root/drivers/usb/gadget/legacy/gmidi.c

DEFINITIONS

1. midi_unbind
2. midi_bind_config
3. midi_bind

   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 
  33 MODULE_AUTHOR("Ben Williamson");
  34 MODULE_LICENSE("GPL v2");
  35 
  36 static const char longname[] = "MIDI Gadget";
  37 
  38 USB_GADGET_COMPOSITE_OPTIONS();
  39 
  40 static int index = SNDRV_DEFAULT_IDX1;
  41 module_param(index, int, S_IRUGO);
  42 MODULE_PARM_DESC(index, "Index value for the USB MIDI Gadget adapter.");
  43 
  44 static char *id = SNDRV_DEFAULT_STR1;
  45 module_param(id, charp, S_IRUGO);
  46 MODULE_PARM_DESC(id, "ID string for the USB MIDI Gadget adapter.");
  47 
  48 static unsigned int buflen = 512;
  49 module_param(buflen, uint, S_IRUGO);
  50 MODULE_PARM_DESC(buflen, "MIDI buffer length");
  51 
  52 static unsigned int qlen = 32;
  53 module_param(qlen, uint, S_IRUGO);
  54 MODULE_PARM_DESC(qlen, "USB read and write request queue length");
  55 
  56 static unsigned int in_ports = 1;
  57 module_param(in_ports, uint, S_IRUGO);
  58 MODULE_PARM_DESC(in_ports, "Number of MIDI input ports");
  59 
  60 static unsigned int out_ports = 1;
  61 module_param(out_ports, uint, S_IRUGO);
  62 MODULE_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 
  76 static 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 
  88 static 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 
  96 static struct usb_gadget_strings stringtab_dev = {
  97         .language       = 0x0409,       /* en-us */
  98         .strings        = strings_dev,
  99 };
 100 
 101 static struct usb_gadget_strings *dev_strings[] = {
 102         &stringtab_dev,
 103         NULL,
 104 };
 105 
 106 static struct usb_function_instance *fi_midi;
 107 static struct usb_function *f_midi;
 108 
 109 static 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 
 116 static 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 
 124 static 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 
 141 static 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;
 171 put:
 172         usb_put_function_instance(fi_midi);
 173         return status;
 174 }
 175 
 176 static struct usb_composite_driver midi_driver = {
 177         .name           = (char *) 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 
 185 module_usb_composite_driver(midi_driver);