xref: /linux/drivers/usb/gadget/function/f_loopback.c (revision 3a39d672e7f48b8d6b91a09afa4b55352773b4b5)
15fd54aceSGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0+
200a2430fSAndrzej Pietrasiewicz /*
300a2430fSAndrzej Pietrasiewicz  * f_loopback.c - USB peripheral loopback configuration driver
400a2430fSAndrzej Pietrasiewicz  *
500a2430fSAndrzej Pietrasiewicz  * Copyright (C) 2003-2008 David Brownell
600a2430fSAndrzej Pietrasiewicz  * Copyright (C) 2008 by Nokia Corporation
700a2430fSAndrzej Pietrasiewicz  */
800a2430fSAndrzej Pietrasiewicz 
900a2430fSAndrzej Pietrasiewicz /* #define VERBOSE_DEBUG */
1000a2430fSAndrzej Pietrasiewicz 
1100a2430fSAndrzej Pietrasiewicz #include <linux/slab.h>
1200a2430fSAndrzej Pietrasiewicz #include <linux/kernel.h>
1300a2430fSAndrzej Pietrasiewicz #include <linux/device.h>
1400a2430fSAndrzej Pietrasiewicz #include <linux/module.h>
1500a2430fSAndrzej Pietrasiewicz #include <linux/err.h>
1600a2430fSAndrzej Pietrasiewicz #include <linux/usb/composite.h>
17*d9c61bb3SMichael Grzeschik #include <linux/usb/func_utils.h>
1800a2430fSAndrzej Pietrasiewicz 
1900a2430fSAndrzej Pietrasiewicz #include "g_zero.h"
2000a2430fSAndrzej Pietrasiewicz 
2100a2430fSAndrzej Pietrasiewicz /*
2200a2430fSAndrzej Pietrasiewicz  * LOOPBACK FUNCTION ... a testing vehicle for USB peripherals,
2300a2430fSAndrzej Pietrasiewicz  *
2400a2430fSAndrzej Pietrasiewicz  * This takes messages of various sizes written OUT to a device, and loops
2500a2430fSAndrzej Pietrasiewicz  * them back so they can be read IN from it.  It has been used by certain
2600a2430fSAndrzej Pietrasiewicz  * test applications.  It supports limited testing of data queueing logic.
2700a2430fSAndrzej Pietrasiewicz  */
2800a2430fSAndrzej Pietrasiewicz struct f_loopback {
2900a2430fSAndrzej Pietrasiewicz 	struct usb_function	function;
3000a2430fSAndrzej Pietrasiewicz 
3100a2430fSAndrzej Pietrasiewicz 	struct usb_ep		*in_ep;
3200a2430fSAndrzej Pietrasiewicz 	struct usb_ep		*out_ep;
333e9d992fSKrzysztof Opasiak 
343e9d992fSKrzysztof Opasiak 	unsigned                qlen;
353e9d992fSKrzysztof Opasiak 	unsigned                buflen;
3600a2430fSAndrzej Pietrasiewicz };
3700a2430fSAndrzej Pietrasiewicz 
func_to_loop(struct usb_function * f)3800a2430fSAndrzej Pietrasiewicz static inline struct f_loopback *func_to_loop(struct usb_function *f)
3900a2430fSAndrzej Pietrasiewicz {
4000a2430fSAndrzej Pietrasiewicz 	return container_of(f, struct f_loopback, function);
4100a2430fSAndrzej Pietrasiewicz }
4200a2430fSAndrzej Pietrasiewicz 
4300a2430fSAndrzej Pietrasiewicz /*-------------------------------------------------------------------------*/
4400a2430fSAndrzej Pietrasiewicz 
4500a2430fSAndrzej Pietrasiewicz static struct usb_interface_descriptor loopback_intf = {
463e9d992fSKrzysztof Opasiak 	.bLength =		sizeof(loopback_intf),
4700a2430fSAndrzej Pietrasiewicz 	.bDescriptorType =	USB_DT_INTERFACE,
4800a2430fSAndrzej Pietrasiewicz 
4900a2430fSAndrzej Pietrasiewicz 	.bNumEndpoints =	2,
5000a2430fSAndrzej Pietrasiewicz 	.bInterfaceClass =	USB_CLASS_VENDOR_SPEC,
5100a2430fSAndrzej Pietrasiewicz 	/* .iInterface = DYNAMIC */
5200a2430fSAndrzej Pietrasiewicz };
5300a2430fSAndrzej Pietrasiewicz 
5400a2430fSAndrzej Pietrasiewicz /* full speed support: */
5500a2430fSAndrzej Pietrasiewicz 
5600a2430fSAndrzej Pietrasiewicz static struct usb_endpoint_descriptor fs_loop_source_desc = {
5700a2430fSAndrzej Pietrasiewicz 	.bLength =		USB_DT_ENDPOINT_SIZE,
5800a2430fSAndrzej Pietrasiewicz 	.bDescriptorType =	USB_DT_ENDPOINT,
5900a2430fSAndrzej Pietrasiewicz 
6000a2430fSAndrzej Pietrasiewicz 	.bEndpointAddress =	USB_DIR_IN,
6100a2430fSAndrzej Pietrasiewicz 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
6200a2430fSAndrzej Pietrasiewicz };
6300a2430fSAndrzej Pietrasiewicz 
6400a2430fSAndrzej Pietrasiewicz static struct usb_endpoint_descriptor fs_loop_sink_desc = {
6500a2430fSAndrzej Pietrasiewicz 	.bLength =		USB_DT_ENDPOINT_SIZE,
6600a2430fSAndrzej Pietrasiewicz 	.bDescriptorType =	USB_DT_ENDPOINT,
6700a2430fSAndrzej Pietrasiewicz 
6800a2430fSAndrzej Pietrasiewicz 	.bEndpointAddress =	USB_DIR_OUT,
6900a2430fSAndrzej Pietrasiewicz 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
7000a2430fSAndrzej Pietrasiewicz };
7100a2430fSAndrzej Pietrasiewicz 
7200a2430fSAndrzej Pietrasiewicz static struct usb_descriptor_header *fs_loopback_descs[] = {
