1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * gmidi.c -- USB MIDI Gadget Driver |
4 | * |
5 | * Copyright (C) 2006 Thumtronics Pty Ltd. |
6 | * Developed for Thumtronics by Grey Innovation |
7 | * Ben Williamson <ben.williamson@greyinnovation.com> |
8 | * |
9 | * This code is based in part on: |
10 | * |
11 | * Gadget Zero driver, Copyright (C) 2003-2004 David Brownell. |
12 | * USB Audio driver, Copyright (C) 2002 by Takashi Iwai. |
13 | * USB MIDI driver, Copyright (C) 2002-2005 Clemens Ladisch. |
14 | * |
15 | * Refer to the USB Device Class Definition for MIDI Devices: |
16 | * http://www.usb.org/developers/devclass_docs/midi10.pdf |
17 | */ |
18 | |
19 | /* #define VERBOSE_DEBUG */ |
20 | |
21 | #include <linux/kernel.h> |
22 | #include <linux/module.h> |
23 | |
24 | #include <sound/initval.h> |
25 | |
26 | #include <linux/usb/composite.h> |
27 | #include <linux/usb/gadget.h> |
28 | |
29 | #include "u_midi.h" |
30 | |
31 | /*-------------------------------------------------------------------------*/ |
32 | |
33 | MODULE_AUTHOR("Ben Williamson" ); |
34 | MODULE_LICENSE("GPL v2" ); |
35 | |
36 | static const char longname[] = "MIDI Gadget" ; |
37 | |
38 | USB_GADGET_COMPOSITE_OPTIONS(); |
39 | |
40 | static int index = SNDRV_DEFAULT_IDX1; |
41 | module_param(index, int, S_IRUGO); |
42 | MODULE_PARM_DESC(index, "Index value for the USB MIDI Gadget adapter." ); |
43 | |
44 | static char *id = SNDRV_DEFAULT_STR1; |
45 | module_param(id, charp, S_IRUGO); |
46 | MODULE_PARM_DESC(id, "ID string for the USB MIDI Gadget adapter." ); |
47 | |
48 | static unsigned int buflen = 512; |
49 | module_param(buflen, uint, S_IRUGO); |
50 | MODULE_PARM_DESC(buflen, "MIDI buffer length" ); |
51 | |
52 | static unsigned int qlen = 32; |
53 | module_param(qlen, uint, S_IRUGO); |
54 | MODULE_PARM_DESC(qlen, "USB read and write request queue length" ); |
55 | |
56 | static unsigned int in_ports = 1; |
57 | module_param(in_ports, uint, S_IRUGO); |
58 | MODULE_PARM_DESC(in_ports, "Number of MIDI input ports" ); |
59 | |
60 | static unsigned int out_ports = 1; |
61 | module_param(out_ports, uint, S_IRUGO); |
62 | MODULE_PARM_DESC(out_ports, "Number of MIDI output ports" ); |
63 | |
64 | /* Thanks to Grey Innovation for donating this product ID. |
65 | * |
66 | * DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!! |
67 | * Instead: allocate your own, using normal USB-IF procedures. |
68 | */ |
69 | #define DRIVER_VENDOR_NUM 0x17b3 /* Grey Innovation */ |
70 | #define DRIVER_PRODUCT_NUM 0x0004 /* Linux-USB "MIDI Gadget" */ |
71 | |
72 | /* string IDs are assigned dynamically */ |
73 | |
74 | #define STRING_DESCRIPTION_IDX USB_GADGET_FIRST_AVAIL_IDX |
75 | |
76 | static struct usb_device_descriptor device_desc = { |
77 | .bLength = USB_DT_DEVICE_SIZE, |
78 | .bDescriptorType = USB_DT_DEVICE, |
79 | /* .bcdUSB = DYNAMIC */ |
80 | .bDeviceClass = USB_CLASS_PER_INTERFACE, |
81 | .idVendor = cpu_to_le16(DRIVER_VENDOR_NUM), |
82 | .idProduct = cpu_to_le16(DRIVER_PRODUCT_NUM), |
83 | /* .iManufacturer = DYNAMIC */ |
84 | /* .iProduct = DYNAMIC */ |
85 | .bNumConfigurations = 1, |
