drivers/usb/gadget/function/f_obex.c - linux/kernel/git/herbert/crypto-2.6 - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * f_obex.c -- USB CDC OBEX function driver
  *
  * Copyright (C) 2008 Nokia Corporation
  * Contact: Felipe Balbi <felipe.balbi@nokia.com>
  *
  * Based on f_acm.c by Al Borchers and David Brownell.
  */

 /* #define VERBOSE_DEBUG */

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

 #include "u_serial.h"


 /*
  * This CDC OBEX function support just packages a TTY-ish byte stream.
  * A user mode server will put it into "raw" mode and handle all the
  * relevant protocol details ... this is just a kernel passthrough.
  * When possible, we prevent gadget enumeration until that server is
  * ready to handle the commands.
  */

 struct f_obex {
 	struct gserial			port;
 	u8				ctrl_id;
 	u8				data_id;
 	u8				cur_alt;
 	u8				port_num;
 };

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

 static inline struct f_obex *port_to_obex(struct gserial *p)
 {
 	return container_of(p, struct f_obex, port);
 }

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

 #define OBEX_CTRL_IDX	0
 #define OBEX_DATA_IDX	1

 static struct usb_string obex_string_defs[] = {
 	[OBEX_CTRL_IDX].s	= "CDC Object Exchange (OBEX)",
 	[OBEX_DATA_IDX].s	= "CDC OBEX Data",
 	{  },	/* end of list */
 };

 static struct usb_gadget_strings obex_string_table = {
 	.language		= 0x0409,	/* en-US */
 	.strings		= obex_string_defs,
 };

 static struct usb_gadget_strings *obex_strings[] = {
 	&obex_string_table,
 	NULL,
 };

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

 static struct usb_interface_descriptor obex_control_intf = {
 	.bLength		= sizeof(obex_control_intf),
 	.bDescriptorType	= USB_DT_INTERFACE,
 	.bInterfaceNumber	= 0,

 	.bAlternateSetting	= 0,
 	.bNumEndpoints		= 0,
 	.bInterfaceClass	= USB_CLASS_COMM,
 	.bInterfaceSubClass	= USB_CDC_SUBCLASS_OBEX,
 };

 static struct usb_interface_descriptor obex_data_nop_intf = {
 	.bLength		= sizeof(obex_data_nop_intf),
 	.bDescriptorType	= USB_DT_INTERFACE,
 	.bInterfaceNumber	= 1,

 	.bAlternateSetting	= 0,
 	.bNumEndpoints		= 0,
 	.bInterfaceClass	= USB_CLASS_CDC_DATA,
 };

 static struct usb_interface_descriptor obex_data_intf = {
 	.bLength		= sizeof(obex_data_intf),
 	.bDescriptorType	= USB_DT_INTERFACE,
 	.bInterfaceNumber	= 2,

 	.bAlternateSetting	= 1,
 	.bNumEndpoints		= 2,
 	.bInterfaceClass	= USB_CLASS_CDC_DATA,
 };

 static struct usb_cdc_header_desc obex_cdc_header_desc = {
 	.bLength		= sizeof(obex_cdc_header_desc),
 	.bDescriptorType	= USB_DT_CS_INTERFACE,
 	.bDescriptorSubType	= USB_CDC_HEADER_TYPE,
 	.bcdCDC			= cpu_to_le16(0x0120),
 };

 static struct usb_cdc_union_desc obex_cdc_union_desc = {
 	.bLength		= sizeof(obex_cdc_union_desc),
 	.bDescriptorType	= USB_DT_CS_INTERFACE,
 	.bDescriptorSubType	= USB_CDC_UNION_TYPE,
 	.bMasterInterface0	= 1,
 	.bSlaveInterface0	= 2,
 };

 static struct usb_cdc_obex_desc obex_desc = {
 	.bLength		= sizeof(obex_desc),
 	.bDescriptorType	= USB_DT_CS_INTERFACE,
 	.bDescriptorSubType	= USB_CDC_OBEX_TYPE,
 	.bcdVersion		= cpu_to_le16(0x0100),
 };

