xref: /openbmc/linux/drivers/usb/gadget/legacy/gmidi.c (revision 6774def6)
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 "f_midi.c"
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 int __exit midi_unbind(struct usb_composite_dev *dev)
119 {
120 	return 0;
121 }
122 
123 static struct usb_configuration midi_config = {
124 	.label		= "MIDI Gadget",
125 	.bConfigurationValue = 1,
126 	/* .iConfiguration = DYNAMIC */
127 	.bmAttributes	= USB_CONFIG_ATT_ONE,
128 	.MaxPower	= CONFIG_USB_GADGET_VBUS_DRAW,
129 };
130 
131 static int __init midi_bind_config(struct usb_configuration *c)
132 {
133 	return f_midi_bind_config(c, index, id,
134 				  in_ports, out_ports,
135 				  buflen, qlen);
136 }
137 
138 static int __init midi_bind(struct usb_composite_dev *cdev)
139 {
140 	int status;
141 
142 	status = usb_string_ids_tab(cdev, strings_dev);
143 	if (status < 0)
144 		return status;
145 	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
146 	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
147 	midi_config.iConfiguration = strings_dev[STRING_DESCRIPTION_IDX].id;
148 
149 	status = usb_add_config(cdev, &midi_config, midi_bind_config);
150 	if (status < 0)
151 		return status;
152 	usb_composite_overwrite_options(cdev, &coverwrite);
153 	pr_info("%s\n", longname);
154 	return 0;
155 }
156 
157 static __refdata struct usb_composite_driver midi_driver = {
158 	.name		= (char *) longname,
159 	.dev		= &device_desc,
160 	.strings	= dev_strings,
161 	.max_speed	= USB_SPEED_HIGH,
162 	.bind		= midi_bind,
163 	.unbind		= __exit_p(midi_unbind),
164 };
165 
166 module_usb_composite_driver(midi_driver);
167