[deliverable/linux.git] / drivers / usb / gadget / f_eem.c

/*
 * f_eem.c -- USB CDC Ethernet (EEM) link function driver
 *
 * Copyright (C) 2003-2005,2008 David Brownell
 * Copyright (C) 2008 Nokia Corporation
 * Copyright (C) 2009 EF Johnson Technologies
 *
 * 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
 */

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/etherdevice.h>
#include <linux/crc32.h>
#include <linux/slab.h>

#include "u_ether.h"

#define EEM_HLEN 2

/*
 * This function is a "CDC Ethernet Emulation Model" (CDC EEM)
 * Ethernet link.
 */

struct f_eem {
	struct gether			port;
	u8				ctrl_id;
};

static inline struct f_eem *func_to_eem(struct usb_function *f)
{
	return container_of(f, struct f_eem, port.func);
}

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

/* interface descriptor: */

static struct usb_interface_descriptor eem_intf __initdata = {
	.bLength =		sizeof eem_intf,
	.bDescriptorType =	USB_DT_INTERFACE,

	/* .bInterfaceNumber = DYNAMIC */
	.bNumEndpoints =	2,
	.bInterfaceClass =	USB_CLASS_COMM,
	.bInterfaceSubClass =	USB_CDC_SUBCLASS_EEM,
	.bInterfaceProtocol =	USB_CDC_PROTO_EEM,
	/* .iInterface = DYNAMIC */
};

/* full speed support: */

static struct usb_endpoint_descriptor eem_fs_in_desc __initdata = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

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

static struct usb_endpoint_descriptor eem_fs_out_desc __initdata = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

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

static struct usb_descriptor_header *eem_fs_function[] __initdata = {
	/* CDC EEM control descriptors */
	(struct usb_descriptor_header *) &eem_intf,
	(struct usb_descriptor_header *) &eem_fs_in_desc,
	(struct usb_descriptor_header *) &eem_fs_out_desc,
	NULL,
};

/* high speed support: */

static struct usb_endpoint_descriptor eem_hs_in_desc __initdata = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

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

static struct usb_endpoint_descriptor eem_hs_out_desc __initdata = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

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

static struct usb_descriptor_header *eem_hs_function[] __initdata = {
	/* CDC EEM control descriptors */
	(struct usb_descriptor_header *) &eem_intf,
	(struct usb_descriptor_header *) &eem_hs_in_desc,
	(struct usb_descriptor_header *) &eem_hs_out_desc,
	NULL,
};

/* string descriptors: */

static struct usb_string eem_string_defs[] = {
	[0].s = "CDC Ethernet Emulation Model (EEM)",
	{  } /* end of list */
};

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

static struct usb_gadget_strings *eem_strings[] = {
	&eem_string_table,
	NULL,
};

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

static int eem_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
{
	struct usb_composite_dev *cdev = f->config->cdev;
	int			value = -EOPNOTSUPP;
	u16			w_index = le16_to_cpu(ctrl->wIndex);
	u16			w_value = le16_to_cpu(ctrl->wValue);
	u16			w_length = le16_to_cpu(ctrl->wLength);

	DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
		ctrl->bRequestType, ctrl->bRequest,
		w_value, w_index, w_length);

	/* device either stalls (value < 0) or reports success */
	return value;
}


static int eem_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
{
	struct f_eem		*eem = func_to_eem(f);
	struct usb_composite_dev *cdev = f->config->cdev;
	struct net_device	*net;

	/* we know alt == 0, so this is an activation or a reset */
	if (alt != 0)
		goto fail;

	if (intf == eem->ctrl_id) {

		if (eem->port.in_ep->driver_data) {
			DBG(cdev, "reset eem\n");
			gether_disconnect(&eem->port);
		}

		if (!eem->port.in_ep->desc || !eem->port.out_ep->desc) {
			DBG(cdev, "init eem\n");
			if (config_ep_by_speed(cdev->gadget, f,
					       eem->port.in_ep) ||
			    config_ep_by_speed(cdev->gadget, f,
					       eem->port.out_ep)) {
				eem->port.in_ep->desc = NULL;
				eem->port.out_ep->desc = NULL;
				goto fail;
			}
		}