 /* High-Speed Support */

 static struct usb_endpoint_descriptor obex_hs_ep_out_desc = {
 	.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_endpoint_descriptor obex_hs_ep_in_desc = {
 	.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_descriptor_header *hs_function[] = {
 	(struct usb_descriptor_header *) &obex_control_intf,
 	(struct usb_descriptor_header *) &obex_cdc_header_desc,
 	(struct usb_descriptor_header *) &obex_desc,
 	(struct usb_descriptor_header *) &obex_cdc_union_desc,

 	(struct usb_descriptor_header *) &obex_data_nop_intf,
 	(struct usb_descriptor_header *) &obex_data_intf,
 	(struct usb_descriptor_header *) &obex_hs_ep_in_desc,
 	(struct usb_descriptor_header *) &obex_hs_ep_out_desc,
 	NULL,
 };

 /* Full-Speed Support */

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

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

 static struct usb_endpoint_descriptor obex_fs_ep_out_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_function[] = {
 	(struct usb_descriptor_header *) &obex_control_intf,
 	(struct usb_descriptor_header *) &obex_cdc_header_desc,
 	(struct usb_descriptor_header *) &obex_desc,
 	(struct usb_descriptor_header *) &obex_cdc_union_desc,

 	(struct usb_descriptor_header *) &obex_data_nop_intf,
 	(struct usb_descriptor_header *) &obex_data_intf,
 	(struct usb_descriptor_header *) &obex_fs_ep_in_desc,
 	(struct usb_descriptor_header *) &obex_fs_ep_out_desc,
 	NULL,
 };

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

 static int obex_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 {
 	struct f_obex		*obex = func_to_obex(f);
 	struct usb_composite_dev *cdev = f->config->cdev;

 	if (intf == obex->ctrl_id) {
 		if (alt != 0)
 			goto fail;
 		/* NOP */
 		dev_dbg(&cdev->gadget->dev,
 			"reset obex ttyGS%d control\n", obex->port_num);

 	} else if (intf == obex->data_id) {
 		if (alt > 1)
 			goto fail;

 		if (obex->port.in->enabled) {
 			dev_dbg(&cdev->gadget->dev,
 				"reset obex ttyGS%d\n", obex->port_num);
 			gserial_disconnect(&obex->port);
 		}

 		if (!obex->port.in->desc || !obex->port.out->desc) {
 			dev_dbg(&cdev->gadget->dev,
 				"init obex ttyGS%d\n", obex->port_num);
 			if (config_ep_by_speed(cdev->gadget, f,
 					       obex->port.in) ||
 			    config_ep_by_speed(cdev->gadget, f,
 					       obex->port.out)) {
 				obex->port.out->desc = NULL;
 				obex->port.in->desc = NULL;
 				goto fail;
 			}
 		}

 		if (alt == 1) {
 			dev_dbg(&cdev->gadget->dev,
 				"activate obex ttyGS%d\n", obex->port_num);
 			gserial_connect(&obex->port, obex->port_num);
 		}

 	} else
 		goto fail;

 	obex->cur_alt = alt;

 	return 0;

 fail:
 	return -EINVAL;
 }

 static int obex_get_alt(struct usb_function *f, unsigned intf)
 {
 	struct f_obex		*obex = func_to_obex(f);

 	return obex->cur_alt;
 }

 static void obex_disable(struct usb_function *f)
 {
 	struct f_obex	*obex = func_to_obex(f);
 	struct usb_composite_dev *cdev = f->config->cdev;

 	dev_dbg(&cdev->gadget->dev, "obex ttyGS%d disable\n", obex->port_num);
 	gserial_disconnect(&obex->port);
 }

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

 static void obex_connect(struct gserial *g)
 {
 	struct f_obex		*obex = port_to_obex(g);
 	struct usb_composite_dev *cdev = g->func.config->cdev;
 	int			status;

 	status = usb_function_activate(&g->func);
 	if (status)
 		dev_dbg(&cdev->gadget->dev,
 			"obex ttyGS%d function activate --> %d\n",
 			obex->port_num, status);
 }

 static void obex_disconnect(struct gserial *g)
 {
 	struct f_obex		*obex = port_to_obex(g);
 	struct usb_composite_dev *cdev = g->func.config->cdev;
 	int			status;

 	status = usb_function_deactivate(&g->func);
 	if (status)
 		dev_dbg(&cdev->gadget->dev,
 			"obex ttyGS%d function deactivate --> %d\n",
 			obex->port_num, status);
 }

