[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / usb / gadget / f_loopback.c

/*
 * f_loopback.c - USB peripheral loopback configuration driver
 *
 * 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.
 */

/* #define VERBOSE_DEBUG */

#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/usb/composite.h>

#include "g_zero.h"

/*
 * LOOPBACK FUNCTION ... a testing vehicle for USB peripherals,
 *
 * This takes messages of various sizes written OUT to a device, and loops
 * them back so they can be read IN from it.  It has been used by certain
 * test applications.  It supports limited testing of data queueing logic.
 *
 *
 * This is currently packaged as a configuration driver, which can't be
 * combined with other functions to make composite devices.  However, it
 * can be combined with other independent configurations.
 */
struct f_loopback {
	struct usb_function	function;

	struct usb_ep		*in_ep;
	struct usb_ep		*out_ep;
};

static inline struct f_loopback *func_to_loop(struct usb_function *f)
{
	return container_of(f, struct f_loopback, function);
}

static unsigned qlen;
static unsigned buflen;

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

static struct usb_interface_descriptor loopback_intf = {
	.bLength =		sizeof loopback_intf,
	.bDescriptorType =	USB_DT_INTERFACE,

	.bNumEndpoints =	2,
	.bInterfaceClass =	USB_CLASS_VENDOR_SPEC,
	/* .iInterface = DYNAMIC */
};

/* full speed support: */

static struct usb_endpoint_descriptor fs_loop_source_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

static struct usb_endpoint_descriptor fs_loop_sink_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_OUT,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

static struct usb_descriptor_header *fs_loopback_descs[] = {
	(struct usb_descriptor_header *) &loopback_intf,
	(struct usb_descriptor_header *) &fs_loop_sink_desc,
	(struct usb_descriptor_header *) &fs_loop_source_desc,
	NULL,
};

/* high speed support: */

static struct usb_endpoint_descriptor hs_loop_source_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	cpu_to_le16(512),
};

static struct usb_endpoint_descriptor hs_loop_sink_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	cpu_to_le16(512),
};

static struct usb_descriptor_header *hs_loopback_descs[] = {
	(struct usb_descriptor_header *) &loopback_intf,
	(struct usb_descriptor_header *) &hs_loop_source_desc,
	(struct usb_descriptor_header *) &hs_loop_sink_desc,
	NULL,
};

/* super speed support: */

static struct usb_endpoint_descriptor ss_loop_source_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	cpu_to_le16(1024),
};

struct usb_ss_ep_comp_descriptor ss_loop_source_comp_desc = {
	.bLength =		USB_DT_SS_EP_COMP_SIZE,
	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
	.bMaxBurst =		0,
	.bmAttributes =		0,
	.wBytesPerInterval =	0,
};

static struct usb_endpoint_descriptor ss_loop_sink_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	cpu_to_le16(1024),
};

struct usb_ss_ep_comp_descriptor ss_loop_sink_comp_desc = {
	.bLength =		USB_DT_SS_EP_COMP_SIZE,
	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
	.bMaxBurst =		0,
	.bmAttributes =		0,
	.wBytesPerInterval =	0,
};

static struct usb_descriptor_header *ss_loopback_descs[] = {
	(struct usb_descriptor_header *) &loopback_intf,
	(struct usb_descriptor_header *) &ss_loop_source_desc,
	(struct usb_descriptor_header *) &ss_loop_source_comp_desc,
	(struct usb_descriptor_header *) &ss_loop_sink_desc,
	(struct usb_descriptor_header *) &ss_loop_sink_comp_desc,
	NULL,
};

/* function-specific strings: */

static struct usb_string strings_loopback[] = {
	[0].s = "loop input to output",
	{  }			/* end of list */
};

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

static struct usb_gadget_strings *loopback_strings[] = {
	&stringtab_loop,
	NULL,
};