		/* zlps should not occur because zero-length EEM packets
		 * will be inserted in those cases where they would occur
		 */
		eem->port.is_zlp_ok = 1;
		eem->port.cdc_filter = DEFAULT_FILTER;
		DBG(cdev, "activate eem\n");
		net = gether_connect(&eem->port);
		if (IS_ERR(net))
			return PTR_ERR(net);
	} else
		goto fail;

	return 0;
fail:
	return -EINVAL;
}

static void eem_disable(struct usb_function *f)
{
	struct f_eem		*eem = func_to_eem(f);
	struct usb_composite_dev *cdev = f->config->cdev;

	DBG(cdev, "eem deactivated\n");

	if (eem->port.in_ep->driver_data)
		gether_disconnect(&eem->port);
}

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

/* EEM function driver setup/binding */

static int __init
eem_bind(struct usb_configuration *c, struct usb_function *f)
{
	struct usb_composite_dev *cdev = c->cdev;
	struct f_eem		*eem = func_to_eem(f);
	int			status;
	struct usb_ep		*ep;

	/* allocate instance-specific interface IDs */
	status = usb_interface_id(c, f);
	if (status < 0)
		goto fail;
	eem->ctrl_id = status;
	eem_intf.bInterfaceNumber = status;

	status = -ENODEV;

	/* allocate instance-specific endpoints */
	ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_in_desc);
	if (!ep)
		goto fail;
	eem->port.in_ep = ep;
	ep->driver_data = cdev;	/* claim */

	ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_out_desc);
	if (!ep)
		goto fail;
	eem->port.out_ep = ep;
	ep->driver_data = cdev;	/* claim */

	status = -ENOMEM;

	/* copy descriptors, and track endpoint copies */
	f->descriptors = usb_copy_descriptors(eem_fs_function);
	if (!f->descriptors)
		goto fail;

	/* support all relevant hardware speeds... we expect that when
	 * hardware is dual speed, all bulk-capable endpoints work at
	 * both speeds
	 */
	if (gadget_is_dualspeed(c->cdev->gadget)) {
		eem_hs_in_desc.bEndpointAddress =
				eem_fs_in_desc.bEndpointAddress;
		eem_hs_out_desc.bEndpointAddress =
				eem_fs_out_desc.bEndpointAddress;

		/* copy descriptors, and track endpoint copies */
		f->hs_descriptors = usb_copy_descriptors(eem_hs_function);
		if (!f->hs_descriptors)
			goto fail;
	}

	DBG(cdev, "CDC Ethernet (EEM): %s speed IN/%s OUT/%s\n",
			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
			eem->port.in_ep->name, eem->port.out_ep->name);
	return 0;

fail:
	if (f->descriptors)
		usb_free_descriptors(f->descriptors);

	/* we might as well release our claims on endpoints */
	if (eem->port.out_ep->desc)
		eem->port.out_ep->driver_data = NULL;
	if (eem->port.in_ep->desc)
		eem->port.in_ep->driver_data = NULL;

	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);

	return status;
}

static void
eem_unbind(struct usb_configuration *c, struct usb_function *f)
{
	struct f_eem	*eem = func_to_eem(f);

	DBG(c->cdev, "eem unbind\n");

	if (gadget_is_dualspeed(c->cdev->gadget))
		usb_free_descriptors(f->hs_descriptors);
	usb_free_descriptors(f->descriptors);
	kfree(eem);
}

static void eem_cmd_complete(struct usb_ep *ep, struct usb_request *req)
{
	struct sk_buff *skb = (struct sk_buff *)req->context;

	dev_kfree_skb_any(skb);
}

/*
 * Add the EEM header and ethernet checksum.
 * We currently do not attempt to put multiple ethernet frames
 * into a single USB transfer
 */
static struct sk_buff *eem_wrap(struct gether *port, struct sk_buff *skb)
{
	struct sk_buff	*skb2 = NULL;
	struct usb_ep	*in = port->in_ep;
	int		padlen = 0;
	u16		len = skb->len;

	if (!skb_cloned(skb)) {
		int headroom = skb_headroom(skb);
		int tailroom = skb_tailroom(skb);

		/* When (len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) is 0,
		 * stick two bytes of zero-length EEM packet on the end.
		 */
		if (((len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) == 0)
			padlen += 2;

		if ((tailroom >= (ETH_FCS_LEN + padlen)) &&
				(headroom >= EEM_HLEN))
			goto done;
	}

	skb2 = skb_copy_expand(skb, EEM_HLEN, ETH_FCS_LEN + padlen, GFP_ATOMIC);
	dev_kfree_skb_any(skb);
	skb = skb2;
	if (!skb)
		return skb;

done:
	/* use the "no CRC" option */
	put_unaligned_be32(0xdeadbeef, skb_put(skb, 4));

