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 "gadget_chips.h" 39 40 #include "u_midi.h" 41 42 /*-------------------------------------------------------------------------*/ 43 44 MODULE_AUTHOR("Ben Williamson"); 45 MODULE_LICENSE("GPL v2"); 46 47 static const char shortname[] = "g_midi"; 48 static const char longname[] = "MIDI Gadget"; 49 50 USB_GADGET_COMPOSITE_OPTIONS(); 51 52 static int index = SNDRV_DEFAULT_IDX1; 53 module_param(index, int, S_IRUGO); 54 MODULE_PARM_DESC(index, "Index value for the USB MIDI Gadget adapter."); 55 56 static char *id = SNDRV_DEFAULT_STR1; 57 module_param(id, charp, S_IRUGO); 58 MODULE_PARM_DESC(id, "ID string for the USB MIDI Gadget adapter."); 59 60 static unsigned int buflen = 256; 61 module_param(buflen, uint, S_IRUGO); 62 MODULE_PARM_DESC(buflen, "MIDI buffer length"); 63 64 static unsigned int qlen = 32; 65 module_param(qlen, uint, S_IRUGO); 66 MODULE_PARM_DESC(qlen, "USB read request queue length"); 67 68 static unsigned int in_ports = 1; 69 module_param(in_ports, uint, S_IRUGO); 70 MODULE_PARM_DESC(in_ports, "Number of MIDI input ports"); 71 72 static unsigned int out_ports = 1; 73 module_param(out_ports, uint, S_IRUGO); 74 MODULE_PARM_DESC(out_ports, "Number of MIDI output ports"); 75 76 /* Thanks to Grey Innovation for donating this product ID. 77 * 78 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!! 79 * Instead: allocate your own, using normal USB-IF procedures. 80 */ 81 #define DRIVER_VENDOR_NUM 0x17b3 /* Grey Innovation */ 82 #define DRIVER_PRODUCT_NUM 0x0004 /* Linux-USB "MIDI Gadget" */ 83 84 /* string IDs are assigned dynamically */ 85 86 #define STRING_DESCRIPTION_IDX USB_GADGET_FIRST_AVAIL_IDX 87 88 static struct usb_device_descriptor device_desc = { 89 .bLength = USB_DT_DEVICE_SIZE, 90 .bDescriptorType = USB_DT_DEVICE, 91 .bcdUSB = __constant_cpu_to_le16(0x0200), 92 .bDeviceClass = USB_CLASS_PER_INTERFACE, 93 .idVendor = __constant_cpu_to_le16(DRIVER_VENDOR_NUM), 94 .idProduct = __constant_cpu_to_le16(DRIVER_PRODUCT_NUM), 95 /* .iManufacturer = DYNAMIC */ 96 /* .iProduct = DYNAMIC */ 97 .bNumConfigurations = 1, 98 }; 99 100 static struct usb_string strings_dev[] = { 101 [USB_GADGET_MANUFACTURER_IDX].s = "Grey Innovation", 102 [USB_GADGET_PRODUCT_IDX].s = "MIDI Gadget", 103 [USB_GADGET_SERIAL_IDX].s = "", 104 [STRING_DESCRIPTION_IDX].s = "MIDI", 105 { } /* end of list */ 106 }; 107 108 static struct usb_gadget_strings stringtab_dev = { 109 .language = 0x0409, /* en-us */ 110 .strings = strings_dev, 111 }; 112 113 static struct usb_gadget_strings *dev_strings[] = { 114 &stringtab_dev, 115 NULL, 116 }; 117 118 static struct usb_function_instance *fi_midi; 119 static struct usb_function *f_midi; 120 121 static int midi_unbind(struct usb_composite_dev *dev) 122 { 123 usb_put_function(f_midi); 124 usb_put_function_instance(fi_midi); 125 return 0; 126 } 127 128 static struct usb_configuration midi_config = { 129 .label = "MIDI Gadget", 130 .bConfigurationValue = 1, 131 /* .iConfiguration = DYNAMIC */ 132 .bmAttributes = USB_CONFIG_ATT_ONE, 133 .MaxPower = CONFIG_USB_GADGET_VBUS_DRAW, 134 }; 135 136 static int midi_bind_config(struct usb_configuration *c) 137 { 138 int status; 139 140 f_midi = usb_get_function(fi_midi); 141 if (IS_ERR(f_midi)) 142 return PTR_ERR(f_midi); 143 144 status = usb_add_function(c, f_midi); 145 if (status < 0) { 146 usb_put_function(f_midi); 147 return status; 148 } 149 150 return 0; 151 } 152 153 static int midi_bind(struct usb_composite_dev *cdev) 154 { 155 struct f_midi_opts *midi_opts; 156 int status; 157 158 fi_midi = usb_get_function_instance("midi"); 159 if (IS_ERR(fi_midi)) 160 return PTR_ERR(fi_midi); 161 162 midi_opts = container_of(fi_midi, struct f_midi_opts, func_inst); 163 midi_opts->index = index; 164 midi_opts->id = id; 165 midi_opts->in_ports = in_ports; 166 midi_opts->out_ports = out_ports; 167 midi_opts->buflen = buflen; 168 midi_opts->qlen = qlen; 169 170 status = usb_string_ids_tab(cdev, strings_dev); 171 if (status < 0) 172 goto put; 173 device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id; 174 device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; 175 midi_config.iConfiguration = strings_dev[STRING_DESCRIPTION_IDX].id; 176 177 status = usb_add_config(cdev, &midi_config, midi_bind_config); 178 if (status < 0) 179 goto put; 180 usb_composite_overwrite_options(cdev, &coverwrite); 181 pr_info("%s\n", longname); 182 return 0; 183 put: 184 usb_put_function_instance(fi_midi); 185 return status; 186 } 187 188 static struct usb_composite_driver midi_driver = { 189 .name = (char *) longname, 190 .dev = &device_desc, 191 .strings = dev_strings, 192 .max_speed = USB_SPEED_HIGH, 193 .bind = midi_bind, 194 .unbind = midi_unbind, 195 }; 196 197 module_usb_composite_driver(midi_driver); 198