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

struct usb_request *alloc_ep_req(struct usb_ep *ep, int len)
{
	struct usb_request      *req;

	req = usb_ep_alloc_request(ep, GFP_ATOMIC);
	if (req) {
		if (len)
			req->length = len;
		else
			req->length = buflen;
		req->buf = kmalloc(req->length, 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,
		struct usb_ep *iso_in, struct usb_ep *iso_out)
{
	disable_ep(cdev, in);
	disable_ep(cdev, out);
	if (iso_in)
		disable_ep(cdev, iso_in);
	if (iso_out)
		disable_ep(cdev, iso_out);
}

static int loopback_bind(struct usb_configuration *c, struct usb_function *f)
{
	struct usb_composite_dev *cdev = c->cdev;
	struct f_loopback	*loop = func_to_loop(f);
	int			id;
	int ret;

	/* allocate interface ID(s) */
	id = usb_interface_id(c, f);
	if (id < 0)
		return id;
	loopback_intf.bInterfaceNumber = id;

	id = usb_string_id(cdev);
	if (id < 0)
		return id;
	strings_loopback[0].id = id;
	loopback_intf.iInterface = id;

	/* allocate endpoints */

	loop->in_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_source_desc);
	if (!loop->in_ep) {
autoconf_fail:
		ERROR(cdev, "%s: can't autoconfigure on %s\n",
			f->name, cdev->gadget->name);
		return -ENODEV;
	}
	loop->in_ep->driver_data = cdev;	/* claim */

	loop->out_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_sink_desc);
	if (!loop->out_ep)
		goto autoconf_fail;
	loop->out_ep->driver_data = cdev;	/* claim */

	/* support high speed hardware */
	hs_loop_source_desc.bEndpointAddress =
		fs_loop_source_desc.bEndpointAddress;
	hs_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress;

	/* support super speed hardware */
	ss_loop_source_desc.bEndpointAddress =
		fs_loop_source_desc.bEndpointAddress;
	ss_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress;

	ret = usb_assign_descriptors(f, fs_loopback_descs, hs_loopback_descs,
			ss_loopback_descs);
	if (ret)
		return ret;

	DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
	    (gadget_is_superspeed(c->cdev->gadget) ? "super" :
	     (gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full")),
			f->name, loop->in_ep->name, loop->out_ep->name);
	return 0;
}

static void lb_free_func(struct usb_function *f)
{
	usb_free_all_descriptors(f);
	kfree(func_to_loop(f));
}

static void loopback_complete(struct usb_ep *ep, struct usb_request *req)
{
	struct f_loopback	*loop = ep->driver_data;
	struct usb_composite_dev *cdev = loop->function.config->cdev;
	int			status = req->status;

	switch (status) {

	case 0:				/* normal completion? */
		if (ep == loop->out_ep) {
			/* loop this OUT packet back IN to the host */
			struct usb_request *in_req = req->context;
			in_req->zero = (req->actual % ep->maxpacket == 0)?1:0;
			in_req->length = req->actual;
			in_req->actual = 0;

			memcpy(in_req->buf, req->buf, req->length);

			status = usb_ep_queue(loop->in_ep, in_req, GFP_ATOMIC);
			if (status == 0)
				return;

			/* "should never get here" */
			ERROR(cdev, "can't loop %s to %s: %d\n",
				ep->name, loop->in_ep->name,
				status);
		}

		if (ep == loop->in_ep) {
			struct usb_request *out_req = req->context;
			/* queue the buffer for some later OUT packet */
			out_req->length = buflen;
			status = usb_ep_queue(loop->out_ep, out_req, GFP_ATOMIC);
			if (status == 0)
				return;
		}

		/* "should never get here" */
		/* FALLTHROUGH */

	default:
		ERROR(cdev, "%s loop complete --> %d, %d/%d\n", ep->name,
				status, req->actual, req->length);
		/* FALLTHROUGH */

	/* NOTE:  since this driver doesn't maintain an explicit record
	 * of requests it submitted (just maintains qlen count), we
	 * rely on the hardware driver to clean up on disconnect or
	 * endpoint disable.
	 */
	case -ECONNABORTED:		/* hardware forced ep reset */
	case -ECONNRESET:		/* request dequeued */
	case -ESHUTDOWN:		/* disconnect from host */
		free_ep_req(ep, req);
		return;
	}
}

static void disable_loopback(struct f_loopback *loop)
{
	struct usb_composite_dev	*cdev;

	cdev = loop->function.config->cdev;
	disable_endpoints(cdev, loop->in_ep, loop->out_ep, NULL, NULL);
	VDBG(cdev, "%s disabled\n", loop->function.name);
}

static int
enable_loopback(struct usb_composite_dev *cdev, struct f_loopback *loop)
{
	int					result = 0;
	struct usb_ep				*ep;
	unsigned				i;