7300a2430fSAndrzej Pietrasiewicz 	(struct usb_descriptor_header *) &loopback_intf,
7400a2430fSAndrzej Pietrasiewicz 	(struct usb_descriptor_header *) &fs_loop_sink_desc,
7500a2430fSAndrzej Pietrasiewicz 	(struct usb_descriptor_header *) &fs_loop_source_desc,
7600a2430fSAndrzej Pietrasiewicz 	NULL,
7700a2430fSAndrzej Pietrasiewicz };
7800a2430fSAndrzej Pietrasiewicz 
7900a2430fSAndrzej Pietrasiewicz /* high speed support: */
8000a2430fSAndrzej Pietrasiewicz 
8100a2430fSAndrzej Pietrasiewicz static struct usb_endpoint_descriptor hs_loop_source_desc = {
8200a2430fSAndrzej Pietrasiewicz 	.bLength =		USB_DT_ENDPOINT_SIZE,
8300a2430fSAndrzej Pietrasiewicz 	.bDescriptorType =	USB_DT_ENDPOINT,
8400a2430fSAndrzej Pietrasiewicz 
8500a2430fSAndrzej Pietrasiewicz 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
8600a2430fSAndrzej Pietrasiewicz 	.wMaxPacketSize =	cpu_to_le16(512),
8700a2430fSAndrzej Pietrasiewicz };
8800a2430fSAndrzej Pietrasiewicz 
8900a2430fSAndrzej Pietrasiewicz static struct usb_endpoint_descriptor hs_loop_sink_desc = {
9000a2430fSAndrzej Pietrasiewicz 	.bLength =		USB_DT_ENDPOINT_SIZE,
9100a2430fSAndrzej Pietrasiewicz 	.bDescriptorType =	USB_DT_ENDPOINT,
9200a2430fSAndrzej Pietrasiewicz 
9300a2430fSAndrzej Pietrasiewicz 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
9400a2430fSAndrzej Pietrasiewicz 	.wMaxPacketSize =	cpu_to_le16(512),
9500a2430fSAndrzej Pietrasiewicz };
9600a2430fSAndrzej Pietrasiewicz 
9700a2430fSAndrzej Pietrasiewicz static struct usb_descriptor_header *hs_loopback_descs[] = {
9800a2430fSAndrzej Pietrasiewicz 	(struct usb_descriptor_header *) &loopback_intf,
9900a2430fSAndrzej Pietrasiewicz 	(struct usb_descriptor_header *) &hs_loop_source_desc,
10000a2430fSAndrzej Pietrasiewicz 	(struct usb_descriptor_header *) &hs_loop_sink_desc,
10100a2430fSAndrzej Pietrasiewicz 	NULL,
10200a2430fSAndrzej Pietrasiewicz };
10300a2430fSAndrzej Pietrasiewicz 
10400a2430fSAndrzej Pietrasiewicz /* super speed support: */
10500a2430fSAndrzej Pietrasiewicz 
10600a2430fSAndrzej Pietrasiewicz static struct usb_endpoint_descriptor ss_loop_source_desc = {
10700a2430fSAndrzej Pietrasiewicz 	.bLength =		USB_DT_ENDPOINT_SIZE,
10800a2430fSAndrzej Pietrasiewicz 	.bDescriptorType =	USB_DT_ENDPOINT,
10900a2430fSAndrzej Pietrasiewicz 
11000a2430fSAndrzej Pietrasiewicz 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
11100a2430fSAndrzej Pietrasiewicz 	.wMaxPacketSize =	cpu_to_le16(1024),
11200a2430fSAndrzej Pietrasiewicz };
11300a2430fSAndrzej Pietrasiewicz 
11400a2430fSAndrzej Pietrasiewicz static struct usb_ss_ep_comp_descriptor ss_loop_source_comp_desc = {
11500a2430fSAndrzej Pietrasiewicz 	.bLength =		USB_DT_SS_EP_COMP_SIZE,
11600a2430fSAndrzej Pietrasiewicz 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
11700a2430fSAndrzej Pietrasiewicz 	.bMaxBurst =		0,
11800a2430fSAndrzej Pietrasiewicz 	.bmAttributes =		0,
11900a2430fSAndrzej Pietrasiewicz 	.wBytesPerInterval =	0,
12000a2430fSAndrzej Pietrasiewicz };
12100a2430fSAndrzej Pietrasiewicz 
12200a2430fSAndrzej Pietrasiewicz static struct usb_endpoint_descriptor ss_loop_sink_desc = {
12300a2430fSAndrzej Pietrasiewicz 	.bLength =		USB_DT_ENDPOINT_SIZE,
12400a2430fSAndrzej Pietrasiewicz 	.bDescriptorType =	USB_DT_ENDPOINT,
12500a2430fSAndrzej Pietrasiewicz 
12600a2430fSAndrzej Pietrasiewicz 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
12700a2430fSAndrzej Pietrasiewicz 	.wMaxPacketSize =	cpu_to_le16(1024),
12800a2430fSAndrzej Pietrasiewicz };
12900a2430fSAndrzej Pietrasiewicz 
13000a2430fSAndrzej Pietrasiewicz static struct usb_ss_ep_comp_descriptor ss_loop_sink_comp_desc = {
13100a2430fSAndrzej Pietrasiewicz 	.bLength =		USB_DT_SS_EP_COMP_SIZE,
13200a2430fSAndrzej Pietrasiewicz 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
13300a2430fSAndrzej Pietrasiewicz 	.bMaxBurst =		0,
13400a2430fSAndrzej Pietrasiewicz 	.bmAttributes =		0,
13500a2430fSAndrzej Pietrasiewicz 	.wBytesPerInterval =	0,
13600a2430fSAndrzej Pietrasiewicz };
13700a2430fSAndrzej Pietrasiewicz 
13800a2430fSAndrzej Pietrasiewicz static struct usb_descriptor_header *ss_loopback_descs[] = {
13900a2430fSAndrzej Pietrasiewicz 	(struct usb_descriptor_header *) &loopback_intf,
14000a2430fSAndrzej Pietrasiewicz 	(struct usb_descriptor_header *) &ss_loop_source_desc,
14100a2430fSAndrzej Pietrasiewicz 	(struct usb_descriptor_header *) &ss_loop_source_comp_desc,
