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David Brownelle5760fd2008-06-19 17:55:35 -07001/*
2 * f_loopback.c - USB peripheral loopback configuration driver
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/* #define VERBOSE_DEBUG */
23
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090024#include <linux/slab.h>
David Brownelle5760fd2008-06-19 17:55:35 -070025#include <linux/kernel.h>
David Brownelle5760fd2008-06-19 17:55:35 -070026#include <linux/device.h>
27
28#include "g_zero.h"
29#include "gadget_chips.h"
30
31
32/*
33 * LOOPBACK FUNCTION ... a testing vehicle for USB peripherals,
34 *
35 * This takes messages of various sizes written OUT to a device, and loops
36 * them back so they can be read IN from it. It has been used by certain
37 * test applications. It supports limited testing of data queueing logic.
38 *
39 *
40 * This is currently packaged as a configuration driver, which can't be
41 * combined with other functions to make composite devices. However, it
42 * can be combined with other independent configurations.
43 */
44struct f_loopback {
45 struct usb_function function;
46
47 struct usb_ep *in_ep;
48 struct usb_ep *out_ep;
49};
50
51static inline struct f_loopback *func_to_loop(struct usb_function *f)
52{
53 return container_of(f, struct f_loopback, function);
54}
55
56static unsigned qlen = 32;
57module_param(qlen, uint, 0);
58MODULE_PARM_DESC(qlenn, "depth of loopback queue");
59
60/*-------------------------------------------------------------------------*/
61
62static struct usb_interface_descriptor loopback_intf = {
63 .bLength = sizeof loopback_intf,
64 .bDescriptorType = USB_DT_INTERFACE,
65
66 .bNumEndpoints = 2,
67 .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
68 /* .iInterface = DYNAMIC */
69};
70
71/* full speed support: */
72
David Brownell7e75bc02008-08-18 17:41:31 -070073static struct usb_endpoint_descriptor fs_loop_source_desc = {
David Brownelle5760fd2008-06-19 17:55:35 -070074 .bLength = USB_DT_ENDPOINT_SIZE,
75 .bDescriptorType = USB_DT_ENDPOINT,
76
77 .bEndpointAddress = USB_DIR_IN,
78 .bmAttributes = USB_ENDPOINT_XFER_BULK,
79};
80
David Brownell7e75bc02008-08-18 17:41:31 -070081static struct usb_endpoint_descriptor fs_loop_sink_desc = {
David Brownelle5760fd2008-06-19 17:55:35 -070082 .bLength = USB_DT_ENDPOINT_SIZE,
83 .bDescriptorType = USB_DT_ENDPOINT,
84
85 .bEndpointAddress = USB_DIR_OUT,
86 .bmAttributes = USB_ENDPOINT_XFER_BULK,
87};
88
89static struct usb_descriptor_header *fs_loopback_descs[] = {
90 (struct usb_descriptor_header *) &loopback_intf,
David Brownell7e75bc02008-08-18 17:41:31 -070091 (struct usb_descriptor_header *) &fs_loop_sink_desc,
92 (struct usb_descriptor_header *) &fs_loop_source_desc,
David Brownelle5760fd2008-06-19 17:55:35 -070093 NULL,
94};
95
96/* high speed support: */
97
David Brownell7e75bc02008-08-18 17:41:31 -070098static struct usb_endpoint_descriptor hs_loop_source_desc = {
David Brownelle5760fd2008-06-19 17:55:35 -070099 .bLength = USB_DT_ENDPOINT_SIZE,
100 .bDescriptorType = USB_DT_ENDPOINT,
101
102 .bmAttributes = USB_ENDPOINT_XFER_BULK,
Harvey Harrison551509d2009-02-11 14:11:36 -0800103 .wMaxPacketSize = cpu_to_le16(512),
David Brownelle5760fd2008-06-19 17:55:35 -0700104};
105
David Brownell7e75bc02008-08-18 17:41:31 -0700106static struct usb_endpoint_descriptor hs_loop_sink_desc = {
David Brownelle5760fd2008-06-19 17:55:35 -0700107 .bLength = USB_DT_ENDPOINT_SIZE,
108 .bDescriptorType = USB_DT_ENDPOINT,
109
110 .bmAttributes = USB_ENDPOINT_XFER_BULK,
Harvey Harrison551509d2009-02-11 14:11:36 -0800111 .wMaxPacketSize = cpu_to_le16(512),
David Brownelle5760fd2008-06-19 17:55:35 -0700112};
113
114static struct usb_descriptor_header *hs_loopback_descs[] = {
115 (struct usb_descriptor_header *) &loopback_intf,