	/* one endpoint writes data back IN to the host */
	ep = loop->in_ep;
	result = config_ep_by_speed(cdev->gadget, &(loop->function), ep);
	if (result)
		return result;
	result = usb_ep_enable(ep);
	if (result < 0)
		return result;
	ep->driver_data = loop;

	/* one endpoint just reads OUT packets */
	ep = loop->out_ep;
	result = config_ep_by_speed(cdev->gadget, &(loop->function), ep);
	if (result)
		goto fail0;

	result = usb_ep_enable(ep);
	if (result < 0) {
fail0:
		ep = loop->in_ep;
		usb_ep_disable(ep);
		ep->driver_data = NULL;
		return result;
	}
	ep->driver_data = loop;

	/* allocate a bunch of read buffers and queue them all at once.
	 * we buffer at most 'qlen' transfers; fewer if any need more
	 * than 'buflen' bytes each.
	 */
	for (i = 0; i < qlen && result == 0; i++) {
		struct usb_request			*out_req;
		struct usb_request			*in_req;
		out_req = alloc_ep_req(loop->out_ep, 0);
		if (out_req) {
			out_req->complete = loopback_complete;
			result = usb_ep_queue(loop->out_ep, out_req, GFP_ATOMIC);
			if (result)
				ERROR(cdev, "%s queue req --> %d\n",
						loop->out_ep->name, result);
		} else {
			usb_ep_disable(loop->out_ep);
			loop->out_ep->driver_data = NULL;
			result = -ENOMEM;
			goto fail0;
		}
		in_req = alloc_ep_req(loop->in_ep, 0);
		if (in_req) {
			in_req->complete = loopback_complete;
		} else {
			usb_ep_disable(loop->in_ep);
			loop->in_ep->driver_data = NULL;
			result = -ENOMEM;
			goto fail0;
		}
		in_req->context = out_req;
		out_req->context = in_req;
	}

	DBG(cdev, "%s enabled\n", loop->function.name);
	return result;
}

static int loopback_set_alt(struct usb_function *f,
		unsigned intf, unsigned alt)
{
	struct f_loopback	*loop = func_to_loop(f);
	struct usb_composite_dev *cdev = f->config->cdev;

	/* we know alt is zero */
	if (loop->in_ep->driver_data)
		disable_loopback(loop);
	return enable_loopback(cdev, loop);
}

static void loopback_disable(struct usb_function *f)
{
	struct f_loopback	*loop = func_to_loop(f);

	disable_loopback(loop);
}

static struct usb_function *loopback_alloc(struct usb_function_instance *fi)
{
	struct f_loopback	*loop;
	struct f_lb_opts	*lb_opts;

	loop = kzalloc(sizeof *loop, GFP_KERNEL);
	if (!loop)
		return ERR_PTR(-ENOMEM);

	lb_opts = container_of(fi, struct f_lb_opts, func_inst);
	buflen = lb_opts->bulk_buflen;
	if (!buflen)
		buflen = 512;

	qlen = lb_opts->qlen;
	if (!qlen)
		qlen = 8;

	loop->function.name = "loopback";
	loop->function.bind = loopback_bind;
	loop->function.set_alt = loopback_set_alt;
	loop->function.disable = loopback_disable;
	loop->function.strings = loopback_strings;

	loop->function.free_func = lb_free_func;

	return &loop->function;
}

static void lb_free_instance(struct usb_function_instance *fi)
{
	struct f_lb_opts *lb_opts;

	lb_opts = container_of(fi, struct f_lb_opts, func_inst);
	kfree(lb_opts);
}

static struct usb_function_instance *loopback_alloc_instance(void)
{
	struct f_lb_opts *lb_opts;

	lb_opts = kzalloc(sizeof(*lb_opts), GFP_KERNEL);
	if (!lb_opts)
		return ERR_PTR(-ENOMEM);
	lb_opts->func_inst.free_func_inst = lb_free_instance;
	return  &lb_opts->func_inst;
}
DECLARE_USB_FUNCTION_INIT(loopback, loopback_alloc_instance, loopback_alloc);