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

 /* Some controllers can't support CDC OBEX ... */
 static inline bool can_support_obex(struct usb_configuration *c)
 {
 	/* Since the first interface is a NOP, we can ignore the
 	 * issue of multi-interface support on most controllers.
 	 *
 	 * Altsettings are mandatory, however...
 	 */
 	if (!gadget_is_altset_supported(c->cdev->gadget))
 		return false;

 	/* everything else is *probably* fine ... */
 	return true;
 }

 static int obex_bind(struct usb_configuration *c, struct usb_function *f)
 {
 	struct usb_composite_dev *cdev = c->cdev;
 	struct f_obex		*obex = func_to_obex(f);
 	struct usb_string	*us;
 	int			status;
 	struct usb_ep		*ep;

 	if (!can_support_obex(c))
 		return -EINVAL;

 	us = usb_gstrings_attach(cdev, obex_strings,
 				 ARRAY_SIZE(obex_string_defs));
 	if (IS_ERR(us))
 		return PTR_ERR(us);
 	obex_control_intf.iInterface = us[OBEX_CTRL_IDX].id;
 	obex_data_nop_intf.iInterface = us[OBEX_DATA_IDX].id;
 	obex_data_intf.iInterface = us[OBEX_DATA_IDX].id;

 	/* allocate instance-specific interface IDs, and patch descriptors */

 	status = usb_interface_id(c, f);
 	if (status < 0)
 		goto fail;
 	obex->ctrl_id = status;

 	obex_control_intf.bInterfaceNumber = status;
 	obex_cdc_union_desc.bMasterInterface0 = status;

 	status = usb_interface_id(c, f);
 	if (status < 0)
 		goto fail;
 	obex->data_id = status;

 	obex_data_nop_intf.bInterfaceNumber = status;
 	obex_data_intf.bInterfaceNumber = status;
 	obex_cdc_union_desc.bSlaveInterface0 = status;

 	/* allocate instance-specific endpoints */

 	status = -ENODEV;
 	ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
 	if (!ep)
 		goto fail;
 	obex->port.in = ep;

 	ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
 	if (!ep)
 		goto fail;
 	obex->port.out = ep;

 	/* support all relevant hardware speeds... we expect that when
 	 * hardware is dual speed, all bulk-capable endpoints work at
 	 * both speeds
 	 */

 	obex_hs_ep_in_desc.bEndpointAddress =
 		obex_fs_ep_in_desc.bEndpointAddress;
 	obex_hs_ep_out_desc.bEndpointAddress =
 		obex_fs_ep_out_desc.bEndpointAddress;

 	status = usb_assign_descriptors(f, fs_function, hs_function, NULL,
 					NULL);
 	if (status)
 		goto fail;

 	dev_dbg(&cdev->gadget->dev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
 		obex->port_num,
 		gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 		obex->port.in->name, obex->port.out->name);

 	return 0;

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

 	return status;
 }

 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
 {
 	return container_of(to_config_group(item), struct f_serial_opts,
 			    func_inst.group);
 }

 static void obex_attr_release(struct config_item *item)
 {
 	struct f_serial_opts *opts = to_f_serial_opts(item);

 	usb_put_function_instance(&opts->func_inst);
 }

 static struct configfs_item_operations obex_item_ops = {
 	.release	= obex_attr_release,
 };

 static ssize_t f_obex_port_num_show(struct config_item *item, char *page)
 {
 	return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
 }

 CONFIGFS_ATTR_RO(f_obex_, port_num);

 static struct configfs_attribute *acm_attrs[] = {
 	&f_obex_attr_port_num,
 	NULL,
 };

 static const struct config_item_type obex_func_type = {
 	.ct_item_ops	= &obex_item_ops,
 	.ct_attrs	= acm_attrs,
 	.ct_owner	= THIS_MODULE,
 };

 static void obex_free_inst(struct usb_function_instance *f)
 {
 	struct f_serial_opts *opts;

 	opts = container_of(f, struct f_serial_opts, func_inst);
 	gserial_free_line(opts->port_num);
 	kfree(opts);
 }

 static struct usb_function_instance *obex_alloc_inst(void)
 {
 	struct f_serial_opts *opts;
 	int ret;

