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
44MODULE_AUTHOR("Ben Williamson");
45MODULE_LICENSE("GPL v2");
46
47static const char shortname[] = "g_midi";
48static const char longname[] = "MIDI Gadget";
49
50USB_GADGET_COMPOSITE_OPTIONS();
51
52static int index = SNDRV_DEFAULT_IDX1;
53module_param(index, int, S_IRUGO);
54MODULE_PARM_DESC(index, "Index value for the USB MIDI Gadget adapter.");
55
56static char *id = SNDRV_DEFAULT_STR1;
57module_param(id, charp, S_IRUGO);
58MODULE_PARM_DESC(id, "ID string for the USB MIDI Gadget adapter.");
59
60static unsigned int buflen = 256;
61module_param(buflen, uint, S_IRUGO);
62MODULE_PARM_DESC(buflen, "MIDI buffer length");
63
64static unsigned int qlen = 32;
65module_param(qlen, uint, S_IRUGO);
66MODULE_PARM_DESC(qlen, "USB read request queue length");
67
68static unsigned int in_ports = 1;
69module_param(in_ports, uint, S_IRUGO);
70MODULE_PARM_DESC(in_ports, "Number of MIDI input ports");
71
72static unsigned int out_ports = 1;
73module_param(out_ports, uint, S_IRUGO);
74MODULE_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
88static 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
100static 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
108static struct usb_gadget_strings stringtab_dev = {
109	.language	= 0x0409,	/* en-us */
110	.strings	= strings_dev,
111};
112
113static struct usb_gadget_strings *dev_strings[] = {
114	&stringtab_dev,
115	NULL,
116};
117
118static struct usb_function_instance *fi_midi;
119static struct usb_function *f_midi;
120
121static 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
128static 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
136static 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
153static 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;
183put:
184	usb_put_function_instance(fi_midi);
185	return status;
186}
187
188static 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
197module_usb_composite_driver(midi_driver);
198