David Brownell7e75bc02008-08-18 17:41:31 -0700116 (struct usb_descriptor_header *) &hs_loop_source_desc,
117 (struct usb_descriptor_header *) &hs_loop_sink_desc,
David Brownelle5760fd2008-06-19 17:55:35 -0700118 NULL,
119};
120
121/* function-specific strings: */
122
123static struct usb_string strings_loopback[] = {
124 [0].s = "loop input to output",
125 { } /* end of list */
126};
127
128static struct usb_gadget_strings stringtab_loop = {
129 .language = 0x0409, /* en-us */
130 .strings = strings_loopback,
131};
132
133static struct usb_gadget_strings *loopback_strings[] = {
134 &stringtab_loop,
135 NULL,
136};
137
138/*-------------------------------------------------------------------------*/
139
140static int __init
141loopback_bind(struct usb_configuration *c, struct usb_function *f)
142{
143 struct usb_composite_dev *cdev = c->cdev;
144 struct f_loopback *loop = func_to_loop(f);
145 int id;
146
147 /* allocate interface ID(s) */
148 id = usb_interface_id(c, f);
149 if (id < 0)
150 return id;
151 loopback_intf.bInterfaceNumber = id;
152
153 /* allocate endpoints */
154
David Brownell7e75bc02008-08-18 17:41:31 -0700155 loop->in_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_source_desc);
David Brownelle5760fd2008-06-19 17:55:35 -0700156 if (!loop->in_ep) {
157autoconf_fail:
158 ERROR(cdev, "%s: can't autoconfigure on %s\n",
159 f->name, cdev->gadget->name);
160 return -ENODEV;
161 }
162 loop->in_ep->driver_data = cdev; /* claim */
163
David Brownell7e75bc02008-08-18 17:41:31 -0700164 loop->out_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_sink_desc);
David Brownelle5760fd2008-06-19 17:55:35 -0700165 if (!loop->out_ep)
166 goto autoconf_fail;
167 loop->out_ep->driver_data = cdev; /* claim */
168
169 /* support high speed hardware */
170 if (gadget_is_dualspeed(c->cdev->gadget)) {
David Brownell7e75bc02008-08-18 17:41:31 -0700171 hs_loop_source_desc.bEndpointAddress =
172 fs_loop_source_desc.bEndpointAddress;
173 hs_loop_sink_desc.bEndpointAddress =
174 fs_loop_sink_desc.bEndpointAddress;
David Brownelle5760fd2008-06-19 17:55:35 -0700175 f->hs_descriptors = hs_loopback_descs;
176 }
177
178 DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
179 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
180 f->name, loop->in_ep->name, loop->out_ep->name);
181 return 0;
182}
183
184static void
185loopback_unbind(struct usb_configuration *c, struct usb_function *f)
186{
187 kfree(func_to_loop(f));
188}
189
190static void loopback_complete(struct usb_ep *ep, struct usb_request *req)
191{
192 struct f_loopback *loop = ep->driver_data;
193 struct usb_composite_dev *cdev = loop->function.config->cdev;
194 int status = req->status;
195
196 switch (status) {
197
198 case 0: /* normal completion? */
199 if (ep == loop->out_ep) {
200 /* loop this OUT packet back IN to the host */
201 req->zero = (req->actual < req->length);
202 req->length = req->actual;
203 status = usb_ep_queue(loop->in_ep, req, GFP_ATOMIC);
204 if (status == 0)
205 return;
206
207 /* "should never get here" */
208 ERROR(cdev, "can't loop %s to %s: %d\n",
209 ep->name, loop->in_ep->name,
210 status);
211 }
212
213 /* queue the buffer for some later OUT packet */
214 req->length = buflen;
215 status = usb_ep_queue(loop->out_ep, req, GFP_ATOMIC);
216 if (status == 0)
217 return;
218
219 /* "should never get here" */
220 /* FALLTHROUGH */
221
222 default:
223 ERROR(cdev, "%s loop complete --> %d, %d/%d\n", ep->name,
224 status, req->actual, req->length);
225 /* FALLTHROUGH */
226
227 /* NOTE: since this driver doesn't maintain an explicit record
228 * of requests it submitted (just maintains qlen count), we
229 * rely on the hardware driver to clean up on disconnect or
230 * endpoint disable.