	/* EEM packet header format:
	 * b0..13:	length of ethernet frame
	 * b14:		bmCRC (0 == sentinel CRC)
	 * b15:		bmType (0 == data)
	 */
	len = skb->len;
	put_unaligned_le16(len & 0x3FFF, skb_push(skb, 2));

	/* add a zero-length EEM packet, if needed */
	if (padlen)
		put_unaligned_le16(0, skb_put(skb, 2));

	return skb;
}

/*
 * Remove the EEM header.  Note that there can be many EEM packets in a single
 * USB transfer, so we need to break them out and handle them independently.
 */
static int eem_unwrap(struct gether *port,
			struct sk_buff *skb,
			struct sk_buff_head *list)
{
	struct usb_composite_dev	*cdev = port->func.config->cdev;
	int				status = 0;

	do {
		struct sk_buff	*skb2;
		u16		header;
		u16		len = 0;

		if (skb->len < EEM_HLEN) {
			status = -EINVAL;
			DBG(cdev, "invalid EEM header\n");
			goto error;
		}

		/* remove the EEM header */
		header = get_unaligned_le16(skb->data);
		skb_pull(skb, EEM_HLEN);

		/* EEM packet header format:
		 * b0..14:	EEM type dependent (data or command)
		 * b15:		bmType (0 == data, 1 == command)
		 */
		if (header & BIT(15)) {
			struct usb_request	*req = cdev->req;
			u16			bmEEMCmd;

			/* EEM command packet format:
			 * b0..10:	bmEEMCmdParam
			 * b11..13:	bmEEMCmd
			 * b14:		reserved (must be zero)
			 * b15:		bmType (1 == command)
			 */
			if (header & BIT(14))
				continue;

			bmEEMCmd = (header >> 11) & 0x7;
			switch (bmEEMCmd) {
			case 0: /* echo */
				len = header & 0x7FF;
				if (skb->len < len) {
					status = -EOVERFLOW;
					goto error;
				}

				skb2 = skb_clone(skb, GFP_ATOMIC);
				if (unlikely(!skb2)) {
					DBG(cdev, "EEM echo response error\n");
					goto next;
				}
				skb_trim(skb2, len);
				put_unaligned_le16(BIT(15) | BIT(11) | len,
							skb_push(skb2, 2));
				skb_copy_bits(skb2, 0, req->buf, skb2->len);
				req->length = skb2->len;
				req->complete = eem_cmd_complete;
				req->zero = 1;
				req->context = skb2;
				if (usb_ep_queue(port->in_ep, req, GFP_ATOMIC))
					DBG(cdev, "echo response queue fail\n");
				break;

			case 1:  /* echo response */
			case 2:  /* suspend hint */
			case 3:  /* response hint */
			case 4:  /* response complete hint */
			case 5:  /* tickle */
			default: /* reserved */
				continue;
			}
		} else {
			u32		crc, crc2;
			struct sk_buff	*skb3;

			/* check for zero-length EEM packet */
			if (header == 0)
				continue;

			/* EEM data packet format:
			 * b0..13:	length of ethernet frame
			 * b14:		bmCRC (0 == sentinel, 1 == calculated)
			 * b15:		bmType (0 == data)
			 */
			len = header & 0x3FFF;
			if ((skb->len < len)
					|| (len < (ETH_HLEN + ETH_FCS_LEN))) {
				status = -EINVAL;
				goto error;
			}

			/* validate CRC */
			if (header & BIT(14)) {
				crc = get_unaligned_le32(skb->data + len
							- ETH_FCS_LEN);
				crc2 = ~crc32_le(~0,
						skb->data, len - ETH_FCS_LEN);
			} else {
				crc = get_unaligned_be32(skb->data + len
							- ETH_FCS_LEN);
				crc2 = 0xdeadbeef;
			}
			if (crc != crc2) {
				DBG(cdev, "invalid EEM CRC\n");
				goto next;
			}

			skb2 = skb_clone(skb, GFP_ATOMIC);
			if (unlikely(!skb2)) {
				DBG(cdev, "unable to unframe EEM packet\n");
				continue;
			}
			skb_trim(skb2, len - ETH_FCS_LEN);