#if 0
int __init lb_modinit(void)
{
	int ret;

	ret = usb_function_register(&Loopbackusb_func);
	if (ret)
		return ret;
	return ret;
}
void __exit lb_modexit(void)
{
	usb_function_unregister(&Loopbackusb_func);
}
#endif
MODULE_LICENSE("GPL");
Commit	Line	Data
e5760fda DB	1	/*
	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.
e5760fda DB	11	*/
	12
	13	/* #define VERBOSE_DEBUG */
	14
5a0e3ad6	15	#include <linux/slab.h>
e5760fda	16	#include <linux/kernel.h>
e5760fda	17	#include <linux/device.h>
cf9a08ae SAS	18	#include <linux/module.h>
	19	#include <linux/err.h>
	20	#include <linux/usb/composite.h>
e5760fda DB	21
e5760fda DB	22	#include "g_zero.h"
e5760fda DB	23
	24	/*
	25	* LOOPBACK FUNCTION ... a testing vehicle for USB peripherals,
	26	*
	27	* This takes messages of various sizes written OUT to a device, and loops
	28	* them back so they can be read IN from it. It has been used by certain
	29	* test applications. It supports limited testing of data queueing logic.
	30	*
	31	*
	32	* This is currently packaged as a configuration driver, which can't be
	33	* combined with other functions to make composite devices. However, it
	34	* can be combined with other independent configurations.
	35	*/
	36	struct f_loopback {
	37	struct usb_function function;
	38
	39	struct usb_ep *in_ep;
	40	struct usb_ep *out_ep;
	41	};
	42
	43	static inline struct f_loopback func_to_loop(struct usb_function f)
	44	{
	45	return container_of(f, struct f_loopback, function);
	46	}
	47
cf9a08ae SAS	48	static unsigned qlen;
cf9a08ae SAS	49	static unsigned buflen;
e5760fda DB	50
	51	/-------------------------------------------------------------------------/
	52
	53	static struct usb_interface_descriptor loopback_intf = {
	54	.bLength = sizeof loopback_intf,
	55	.bDescriptorType = USB_DT_INTERFACE,
	56
	57	.bNumEndpoints = 2,
	58	.bInterfaceClass = USB_CLASS_VENDOR_SPEC,
	59	/* .iInterface = DYNAMIC */
	60	};
	61
	62	/* full speed support: */
	63
7e75bc0f	64	static struct usb_endpoint_descriptor fs_loop_source_desc = {
e5760fda DB	65	.bLength = USB_DT_ENDPOINT_SIZE,
	66	.bDescriptorType = USB_DT_ENDPOINT,
	67
	68	.bEndpointAddress = USB_DIR_IN,
	69	.bmAttributes = USB_ENDPOINT_XFER_BULK,
	70	};
	71
7e75bc0f	72	static struct usb_endpoint_descriptor fs_loop_sink_desc = {
e5760fda DB	73	.bLength = USB_DT_ENDPOINT_SIZE,
	74	.bDescriptorType = USB_DT_ENDPOINT,
	75
	76	.bEndpointAddress = USB_DIR_OUT,
	77	.bmAttributes = USB_ENDPOINT_XFER_BULK,
	78	};
	79
	80	static struct usb_descriptor_header *fs_loopback_descs[] = {
	81	(struct usb_descriptor_header *) &loopback_intf,
7e75bc0f DB	82	(struct usb_descriptor_header *) &fs_loop_sink_desc,
7e75bc0f DB	83	(struct usb_descriptor_header *) &fs_loop_source_desc,
e5760fda DB	84	NULL,
	85	};
	86
	87	/* high speed support: */
	88
7e75bc0f	89	static struct usb_endpoint_descriptor hs_loop_source_desc = {
e5760fda DB	90	.bLength = USB_DT_ENDPOINT_SIZE,
	91	.bDescriptorType = USB_DT_ENDPOINT,
	92
	93	.bmAttributes = USB_ENDPOINT_XFER_BULK,
551509d2	94	.wMaxPacketSize = cpu_to_le16(512),
e5760fda DB	95	};
e5760fda DB	96
7e75bc0f	97	static struct usb_endpoint_descriptor hs_loop_sink_desc = {