14200a2430fSAndrzej Pietrasiewicz 	(struct usb_descriptor_header *) &ss_loop_sink_desc,
14300a2430fSAndrzej Pietrasiewicz 	(struct usb_descriptor_header *) &ss_loop_sink_comp_desc,
14400a2430fSAndrzej Pietrasiewicz 	NULL,
14500a2430fSAndrzej Pietrasiewicz };
14600a2430fSAndrzej Pietrasiewicz 
14700a2430fSAndrzej Pietrasiewicz /* function-specific strings: */
14800a2430fSAndrzej Pietrasiewicz 
14900a2430fSAndrzej Pietrasiewicz static struct usb_string strings_loopback[] = {
15000a2430fSAndrzej Pietrasiewicz 	[0].s = "loop input to output",
15100a2430fSAndrzej Pietrasiewicz 	{  }			/* end of list */
15200a2430fSAndrzej Pietrasiewicz };
15300a2430fSAndrzej Pietrasiewicz 
15400a2430fSAndrzej Pietrasiewicz static struct usb_gadget_strings stringtab_loop = {
15500a2430fSAndrzej Pietrasiewicz 	.language	= 0x0409,	/* en-us */
15600a2430fSAndrzej Pietrasiewicz 	.strings	= strings_loopback,
15700a2430fSAndrzej Pietrasiewicz };
15800a2430fSAndrzej Pietrasiewicz 
15900a2430fSAndrzej Pietrasiewicz static struct usb_gadget_strings *loopback_strings[] = {
16000a2430fSAndrzej Pietrasiewicz 	&stringtab_loop,
16100a2430fSAndrzej Pietrasiewicz 	NULL,
16200a2430fSAndrzej Pietrasiewicz };
16300a2430fSAndrzej Pietrasiewicz 
16400a2430fSAndrzej Pietrasiewicz /*-------------------------------------------------------------------------*/
16500a2430fSAndrzej Pietrasiewicz 
loopback_bind(struct usb_configuration * c,struct usb_function * f)16600a2430fSAndrzej Pietrasiewicz static int loopback_bind(struct usb_configuration *c, struct usb_function *f)
16700a2430fSAndrzej Pietrasiewicz {
16800a2430fSAndrzej Pietrasiewicz 	struct usb_composite_dev *cdev = c->cdev;
16900a2430fSAndrzej Pietrasiewicz 	struct f_loopback	*loop = func_to_loop(f);
17000a2430fSAndrzej Pietrasiewicz 	int			id;
17100a2430fSAndrzej Pietrasiewicz 	int ret;
17200a2430fSAndrzej Pietrasiewicz 
17300a2430fSAndrzej Pietrasiewicz 	/* allocate interface ID(s) */
17400a2430fSAndrzej Pietrasiewicz 	id = usb_interface_id(c, f);
17500a2430fSAndrzej Pietrasiewicz 	if (id < 0)
17600a2430fSAndrzej Pietrasiewicz 		return id;
17700a2430fSAndrzej Pietrasiewicz 	loopback_intf.bInterfaceNumber = id;
17800a2430fSAndrzej Pietrasiewicz 
17900a2430fSAndrzej Pietrasiewicz 	id = usb_string_id(cdev);
18000a2430fSAndrzej Pietrasiewicz 	if (id < 0)
18100a2430fSAndrzej Pietrasiewicz 		return id;
18200a2430fSAndrzej Pietrasiewicz 	strings_loopback[0].id = id;
18300a2430fSAndrzej Pietrasiewicz 	loopback_intf.iInterface = id;
18400a2430fSAndrzej Pietrasiewicz 
18500a2430fSAndrzej Pietrasiewicz 	/* allocate endpoints */
18600a2430fSAndrzej Pietrasiewicz 
18700a2430fSAndrzej Pietrasiewicz 	loop->in_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_source_desc);
18800a2430fSAndrzej Pietrasiewicz 	if (!loop->in_ep) {
18900a2430fSAndrzej Pietrasiewicz autoconf_fail:
19000a2430fSAndrzej Pietrasiewicz 		ERROR(cdev, "%s: can't autoconfigure on %s\n",
19100a2430fSAndrzej Pietrasiewicz 			f->name, cdev->gadget->name);
19200a2430fSAndrzej Pietrasiewicz 		return -ENODEV;
19300a2430fSAndrzej Pietrasiewicz 	}
19400a2430fSAndrzej Pietrasiewicz 
19500a2430fSAndrzej Pietrasiewicz 	loop->out_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_sink_desc);
19600a2430fSAndrzej Pietrasiewicz 	if (!loop->out_ep)
19700a2430fSAndrzej Pietrasiewicz 		goto autoconf_fail;
19800a2430fSAndrzej Pietrasiewicz 
19900a2430fSAndrzej Pietrasiewicz 	/* support high speed hardware */
20000a2430fSAndrzej Pietrasiewicz 	hs_loop_source_desc.bEndpointAddress =
20100a2430fSAndrzej Pietrasiewicz 		fs_loop_source_desc.bEndpointAddress;
20200a2430fSAndrzej Pietrasiewicz 	hs_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress;
20300a2430fSAndrzej Pietrasiewicz 
20400a2430fSAndrzej Pietrasiewicz 	/* support super speed hardware */
20500a2430fSAndrzej Pietrasiewicz 	ss_loop_source_desc.bEndpointAddress =
20600a2430fSAndrzej Pietrasiewicz 		fs_loop_source_desc.bEndpointAddress;
20700a2430fSAndrzej Pietrasiewicz 	ss_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress;
20800a2430fSAndrzej Pietrasiewicz 
20900a2430fSAndrzej Pietrasiewicz 	ret = usb_assign_descriptors(f, fs_loopback_descs, hs_loopback_descs,
21090c4d057SMaciej Żenczykowski 			ss_loopback_descs, ss_loopback_descs);
21100a2430fSAndrzej Pietrasiewicz 	if (ret)
21200a2430fSAndrzej Pietrasiewicz 		return ret;
21300a2430fSAndrzej Pietrasiewicz 