			skb3 = skb_copy_expand(skb2,
						NET_IP_ALIGN,
						0,
						GFP_ATOMIC);
			if (unlikely(!skb3)) {
				DBG(cdev, "unable to realign EEM packet\n");
				dev_kfree_skb_any(skb2);
				continue;
			}
			dev_kfree_skb_any(skb2);
			skb_queue_tail(list, skb3);
		}
next:
		skb_pull(skb, len);
	} while (skb->len);

error:
	dev_kfree_skb_any(skb);
	return status;
}

/**
 * eem_bind_config - add CDC Ethernet (EEM) network link to a configuration
 * @c: the configuration to support the network link
 * Context: single threaded during gadget setup
 *
 * Returns zero on success, else negative errno.
 *
 * Caller must have called @gether_setup().  Caller is also responsible
 * for calling @gether_cleanup() before module unload.
 */
int __init eem_bind_config(struct usb_configuration *c)
{
	struct f_eem	*eem;
	int		status;

	/* maybe allocate device-global string IDs */
	if (eem_string_defs[0].id == 0) {

		/* control interface label */
		status = usb_string_id(c->cdev);
		if (status < 0)
			return status;
		eem_string_defs[0].id = status;
		eem_intf.iInterface = status;
	}

	/* allocate and initialize one new instance */
	eem = kzalloc(sizeof *eem, GFP_KERNEL);
	if (!eem)
		return -ENOMEM;

	eem->port.cdc_filter = DEFAULT_FILTER;

	eem->port.func.name = "cdc_eem";
	eem->port.func.strings = eem_strings;
	/* descriptors are per-instance copies */
	eem->port.func.bind = eem_bind;
	eem->port.func.unbind = eem_unbind;
	eem->port.func.set_alt = eem_set_alt;
	eem->port.func.setup = eem_setup;
	eem->port.func.disable = eem_disable;
	eem->port.wrap = eem_wrap;
	eem->port.unwrap = eem_unwrap;
	eem->port.header_len = EEM_HLEN;