e5760fda DB	98	.bLength = USB_DT_ENDPOINT_SIZE,
	99	.bDescriptorType = USB_DT_ENDPOINT,
	100
	101	.bmAttributes = USB_ENDPOINT_XFER_BULK,
551509d2	102	.wMaxPacketSize = cpu_to_le16(512),
e5760fda DB	103	};
	104
	105	static struct usb_descriptor_header *hs_loopback_descs[] = {
	106	(struct usb_descriptor_header *) &loopback_intf,
7e75bc0f DB	107	(struct usb_descriptor_header *) &hs_loop_source_desc,
7e75bc0f DB	108	(struct usb_descriptor_header *) &hs_loop_sink_desc,
e5760fda DB	109	NULL,
	110	};
	111
57c97c02 AB	112	/* super speed support: */
	113
	114	static struct usb_endpoint_descriptor ss_loop_source_desc = {
	115	.bLength = USB_DT_ENDPOINT_SIZE,
	116	.bDescriptorType = USB_DT_ENDPOINT,
	117
	118	.bmAttributes = USB_ENDPOINT_XFER_BULK,
	119	.wMaxPacketSize = cpu_to_le16(1024),
	120	};
	121
	122	struct usb_ss_ep_comp_descriptor ss_loop_source_comp_desc = {
	123	.bLength = USB_DT_SS_EP_COMP_SIZE,
	124	.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
	125	.bMaxBurst = 0,
	126	.bmAttributes = 0,
	127	.wBytesPerInterval = 0,
	128	};
	129
	130	static struct usb_endpoint_descriptor ss_loop_sink_desc = {
	131	.bLength = USB_DT_ENDPOINT_SIZE,
	132	.bDescriptorType = USB_DT_ENDPOINT,
	133
	134	.bmAttributes = USB_ENDPOINT_XFER_BULK,
	135	.wMaxPacketSize = cpu_to_le16(1024),
	136	};
	137
	138	struct usb_ss_ep_comp_descriptor ss_loop_sink_comp_desc = {
	139	.bLength = USB_DT_SS_EP_COMP_SIZE,
	140	.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
	141	.bMaxBurst = 0,
	142	.bmAttributes = 0,
	143	.wBytesPerInterval = 0,
	144	};
	145
	146	static struct usb_descriptor_header *ss_loopback_descs[] = {
	147	(struct usb_descriptor_header *) &loopback_intf,
	148	(struct usb_descriptor_header *) &ss_loop_source_desc,
	149	(struct usb_descriptor_header *) &ss_loop_source_comp_desc,
	150	(struct usb_descriptor_header *) &ss_loop_sink_desc,
	151	(struct usb_descriptor_header *) &ss_loop_sink_comp_desc,
	152	NULL,
	153	};
	154
e5760fda DB	155	/* function-specific strings: */
	156
	157	static struct usb_string strings_loopback[] = {
	158	[0].s = "loop input to output",
	159	{ } /* end of list */
	160	};
	161
	162	static struct usb_gadget_strings stringtab_loop = {
	163	.language = 0x0409, /* en-us */
	164	.strings = strings_loopback,
	165	};
	166
	167	static struct usb_gadget_strings *loopback_strings[] = {
	168	&stringtab_loop,
	169	NULL,
	170	};
	171
	172	/-------------------------------------------------------------------------/
	173
6fa3eb70 S	174	struct usb_request alloc_ep_req(struct usb_ep ep, int len)
	175	{
	176	struct usb_request *req;
	177
	178	req = usb_ep_alloc_request(ep, GFP_ATOMIC);
	179	if (req) {
	180	if (len)
	181	req->length = len;
	182	else
	183	req->length = buflen;
	184	req->buf = kmalloc(req->length, GFP_ATOMIC);
	185	if (!req->buf) {
	186	usb_ep_free_request(ep, req);
	187	req = NULL;
	188	}
	189	}
	190	return req;
	191	}
	192
	193	void free_ep_req(struct usb_ep ep, struct usb_request req)
	194	{
	195	kfree(req->buf);
	196	usb_ep_free_request(ep, req);
	197	}
	198
	199	static void disable_ep(struct usb_composite_dev cdev, struct usb_ep ep)
	200	{
	201	int value;
	202