214333ab99eSLinyu Yuan 	DBG(cdev, "%s: IN/%s, OUT/%s\n",
21500a2430fSAndrzej Pietrasiewicz 			f->name, loop->in_ep->name, loop->out_ep->name);
21600a2430fSAndrzej Pietrasiewicz 	return 0;
21700a2430fSAndrzej Pietrasiewicz }
21800a2430fSAndrzej Pietrasiewicz 
lb_free_func(struct usb_function * f)21900a2430fSAndrzej Pietrasiewicz static void lb_free_func(struct usb_function *f)
22000a2430fSAndrzej Pietrasiewicz {
22100a2430fSAndrzej Pietrasiewicz 	struct f_lb_opts *opts;
22200a2430fSAndrzej Pietrasiewicz 
22300a2430fSAndrzej Pietrasiewicz 	opts = container_of(f->fi, struct f_lb_opts, func_inst);
22400a2430fSAndrzej Pietrasiewicz 
22500a2430fSAndrzej Pietrasiewicz 	mutex_lock(&opts->lock);
22600a2430fSAndrzej Pietrasiewicz 	opts->refcnt--;
22700a2430fSAndrzej Pietrasiewicz 	mutex_unlock(&opts->lock);
22800a2430fSAndrzej Pietrasiewicz 
22900a2430fSAndrzej Pietrasiewicz 	usb_free_all_descriptors(f);
23000a2430fSAndrzej Pietrasiewicz 	kfree(func_to_loop(f));
23100a2430fSAndrzej Pietrasiewicz }
23200a2430fSAndrzej Pietrasiewicz 
loopback_complete(struct usb_ep * ep,struct usb_request * req)23300a2430fSAndrzej Pietrasiewicz static void loopback_complete(struct usb_ep *ep, struct usb_request *req)
23400a2430fSAndrzej Pietrasiewicz {
23500a2430fSAndrzej Pietrasiewicz 	struct f_loopback	*loop = ep->driver_data;
23600a2430fSAndrzej Pietrasiewicz 	struct usb_composite_dev *cdev = loop->function.config->cdev;
23700a2430fSAndrzej Pietrasiewicz 	int			status = req->status;
23800a2430fSAndrzej Pietrasiewicz 
23900a2430fSAndrzej Pietrasiewicz 	switch (status) {
24000a2430fSAndrzej Pietrasiewicz 	case 0:				/* normal completion? */
24100a2430fSAndrzej Pietrasiewicz 		if (ep == loop->out_ep) {
24291c42b0dSKrzysztof Opasiak 			/*
24391c42b0dSKrzysztof Opasiak 			 * We received some data from the host so let's
24491c42b0dSKrzysztof Opasiak 			 * queue it so host can read the from our in ep
24591c42b0dSKrzysztof Opasiak 			 */
24691c42b0dSKrzysztof Opasiak 			struct usb_request *in_req = req->context;
24791c42b0dSKrzysztof Opasiak 
24891c42b0dSKrzysztof Opasiak 			in_req->zero = (req->actual < req->length);
24991c42b0dSKrzysztof Opasiak 			in_req->length = req->actual;
25091c42b0dSKrzysztof Opasiak 			ep = loop->in_ep;
25191c42b0dSKrzysztof Opasiak 			req = in_req;
25291c42b0dSKrzysztof Opasiak 		} else {
25391c42b0dSKrzysztof Opasiak 			/*
25491c42b0dSKrzysztof Opasiak 			 * We have just looped back a bunch of data
25591c42b0dSKrzysztof Opasiak 			 * to host. Now let's wait for some more data.
25691c42b0dSKrzysztof Opasiak 			 */
25791c42b0dSKrzysztof Opasiak 			req = req->context;
25891c42b0dSKrzysztof Opasiak 			ep = loop->out_ep;
25900a2430fSAndrzej Pietrasiewicz 		}
26000a2430fSAndrzej Pietrasiewicz 
26191c42b0dSKrzysztof Opasiak 		/* queue the buffer back to host or for next bunch of data */
262e0857ce5SFelipe Balbi 		status = usb_ep_queue(ep, req, GFP_ATOMIC);
26391c42b0dSKrzysztof Opasiak 		if (status == 0) {
26400a2430fSAndrzej Pietrasiewicz 			return;
26591c42b0dSKrzysztof Opasiak 		} else {
26691c42b0dSKrzysztof Opasiak 			ERROR(cdev, "Unable to loop back buffer to %s: %d\n",
26791c42b0dSKrzysztof Opasiak 			      ep->name, status);
26891c42b0dSKrzysztof Opasiak 			goto free_req;
26991c42b0dSKrzysztof Opasiak 		}
27000a2430fSAndrzej Pietrasiewicz 
27100a2430fSAndrzej Pietrasiewicz 		/* "should never get here" */
27200a2430fSAndrzej Pietrasiewicz 	default:
27300a2430fSAndrzej Pietrasiewicz 		ERROR(cdev, "%s loop complete --> %d, %d/%d\n", ep->name,
27400a2430fSAndrzej Pietrasiewicz 				status, req->actual, req->length);
27593c747edSGustavo A. R. Silva 		fallthrough;
27600a2430fSAndrzej Pietrasiewicz 
27700a2430fSAndrzej Pietrasiewicz 	/* NOTE:  since this driver doesn't maintain an explicit record
27800a2430fSAndrzej Pietrasiewicz 	 * of requests it submitted (just maintains qlen count), we
27900a2430fSAndrzej Pietrasiewicz 	 * rely on the hardware driver to clean up on disconnect or
28000a2430fSAndrzej Pietrasiewicz 	 * endpoint disable.
28100a2430fSAndrzej Pietrasiewicz 	 */
28200a2430fSAndrzej Pietrasiewicz 	case -ECONNABORTED:		/* hardware forced ep reset */
28300a2430fSAndrzej Pietrasiewicz 	case -ECONNRESET:		/* request dequeued */
28400a2430fSAndrzej Pietrasiewicz 	case -ESHUTDOWN:		/* disconnect from host */
28591c42b0dSKrzysztof Opasiak free_req:
28691c42b0dSKrzysztof Opasiak 		usb_ep_free_request(ep == loop->in_ep ?
