1 /*
2 * zero.c -- Gadget Zero, for USB development
3 *
4 * Copyright (C) 2003-2008 David Brownell
5 * Copyright (C) 2008 by Nokia Corporation
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22
23 /*
24 * Gadget Zero only needs two bulk endpoints, and is an example of how you
25 * can write a hardware-agnostic gadget driver running inside a USB device.
26 * Some hardware details are visible, but don't affect most of the driver.
27 *
28 * Use it with the Linux host/master side "usbtest" driver to get a basic
29 * functional test of your device-side usb stack, or with "usb-skeleton".
30 *
31 * It supports two similar configurations. One sinks whatever the usb host
32 * writes, and in return sources zeroes. The other loops whatever the host
33 * writes back, so the host can read it.
34 *
35 * Many drivers will only have one configuration, letting them be much
36 * simpler if they also don't support high speed operation (like this
37 * driver does).
38 *
39 * Why is *this* driver using two configurations, rather than setting up
40 * two interfaces with different functions? To help verify that multiple
41 * configuration infrastucture is working correctly; also, so that it can
42 * work with low capability USB controllers without four bulk endpoints.
43 */
44
45 /*
46 * driver assumes self-powered hardware, and
47 * has no way for users to trigger remote wakeup.
48 */
49
50 /* #define VERBOSE_DEBUG */
51
52 #include <linux/kernel.h>
53 #include <linux/utsname.h>
54 #include <linux/device.h>
55
56 #include "g_zero.h"
57 #include "gadget_chips.h"
58
59
60 /*-------------------------------------------------------------------------*/
61
62 /*
63 * Kbuild is not very cooperative with respect to linking separately
64 * compiled library objects into one module. So for now we won't use
65 * separate compilation ... ensuring init/exit sections work to shrink
66 * the runtime footprint, and giving us at least some parts of what
67 * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
68 */
69 #include "composite.c"
70 #include "usbstring.c"
71 #include "config.c"
72 #include "epautoconf.c"
73
74 #include "f_sourcesink.c"
75 #include "f_loopback.c"
76
77 /*-------------------------------------------------------------------------*/
78
79 #define DRIVER_VERSION "Cinco de Mayo 2008"
80
81 static const char longname[] = "Gadget Zero";
82
83 unsigned buflen = 4096;
84 module_param(buflen, uint, 0);
85
86 /*
87 * Normally the "loopback" configuration is second (index 1) so
88 * it's not the default. Here's where to change that order, to
89 * work better with hosts where config changes are problematic or
90 * controllers (like original superh) that only support one config.
91 */
92 static int loopdefault = 0;
93 module_param(loopdefault, bool, S_IRUGO|S_IWUSR);
94
95 /*-------------------------------------------------------------------------*/
96
97 /* Thanks to NetChip Technologies for donating this product ID.
98 *
99 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!!
100 * Instead: allocate your own, using normal USB-IF procedures.
101 */
102 #ifndef CONFIG_USB_ZERO_HNPTEST
103 #define DRIVER_VENDOR_NUM 0x0525 /* NetChip */
104 #define DRIVER_PRODUCT_NUM 0xa4a0 /* Linux-USB "Gadget Zero" */
105 #else
106 #define DRIVER_VENDOR_NUM 0x1a0a /* OTG test device IDs */
107 #define DRIVER_PRODUCT_NUM 0xbadd
108 #endif
109
110 /*-------------------------------------------------------------------------*/
111
112 static struct usb_device_descriptor device_desc = {
113 .bLength = sizeof device_desc,
114 .bDescriptorType = USB_DT_DEVICE,
115
116 .bcdUSB = __constant_cpu_to_le16(0x0200),
117 .bDeviceClass = USB_CLASS_VENDOR_SPEC,
118
119 .idVendor = __constant_cpu_to_le16(DRIVER_VENDOR_NUM),
120 .idProduct = __constant_cpu_to_le16(DRIVER_PRODUCT_NUM),
121 .bNumConfigurations = 2,
122 };
123
124 #ifdef CONFIG_USB_OTG
125 static struct usb_otg_descriptor otg_descriptor = {
126 .bLength = sizeof otg_descriptor,
127 .bDescriptorType = USB_DT_OTG,
128
129 /* REVISIT SRP-only hardware is possible, although
130 * it would not be called "OTG" ...