	203	if (ep->driver_data) {
	204	value = usb_ep_disable(ep);
	205	if (value < 0)
	206	DBG(cdev, "disable %s --> %d\n",
	207	ep->name, value);
	208	ep->driver_data = NULL;
	209	}
	210	}
	211
	212	void disable_endpoints(struct usb_composite_dev *cdev,
	213	struct usb_ep in, struct usb_ep out,
	214	struct usb_ep iso_in, struct usb_ep iso_out)
	215	{
	216	disable_ep(cdev, in);
	217	disable_ep(cdev, out);
	218	if (iso_in)
	219	disable_ep(cdev, iso_in);
	220	if (iso_out)
	221	disable_ep(cdev, iso_out);
	222	}
	223
cf9a08ae	224	static int loopback_bind(struct usb_configuration c, struct usb_function f)
e5760fda DB	225	{
	226	struct usb_composite_dev *cdev = c->cdev;
	227	struct f_loopback *loop = func_to_loop(f);
	228	int id;
10287bae	229	int ret;
e5760fda DB	230
	231	/* allocate interface ID(s) */
	232	id = usb_interface_id(c, f);
	233	if (id < 0)
	234	return id;
	235	loopback_intf.bInterfaceNumber = id;
	236
78f46f09 SAS	237	id = usb_string_id(cdev);
	238	if (id < 0)
	239	return id;
	240	strings_loopback[0].id = id;
	241	loopback_intf.iInterface = id;
	242
e5760fda DB	243	/* allocate endpoints */
e5760fda DB	244
7e75bc0f	245	loop->in_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_source_desc);
e5760fda DB	246	if (!loop->in_ep) {
	247	autoconf_fail:
	248	ERROR(cdev, "%s: can't autoconfigure on %s\n",
	249	f->name, cdev->gadget->name);
	250	return -ENODEV;
	251	}
	252	loop->in_ep->driver_data = cdev; /* claim */
	253
7e75bc0f	254	loop->out_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_sink_desc);
e5760fda DB	255	if (!loop->out_ep)
	256	goto autoconf_fail;
	257	loop->out_ep->driver_data = cdev; /* claim */
	258
	259	/* support high speed hardware */
10287bae SAS	260	hs_loop_source_desc.bEndpointAddress =
	261	fs_loop_source_desc.bEndpointAddress;
	262	hs_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress;
e5760fda	263
57c97c02	264	/* support super speed hardware */
10287bae SAS	265	ss_loop_source_desc.bEndpointAddress =
	266	fs_loop_source_desc.bEndpointAddress;
	267	ss_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress;
	268
	269	ret = usb_assign_descriptors(f, fs_loopback_descs, hs_loopback_descs,
	270	ss_loopback_descs);
	271	if (ret)
	272	return ret;
57c97c02	273
e5760fda	274	DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
57c97c02 AB	275	(gadget_is_superspeed(c->cdev->gadget) ? "super" :
57c97c02 AB	276	(gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full")),
e5760fda DB	277	f->name, loop->in_ep->name, loop->out_ep->name);
	278	return 0;
	279	}
	280
cf9a08ae	281	static void lb_free_func(struct usb_function *f)
e5760fda	282	{
10287bae	283	usb_free_all_descriptors(f);
e5760fda DB	284	kfree(func_to_loop(f));
	285	}
	286
	287	static void loopback_complete(struct usb_ep ep, struct usb_request req)
	288	{
	289	struct f_loopback *loop = ep->driver_data;
	290	struct usb_composite_dev *cdev = loop->function.config->cdev;
	291	int status = req->status;
	292
	293	switch (status) {
	294
	295	case 0: /* normal completion? */
	296	if (ep == loop->out_ep) {
	297	/* loop this OUT packet back IN to the host */
6fa3eb70 S	298	struct usb_request *in_req = req->context;