	status = usb_add_function(c, &eem->port.func);
	if (status)
		kfree(eem);
	return status;
}
Commit	Line	Data
9b39e9dd BN	1	/*
	2	* f_eem.c -- USB CDC Ethernet (EEM) link function driver
	3	*
	4	* Copyright (C) 2003-2005,2008 David Brownell
	5	* Copyright (C) 2008 Nokia Corporation
	6	* Copyright (C) 2009 EF Johnson Technologies
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	21	*/
	22
	23	#include <linux/kernel.h>
	24	#include <linux/device.h>
	25	#include <linux/etherdevice.h>
	26	#include <linux/crc32.h>
5a0e3ad6	27	#include <linux/slab.h>
9b39e9dd BN	28
	29	#include "u_ether.h"
	30
	31	#define EEM_HLEN 2
	32
	33	/*
	34	* This function is a "CDC Ethernet Emulation Model" (CDC EEM)
	35	* Ethernet link.
	36	*/
	37
9b39e9dd BN	38	struct f_eem {
	39	struct gether port;
	40	u8 ctrl_id;
9b39e9dd BN	41	};
	42
	43	static inline struct f_eem func_to_eem(struct usb_function f)
	44	{
	45	return container_of(f, struct f_eem, port.func);
	46	}
	47
	48	/-------------------------------------------------------------------------/
	49
	50	/* interface descriptor: */
	51
	52	static struct usb_interface_descriptor eem_intf __initdata = {
	53	.bLength = sizeof eem_intf,
	54	.bDescriptorType = USB_DT_INTERFACE,
	55
	56	/* .bInterfaceNumber = DYNAMIC */
	57	.bNumEndpoints = 2,
	58	.bInterfaceClass = USB_CLASS_COMM,
	59	.bInterfaceSubClass = USB_CDC_SUBCLASS_EEM,
	60	.bInterfaceProtocol = USB_CDC_PROTO_EEM,
	61	/* .iInterface = DYNAMIC */
	62	};
	63
	64	/* full speed support: */
	65
	66	static struct usb_endpoint_descriptor eem_fs_in_desc __initdata = {
	67	.bLength = USB_DT_ENDPOINT_SIZE,
	68	.bDescriptorType = USB_DT_ENDPOINT,
	69
	70	.bEndpointAddress = USB_DIR_IN,
	71	.bmAttributes = USB_ENDPOINT_XFER_BULK,
	72	};
	73
	74	static struct usb_endpoint_descriptor eem_fs_out_desc __initdata = {
	75	.bLength = USB_DT_ENDPOINT_SIZE,
	76	.bDescriptorType = USB_DT_ENDPOINT,
	77
	78	.bEndpointAddress = USB_DIR_OUT,
	79	.bmAttributes = USB_ENDPOINT_XFER_BULK,
	80	};
	81
	82	static struct usb_descriptor_header *eem_fs_function[] __initdata = {
	83	/* CDC EEM control descriptors */
	84	(struct usb_descriptor_header *) &eem_intf,
	85	(struct usb_descriptor_header *) &eem_fs_in_desc,
	86	(struct usb_descriptor_header *) &eem_fs_out_desc,
	87	NULL,
	88	};
	89
	90	/* high speed support: */
	91
	92	static struct usb_endpoint_descriptor eem_hs_in_desc __initdata = {
	93	.bLength = USB_DT_ENDPOINT_SIZE,
	94	.bDescriptorType = USB_DT_ENDPOINT,
	95
	96	.bEndpointAddress = USB_DIR_IN,
	97	.bmAttributes = USB_ENDPOINT_XFER_BULK,
	98	.wMaxPacketSize = cpu_to_le16(512),
	99	};
	100
	101	static struct usb_endpoint_descriptor eem_hs_out_desc __initdata = {
	102	.bLength = USB_DT_ENDPOINT_SIZE,
	103	.bDescriptorType = USB_DT_ENDPOINT,
	104
105	.bEndpointAddress = USB_DIR_OUT,
106	.bmAttributes = USB_ENDPOINT_XFER_BULK,
107	.wMaxPacketSize = cpu_to_le16(512),
108	};
109
110	static struct usb_descriptor_header *eem_hs_function[] __initdata = {
111	/* CDC EEM control descriptors */
112	(struct usb_descriptor_header *) &eem_intf,
113	(struct usb_descriptor_header *) &eem_hs_in_desc,
114	(struct usb_descriptor_header *) &eem_hs_out_desc,
115	NULL,
116	};
117
118	/* string descriptors: */
119
120	static struct usb_string eem_string_defs[] = {
121	[0].s = "CDC Ethernet Emulation Model (EEM)",
122	{ } /* end of list */
123	};
124
125	static struct usb_gadget_strings eem_string_table = {
126	.language = 0x0409, /* en-us */
127	.strings = eem_string_defs,
128	};
129
130	static struct usb_gadget_strings *eem_strings[] = {
131	&eem_string_table,
132	NULL,
133	};
134
135	/-------------------------------------------------------------------------/
136
137	static int eem_setup(struct usb_function f, const struct usb_ctrlrequest ctrl)
138	{
139	struct usb_composite_dev *cdev = f->config->cdev;
140	int value = -EOPNOTSUPP;
