drivers/usb/gadget/gmidi.c

   1 /*
   2  * gmidi.c -- USB MIDI Gadget Driver
   3  *
   4  * Copyright (C) 2006 Thumtronics Pty Ltd.
   5  * Developed for Thumtronics by Grey Innovation
   6  * Ben Williamson <ben.williamson@greyinnovation.com>
   7  *
   8  * This software is distributed under the terms of the GNU General Public
   9  * License ("GPL") version 2, as published by the Free Software Foundation.
  10  *
  11  * This code is based in part on:
  12  *
  13  * Gadget Zero driver, Copyright (C) 2003-2004 David Brownell.
  14  * USB Audio driver, Copyright (C) 2002 by Takashi Iwai.
  15  * USB MIDI driver, Copyright (C) 2002-2005 Clemens Ladisch.
  16  *
  17  * Refer to the USB Device Class Definition for MIDI Devices:
  18  * http://www.usb.org/developers/devclass_docs/midi10.pdf
  19  */
  20
  21 /* #define VERBOSE_DEBUG */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/slab.h>
  25 #include <linux/utsname.h>
  26 #include <linux/device.h>
  27
  28 #include <sound/core.h>
  29 #include <sound/initval.h>
  30 #include <sound/rawmidi.h>
  31
  32 #include <linux/usb/ch9.h>
  33 #include <linux/usb/gadget.h>
  34 #include <linux/usb/audio.h>
  35 #include <linux/usb/midi.h>
  36
  37 #include "gadget_chips.h"
  38
  39 #include "composite.c"
  40 #include "usbstring.c"
  41 #include "config.c"
  42 #include "epautoconf.c"
  43 #include "f_midi.c"
  44
  45 /*-------------------------------------------------------------------------*/
  46
  47 MODULE_AUTHOR("Ben Williamson");
  48 MODULE_LICENSE("GPL v2");
  49
  50 static const char shortname[] = "g_midi";
  51 static const char longname[] = "MIDI Gadget";
  52
  53 static int index = SNDRV_DEFAULT_IDX1;
  54 module_param(index, int, S_IRUGO);
  55 MODULE_PARM_DESC(index, "Index value for the USB MIDI Gadget adapter.");
  56
  57 static char *id = SNDRV_DEFAULT_STR1;
  58 module_param(id, charp, S_IRUGO);
  59 MODULE_PARM_DESC(id, "ID string for the USB MIDI Gadget adapter.");
  60
  61 static unsigned int buflen = 256;
  62 module_param(buflen, uint, S_IRUGO);
  63 MODULE_PARM_DESC(buflen, "MIDI buffer length");
  64
  65 static unsigned int qlen = 32;
  66 module_param(qlen, uint, S_IRUGO);
  67 MODULE_PARM_DESC(qlen, "USB read request queue length");
  68
  69 static unsigned int in_ports = 1;
  70 module_param(in_ports, uint, S_IRUGO);
  71 MODULE_PARM_DESC(in_ports, "Number of MIDI input ports");
  72
  73 static unsigned int out_ports = 1;
  74 module_param(out_ports, uint, S_IRUGO);
  75 MODULE_PARM_DESC(out_ports, "Number of MIDI output ports");
  76
  77 /* Thanks to Grey Innovation for donating this product ID.
  78  *
  79  * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  80  * Instead:  allocate your own, using normal USB-IF procedures.