28791c42b0dSKrzysztof Opasiak 				    loop->out_ep : loop->in_ep,
28891c42b0dSKrzysztof Opasiak 				    req->context);
28900a2430fSAndrzej Pietrasiewicz 		free_ep_req(ep, req);
29000a2430fSAndrzej Pietrasiewicz 		return;
29100a2430fSAndrzej Pietrasiewicz 	}
29200a2430fSAndrzej Pietrasiewicz }
29300a2430fSAndrzej Pietrasiewicz 
disable_loopback(struct f_loopback * loop)29400a2430fSAndrzej Pietrasiewicz static void disable_loopback(struct f_loopback *loop)
29500a2430fSAndrzej Pietrasiewicz {
29600a2430fSAndrzej Pietrasiewicz 	struct usb_composite_dev	*cdev;
29700a2430fSAndrzej Pietrasiewicz 
29800a2430fSAndrzej Pietrasiewicz 	cdev = loop->function.config->cdev;
2992c247804SFelipe Balbi 	disable_endpoints(cdev, loop->in_ep, loop->out_ep, NULL, NULL);
30000a2430fSAndrzej Pietrasiewicz 	VDBG(cdev, "%s disabled\n", loop->function.name);
30100a2430fSAndrzej Pietrasiewicz }
30200a2430fSAndrzej Pietrasiewicz 
lb_alloc_ep_req(struct usb_ep * ep,int len)30300a2430fSAndrzej Pietrasiewicz static inline struct usb_request *lb_alloc_ep_req(struct usb_ep *ep, int len)
30400a2430fSAndrzej Pietrasiewicz {
305aadbe812SFelipe F. Tonello 	return alloc_ep_req(ep, len);
30600a2430fSAndrzej Pietrasiewicz }
30700a2430fSAndrzej Pietrasiewicz 
alloc_requests(struct usb_composite_dev * cdev,struct f_loopback * loop)30891c42b0dSKrzysztof Opasiak static int alloc_requests(struct usb_composite_dev *cdev,
30991c42b0dSKrzysztof Opasiak 			  struct f_loopback *loop)
31000a2430fSAndrzej Pietrasiewicz {
31191c42b0dSKrzysztof Opasiak 	struct usb_request *in_req, *out_req;
31291c42b0dSKrzysztof Opasiak 	int i;
31391c42b0dSKrzysztof Opasiak 	int result = 0;
31400a2430fSAndrzej Pietrasiewicz 
315e0857ce5SFelipe Balbi 	/*
316e0857ce5SFelipe Balbi 	 * allocate a bunch of read buffers and queue them all at once.
31791c42b0dSKrzysztof Opasiak 	 * we buffer at most 'qlen' transfers; We allocate buffers only
31891c42b0dSKrzysztof Opasiak 	 * for out transfer and reuse them in IN transfers to implement
31991c42b0dSKrzysztof Opasiak 	 * our loopback functionality
32000a2430fSAndrzej Pietrasiewicz 	 */
3213e9d992fSKrzysztof Opasiak 	for (i = 0; i < loop->qlen && result == 0; i++) {
32291c42b0dSKrzysztof Opasiak 		result = -ENOMEM;
323e0857ce5SFelipe Balbi 
3245e216d54SPeter Chen 		in_req = usb_ep_alloc_request(loop->in_ep, GFP_ATOMIC);
32591c42b0dSKrzysztof Opasiak 		if (!in_req)
32691c42b0dSKrzysztof Opasiak 			goto fail;
32791c42b0dSKrzysztof Opasiak 
328aadbe812SFelipe F. Tonello 		out_req = lb_alloc_ep_req(loop->out_ep, loop->buflen);
32991c42b0dSKrzysztof Opasiak 		if (!out_req)
33091c42b0dSKrzysztof Opasiak 			goto fail_in;
33191c42b0dSKrzysztof Opasiak 
33291c42b0dSKrzysztof Opasiak 		in_req->complete = loopback_complete;
33391c42b0dSKrzysztof Opasiak 		out_req->complete = loopback_complete;
33491c42b0dSKrzysztof Opasiak 
33591c42b0dSKrzysztof Opasiak 		in_req->buf = out_req->buf;
33691c42b0dSKrzysztof Opasiak 		/* length will be set in complete routine */
33791c42b0dSKrzysztof Opasiak 		in_req->context = out_req;
33891c42b0dSKrzysztof Opasiak 		out_req->context = in_req;
33991c42b0dSKrzysztof Opasiak 
34091c42b0dSKrzysztof Opasiak 		result = usb_ep_queue(loop->out_ep, out_req, GFP_ATOMIC);
341e0857ce5SFelipe Balbi 		if (result) {
34200a2430fSAndrzej Pietrasiewicz 			ERROR(cdev, "%s queue req --> %d\n",
34391c42b0dSKrzysztof Opasiak 					loop->out_ep->name, result);
34491c42b0dSKrzysztof Opasiak 			goto fail_out;
345e0857ce5SFelipe Balbi 		}
346e0857ce5SFelipe Balbi 	}
347e0857ce5SFelipe Balbi 
348e0857ce5SFelipe Balbi 	return 0;
349e0857ce5SFelipe Balbi 
35091c42b0dSKrzysztof Opasiak fail_out:
35191c42b0dSKrzysztof Opasiak 	free_ep_req(loop->out_ep, out_req);
35291c42b0dSKrzysztof Opasiak fail_in:
35391c42b0dSKrzysztof Opasiak 	usb_ep_free_request(loop->in_ep, in_req);
35491c42b0dSKrzysztof Opasiak fail:
35591c42b0dSKrzysztof Opasiak 	return result;
35691c42b0dSKrzysztof Opasiak }
357e0857ce5SFelipe Balbi 
enable_endpoint(struct usb_composite_dev * cdev,struct f_loopback * loop,struct usb_ep * ep)35891c42b0dSKrzysztof Opasiak static int enable_endpoint(struct usb_composite_dev *cdev,
35991c42b0dSKrzysztof Opasiak 			   struct f_loopback *loop, struct usb_ep *ep)
36091c42b0dSKrzysztof Opasiak {
36191c42b0dSKrzysztof Opasiak 	int					result;
36291c42b0dSKrzysztof Opasiak 
36391c42b0dSKrzysztof Opasiak 	result = config_ep_by_speed(cdev->gadget, &(loop->function), ep);
