summaryrefslogtreecommitdiff
path: root/drivers/usb/gadget/zero.c
blob: aa0bd4f126a1e5f7892e1ce645b187d88e4ea7f1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
/*
 * zero.c -- Gadget Zero, for USB development
 *
 * Copyright (C) 2003-2008 David Brownell
 * Copyright (C) 2008 by Nokia Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


/*
 * Gadget Zero only needs two bulk endpoints, and is an example of how you
 * can write a hardware-agnostic gadget driver running inside a USB device.
 * Some hardware details are visible, but don't affect most of the driver.
 *
 * Use it with the Linux host/master side "usbtest" driver to get a basic
 * functional test of your device-side usb stack, or with "usb-skeleton".
 *
 * It supports two similar configurations.  One sinks whatever the usb host
 * writes, and in return sources zeroes.  The other loops whatever the host
 * writes back, so the host can read it.
 *
 * Many drivers will only have one configuration, letting them be much
 * simpler if they also don't support high speed operation (like this
 * driver does).
 *
 * Why is *this* driver using two configurations, rather than setting up
 * two interfaces with different functions?  To help verify that multiple
 * configuration infrastucture is working correctly; also, so that it can
 * work with low capability USB controllers without four bulk endpoints.
 */

/*
 * driver assumes self-powered hardware, and
 * has no way for users to trigger remote wakeup.
 */

/* #define VERBOSE_DEBUG */

#include <linux/kernel.h>
#include <linux/utsname.h>
#include <linux/device.h>

#include "g_zero.h"
#include "gadget_chips.h"


/*-------------------------------------------------------------------------*/

#define DRIVER_VERSION		"Cinco de Mayo 2008"

static const char longname[] = "Gadget Zero";

unsigned buflen = 4096;
module_param(buflen, uint, 0);

/*
 * Normally the "loopback" configuration is second (index 1) so
 * it's not the default.  Here's where to change that order, to
 * work better with hosts where config changes are problematic or
 * controllers (like original superh) that only support one config.
 */
static int loopdefault = 0;
module_param(loopdefault, bool, S_IRUGO|S_IWUSR);

/*-------------------------------------------------------------------------*/

/* Thanks to NetChip Technologies for donating this product ID.
 *
 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
 * Instead:  allocate your own, using normal USB-IF procedures.
 */
#ifndef	CONFIG_USB_ZERO_HNPTEST
#define DRIVER_VENDOR_NUM	0x0525		/* NetChip */
#define DRIVER_PRODUCT_NUM	0xa4a0		/* Linux-USB "Gadget Zero" */
#else
#define DRIVER_VENDOR_NUM	0x1a0a		/* OTG test device IDs */
#define DRIVER_PRODUCT_NUM	0xbadd
#endif

/*-------------------------------------------------------------------------*/

static struct usb_device_descriptor device_desc = {
	.bLength =		sizeof device_desc,
	.bDescriptorType =	USB_DT_DEVICE,

	.bcdUSB =		__constant_cpu_to_le16(0x0200),
	.bDeviceClass =		USB_CLASS_VENDOR_SPEC,

	.idVendor =		__constant_cpu_to_le16(DRIVER_VENDOR_NUM),
	.idProduct =		__constant_cpu_to_le16(DRIVER_PRODUCT_NUM),
	.bNumConfigurations =	2,
};

#ifdef CONFIG_USB_OTG
static struct usb_otg_descriptor otg_descriptor = {
	.bLength =		sizeof otg_descriptor,
	.bDescriptorType =	USB_DT_OTG,

	/* REVISIT SRP-only hardware is possible, although
	 * it would not be called "OTG" ...
	 */
	.bmAttributes =		USB_OTG_SRP | USB_OTG_HNP,
};

const struct usb_descriptor_header *otg_desc[] = {
	(struct usb_descriptor_header *) &otg_descriptor,
	NULL,
};
#endif

/* string IDs are assigned dynamically */

#define STRING_MANUFACTURER_IDX		0
#define STRING_PRODUCT_IDX		1
#define STRING_SERIAL_IDX		2

static char manufacturer[50];