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

 	opts->func_inst.free_func_inst = obex_free_inst;
 	ret = gserial_alloc_line_no_console(&opts->port_num);
 	if (ret) {
 		kfree(opts);
 		return ERR_PTR(ret);
 	}
 	config_group_init_type_name(&opts->func_inst.group, "",
 				    &obex_func_type);

 	return &opts->func_inst;
 }

 static void obex_free(struct usb_function *f)
 {
 	struct f_obex *obex;

 	obex = func_to_obex(f);
 	kfree(obex);
 }

 static void obex_unbind(struct usb_configuration *c, struct usb_function *f)
 {
 	usb_free_all_descriptors(f);
 }

 static struct usb_function *obex_alloc(struct usb_function_instance *fi)
 {
 	struct f_obex	*obex;
 	struct f_serial_opts *opts;

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

 	opts = container_of(fi, struct f_serial_opts, func_inst);

 	obex->port_num = opts->port_num;

 	obex->port.connect = obex_connect;
 	obex->port.disconnect = obex_disconnect;

 	obex->port.func.name = "obex";
 	/* descriptors are per-instance copies */
 	obex->port.func.bind = obex_bind;
 	obex->port.func.unbind = obex_unbind;
 	obex->port.func.set_alt = obex_set_alt;
 	obex->port.func.get_alt = obex_get_alt;
 	obex->port.func.disable = obex_disable;
 	obex->port.func.free_func = obex_free;
 	obex->port.func.bind_deactivated = true;

 	return &obex->port.func;
 }

 DECLARE_USB_FUNCTION_INIT(obex, obex_alloc_inst, obex_alloc);
 MODULE_AUTHOR("Felipe Balbi");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* f_obex.c -- USB CDC OBEX function driver
	*
	* Copyright (C) 2008 Nokia Corporation
	* Contact: Felipe Balbi <felipe.balbi@nokia.com>
	*
	* Based on f_acm.c by Al Borchers and David Brownell.
	*/

	/* #define VERBOSE_DEBUG */

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

	#include "u_serial.h"


	/*
	* This CDC OBEX function support just packages a TTY-ish byte stream.
	* A user mode server will put it into "raw" mode and handle all the
	* relevant protocol details ... this is just a kernel passthrough.
	* When possible, we prevent gadget enumeration until that server is
	* ready to handle the commands.
	*/

	struct f_obex {
	struct gserial port;
	u8 ctrl_id;
	u8 data_id;
	u8 cur_alt;
	u8 port_num;
	};

	static inline struct f_obex func_to_obex(struct usb_function f)
	{
	return container_of(f, struct f_obex, port.func);
	}

	static inline struct f_obex port_to_obex(struct gserial p)
	{
	return container_of(p, struct f_obex, port);
	}

	/-------------------------------------------------------------------------/

	#define OBEX_CTRL_IDX 0
	#define OBEX_DATA_IDX 1

	static struct usb_string obex_string_defs[] = {
	[OBEX_CTRL_IDX].s = "CDC Object Exchange (OBEX)",
	[OBEX_DATA_IDX].s = "CDC OBEX Data",
	{ }, /* end of list */
	};

	static struct usb_gadget_strings obex_string_table = {
	.language = 0x0409, /* en-US */
	.strings = obex_string_defs,
	};

	static struct usb_gadget_strings *obex_strings[] = {
	&obex_string_table,
	NULL,
	};

	/-------------------------------------------------------------------------/

	static struct usb_interface_descriptor obex_control_intf = {
	.bLength = sizeof(obex_control_intf),
	.bDescriptorType = USB_DT_INTERFACE,
	.bInterfaceNumber = 0,

	.bAlternateSetting = 0,
	.bNumEndpoints = 0,
	.bInterfaceClass = USB_CLASS_COMM,
	.bInterfaceSubClass = USB_CDC_SUBCLASS_OBEX,
	};

	static struct usb_interface_descriptor obex_data_nop_intf = {
	.bLength = sizeof(obex_data_nop_intf),
	.bDescriptorType = USB_DT_INTERFACE,
	.bInterfaceNumber = 1,

