drivers/usb/gadget/legacy/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/module.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/composite.h>
  34 #include <linux/usb/gadget.h>
  35 #include <linux/usb/audio.h>
  36 #include <linux/usb/midi.h>
  37
  38 #include "u_midi.h"
  39
  40 /*-------------------------------------------------------------------------*/
  41
  42 MODULE_AUTHOR("Ben Williamson");
  43 MODULE_LICENSE("GPL v2");
  44
  45 static const char shortname[] = "g_midi";
  46 static const char longname[] = "MIDI Gadget";
  47
  48 USB_GADGET_COMPOSITE_OPTIONS();
  49
  50 static int index = SNDRV_DEFAULT_IDX1;
  51 module_param(index, int, S_IRUGO);
  52 MODULE_PARM_DESC(index, "Index value for the USB MIDI Gadget adapter.");
  53
  54 static char *id = SNDRV_DEFAULT_STR1;
  55 module_param(id, charp, S_IRUGO);
  56 MODULE_PARM_DESC(id, "ID string for the USB MIDI Gadget adapter.");
  57
  58 static unsigned int buflen = 256;
  59 module_param(buflen, uint, S_IRUGO);
  60 MODULE_PARM_DESC(buflen, "MIDI buffer length");
  61
  62 static unsigned int qlen = 32;
  63 module_param(qlen, uint, S_IRUGO);
  64 MODULE_PARM_DESC(qlen, "USB read request queue length");
  65
  66 static unsigned int in_ports = 1;
  67 module_param(in_ports, uint, S_IRUGO);
  68 MODULE_PARM_DESC(in_ports, "Number of MIDI input ports");
  69
  70 static unsigned int out_ports = 1;
  71 module_param(out_ports, uint, S_IRUGO);
  72 MODULE_PARM_DESC(out_ports, "Number of MIDI output ports");
  73
  74 /* Thanks to Grey Innovation for donating this product ID.
  75  *
  76  * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  77  * Instead:  allocate your own, using normal USB-IF procedures.
  78  */
  79 #define DRIVER_VENDOR_NUM       0x17b3          /* Grey Innovation */
  80 #define DRIVER_PRODUCT_NUM      0x0004          /* Linux-USB "MIDI Gadget" */
  81
  82 /* string IDs are assigned dynamically */
  83
  84 #define STRING_DESCRIPTION_IDX          USB_GADGET_FIRST_AVAIL_IDX
  85
  86 static struct usb_device_descriptor device_desc = {
  87         .bLength =              USB_DT_DEVICE_SIZE,
  88         .bDescriptorType =      USB_DT_DEVICE,
  89         .bcdUSB =               cpu_to_le16(0x0200),
  90         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
  91         .idVendor =             cpu_to_le16(DRIVER_VENDOR_NUM),
  92         .idProduct =            cpu_to_le16(DRIVER_PRODUCT_NUM),
  93         /* .iManufacturer =     DYNAMIC */
  94         /* .iProduct =          DYNAMIC */
  95         .bNumConfigurations =   1,
  96 };
  97
  98 static struct usb_string strings_dev[] = {
  99         [USB_GADGET_MANUFACTURER_IDX].s = "Grey Innovation",
 100         [USB_GADGET_PRODUCT_IDX].s      = "MIDI Gadget",
 101         [USB_GADGET_SERIAL_IDX].s       = "",
 102         [STRING_DESCRIPTION_IDX].s      = "MIDI",
 103         {  } /* end of list */
 104 };
 105
 106 static struct usb_gadget_strings stringtab_dev = {
 107         .language       = 0x0409,       /* en-us */
 108         .strings        = strings_dev,
 109 };
 110
 111 static struct usb_gadget_strings *dev_strings[] = {
 112         &stringtab_dev,
 113         NULL,
 114 };
 115
 116 static struct usb_function_instance *fi_midi;
 117 static struct usb_function *f_midi;
 118
 119 static int midi_unbind(struct usb_composite_dev *dev)
 120 {
 121         usb_put_function(f_midi);
 122         usb_put_function_instance(fi_midi);
 123         return 0;
 124 }
 125
 126 static struct usb_configuration midi_config = {
 127         .label          = "MIDI Gadget",
 128         .bConfigurationValue = 1,
 129         /* .iConfiguration = DYNAMIC */
 130         .bmAttributes   = USB_CONFIG_ATT_ONE,
 131         .MaxPower       = CONFIG_USB_GADGET_VBUS_DRAW,
 132 };
 133
 134 static int midi_bind_config(struct usb_configuration *c)
 135 {
 136         int status;
 137
 138         f_midi = usb_get_function(fi_midi);
 139         if (IS_ERR(f_midi))
 140                 return PTR_ERR(f_midi);
 141
 142         status = usb_add_function(c, f_midi);
 143         if (status < 0) {
 144                 usb_put_function(f_midi);
 145                 return status;
 146         }
 147
 148         return 0;
 149 }
 150
 151 static int midi_bind(struct usb_composite_dev *cdev)
 152 {
 153         struct f_midi_opts *midi_opts;
 154         int status;
 155
 156         fi_midi = usb_get_function_instance("midi");
 157         if (IS_ERR(fi_midi))
 158                 return PTR_ERR(fi_midi);
 159
 160         midi_opts = container_of(fi_midi, struct f_midi_opts, func_inst);
 161         midi_opts->index = index;
 162         midi_opts->id = id;
 163         midi_opts->in_ports = in_ports;
 164         midi_opts->out_ports = out_ports;
 165         midi_opts->buflen = buflen;
 166         midi_opts->qlen = qlen;
 167
 168         status = usb_string_ids_tab(cdev, strings_dev);
 169         if (status < 0)
 170                 goto put;
 171         device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
 172         device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
 173         midi_config.iConfiguration = strings_dev[STRING_DESCRIPTION_IDX].id;
 174
 175         status = usb_add_config(cdev, &midi_config, midi_bind_config);
 176         if (status < 0)
 177                 goto put;
 178         usb_composite_overwrite_options(cdev, &coverwrite);
 179         pr_info("%s\n", longname);
 180         return 0;
 181 put:
 182         usb_put_function_instance(fi_midi);
 183         return status;
 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         .bind           = midi_bind,
 192         .unbind         = midi_unbind,
 193 };
 194
 195 module_usb_composite_driver(midi_driver);