36491c42b0dSKrzysztof Opasiak 	if (result)
36591c42b0dSKrzysztof Opasiak 		goto out;
36691c42b0dSKrzysztof Opasiak 
36791c42b0dSKrzysztof Opasiak 	result = usb_ep_enable(ep);
36891c42b0dSKrzysztof Opasiak 	if (result < 0)
36991c42b0dSKrzysztof Opasiak 		goto out;
37091c42b0dSKrzysztof Opasiak 	ep->driver_data = loop;
37191c42b0dSKrzysztof Opasiak 	result = 0;
37291c42b0dSKrzysztof Opasiak 
37391c42b0dSKrzysztof Opasiak out:
374e0857ce5SFelipe Balbi 	return result;
37500a2430fSAndrzej Pietrasiewicz }
376e0857ce5SFelipe Balbi 
377e0857ce5SFelipe Balbi static int
enable_loopback(struct usb_composite_dev * cdev,struct f_loopback * loop)378e0857ce5SFelipe Balbi enable_loopback(struct usb_composite_dev *cdev, struct f_loopback *loop)
379e0857ce5SFelipe Balbi {
380e0857ce5SFelipe Balbi 	int					result = 0;
381e0857ce5SFelipe Balbi 
382e0857ce5SFelipe Balbi 	result = enable_endpoint(cdev, loop, loop->in_ep);
383e0857ce5SFelipe Balbi 	if (result)
38491c42b0dSKrzysztof Opasiak 		goto out;
385e0857ce5SFelipe Balbi 
386e0857ce5SFelipe Balbi 	result = enable_endpoint(cdev, loop, loop->out_ep);
387e0857ce5SFelipe Balbi 	if (result)
38891c42b0dSKrzysztof Opasiak 		goto disable_in;
38991c42b0dSKrzysztof Opasiak 
39091c42b0dSKrzysztof Opasiak 	result = alloc_requests(cdev, loop);
39191c42b0dSKrzysztof Opasiak 	if (result)
39291c42b0dSKrzysztof Opasiak 		goto disable_out;
39300a2430fSAndrzej Pietrasiewicz 
39400a2430fSAndrzej Pietrasiewicz 	DBG(cdev, "%s enabled\n", loop->function.name);
39591c42b0dSKrzysztof Opasiak 	return 0;
39691c42b0dSKrzysztof Opasiak 
39791c42b0dSKrzysztof Opasiak disable_out:
39891c42b0dSKrzysztof Opasiak 	usb_ep_disable(loop->out_ep);
39991c42b0dSKrzysztof Opasiak disable_in:
40091c42b0dSKrzysztof Opasiak 	usb_ep_disable(loop->in_ep);
40191c42b0dSKrzysztof Opasiak out:
40200a2430fSAndrzej Pietrasiewicz 	return result;
40300a2430fSAndrzej Pietrasiewicz }
40400a2430fSAndrzej Pietrasiewicz 
loopback_set_alt(struct usb_function * f,unsigned intf,unsigned alt)40500a2430fSAndrzej Pietrasiewicz static int loopback_set_alt(struct usb_function *f,
40600a2430fSAndrzej Pietrasiewicz 		unsigned intf, unsigned alt)
40700a2430fSAndrzej Pietrasiewicz {
40800a2430fSAndrzej Pietrasiewicz 	struct f_loopback	*loop = func_to_loop(f);
40900a2430fSAndrzej Pietrasiewicz 	struct usb_composite_dev *cdev = f->config->cdev;
41000a2430fSAndrzej Pietrasiewicz 
41100a2430fSAndrzej Pietrasiewicz 	/* we know alt is zero */
41200a2430fSAndrzej Pietrasiewicz 	disable_loopback(loop);
41300a2430fSAndrzej Pietrasiewicz 	return enable_loopback(cdev, loop);
41400a2430fSAndrzej Pietrasiewicz }
41500a2430fSAndrzej Pietrasiewicz 
loopback_disable(struct usb_function * f)41600a2430fSAndrzej Pietrasiewicz static void loopback_disable(struct usb_function *f)
41700a2430fSAndrzej Pietrasiewicz {
41800a2430fSAndrzej Pietrasiewicz 	struct f_loopback	*loop = func_to_loop(f);
41900a2430fSAndrzej Pietrasiewicz 
42000a2430fSAndrzej Pietrasiewicz 	disable_loopback(loop);
42100a2430fSAndrzej Pietrasiewicz }
42200a2430fSAndrzej Pietrasiewicz 
loopback_alloc(struct usb_function_instance * fi)42300a2430fSAndrzej Pietrasiewicz static struct usb_function *loopback_alloc(struct usb_function_instance *fi)
42400a2430fSAndrzej Pietrasiewicz {
42500a2430fSAndrzej Pietrasiewicz 	struct f_loopback	*loop;
42600a2430fSAndrzej Pietrasiewicz 	struct f_lb_opts	*lb_opts;
42700a2430fSAndrzej Pietrasiewicz 
42800a2430fSAndrzej Pietrasiewicz 	loop = kzalloc(sizeof *loop, GFP_KERNEL);
42900a2430fSAndrzej Pietrasiewicz 	if (!loop)
43000a2430fSAndrzej Pietrasiewicz 		return ERR_PTR(-ENOMEM);
43100a2430fSAndrzej Pietrasiewicz 
43200a2430fSAndrzej Pietrasiewicz 	lb_opts = container_of(fi, struct f_lb_opts, func_inst);
43300a2430fSAndrzej Pietrasiewicz 
43400a2430fSAndrzej Pietrasiewicz 	mutex_lock(&lb_opts->lock);
43500a2430fSAndrzej Pietrasiewicz 	lb_opts->refcnt++;
43600a2430fSAndrzej Pietrasiewicz 	mutex_unlock(&lb_opts->lock);
43700a2430fSAndrzej Pietrasiewicz 
4383e9d992fSKrzysztof Opasiak 	loop->buflen = lb_opts->bulk_buflen;
4393e9d992fSKrzysztof Opasiak 	loop->qlen = lb_opts->qlen;
4403e9d992fSKrzysztof Opasiak 	if (!loop->qlen)
4413e9d992fSKrzysztof Opasiak 		loop->qlen = 32;
44200a2430fSAndrzej Pietrasiewicz 
44300a2430fSAndrzej Pietrasiewicz 	loop->function.name = "loopback";
44400a2430fSAndrzej Pietrasiewicz 	loop->function.bind = loopback_bind;