/* default serial number takes at least two packets */
static char serial[] = "0123456789.0123456789.0123456789";

static struct usb_string strings_dev[] = {
	[STRING_MANUFACTURER_IDX].s = manufacturer,
	[STRING_PRODUCT_IDX].s = longname,
	[STRING_SERIAL_IDX].s = serial,
	{  }			/* end of list */
};

static struct usb_gadget_strings stringtab_dev = {
	.language	= 0x0409,	/* en-us */
	.strings	= strings_dev,
};

static struct usb_gadget_strings *dev_strings[] = {
	&stringtab_dev,
	NULL,
};

/*-------------------------------------------------------------------------*/

struct usb_request *alloc_ep_req(struct usb_ep *ep)
{
	struct usb_request	*req;

	req = usb_ep_alloc_request(ep, GFP_ATOMIC);
	if (req) {
		req->length = buflen;
		req->buf = kmalloc(buflen, GFP_ATOMIC);
		if (!req->buf) {
			usb_ep_free_request(ep, req);
			req = NULL;
		}
	}
	return req;
}

void free_ep_req(struct usb_ep *ep, struct usb_request *req)
{
	kfree(req->buf);
	usb_ep_free_request(ep, req);
}

static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
{
	int			value;

	if (ep->driver_data) {
		value = usb_ep_disable(ep);
		if (value < 0)
			DBG(cdev, "disable %s --> %d\n",
					ep->name, value);
		ep->driver_data = NULL;
	}
}

void disable_endpoints(struct usb_composite_dev *cdev,
		struct usb_ep *in, struct usb_ep *out)
{
	disable_ep(cdev, in);
	disable_ep(cdev, out);
}

/*-------------------------------------------------------------------------*/

static int __init zero_bind(struct usb_composite_dev *cdev)
{
	int			gcnum;
	struct usb_gadget	*gadget = cdev->gadget;
	int			id;

	/* Allocate string descriptor numbers ... note that string
	 * contents can be overridden by the composite_dev glue.
	 */
	id = usb_string_id(cdev);
	if (id < 0)
		return id;
	strings_dev[STRING_MANUFACTURER_IDX].id = id;
	device_desc.iManufacturer = id;

	id = usb_string_id(cdev);
	if (id < 0)
		return id;
	strings_dev[STRING_PRODUCT_IDX].id = id;
	device_desc.iProduct = id;

	id = usb_string_id(cdev);
	if (id < 0)
		return id;
	strings_dev[STRING_SERIAL_IDX].id = id;
	device_desc.iSerialNumber = id;

	/* Register primary, then secondary configuration.  Note that
	 * SH3 only allows one config...
	 */
	if (loopdefault) {
		loopback_add(cdev);
		if (!gadget_is_sh(gadget))
			sourcesink_add(cdev);
	} else {
		sourcesink_add(cdev);
		if (!gadget_is_sh(gadget))
			loopback_add(cdev);
	}

	gcnum = usb_gadget_controller_number(gadget);
	if (gcnum >= 0)
		device_desc.bcdDevice = cpu_to_le16(0x0200 + gcnum);
	else {
		/* gadget zero is so simple (for now, no altsettings) that
		 * it SHOULD NOT have problems with bulk-capable hardware.
		 * so just warn about unrcognized controllers -- don't panic.
		 *
		 * things like configuration and altsetting numbering
		 * can need hardware-specific attention though.
		 */
		pr_warning("%s: controller '%s' not recognized\n",
			longname, gadget->name);
		device_desc.bcdDevice = __constant_cpu_to_le16(0x9999);
	}


	INFO(cdev, "%s, version: " DRIVER_VERSION "\n", longname);

	snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
		init_utsname()->sysname, init_utsname()->release,
		gadget->name);

	return 0;
}

static struct usb_composite_driver zero_driver = {
	.name		= "zero",
	.dev		= &device_desc,
	.strings	= dev_strings,
	.bind		= zero_bind,
};

MODULE_AUTHOR("David Brownell");
MODULE_LICENSE("GPL");

static int __init init(void)
{
	return usb_composite_register(&zero_driver);
}
module_init(init);

static void __exit cleanup(void)
{
	usb_composite_unregister(&zero_driver);
}
module_exit(cleanup);