	.bAlternateSetting = 0,
	.bNumEndpoints = 0,
	.bInterfaceClass = USB_CLASS_CDC_DATA,
	};

	static struct usb_interface_descriptor obex_data_intf = {
	.bLength = sizeof(obex_data_intf),
	.bDescriptorType = USB_DT_INTERFACE,
	.bInterfaceNumber = 2,

	.bAlternateSetting = 1,
	.bNumEndpoints = 2,
	.bInterfaceClass = USB_CLASS_CDC_DATA,
	};

	static struct usb_cdc_header_desc obex_cdc_header_desc = {
	.bLength = sizeof(obex_cdc_header_desc),
	.bDescriptorType = USB_DT_CS_INTERFACE,
	.bDescriptorSubType = USB_CDC_HEADER_TYPE,
	.bcdCDC = cpu_to_le16(0x0120),
	};

	static struct usb_cdc_union_desc obex_cdc_union_desc = {
	.bLength = sizeof(obex_cdc_union_desc),
	.bDescriptorType = USB_DT_CS_INTERFACE,
	.bDescriptorSubType = USB_CDC_UNION_TYPE,
	.bMasterInterface0 = 1,
	.bSlaveInterface0 = 2,
	};

	static struct usb_cdc_obex_desc obex_desc = {
	.bLength = sizeof(obex_desc),
	.bDescriptorType = USB_DT_CS_INTERFACE,
	.bDescriptorSubType = USB_CDC_OBEX_TYPE,
	.bcdVersion = cpu_to_le16(0x0100),
	};

	/* High-Speed Support */

	static struct usb_endpoint_descriptor obex_hs_ep_out_desc = {
	.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_endpoint_descriptor obex_hs_ep_in_desc = {
	.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_descriptor_header *hs_function[] = {
	(struct usb_descriptor_header *) &obex_control_intf,
	(struct usb_descriptor_header *) &obex_cdc_header_desc,
	(struct usb_descriptor_header *) &obex_desc,
	(struct usb_descriptor_header *) &obex_cdc_union_desc,

	(struct usb_descriptor_header *) &obex_data_nop_intf,
	(struct usb_descriptor_header *) &obex_data_intf,
	(struct usb_descriptor_header *) &obex_hs_ep_in_desc,
	(struct usb_descriptor_header *) &obex_hs_ep_out_desc,
	NULL,
	};

	/* Full-Speed Support */

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

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

	static struct usb_endpoint_descriptor obex_fs_ep_out_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_function[] = {
	(struct usb_descriptor_header *) &obex_control_intf,
	(struct usb_descriptor_header *) &obex_cdc_header_desc,
	(struct usb_descriptor_header *) &obex_desc,
	(struct usb_descriptor_header *) &obex_cdc_union_desc,

	(struct usb_descriptor_header *) &obex_data_nop_intf,
	(struct usb_descriptor_header *) &obex_data_intf,
	(struct usb_descriptor_header *) &obex_fs_ep_in_desc,
	(struct usb_descriptor_header *) &obex_fs_ep_out_desc,
	NULL,
	};

	/-------------------------------------------------------------------------/

	static int obex_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
	{
	struct f_obex *obex = func_to_obex(f);
	struct usb_composite_dev *cdev = f->config->cdev;

	if (intf == obex->ctrl_id) {
	if (alt != 0)
	goto fail;
	/* NOP */
	dev_dbg(&cdev->gadget->dev,
	"reset obex ttyGS%d control\n", obex->port_num);

	} else if (intf == obex->data_id) {
	if (alt > 1)
	goto fail;

	if (obex->port.in->enabled) {
	dev_dbg(&cdev->gadget->dev,
	"reset obex ttyGS%d\n", obex->port_num);
	gserial_disconnect(&obex->port);
	}

	if (!obex->port.in->desc \|\| !obex->port.out->desc) {
	dev_dbg(&cdev->gadget->dev,
	"init obex ttyGS%d\n", obex->port_num);
	if (config_ep_by_speed(cdev->gadget, f,
	obex->port.in) \|\|
	config_ep_by_speed(cdev->gadget, f,
	obex->port.out)) {
	obex->port.out->desc = NULL;
	obex->port.in->desc = NULL;
	goto fail;
	}
	}

	if (alt == 1) {
	dev_dbg(&cdev->gadget->dev,
	"activate obex ttyGS%d\n", obex->port_num);
	gserial_connect(&obex->port, obex->port_num);
	}