44500a2430fSAndrzej Pietrasiewicz 	loop->function.set_alt = loopback_set_alt;
44600a2430fSAndrzej Pietrasiewicz 	loop->function.disable = loopback_disable;
44700a2430fSAndrzej Pietrasiewicz 	loop->function.strings = loopback_strings;
44800a2430fSAndrzej Pietrasiewicz 
44900a2430fSAndrzej Pietrasiewicz 	loop->function.free_func = lb_free_func;
45000a2430fSAndrzej Pietrasiewicz 
45100a2430fSAndrzej Pietrasiewicz 	return &loop->function;
45200a2430fSAndrzej Pietrasiewicz }
45300a2430fSAndrzej Pietrasiewicz 
to_f_lb_opts(struct config_item * item)45400a2430fSAndrzej Pietrasiewicz static inline struct f_lb_opts *to_f_lb_opts(struct config_item *item)
45500a2430fSAndrzej Pietrasiewicz {
45600a2430fSAndrzej Pietrasiewicz 	return container_of(to_config_group(item), struct f_lb_opts,
45700a2430fSAndrzej Pietrasiewicz 			    func_inst.group);
45800a2430fSAndrzej Pietrasiewicz }
45900a2430fSAndrzej Pietrasiewicz 
lb_attr_release(struct config_item * item)46000a2430fSAndrzej Pietrasiewicz static void lb_attr_release(struct config_item *item)
46100a2430fSAndrzej Pietrasiewicz {
46200a2430fSAndrzej Pietrasiewicz 	struct f_lb_opts *lb_opts = to_f_lb_opts(item);
46300a2430fSAndrzej Pietrasiewicz 
46400a2430fSAndrzej Pietrasiewicz 	usb_put_function_instance(&lb_opts->func_inst);
46500a2430fSAndrzej Pietrasiewicz }
46600a2430fSAndrzej Pietrasiewicz 
46700a2430fSAndrzej Pietrasiewicz static struct configfs_item_operations lb_item_ops = {
46800a2430fSAndrzej Pietrasiewicz 	.release		= lb_attr_release,
46900a2430fSAndrzej Pietrasiewicz };
47000a2430fSAndrzej Pietrasiewicz 
f_lb_opts_qlen_show(struct config_item * item,char * page)47175ab2256SChristoph Hellwig static ssize_t f_lb_opts_qlen_show(struct config_item *item, char *page)
47200a2430fSAndrzej Pietrasiewicz {
47375ab2256SChristoph Hellwig 	struct f_lb_opts *opts = to_f_lb_opts(item);
47400a2430fSAndrzej Pietrasiewicz 	int result;
47500a2430fSAndrzej Pietrasiewicz 
47600a2430fSAndrzej Pietrasiewicz 	mutex_lock(&opts->lock);
477902d03c7SKrzysztof Opasiak 	result = sprintf(page, "%d\n", opts->qlen);
47800a2430fSAndrzej Pietrasiewicz 	mutex_unlock(&opts->lock);
47900a2430fSAndrzej Pietrasiewicz 
48000a2430fSAndrzej Pietrasiewicz 	return result;
48100a2430fSAndrzej Pietrasiewicz }
48200a2430fSAndrzej Pietrasiewicz 
f_lb_opts_qlen_store(struct config_item * item,const char * page,size_t len)48375ab2256SChristoph Hellwig static ssize_t f_lb_opts_qlen_store(struct config_item *item,
48400a2430fSAndrzej Pietrasiewicz 				    const char *page, size_t len)
48500a2430fSAndrzej Pietrasiewicz {
48675ab2256SChristoph Hellwig 	struct f_lb_opts *opts = to_f_lb_opts(item);
48700a2430fSAndrzej Pietrasiewicz 	int ret;
48800a2430fSAndrzej Pietrasiewicz 	u32 num;
48900a2430fSAndrzej Pietrasiewicz 
49000a2430fSAndrzej Pietrasiewicz 	mutex_lock(&opts->lock);
49100a2430fSAndrzej Pietrasiewicz 	if (opts->refcnt) {
49200a2430fSAndrzej Pietrasiewicz 		ret = -EBUSY;
49300a2430fSAndrzej Pietrasiewicz 		goto end;
49400a2430fSAndrzej Pietrasiewicz 	}
49500a2430fSAndrzej Pietrasiewicz 
49600a2430fSAndrzej Pietrasiewicz 	ret = kstrtou32(page, 0, &num);
49700a2430fSAndrzej Pietrasiewicz 	if (ret)
49800a2430fSAndrzej Pietrasiewicz 		goto end;
49900a2430fSAndrzej Pietrasiewicz 
50000a2430fSAndrzej Pietrasiewicz 	opts->qlen = num;
50100a2430fSAndrzej Pietrasiewicz 	ret = len;
50200a2430fSAndrzej Pietrasiewicz end:
50300a2430fSAndrzej Pietrasiewicz 	mutex_unlock(&opts->lock);
50400a2430fSAndrzej Pietrasiewicz 	return ret;
50500a2430fSAndrzej Pietrasiewicz }
50600a2430fSAndrzej Pietrasiewicz 
50775ab2256SChristoph Hellwig CONFIGFS_ATTR(f_lb_opts_, qlen);
50800a2430fSAndrzej Pietrasiewicz 
f_lb_opts_bulk_buflen_show(struct config_item * item,char * page)50975ab2256SChristoph Hellwig static ssize_t f_lb_opts_bulk_buflen_show(struct config_item *item, char *page)
51000a2430fSAndrzej Pietrasiewicz {
51175ab2256SChristoph Hellwig 	struct f_lb_opts *opts = to_f_lb_opts(item);
51200a2430fSAndrzej Pietrasiewicz 	int result;
51300a2430fSAndrzej Pietrasiewicz 
51400a2430fSAndrzej Pietrasiewicz 	mutex_lock(&opts->lock);
515902d03c7SKrzysztof Opasiak 	result = sprintf(page, "%d\n", opts->bulk_buflen);
51600a2430fSAndrzej Pietrasiewicz 	mutex_unlock(&opts->lock);
51700a2430fSAndrzej Pietrasiewicz 
51800a2430fSAndrzej Pietrasiewicz 	return result;
51900a2430fSAndrzej Pietrasiewicz }
52000a2430fSAndrzej Pietrasiewicz 