86 | }; |
87 | |
88 | static struct usb_string strings_dev[] = { |
89 | [USB_GADGET_MANUFACTURER_IDX].s = "Grey Innovation" , |
90 | [USB_GADGET_PRODUCT_IDX].s = "MIDI Gadget" , |
91 | [USB_GADGET_SERIAL_IDX].s = "" , |
92 | [STRING_DESCRIPTION_IDX].s = "MIDI" , |
93 | { } /* end of list */ |
94 | }; |
95 | |
96 | static struct usb_gadget_strings stringtab_dev = { |
97 | .language = 0x0409, /* en-us */ |
98 | .strings = strings_dev, |
99 | }; |
100 | |
101 | static struct usb_gadget_strings *dev_strings[] = { |
102 | &stringtab_dev, |
103 | NULL, |
104 | }; |
105 | |
106 | static struct usb_function_instance *fi_midi; |
107 | static struct usb_function *f_midi; |
108 | |
109 | static int midi_unbind(struct usb_composite_dev *dev) |
110 | { |
111 | usb_put_function(f: f_midi); |
112 | usb_put_function_instance(fi: fi_midi); |
113 | return 0; |
114 | } |
115 | |
116 | static struct usb_configuration midi_config = { |
117 | .label = "MIDI Gadget" , |
118 | .bConfigurationValue = 1, |
119 | /* .iConfiguration = DYNAMIC */ |
120 | .bmAttributes = USB_CONFIG_ATT_ONE, |
121 | .MaxPower = CONFIG_USB_GADGET_VBUS_DRAW, |
122 | }; |
123 | |
124 | static int midi_bind_config(struct usb_configuration *c) |
125 | { |
126 | int status; |
127 | |
128 | f_midi = usb_get_function(fi: fi_midi); |
129 | if (IS_ERR(ptr: f_midi)) |
130 | return PTR_ERR(ptr: f_midi); |
131 | |
132 | status = usb_add_function(c, f_midi); |
133 | if (status < 0) { |
134 | usb_put_function(f: f_midi); |
135 | return status; |
136 | } |
137 | |
138 | return 0; |
139 | } |
140 | |
141 | static int midi_bind(struct usb_composite_dev *cdev) |
142 | { |
143 | struct f_midi_opts *midi_opts; |
144 | int status; |
145 | |
146 | fi_midi = usb_get_function_instance(name: "midi" ); |
147 | if (IS_ERR(ptr: fi_midi)) |
148 | return PTR_ERR(ptr: fi_midi); |
149 | |
150 | midi_opts = container_of(fi_midi, struct f_midi_opts, func_inst); |
151 | midi_opts->index = index; |
152 | midi_opts->id = id; |
153 | midi_opts->in_ports = in_ports; |
154 | midi_opts->out_ports = out_ports; |
155 | midi_opts->buflen = buflen; |
156 | midi_opts->qlen = qlen; |
157 | |
158 | status = usb_string_ids_tab(c: cdev, str: strings_dev); |
159 | if (status < 0) |
160 | goto put; |
161 | device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id; |
162 | device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; |
163 | midi_config.iConfiguration = strings_dev[STRING_DESCRIPTION_IDX].id; |
164 | |
165 | status = usb_add_config(cdev, &midi_config, midi_bind_config); |
166 | if (status < 0) |
167 | goto put; |
168 | usb_composite_overwrite_options(cdev, covr: &coverwrite); |
169 | pr_info("%s\n" , longname); |
170 | return 0; |
171 | put: |
172 | usb_put_function_instance(fi: fi_midi); |
173 | return status; |
174 | } |
175 | |
176 | static struct usb_composite_driver midi_driver = { |
177 | .name = longname, |
178 | .dev = &device_desc, |
179 | .strings = dev_strings, |
180 | .max_speed = USB_SPEED_HIGH, |
181 | .bind = midi_bind, |
182 | .unbind = midi_unbind, |
183 | }; |
184 | |
185 | module_usb_composite_driver(midi_driver); |
186 | |