LXR linux/drivers/usb/gadget/legacy/gmidi.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * gmidi.c -- USB MIDI Gadget Driver
   4 *
   5 * Copyright (C) 2006 Thumtronics Pty Ltd.
   6 * Developed for Thumtronics by Grey Innovation
   7 * Ben Williamson <ben.williamson@greyinnovation.com>
   8 *
   9 * This code is based in part on:
  10 *
  11 * Gadget Zero driver, Copyright (C) 2003-2004 David Brownell.
  12 * USB Audio driver, Copyright (C) 2002 by Takashi Iwai.
  13 * USB MIDI driver, Copyright (C) 2002-2005 Clemens Ladisch.
  14 *
  15 * Refer to the USB Device Class Definition for MIDI Devices:
  16 * http://www.usb.org/developers/devclass_docs/midi10.pdf
  17 */
  18
  19/* #define VERBOSE_DEBUG */
  20
  21#include <linux/kernel.h>
  22#include <linux/module.h>
  23
  24#include <sound/initval.h>
  25
  26#include <linux/usb/composite.h>
  27#include <linux/usb/gadget.h>
  28
  29#include "u_midi.h"
  30
  31/*-------------------------------------------------------------------------*/
  32
  33MODULE_AUTHOR("Ben Williamson");
  34MODULE_LICENSE("GPL v2");
  35
  36static const char longname[] = "MIDI Gadget";
  37
  38USB_GADGET_COMPOSITE_OPTIONS();
  39
  40static int index = SNDRV_DEFAULT_IDX1;
  41module_param(index, int, S_IRUGO);
  42MODULE_PARM_DESC(index, "Index value for the USB MIDI Gadget adapter.");
  43
  44static char *id = SNDRV_DEFAULT_STR1;
  45module_param(id, charp, S_IRUGO);
  46MODULE_PARM_DESC(id, "ID string for the USB MIDI Gadget adapter.");
  47
  48static unsigned int buflen = 512;
  49module_param(buflen, uint, S_IRUGO);
  50MODULE_PARM_DESC(buflen, "MIDI buffer length");
  51
  52static unsigned int qlen = 32;
  53module_param(qlen, uint, S_IRUGO);
  54MODULE_PARM_DESC(qlen, "USB read and write request queue length");
  55
  56static unsigned int in_ports = 1;
  57module_param(in_ports, uint, S_IRUGO);
  58MODULE_PARM_DESC(in_ports, "Number of MIDI input ports");
  59
  60static unsigned int out_ports = 1;
  61module_param(out_ports, uint, S_IRUGO);
  62MODULE_PARM_DESC(out_ports, "Number of MIDI output ports");
  63
  64/* Thanks to Grey Innovation for donating this product ID.
  65 *
  66 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  67 * Instead:  allocate your own, using normal USB-IF procedures.
  68 */
  69#define DRIVER_VENDOR_NUM       0x17b3          /* Grey Innovation */
  70#define DRIVER_PRODUCT_NUM      0x0004          /* Linux-USB "MIDI Gadget" */
  71
  72/* string IDs are assigned dynamically */
  73
  74#define STRING_DESCRIPTION_IDX          USB_GADGET_FIRST_AVAIL_IDX
  75
  76static struct usb_device_descriptor device_desc = {
  77        .bLength =              USB_DT_DEVICE_SIZE,
  78        .bDescriptorType =      USB_DT_DEVICE,
  79        /* .bcdUSB = DYNAMIC */
  80        .bDeviceClass =         USB_CLASS_PER_INTERFACE,
  81        .idVendor =             cpu_to_le16(DRIVER_VENDOR_NUM),
  82        .idProduct =            cpu_to_le16(DRIVER_PRODUCT_NUM),
  83        /* .iManufacturer =     DYNAMIC */
  84        /* .iProduct =          DYNAMIC */
  85        .bNumConfigurations =   1,
  86};
  87
  88static struct usb_string strings_dev[] = {
  89        [USB_GADGET_MANUFACTURER_IDX].s = "Grey Innovation",
  90        [USB_GADGET_PRODUCT_IDX].s      = "MIDI Gadget",
  91        [USB_GADGET_SERIAL_IDX].s       = "",
  92        [STRING_DESCRIPTION_IDX].s      = "MIDI",
  93        {  } /* end of list */
  94};
  95
  96static struct usb_gadget_strings stringtab_dev = {
  97        .language       = 0x0409,       /* en-us */
  98        .strings        = strings_dev,
  99};
 100
 101static struct usb_gadget_strings *dev_strings[] = {
 102        &stringtab_dev,
 103        NULL,
 104};
 105
 106static struct usb_function_instance *fi_midi;
 107static struct usb_function *f_midi;
 108
 109static int midi_unbind(struct usb_composite_dev *dev)
 110{
 111        usb_put_function(f_midi);
 112        usb_put_function_instance(fi_midi);
 113        return 0;
 114}
 115
 116static struct usb_configuration midi_config = {
 117        .label          = "MIDI Gadget",
 118        .bConfigurationValue = 1,
 119        /* .iConfiguration = DYNAMIC */
 120        .bmAttributes   = USB_CONFIG_ATT_ONE,
 121        .MaxPower       = CONFIG_USB_GADGET_VBUS_DRAW,
 122};
 123
 124static int midi_bind_config(struct usb_configuration *c)
 125{
 126        int status;
 127
 128        f_midi = usb_get_function(fi_midi);
 129        if (IS_ERR(f_midi))
 130                return PTR_ERR(f_midi);
 131
 132        status = usb_add_function(c, f_midi);
 133        if (status < 0) {
 134                usb_put_function(f_midi);
 135                return status;
 136        }
 137
 138        return 0;
 139}
 140
 141static int midi_bind(struct usb_composite_dev *cdev)
 142{
 143        struct f_midi_opts *midi_opts;
 144        int status;
 145
 146        fi_midi = usb_get_function_instance("midi");
 147        if (IS_ERR(fi_midi))
 148                return PTR_ERR(fi_midi);
 149
 150        midi_opts = container_of(fi_midi, struct f_midi_opts, func_inst);
 151        midi_opts->index = index;
 152        midi_opts->id = id;
 153        midi_opts->in_ports = in_ports;
 154        midi_opts->out_ports = out_ports;
 155        midi_opts->buflen = buflen;
 156        midi_opts->qlen = qlen;
 157
 158        status = usb_string_ids_tab(cdev, strings_dev);
 159        if (status < 0)
 160                goto put;
 161        device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
 162        device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
 163        midi_config.iConfiguration = strings_dev[STRING_DESCRIPTION_IDX].id;
 164
 165        status = usb_add_config(cdev, &midi_config, midi_bind_config);
 166        if (status < 0)
 167                goto put;
 168        usb_composite_overwrite_options(cdev, &coverwrite);
 169        pr_info("%s\n", longname);
 170        return 0;
 171put:
 172        usb_put_function_instance(fi_midi);
 173        return status;
 174}
 175
 176static struct usb_composite_driver midi_driver = {
 177        .name           = longname,
 178        .dev            = &device_desc,
 179        .strings        = dev_strings,
 180        .max_speed      = USB_SPEED_HIGH,
 181        .bind           = midi_bind,
 182        .unbind         = midi_unbind,
 183};
 184
 185module_usb_composite_driver(midi_driver);
 186