f_lb_opts_bulk_buflen_store(struct config_item * item,const char * page,size_t len)52175ab2256SChristoph Hellwig static ssize_t f_lb_opts_bulk_buflen_store(struct config_item *item,
52200a2430fSAndrzej Pietrasiewicz 				    const char *page, size_t len)
52300a2430fSAndrzej Pietrasiewicz {
52475ab2256SChristoph Hellwig 	struct f_lb_opts *opts = to_f_lb_opts(item);
52500a2430fSAndrzej Pietrasiewicz 	int ret;
52600a2430fSAndrzej Pietrasiewicz 	u32 num;
52700a2430fSAndrzej Pietrasiewicz 
52800a2430fSAndrzej Pietrasiewicz 	mutex_lock(&opts->lock);
52900a2430fSAndrzej Pietrasiewicz 	if (opts->refcnt) {
53000a2430fSAndrzej Pietrasiewicz 		ret = -EBUSY;
53100a2430fSAndrzej Pietrasiewicz 		goto end;
53200a2430fSAndrzej Pietrasiewicz 	}
53300a2430fSAndrzej Pietrasiewicz 
53400a2430fSAndrzej Pietrasiewicz 	ret = kstrtou32(page, 0, &num);
53500a2430fSAndrzej Pietrasiewicz 	if (ret)
53600a2430fSAndrzej Pietrasiewicz 		goto end;
53700a2430fSAndrzej Pietrasiewicz 
53800a2430fSAndrzej Pietrasiewicz 	opts->bulk_buflen = num;
53900a2430fSAndrzej Pietrasiewicz 	ret = len;
54000a2430fSAndrzej Pietrasiewicz end:
54100a2430fSAndrzej Pietrasiewicz 	mutex_unlock(&opts->lock);
54200a2430fSAndrzej Pietrasiewicz 	return ret;
54300a2430fSAndrzej Pietrasiewicz }
54400a2430fSAndrzej Pietrasiewicz 
54575ab2256SChristoph Hellwig CONFIGFS_ATTR(f_lb_opts_, bulk_buflen);
54600a2430fSAndrzej Pietrasiewicz 
54700a2430fSAndrzej Pietrasiewicz static struct configfs_attribute *lb_attrs[] = {
54875ab2256SChristoph Hellwig 	&f_lb_opts_attr_qlen,
54975ab2256SChristoph Hellwig 	&f_lb_opts_attr_bulk_buflen,
55000a2430fSAndrzej Pietrasiewicz 	NULL,
55100a2430fSAndrzej Pietrasiewicz };
55200a2430fSAndrzej Pietrasiewicz 
55397363902SBhumika Goyal static const struct config_item_type lb_func_type = {
55400a2430fSAndrzej Pietrasiewicz 	.ct_item_ops    = &lb_item_ops,
55500a2430fSAndrzej Pietrasiewicz 	.ct_attrs	= lb_attrs,
55600a2430fSAndrzej Pietrasiewicz 	.ct_owner       = THIS_MODULE,
55700a2430fSAndrzej Pietrasiewicz };
55800a2430fSAndrzej Pietrasiewicz 
lb_free_instance(struct usb_function_instance * fi)55900a2430fSAndrzej Pietrasiewicz static void lb_free_instance(struct usb_function_instance *fi)
56000a2430fSAndrzej Pietrasiewicz {
56100a2430fSAndrzej Pietrasiewicz 	struct f_lb_opts *lb_opts;
56200a2430fSAndrzej Pietrasiewicz 
56300a2430fSAndrzej Pietrasiewicz 	lb_opts = container_of(fi, struct f_lb_opts, func_inst);
56400a2430fSAndrzej Pietrasiewicz 	kfree(lb_opts);
56500a2430fSAndrzej Pietrasiewicz }
56600a2430fSAndrzej Pietrasiewicz 
loopback_alloc_instance(void)56700a2430fSAndrzej Pietrasiewicz static struct usb_function_instance *loopback_alloc_instance(void)
56800a2430fSAndrzej Pietrasiewicz {
56900a2430fSAndrzej Pietrasiewicz 	struct f_lb_opts *lb_opts;
57000a2430fSAndrzej Pietrasiewicz 
57100a2430fSAndrzej Pietrasiewicz 	lb_opts = kzalloc(sizeof(*lb_opts), GFP_KERNEL);
57200a2430fSAndrzej Pietrasiewicz 	if (!lb_opts)
57300a2430fSAndrzej Pietrasiewicz 		return ERR_PTR(-ENOMEM);
57400a2430fSAndrzej Pietrasiewicz 	mutex_init(&lb_opts->lock);
57500a2430fSAndrzej Pietrasiewicz 	lb_opts->func_inst.free_func_inst = lb_free_instance;
57600a2430fSAndrzej Pietrasiewicz 	lb_opts->bulk_buflen = GZERO_BULK_BUFLEN;
57700a2430fSAndrzej Pietrasiewicz 	lb_opts->qlen = GZERO_QLEN;
57800a2430fSAndrzej Pietrasiewicz 
57900a2430fSAndrzej Pietrasiewicz 	config_group_init_type_name(&lb_opts->func_inst.group, "",
58000a2430fSAndrzej Pietrasiewicz 				    &lb_func_type);
58100a2430fSAndrzej Pietrasiewicz 
58200a2430fSAndrzej Pietrasiewicz 	return  &lb_opts->func_inst;
58300a2430fSAndrzej Pietrasiewicz }
58400a2430fSAndrzej Pietrasiewicz DECLARE_USB_FUNCTION(Loopback, loopback_alloc_instance, loopback_alloc);
58500a2430fSAndrzej Pietrasiewicz 
lb_modinit(void)58600a2430fSAndrzej Pietrasiewicz int __init lb_modinit(void)
58700a2430fSAndrzej Pietrasiewicz {
5885387c920SColin Ian King 	return usb_function_register(&Loopbackusb_func);
58900a2430fSAndrzej Pietrasiewicz }
5905387c920SColin Ian King 
lb_modexit(void)59100a2430fSAndrzej Pietrasiewicz void __exit lb_modexit(void)
59200a2430fSAndrzej Pietrasiewicz {
59300a2430fSAndrzej Pietrasiewicz 	usb_function_unregister(&Loopbackusb_func);
59400a2430fSAndrzej Pietrasiewicz }
59500a2430fSAndrzej Pietrasiewicz 
5961cb9ba5eSJeff Johnson MODULE_DESCRIPTION("USB peripheral loopback configuration driver");
59700a2430fSAndrzej Pietrasiewicz MODULE_LICENSE("GPL");
598