	299	in_req->zero = (req->actual % ep->maxpacket == 0)?1:0;
	300	in_req->length = req->actual;
	301	in_req->actual = 0;
	302
	303	memcpy(in_req->buf, req->buf, req->length);
	304
	305	status = usb_ep_queue(loop->in_ep, in_req, GFP_ATOMIC);
e5760fda DB	306	if (status == 0)
	307	return;
	308
	309	/* "should never get here" */
	310	ERROR(cdev, "can't loop %s to %s: %d\n",
	311	ep->name, loop->in_ep->name,
	312	status);
	313	}
	314
6fa3eb70 S	315	if (ep == loop->in_ep) {
	316	struct usb_request *out_req = req->context;
	317	/* queue the buffer for some later OUT packet */
	318	out_req->length = buflen;
	319	status = usb_ep_queue(loop->out_ep, out_req, GFP_ATOMIC);
	320	if (status == 0)
	321	return;
	322	}
e5760fda DB	323
	324	/* "should never get here" */
	325	/* FALLTHROUGH */
	326
	327	default:
	328	ERROR(cdev, "%s loop complete --> %d, %d/%d\n", ep->name,
	329	status, req->actual, req->length);
	330	/* FALLTHROUGH */
	331
	332	/* NOTE: since this driver doesn't maintain an explicit record
	333	* of requests it submitted (just maintains qlen count), we
	334	* rely on the hardware driver to clean up on disconnect or
	335	* endpoint disable.
	336	*/
	337	case -ECONNABORTED: /* hardware forced ep reset */
	338	case -ECONNRESET: /* request dequeued */
	339	case -ESHUTDOWN: /* disconnect from host */
	340	free_ep_req(ep, req);
	341	return;
	342	}
	343	}
	344
	345	static void disable_loopback(struct f_loopback *loop)
	346	{
	347	struct usb_composite_dev *cdev;
	348
	349	cdev = loop->function.config->cdev;
b4036ccd	350	disable_endpoints(cdev, loop->in_ep, loop->out_ep, NULL, NULL);
e5760fda DB	351	VDBG(cdev, "%s disabled\n", loop->function.name);
	352	}
	353
	354	static int
	355	enable_loopback(struct usb_composite_dev cdev, struct f_loopback loop)
	356	{
	357	int result = 0;
e5760fda	358	struct usb_ep *ep;
e5760fda DB	359	unsigned i;
e5760fda DB	360
e5760fda DB	361	/* one endpoint writes data back IN to the host */
e5760fda DB	362	ep = loop->in_ep;
ea2a1df7 TB	363	result = config_ep_by_speed(cdev->gadget, &(loop->function), ep);
	364	if (result)
	365	return result;
72c973dd	366	result = usb_ep_enable(ep);
e5760fda DB	367	if (result < 0)
	368	return result;
	369	ep->driver_data = loop;
	370
	371	/* one endpoint just reads OUT packets */
	372	ep = loop->out_ep;
ea2a1df7 TB	373	result = config_ep_by_speed(cdev->gadget, &(loop->function), ep);
	374	if (result)
	375	goto fail0;
	376
72c973dd	377	result = usb_ep_enable(ep);
e5760fda DB	378	if (result < 0) {
	379	fail0:
	380	ep = loop->in_ep;
	381	usb_ep_disable(ep);
	382	ep->driver_data = NULL;
	383	return result;
	384	}
	385	ep->driver_data = loop;
	386
	387	/* allocate a bunch of read buffers and queue them all at once.
	388	* we buffer at most 'qlen' transfers; fewer if any need more
	389	* than 'buflen' bytes each.
	390	*/
	391	for (i = 0; i < qlen && result == 0; i++) {
6fa3eb70 S	392	struct usb_request *out_req;
	393	struct usb_request *in_req;
	394	out_req = alloc_ep_req(loop->out_ep, 0);
	395	if (out_req) {
	396	out_req->complete = loopback_complete;
	397	result = usb_ep_queue(loop->out_ep, out_req, GFP_ATOMIC);
e5760fda DB	398	if (result)
e5760fda DB	399	ERROR(cdev, "%s queue req --> %d\n",