  81  */
  82 #define DRIVER_VENDOR_NUM       0x17b3          /* Grey Innovation */
  83 #define DRIVER_PRODUCT_NUM      0x0004          /* Linux-USB "MIDI Gadget" */
  84
  85 /* string IDs are assigned dynamically */
  86
  87 #define STRING_MANUFACTURER_IDX         0
  88 #define STRING_PRODUCT_IDX              1
  89 #define STRING_DESCRIPTION_IDX          2
  90
  91 static struct usb_device_descriptor device_desc = {
  92         .bLength =              USB_DT_DEVICE_SIZE,
  93         .bDescriptorType =      USB_DT_DEVICE,
  94         .bcdUSB =               __constant_cpu_to_le16(0x0200),
  95         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
  96         .idVendor =             __constant_cpu_to_le16(DRIVER_VENDOR_NUM),
  97         .idProduct =            __constant_cpu_to_le16(DRIVER_PRODUCT_NUM),
  98         /* .iManufacturer =     DYNAMIC */
  99         /* .iProduct =          DYNAMIC */
 100         .bNumConfigurations =   1,
 101 };
 102
 103 static struct usb_string strings_dev[] = {
 104         [STRING_MANUFACTURER_IDX].s     = "Grey Innovation",
 105         [STRING_PRODUCT_IDX].s          = "MIDI Gadget",
 106         [STRING_DESCRIPTION_IDX].s      = "MIDI",
 107         {  } /* end of list */
 108 };
 109
 110 static struct usb_gadget_strings stringtab_dev = {
 111         .language       = 0x0409,       /* en-us */
 112         .strings        = strings_dev,
 113 };
 114
 115 static struct usb_gadget_strings *dev_strings[] = {
 116         &stringtab_dev,
 117         NULL,
 118 };
 119
 120 static int __exit midi_unbind(struct usb_composite_dev *dev)
 121 {
 122         return 0;
 123 }
 124
 125 static struct usb_configuration midi_config = {
 126         .label          = "MIDI Gadget",
 127         .bConfigurationValue = 1,
 128         /* .iConfiguration = DYNAMIC */
 129         .bmAttributes   = USB_CONFIG_ATT_ONE,
 130         .bMaxPower      = CONFIG_USB_GADGET_VBUS_DRAW / 2,
 131 };
 132
 133 static int __init midi_bind_config(struct usb_configuration *c)
 134 {
 135         return f_midi_bind_config(c, index, id,
 136                                   in_ports, out_ports,
 137                                   buflen, qlen);
 138 }
 139
 140 static int __init midi_bind(struct usb_composite_dev *cdev)
 141 {
 142         struct usb_gadget *gadget = cdev->gadget;
 143         int gcnum, status;
 144
 145         status = usb_string_id(cdev);
 146         if (status < 0)
 147                 return status;
 148         strings_dev[STRING_MANUFACTURER_IDX].id = status;
 149         device_desc.iManufacturer = status;
 150
 151         status = usb_string_id(cdev);
 152         if (status < 0)
 153                 return status;
 154         strings_dev[STRING_PRODUCT_IDX].id = status;
 155         device_desc.iProduct = status;
 156
 157         /* config description */
 158         status = usb_string_id(cdev);
 159         if (status < 0)
 160                 return status;
 161         strings_dev[STRING_DESCRIPTION_IDX].id = status;
 162
 163         midi_config.iConfiguration = status;
 164
 165         gcnum = usb_gadget_controller_number(gadget);
 166         if (gcnum < 0) {
 167                 /* gmidi is so simple (no altsettings) that
 168                  * it SHOULD NOT have problems with bulk-capable hardware.
 169                  * so warn about unrecognized controllers, don't panic.
 170                  */
 171                 pr_warning("%s: controller '%s' not recognized\n",
 172                            __func__, gadget->name);
 173                 device_desc.bcdDevice = cpu_to_le16(0x9999);
 174         } else {
 175                 device_desc.bcdDevice = cpu_to_le16(0x0200 + gcnum);
 176         }
 177
 178         status = usb_add_config(cdev, &midi_config, midi_bind_config);
 179         if (status < 0)
 180                 return status;
 181
 182         pr_info("%s\n", longname);
 183         return 0;
 184 }
 185
 186 static struct usb_composite_driver midi_driver = {
 187         .name           = (char *) longname,
 188         .dev            = &device_desc,
 189         .strings        = dev_strings,
 190         .max_speed      = USB_SPEED_HIGH,
 191         .unbind         = __exit_p(midi_unbind),
 192 };
 193
 194 static int __init midi_init(void)
 195 {
 196         return usb_composite_probe(&midi_driver, midi_bind);
 197 }
 198 module_init(midi_init);
 199
 200 static void __exit midi_cleanup(void)
 201 {
 202         usb_composite_unregister(&midi_driver);
 203 }
 204 module_exit(midi_cleanup);
 205