141	u16 w_index = le16_to_cpu(ctrl->wIndex);
142	u16 w_value = le16_to_cpu(ctrl->wValue);
143	u16 w_length = le16_to_cpu(ctrl->wLength);
144
145	DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
146	ctrl->bRequestType, ctrl->bRequest,
147	w_value, w_index, w_length);
148
149	/* device either stalls (value < 0) or reports success */
150	return value;
151	}
152
153
154	static int eem_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
155	{
156	struct f_eem *eem = func_to_eem(f);
157	struct usb_composite_dev *cdev = f->config->cdev;
158	struct net_device *net;
159
160	/* we know alt == 0, so this is an activation or a reset */
161	if (alt != 0)
162	goto fail;
163
164	if (intf == eem->ctrl_id) {
165
166	if (eem->port.in_ep->driver_data) {
167	DBG(cdev, "reset eem\n");
168	gether_disconnect(&eem->port);
169	}
170
ea2a1df7	171	if (!eem->port.in_ep->desc \|\| !eem->port.out_ep->desc) {
9b39e9dd	172	DBG(cdev, "init eem\n");
ea2a1df7 TB	173	if (config_ep_by_speed(cdev->gadget, f,
	174	eem->port.in_ep) \|\|
	175	config_ep_by_speed(cdev->gadget, f,
	176	eem->port.out_ep)) {
	177	eem->port.in_ep->desc = NULL;
	178	eem->port.out_ep->desc = NULL;
	179	goto fail;
	180	}
9b39e9dd BN	181	}
	182
	183	/* zlps should not occur because zero-length EEM packets
	184	* will be inserted in those cases where they would occur
	185	*/
	186	eem->port.is_zlp_ok = 1;
	187	eem->port.cdc_filter = DEFAULT_FILTER;
	188	DBG(cdev, "activate eem\n");
	189	net = gether_connect(&eem->port);
	190	if (IS_ERR(net))
	191	return PTR_ERR(net);
	192	} else
	193	goto fail;
	194
	195	return 0;
	196	fail:
	197	return -EINVAL;
	198	}
	199
	200	static void eem_disable(struct usb_function *f)
	201	{
	202	struct f_eem *eem = func_to_eem(f);
	203	struct usb_composite_dev *cdev = f->config->cdev;
	204
	205	DBG(cdev, "eem deactivated\n");
	206
	207	if (eem->port.in_ep->driver_data)
	208	gether_disconnect(&eem->port);
	209	}
	210
	211	/-------------------------------------------------------------------------/
	212
	213	/* EEM function driver setup/binding */
	214
	215	static int __init
	216	eem_bind(struct usb_configuration c, struct usb_function f)
	217	{
	218	struct usb_composite_dev *cdev = c->cdev;
	219	struct f_eem *eem = func_to_eem(f);
	220	int status;
	221	struct usb_ep *ep;
	222
	223	/* allocate instance-specific interface IDs */
	224	status = usb_interface_id(c, f);
	225	if (status < 0)
	226	goto fail;
	227	eem->ctrl_id = status;
	228	eem_intf.bInterfaceNumber = status;
	229
	230	status = -ENODEV;
	231
	232	/* allocate instance-specific endpoints */
	233	ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_in_desc);
	234	if (!ep)
	235	goto fail;
	236	eem->port.in_ep = ep;
	237	ep->driver_data = cdev; /* claim */
	238
	239	ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_out_desc);
	240	if (!ep)
	241	goto fail;
	242	eem->port.out_ep = ep;
	243	ep->driver_data = cdev; /* claim */
	244
245	status = -ENOMEM;
246
247	/* copy descriptors, and track endpoint copies */
248	f->descriptors = usb_copy_descriptors(eem_fs_function);
249	if (!f->descriptors)
250	goto fail;
251
9b39e9dd BN	252	/* support all relevant hardware speeds... we expect that when
	253	* hardware is dual speed, all bulk-capable endpoints work at
	254	* both speeds
	255	*/
	256	if (gadget_is_dualspeed(c->cdev->gadget)) {
	257	eem_hs_in_desc.bEndpointAddress =
	258	eem_fs_in_desc.bEndpointAddress;
	259	eem_hs_out_desc.bEndpointAddress =
	260	eem_fs_out_desc.bEndpointAddress;
	261
	262	/* copy descriptors, and track endpoint copies */
	263	f->hs_descriptors = usb_copy_descriptors(eem_hs_function);
	264	if (!f->hs_descriptors)
	265	goto fail;
9b39e9dd BN	266	}
	267
	268	DBG(cdev, "CDC Ethernet (EEM): %s speed IN/%s OUT/%s\n",
	269	gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
	270	eem->port.in_ep->name, eem->port.out_ep->name);
