapter.");

static char *id = SNDRV_DEFAULT_STR1;
module_param(id, charp, S_IRUGO);
MODULE_PARM_DESC(id, "ID string for the USB MIDI Gadget adapter.");

static unsigned int buflen = 256;
module_param(buflen, uint, S_IRUGO);
MODULE_PARM_DESC(buflen, "MIDI buffer length");

static unsigned int qlen = 32;
module_param(qlen, uint, S_IRUGO);
MODULE_PARM_DESC(qlen, "USB read request queue length");

static unsigned int in_ports = 1;
module_param(in_ports, uint, S_IRUGO);
MODULE_PARM_DESC(in_ports, "Number of MIDI input ports");

static unsigned int out_ports = 1;
module_param(out_ports, uint, S_IRUGO);
MODULE_PARM_DESC(out_ports, "Number of MIDI output ports");

/* Thanks to Grey Innovation for donating this product ID.
 *
 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
 * Instead:  allocate your own, using normal USB-IF procedures.
 */
#define DRIVER_VENDOR_NUM   0x17b3      /* Grey Innovation */
#define DRIVER_PRODUCT_NUM  0x0004      /* Linux-USB "MIDI Gadget" */

/* string IDs are assigned dynamically */

#define STRING_DESCRIPTION_IDX      USB_GADGET_FIRST_AVAIL_IDX

static struct usb_device_descriptor device_desc = {
    .bLength =      USB_DT_DEVICE_SIZE,
    .bDescriptorType =  USB_DT_DEVICE,
    .bcdUSB =       __constant_cpu_to_le16(0x0200),
    .bDeviceClass =     USB_CLASS_PER_INTERFACE,
    .idVendor =     __constant_cpu_to_le16(DRIVER_VENDOR_NUM),
    .idProduct =        __constant_cpu_to_le16(DRIVER_PRODUCT_NUM),
    /* .iManufacturer = DYNAMIC */
    /* .iProduct =      DYNAMIC */
    .bNumConfigurations =   1,
};

static struct usb_string strings_dev[] = {
    [USB_GADGET_MANUFACTURER_IDX].s = "Grey Innovation",
    [USB_GADGET_PRODUCT_IDX].s  = "MIDI Gadget",
    [USB_GADGET_SERIAL_IDX].s   = "",
    [STRING_DESCRIPTION_IDX].s  = "MIDI",
    {  } /* end of list */
};

static struct usb_gadget_strings stringtab_dev = {
    .language   = 0x0409,   /* en-us */
    .strings    = strings_dev,
};

static struct usb_gadget_strings *dev_strings[] = {
    &stringtab_dev,
    NULL,
};

static int __exit midi_unbind(struct usb_composite_dev *dev)
{
    return 0;
}

static struct usb_configuration midi_config = {
    .label      = "MIDI Gadget",
    .bConfigurationValue = 1,
    /* .iConfiguration = DYNAMIC */
    .bmAttributes   = USB_CONFIG_ATT_ONE,
    .bMaxPower  = CONFIG_USB_GADGET_VBUS_DRAW / 2,
};

static int __init midi_bind_config(struct usb_configuration *c)
{
    return f_midi_bind_config(c, index, id,
                  in_ports, out_ports,
                  buflen, qlen);
}

static int __init midi_bind(struct usb_composite_dev *cdev)
{
    int status;

    status = usb_string_ids_tab(cdev, strings_dev);
    if (status < 0)
        return status;
    device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
    device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
    midi_config.iConfiguration = strings_dev[STRING_DESCRIPTION_IDX].id;

    status = usb_add_config(cdev, &midi_config, midi_bind_config);
    if (status < 0)
        return status;
    usb_composite_overwrite_options(cdev, &coverwrite);
    pr_info("%s\n", longname);
    return 0;
}

static __refdata struct usb_composite_driver midi_driver = {
    .name       = (char *) longname,
    .dev        = &device_desc,
    .strings    = dev_strings,
    .max_speed  = USB_SPEED_HIGH,
    .bind       = midi_bind,
    .unbind     = __exit_p(midi_unbind),
};

static int __init midi_init(void)
{
    return usb_composite_probe(&midi_driver);
}
module_init(midi_init);

static void __exit midi_cleanup(void)
{
    usb_composite_unregister(&midi_driver);
}
module_exit(midi_cleanup);