231 */
232 case -ECONNABORTED: /* hardware forced ep reset */
233 case -ECONNRESET: /* request dequeued */
234 case -ESHUTDOWN: /* disconnect from host */
235 free_ep_req(ep, req);
236 return;
237 }
238}
239
240static void disable_loopback(struct f_loopback *loop)
241{
242 struct usb_composite_dev *cdev;
243
244 cdev = loop->function.config->cdev;
245 disable_endpoints(cdev, loop->in_ep, loop->out_ep);
246 VDBG(cdev, "%s disabled\n", loop->function.name);
247}
248
249static int
250enable_loopback(struct usb_composite_dev *cdev, struct f_loopback *loop)
251{
252 int result = 0;
253 const struct usb_endpoint_descriptor *src, *sink;
254 struct usb_ep *ep;
255 struct usb_request *req;
256 unsigned i;
257
David Brownell7e75bc02008-08-18 17:41:31 -0700258 src = ep_choose(cdev->gadget,
259 &hs_loop_source_desc, &fs_loop_source_desc);
260 sink = ep_choose(cdev->gadget,
261 &hs_loop_sink_desc, &fs_loop_sink_desc);
David Brownelle5760fd2008-06-19 17:55:35 -0700262
263 /* one endpoint writes data back IN to the host */
264 ep = loop->in_ep;
265 result = usb_ep_enable(ep, src);
266 if (result < 0)
267 return result;
268 ep->driver_data = loop;
269
270 /* one endpoint just reads OUT packets */
271 ep = loop->out_ep;
272 result = usb_ep_enable(ep, sink);
273 if (result < 0) {
274fail0:
275 ep = loop->in_ep;
276 usb_ep_disable(ep);
277 ep->driver_data = NULL;
278 return result;
279 }
280 ep->driver_data = loop;
281
282 /* allocate a bunch of read buffers and queue them all at once.
283 * we buffer at most 'qlen' transfers; fewer if any need more
284 * than 'buflen' bytes each.
285 */
286 for (i = 0; i < qlen && result == 0; i++) {
287 req = alloc_ep_req(ep);
288 if (req) {
289 req->complete = loopback_complete;
290 result = usb_ep_queue(ep, req, GFP_ATOMIC);
291 if (result)
292 ERROR(cdev, "%s queue req --> %d\n",
293 ep->name, result);
294 } else {
295 usb_ep_disable(ep);
296 ep->driver_data = NULL;
297 result = -ENOMEM;
298 goto fail0;
299 }
300 }
301
302 DBG(cdev, "%s enabled\n", loop->function.name);
303 return result;
304}
305
306static int loopback_set_alt(struct usb_function *f,
307 unsigned intf, unsigned alt)
308{
309 struct f_loopback *loop = func_to_loop(f);
310 struct usb_composite_dev *cdev = f->config->cdev;
311
312 /* we know alt is zero */
313 if (loop->in_ep->driver_data)
314 disable_loopback(loop);
315 return enable_loopback(cdev, loop);
316}
317
318static void loopback_disable(struct usb_function *f)
319{
320 struct f_loopback *loop = func_to_loop(f);
321
322 disable_loopback(loop);
323}
324
325/*-------------------------------------------------------------------------*/
326
327static int __init loopback_bind_config(struct usb_configuration *c)
328{
329 struct f_loopback *loop;
330 int status;
331
332 loop = kzalloc(sizeof *loop, GFP_KERNEL);
333 if (!loop)
334 return -ENOMEM;
335
336 loop->function.name = "loopback";
337 loop->function.descriptors = fs_loopback_descs;
338 loop->function.bind = loopback_bind;
339 loop->function.unbind = loopback_unbind;
340 loop->function.set_alt = loopback_set_alt;
341 loop->function.disable = loopback_disable;
342
343 status = usb_add_function(c, &loop->function);
344 if (status)
345 kfree(loop);
346 return status;
347}
348
349static struct usb_configuration loopback_driver = {
350 .label = "loopback",
351 .strings = loopback_strings,
352 .bind = loopback_bind_config,
353 .bConfigurationValue = 2,
354 .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
David Brownelle5760fd2008-06-19 17:55:35 -0700355 /* .iConfiguration = DYNAMIC */
356};
357
358/**
359 * loopback_add - add a loopback testing configuration to a device
360 * @cdev: the device to support the loopback configuration
361 */
David Brownellab943a22009-03-19 14:16:09 -0700362int __init loopback_add(struct usb_composite_dev *cdev, bool autoresume)
David Brownelle5760fd2008-06-19 17:55:35 -0700363{
364 int id;
365
366 /* allocate string ID(s) */
367 id = usb_string_id(cdev);
368 if (id < 0)
369 return id;
370 strings_loopback[0].id = id;
371
372 loopback_intf.iInterface = id;
373 loopback_driver.iConfiguration = id;
374
David Brownellab943a22009-03-19 14:16:09 -0700375 /* support autoresume for remote wakeup testing */
376 if (autoresume)
377 sourcesink_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
378
David Brownelle5760fd2008-06-19 17:55:35 -0700379 /* support OTG systems */
380 if (gadget_is_otg(cdev->gadget)) {
381 loopback_driver.descriptors = otg_desc;
382 loopback_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
383 }
384
385 return usb_add_config(cdev, &loopback_driver);
386}