	271	return 0;
	272
	273	fail:
	274	if (f->descriptors)
	275	usb_free_descriptors(f->descriptors);
	276
	277	/* we might as well release our claims on endpoints */
72c973dd	278	if (eem->port.out_ep->desc)
9b39e9dd	279	eem->port.out_ep->driver_data = NULL;
72c973dd	280	if (eem->port.in_ep->desc)
9b39e9dd BN	281	eem->port.in_ep->driver_data = NULL;
	282
	283	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
	284
	285	return status;
	286	}
	287
	288	static void
	289	eem_unbind(struct usb_configuration c, struct usb_function f)
	290	{
	291	struct f_eem *eem = func_to_eem(f);
	292
	293	DBG(c->cdev, "eem unbind\n");
	294
	295	if (gadget_is_dualspeed(c->cdev->gadget))
	296	usb_free_descriptors(f->hs_descriptors);
	297	usb_free_descriptors(f->descriptors);
	298	kfree(eem);
	299	}
	300
	301	static void eem_cmd_complete(struct usb_ep ep, struct usb_request req)
	302	{
505d1f69 YK	303	struct sk_buff skb = (struct sk_buff )req->context;
	304
	305	dev_kfree_skb_any(skb);
9b39e9dd BN	306	}
	307
	308	/*
	309	* Add the EEM header and ethernet checksum.
	310	* We currently do not attempt to put multiple ethernet frames
	311	* into a single USB transfer
	312	*/
	313	static struct sk_buff eem_wrap(struct gether port, struct sk_buff *skb)
	314	{
	315	struct sk_buff *skb2 = NULL;
	316	struct usb_ep *in = port->in_ep;
	317	int padlen = 0;
	318	u16 len = skb->len;
	319
	320	if (!skb_cloned(skb)) {
	321	int headroom = skb_headroom(skb);
	322	int tailroom = skb_tailroom(skb);
	323
	324	/* When (len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) is 0,
	325	* stick two bytes of zero-length EEM packet on the end.
	326	*/
	327	if (((len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) == 0)
	328	padlen += 2;
	329
	330	if ((tailroom >= (ETH_FCS_LEN + padlen)) &&
	331	(headroom >= EEM_HLEN))
	332	goto done;
	333	}
	334
	335	skb2 = skb_copy_expand(skb, EEM_HLEN, ETH_FCS_LEN + padlen, GFP_ATOMIC);
	336	dev_kfree_skb_any(skb);
	337	skb = skb2;
	338	if (!skb)
	339	return skb;
	340
	341	done:
	342	/* use the "no CRC" option */
	343	put_unaligned_be32(0xdeadbeef, skb_put(skb, 4));
	344
	345	/* EEM packet header format:
	346	* b0..13: length of ethernet frame
	347	* b14: bmCRC (0 == sentinel CRC)
	348	* b15: bmType (0 == data)
	349	*/
	350	len = skb->len;
31e5d4ab	351	put_unaligned_le16(len & 0x3FFF, skb_push(skb, 2));
9b39e9dd BN	352
	353	/* add a zero-length EEM packet, if needed */
	354	if (padlen)
	355	put_unaligned_le16(0, skb_put(skb, 2));
	356
	357	return skb;
	358	}
	359
	360	/*
	361	* Remove the EEM header. Note that there can be many EEM packets in a single
	362	* USB transfer, so we need to break them out and handle them independently.
	363	*/
	364	static int eem_unwrap(struct gether *port,
	365	struct sk_buff *skb,
	366	struct sk_buff_head *list)
	367	{
	368	struct usb_composite_dev *cdev = port->func.config->cdev;
	369	int status = 0;
	370
	371	do {
	372	struct sk_buff *skb2;
	373	u16 header;
	374	u16 len = 0;
	375
	376	if (skb->len < EEM_HLEN) {
	377	status = -EINVAL;
	378	DBG(cdev, "invalid EEM header\n");
	379	goto error;
	380	}
	381
	382	/* remove the EEM header */
	383	header = get_unaligned_le16(skb->data);
	384	skb_pull(skb, EEM_HLEN);
	385
	386	/* EEM packet header format:
	387	* b0..14: EEM type dependent (data or command)
	388	* b15: bmType (0 == data, 1 == command)
	389	*/
	390	if (header & BIT(15)) {
	391	struct usb_request *req = cdev->req;
	392	u16 bmEEMCmd;
	393
	394	/* EEM command packet format:
	395	* b0..10: bmEEMCmdParam
	396	* b11..13: bmEEMCmd
	397	* b14: reserved (must be zero)
	398	* b15: bmType (1 == command)
	399	*/
	400	if (header & BIT(14))
	401	continue;
	402
	403	bmEEMCmd = (header >> 11) & 0x7;
	404	switch (bmEEMCmd) {
	405	case 0: /* echo */
	406	len = header & 0x7FF;
	407	if (skb->len < len) {
	408	status = -EOVERFLOW;
	409	goto error;
