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/module.h> 25 26 #include <sound/initval.h> 27 28 #include <linux/usb/composite.h> 29 #include <linux/usb/gadget.h> 30 31 #include "u_midi.h" 32 33 /*-------------------------------------------------------------------------*/ 34 35 MODULE_AUTHOR("Ben Williamson"); 36 MODULE_LICENSE("GPL v2"); 37 38 static const char longname[] = "MIDI Gadget"; 39 40 USB_GADGET_COMPOSITE_OPTIONS(); 41 42 static int index = SNDRV_DEFAULT_IDX1; 43 module_param(index, int, S_IRUGO); 44 MODULE_PARM_DESC(index, "Index value for the USB MIDI Gadget adapter."); 45 46 static char *id = SNDRV_DEFAULT_STR1; 47 module_param(id, charp, S_IRUGO); 48 MODULE_PARM_DESC(id, "ID string for the USB MIDI Gadget adapter."); 49 50 static unsigned int buflen = 512; 51 module_param(buflen, uint, S_IRUGO); 52 MODULE_PARM_DESC(buflen, "MIDI buffer length"); 53 54 static unsigned int qlen = 32; 55 module_param(qlen, uint, S_IRUGO); 56 MODULE_PARM_DESC(qlen, "USB read and write request queue length"); 57 58 static unsigned int in_ports = 1; 59 module_param(in_ports, uint, S_IRUGO); 60 MODULE_PARM_DESC(in_ports, "Number of MIDI input ports"); 61 62 static unsigned int out_ports = 1; 63 module_param(out_ports, uint, S_IRUGO); 64 MODULE_PARM_DESC(out_ports, "Number of MIDI output ports"); 65 66 /* Thanks to Grey Innovation for donating this product ID. 67 * 68 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!! 69 * Instead: allocate your own, using normal USB-IF procedures. 70 */ 71 #define DRIVER_VENDOR_NUM 0x17b3 /* Grey Innovation */ 72 #define DRIVER_PRODUCT_NUM 0x0004 /* Linux-USB "MIDI Gadget" */ 73 74 /* string IDs are assigned dynamically */ 75 76 #define STRING_DESCRIPTION_IDX USB_GADGET_FIRST_AVAIL_IDX 77 78 static struct usb_device_descriptor device_desc = { 79 .bLength = USB_DT_DEVICE_SIZE, 80 .bDescriptorType = USB_DT_DEVICE, 81 /* .bcdUSB = DYNAMIC */ 82 .bDeviceClass = USB_CLASS_PER_INTERFACE, 83 .idVendor = cpu_to_le16(DRIVER_VENDOR_NUM), 84 .idProduct = cpu_to_le16(DRIVER_PRODUCT_NUM), 85 /* .iManufacturer = DYNAMIC */ 86 /* .iProduct = DYNAMIC */ 87 .bNumConfigurations = 1, 88 }; 89 90 static struct usb_string strings_dev[] = { 91 [USB_GADGET_MANUFACTURER_IDX].s = "Grey Innovation", 92 [USB_GADGET_PRODUCT_IDX].s = "MIDI Gadget", 93 [USB_GADGET_SERIAL_IDX].s = "", 94 [STRING_DESCRIPTION_IDX].s = "MIDI", 95 { } /* end of list */ 96 }; 97 98 static struct usb_gadget_strings stringtab_dev = { 99 .language = 0x0409, /* en-us */ 100 .strings = strings_dev, 101 }; 102 103 static struct usb_gadget_strings *dev_strings[] = { 104 &stringtab_dev, 105 NULL, 106 }; 107 108 static struct usb_function_instance *fi_midi; 109 static struct usb_function *f_midi; 110 111 static int midi_unbind(struct usb_composite_dev *dev) 112 { 113 usb_put_function(f_midi); 114 usb_put_function_instance(fi_midi); 115 return 0; 116 } 117 118 static struct usb_configuration midi_config = { 119 .label = "MIDI Gadget", 120 .bConfigurationValue = 1, 121 /* .iConfiguration = DYNAMIC */ 122 .bmAttributes = USB_CONFIG_ATT_ONE, 123 .MaxPower = CONFIG_USB_GADGET_VBUS_DRAW, 124 }; 125 126 static int midi_bind_config(struct usb_configuration *c) 127 { 128 int status; 129 130 f_midi = usb_get_function(fi_midi); 131 if (IS_ERR(f_midi)) 132 return PTR_ERR(f_midi); 133 134 status = usb_add_function(c, f_midi); 135 if (status < 0) { 136 usb_put_function(f_midi); 137 return status; 138 } 139 140 return 0; 141 } 142 143 static int midi_bind(struct usb_composite_dev *cdev) 144 { 145 struct f_midi_opts *midi_opts; 146 int status; 147 148 fi_midi = usb_get_function_instance("midi"); 149 if (IS_ERR(fi_midi)) 150 return PTR_ERR(fi_midi); 151 152 midi_opts = container_of(fi_midi, struct f_midi_opts, func_inst); 153 midi_opts->index = index; 154 midi_opts->id = id; 155 midi_opts->in_ports = in_ports; 156 midi_opts->out_ports = out_ports; 157 midi_opts->buflen = buflen; 158 midi_opts->qlen = qlen; 159 160 status = usb_string_ids_tab(cdev, strings_dev); 161 if (status < 0) 162 goto put; 163 device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id; 164 device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; 165 midi_config.iConfiguration = strings_dev[STRING_DESCRIPTION_IDX].id; 166 167 status = usb_add_config(cdev, &midi_config, midi_bind_config); 168 if (status < 0) 169 goto put; 170 usb_composite_overwrite_options(cdev, &coverwrite); 171 pr_info("%s\n", longname); 172 return 0; 173 put: 174 usb_put_function_instance(fi_midi); 175 return status; 176 } 177 178 static struct usb_composite_driver midi_driver = { 179 .name = (char *) longname, 180 .dev = &device_desc, 181 .strings = dev_strings, 182 .max_speed = USB_SPEED_HIGH, 183 .bind = midi_bind, 184 .unbind = midi_unbind, 185 }; 186 187 module_usb_composite_driver(midi_driver); 188