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); 196