	410	}
	411
	412	skb2 = skb_clone(skb, GFP_ATOMIC);
	413	if (unlikely(!skb2)) {
	414	DBG(cdev, "EEM echo response error\n");
	415	goto next;
416	}
417	skb_trim(skb2, len);
418	put_unaligned_le16(BIT(15) \| BIT(11) \| len,
419	skb_push(skb2, 2));
505d1f69 YK	420	skb_copy_bits(skb2, 0, req->buf, skb2->len);
505d1f69 YK	421	req->length = skb2->len;
9b39e9dd BN	422	req->complete = eem_cmd_complete;
9b39e9dd BN	423	req->zero = 1;
505d1f69	424	req->context = skb2;
9b39e9dd BN	425	if (usb_ep_queue(port->in_ep, req, GFP_ATOMIC))
	426	DBG(cdev, "echo response queue fail\n");
	427	break;
	428
	429	case 1: /* echo response */
	430	case 2: /* suspend hint */
	431	case 3: /* response hint */
	432	case 4: /* response complete hint */
	433	case 5: /* tickle */
	434	default: /* reserved */
	435	continue;
	436	}
	437	} else {
	438	u32 crc, crc2;
	439	struct sk_buff *skb3;
	440
	441	/* check for zero-length EEM packet */
	442	if (header == 0)
	443	continue;
	444
	445	/* EEM data packet format:
	446	* b0..13: length of ethernet frame
	447	* b14: bmCRC (0 == sentinel, 1 == calculated)
	448	* b15: bmType (0 == data)
	449	*/
	450	len = header & 0x3FFF;
	451	if ((skb->len < len)
	452	\|\| (len < (ETH_HLEN + ETH_FCS_LEN))) {
	453	status = -EINVAL;
	454	goto error;
	455	}
	456
	457	/* validate CRC */
9b39e9dd BN	458	if (header & BIT(14)) {
	459	crc = get_unaligned_le32(skb->data + len
	460	- ETH_FCS_LEN);
	461	crc2 = ~crc32_le(~0,
03ab7461	462	skb->data, len - ETH_FCS_LEN);
9b39e9dd BN	463	} else {
	464	crc = get_unaligned_be32(skb->data + len
	465	- ETH_FCS_LEN);
	466	crc2 = 0xdeadbeef;
	467	}
	468	if (crc != crc2) {
	469	DBG(cdev, "invalid EEM CRC\n");
	470	goto next;
	471	}
	472
	473	skb2 = skb_clone(skb, GFP_ATOMIC);
	474	if (unlikely(!skb2)) {
	475	DBG(cdev, "unable to unframe EEM packet\n");
	476	continue;
	477	}
	478	skb_trim(skb2, len - ETH_FCS_LEN);
	479
	480	skb3 = skb_copy_expand(skb2,
	481	NET_IP_ALIGN,
	482	0,
	483	GFP_ATOMIC);
	484	if (unlikely(!skb3)) {
	485	DBG(cdev, "unable to realign EEM packet\n");
	486	dev_kfree_skb_any(skb2);
	487	continue;
	488	}
	489	dev_kfree_skb_any(skb2);
	490	skb_queue_tail(list, skb3);
	491	}
	492	next:
	493	skb_pull(skb, len);
	494	} while (skb->len);
	495
	496	error:
	497	dev_kfree_skb_any(skb);
	498	return status;
	499	}
	500
	501	/**
	502	* eem_bind_config - add CDC Ethernet (EEM) network link to a configuration
	503	* @c: the configuration to support the network link
	504	* Context: single threaded during gadget setup
	505	*
	506	* Returns zero on success, else negative errno.
	507	*
	508	* Caller must have called @gether_setup(). Caller is also responsible
	509	* for calling @gether_cleanup() before module unload.
	510	*/
	511	int __init eem_bind_config(struct usb_configuration *c)
	512	{
	513	struct f_eem *eem;
	514	int status;
	515
	516	/* maybe allocate device-global string IDs */
	517	if (eem_string_defs[0].id == 0) {
	518
	519	/* control interface label */
	520	status = usb_string_id(c->cdev);
	521	if (status < 0)
	522	return status;
	523	eem_string_defs[0].id = status;
	524	eem_intf.iInterface = status;
	525	}
	526
527	/* allocate and initialize one new instance */
528	eem = kzalloc(sizeof *eem, GFP_KERNEL);
529	if (!eem)
530	return -ENOMEM;
531
532	eem->port.cdc_filter = DEFAULT_FILTER;
533
534	eem->port.func.name = "cdc_eem";
535	eem->port.func.strings = eem_strings;
536	/* descriptors are per-instance copies */
537	eem->port.func.bind = eem_bind;
538	eem->port.func.unbind = eem_unbind;
539	eem->port.func.set_alt = eem_set_alt;
540	eem->port.func.setup = eem_setup;
541	eem->port.func.disable = eem_disable;
542	eem->port.wrap = eem_wrap;
543	eem->port.unwrap = eem_unwrap;
544	eem->port.header_len = EEM_HLEN;
545
546	status = usb_add_function(c, &eem->port.func);
547	if (status)
548	kfree(eem);
549	return status;
550	}
551