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
midi_unbind(struct usb_composite_dev * dev)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
midi_bind_config(struct usb_configuration * c)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
midi_bind(struct usb_composite_dev * cdev)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