131 */
132 .bmAttributes = USB_OTG_SRP | USB_OTG_HNP,
133 };
134
135 const struct usb_descriptor_header *otg_desc[] = {
136 (struct usb_descriptor_header *) &otg_descriptor,
137 NULL,
138 };
139 #endif
140
141 /* string IDs are assigned dynamically */
142
143 #define STRING_MANUFACTURER_IDX 0
144 #define STRING_PRODUCT_IDX 1
145 #define STRING_SERIAL_IDX 2
146
147 static char manufacturer[50];
148
149 /* default serial number takes at least two packets */
150 static char serial[] = "0123456789.0123456789.0123456789";
151
152 static struct usb_string strings_dev[] = {
153 [STRING_MANUFACTURER_IDX].s = manufacturer,
154 [STRING_PRODUCT_IDX].s = longname,
155 [STRING_SERIAL_IDX].s = serial,
156 { } /* end of list */
157 };
158
159 static struct usb_gadget_strings stringtab_dev = {
160 .language = 0x0409, /* en-us */
161 .strings = strings_dev,
162 };
163
164 static struct usb_gadget_strings *dev_strings[] = {
165 &stringtab_dev,
166 NULL,
167 };
168
169 /*-------------------------------------------------------------------------*/
170
alloc_ep_req(struct usb_ep * ep)171 struct usb_request *alloc_ep_req(struct usb_ep *ep)
172 {
173 struct usb_request *req;
174
175 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
176 if (req) {
177 req->length = buflen;
178 req->buf = kmalloc(buflen, GFP_ATOMIC);
179 if (!req->buf) {
180 usb_ep_free_request(ep, req);
181 req = NULL;
182 }
183 }
184 return req;
185 }
186
free_ep_req(struct usb_ep * ep,struct usb_request * req)187 void free_ep_req(struct usb_ep *ep, struct usb_request *req)
188 {
189 kfree(req->buf);
190 usb_ep_free_request(ep, req);
191 }
192
disable_ep(struct usb_composite_dev * cdev,struct usb_ep * ep)193 static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
194 {
195 int value;
196
197 if (ep->driver_data) {
198 value = usb_ep_disable(ep);
199 if (value < 0)
200 DBG(cdev, "disable %s --> %d\n",
201 ep->name, value);
202 ep->driver_data = NULL;
203 }
204 }
205
disable_endpoints(struct usb_composite_dev * cdev,struct usb_ep * in,struct usb_ep * out)206 void disable_endpoints(struct usb_composite_dev *cdev,
207 struct usb_ep *in, struct usb_ep *out)
208 {
209 disable_ep(cdev, in);
210 disable_ep(cdev, out);
211 }
212
213 /*-------------------------------------------------------------------------*/
214
zero_bind(struct usb_composite_dev * cdev)215 static int __init zero_bind(struct usb_composite_dev *cdev)
216 {
217 int gcnum;
218 struct usb_gadget *gadget = cdev->gadget;
219 int id;
220
221 /* Allocate string descriptor numbers ... note that string
222 * contents can be overridden by the composite_dev glue.
223 */
224 id = usb_string_id(cdev);
225 if (id < 0)
226 return id;
227 strings_dev[STRING_MANUFACTURER_IDX].id = id;
228 device_desc.iManufacturer = id;
229
230 id = usb_string_id(cdev);
231 if (id < 0)
232 return id;
233 strings_dev[STRING_PRODUCT_IDX].id = id;
234 device_desc.iProduct = id;
235
236 id = usb_string_id(cdev);
237 if (id < 0)
238 return id;
239 strings_dev[STRING_SERIAL_IDX].id = id;
240 device_desc.iSerialNumber = id;
241
242 /* Register primary, then secondary configuration. Note that
243 * SH3 only allows one config...
244 */
245 if (loopdefault) {
246 loopback_add(cdev);
247 if (!gadget_is_sh(gadget))
248 sourcesink_add(cdev);
249 } else {
250 sourcesink_add(cdev);
251 if (!gadget_is_sh(gadget))
252 loopback_add(cdev);
253 }
254
255 gcnum = usb_gadget_controller_number(gadget);
256 if (gcnum >= 0)
257 device_desc.bcdDevice = cpu_to_le16(0x0200 + gcnum);
258 else {
259 /* gadget zero is so simple (for now, no altsettings) that
260 * it SHOULD NOT have problems with bulk-capable hardware.
261 * so just warn about unrcognized controllers -- don't panic.
262 *
263 * things like configuration and altsetting numbering
264 * can need hardware-specific attention though.
265 */
266 pr_warning("%s: controller '%s' not recognized\n",
267 longname, gadget->name);
268 device_desc.bcdDevice = __constant_cpu_to_le16(0x9999);
269 }
270
271
272 INFO(cdev, "%s, version: " DRIVER_VERSION "\n", longname);
273
274 snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
275 init_utsname()->sysname, init_utsname()->release,
276 gadget->name);
277
278 return 0;
279 }
280
281 static struct usb_composite_driver zero_driver = {
282 .name = "zero",
283 .dev = &device_desc,
284 .strings = dev_strings,
285 .bind = zero_bind,
286 };
287
288 MODULE_AUTHOR("David Brownell");
289 MODULE_LICENSE("GPL");
290
init(void)291 static int __init init(void)
292 {
293 return usb_composite_register(&zero_driver);
294 }
295 module_init(init);
296
cleanup(void)297 static void __exit cleanup(void)
298 {
299 usb_composite_unregister(&zero_driver);
300 }
301 module_exit(cleanup);
302