6fa3eb70	400	loop->out_ep->name, result);
e5760fda	401	} else {
6fa3eb70 S	402	usb_ep_disable(loop->out_ep);
6fa3eb70 S	403	loop->out_ep->driver_data = NULL;
e5760fda DB	404	result = -ENOMEM;
	405	goto fail0;
	406	}
6fa3eb70 S	407	in_req = alloc_ep_req(loop->in_ep, 0);
	408	if (in_req) {
	409	in_req->complete = loopback_complete;
	410	} else {
	411	usb_ep_disable(loop->in_ep);
	412	loop->in_ep->driver_data = NULL;
	413	result = -ENOMEM;
	414	goto fail0;
	415	}
	416	in_req->context = out_req;
	417	out_req->context = in_req;
e5760fda DB	418	}
	419
	420	DBG(cdev, "%s enabled\n", loop->function.name);
	421	return result;
	422	}
	423
	424	static int loopback_set_alt(struct usb_function *f,
	425	unsigned intf, unsigned alt)
	426	{
	427	struct f_loopback *loop = func_to_loop(f);
	428	struct usb_composite_dev *cdev = f->config->cdev;
	429
	430	/* we know alt is zero */
	431	if (loop->in_ep->driver_data)
	432	disable_loopback(loop);
	433	return enable_loopback(cdev, loop);
	434	}
	435
	436	static void loopback_disable(struct usb_function *f)
	437	{
	438	struct f_loopback *loop = func_to_loop(f);
	439
	440	disable_loopback(loop);
	441	}
	442
cf9a08ae	443	static struct usb_function loopback_alloc(struct usb_function_instance fi)
e5760fda DB	444	{
e5760fda DB	445	struct f_loopback *loop;
cf9a08ae	446	struct f_lb_opts *lb_opts;
e5760fda DB	447
	448	loop = kzalloc(sizeof *loop, GFP_KERNEL);
	449	if (!loop)
cf9a08ae SAS	450	return ERR_PTR(-ENOMEM);
	451
	452	lb_opts = container_of(fi, struct f_lb_opts, func_inst);
	453	buflen = lb_opts->bulk_buflen;
6fa3eb70 S	454	if (!buflen)
	455	buflen = 512;
	456
cf9a08ae SAS	457	qlen = lb_opts->qlen;
cf9a08ae SAS	458	if (!qlen)
6fa3eb70	459	qlen = 8;
e5760fda DB	460
e5760fda DB	461	loop->function.name = "loopback";
e5760fda	462	loop->function.bind = loopback_bind;
e5760fda DB	463	loop->function.set_alt = loopback_set_alt;
e5760fda DB	464	loop->function.disable = loopback_disable;
cf9a08ae SAS	465	loop->function.strings = loopback_strings;
	466
	467	loop->function.free_func = lb_free_func;
	468
	469	return &loop->function;
	470	}
	471
	472	static void lb_free_instance(struct usb_function_instance *fi)
	473	{
	474	struct f_lb_opts *lb_opts;
e5760fda	475
cf9a08ae SAS	476	lb_opts = container_of(fi, struct f_lb_opts, func_inst);
cf9a08ae SAS	477	kfree(lb_opts);
e5760fda	478	}
cf9a08ae SAS	479
	480	static struct usb_function_instance *loopback_alloc_instance(void)
	481	{
	482	struct f_lb_opts *lb_opts;
	483
	484	lb_opts = kzalloc(sizeof(*lb_opts), GFP_KERNEL);
	485	if (!lb_opts)
	486	return ERR_PTR(-ENOMEM);
	487	lb_opts->func_inst.free_func_inst = lb_free_instance;
	488	return &lb_opts->func_inst;
	489	}
6fa3eb70	490	DECLARE_USB_FUNCTION_INIT(loopback, loopback_alloc_instance, loopback_alloc);
cf9a08ae	491
6fa3eb70	492	#if 0
cf9a08ae SAS	493	int __init lb_modinit(void)
	494	{
	495	int ret;
	496
	497	ret = usb_function_register(&Loopbackusb_func);
	498	if (ret)
	499	return ret;
	500	return ret;
	501	}
	502	void __exit lb_modexit(void)
	503	{
	504	usb_function_unregister(&Loopbackusb_func);
	505	}
6fa3eb70	506	#endif
cf9a08ae	507	MODULE_LICENSE("GPL");