	} else
	goto fail;

	obex->cur_alt = alt;

	return 0;

	fail:
	return -EINVAL;
	}

	static int obex_get_alt(struct usb_function *f, unsigned intf)
	{
	struct f_obex *obex = func_to_obex(f);

	return obex->cur_alt;
	}

	static void obex_disable(struct usb_function *f)
	{
	struct f_obex *obex = func_to_obex(f);
	struct usb_composite_dev *cdev = f->config->cdev;

	dev_dbg(&cdev->gadget->dev, "obex ttyGS%d disable\n", obex->port_num);
	gserial_disconnect(&obex->port);
	}

	/-------------------------------------------------------------------------/

	static void obex_connect(struct gserial *g)
	{
	struct f_obex *obex = port_to_obex(g);
	struct usb_composite_dev *cdev = g->func.config->cdev;
	int status;

	status = usb_function_activate(&g->func);
	if (status)
	dev_dbg(&cdev->gadget->dev,
	"obex ttyGS%d function activate --> %d\n",
	obex->port_num, status);
	}

	static void obex_disconnect(struct gserial *g)
	{
	struct f_obex *obex = port_to_obex(g);
	struct usb_composite_dev *cdev = g->func.config->cdev;
	int status;

	status = usb_function_deactivate(&g->func);
	if (status)
	dev_dbg(&cdev->gadget->dev,
	"obex ttyGS%d function deactivate --> %d\n",
	obex->port_num, status);
	}

	/-------------------------------------------------------------------------/

	/* Some controllers can't support CDC OBEX ... */
	static inline bool can_support_obex(struct usb_configuration *c)
	{
	/* Since the first interface is a NOP, we can ignore the
	* issue of multi-interface support on most controllers.
	*
	* Altsettings are mandatory, however...
	*/
	if (!gadget_is_altset_supported(c->cdev->gadget))
	return false;

	/* everything else is probably fine ... */
	return true;
	}

	static int obex_bind(struct usb_configuration c, struct usb_function f)
	{
	struct usb_composite_dev *cdev = c->cdev;
	struct f_obex *obex = func_to_obex(f);
	struct usb_string *us;
	int status;
	struct usb_ep *ep;

	if (!can_support_obex(c))
	return -EINVAL;

	us = usb_gstrings_attach(cdev, obex_strings,
	ARRAY_SIZE(obex_string_defs));
	if (IS_ERR(us))
	return PTR_ERR(us);
	obex_control_intf.iInterface = us[OBEX_CTRL_IDX].id;
	obex_data_nop_intf.iInterface = us[OBEX_DATA_IDX].id;
	obex_data_intf.iInterface = us[OBEX_DATA_IDX].id;

	/* allocate instance-specific interface IDs, and patch descriptors */

	status = usb_interface_id(c, f);
	if (status < 0)
	goto fail;
	obex->ctrl_id = status;

	obex_control_intf.bInterfaceNumber = status;
	obex_cdc_union_desc.bMasterInterface0 = status;

	status = usb_interface_id(c, f);
	if (status < 0)
	goto fail;
	obex->data_id = status;

	obex_data_nop_intf.bInterfaceNumber = status;
	obex_data_intf.bInterfaceNumber = status;
	obex_cdc_union_desc.bSlaveInterface0 = status;

	/* allocate instance-specific endpoints */

	status = -ENODEV;
	ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
	if (!ep)
	goto fail;
	obex->port.in = ep;

	ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
	if (!ep)
	goto fail;
	obex->port.out = ep;

	/* support all relevant hardware speeds... we expect that when
	* hardware is dual speed, all bulk-capable endpoints work at
	* both speeds
	*/

	obex_hs_ep_in_desc.bEndpointAddress =
	obex_fs_ep_in_desc.bEndpointAddress;
	obex_hs_ep_out_desc.bEndpointAddress =
	obex_fs_ep_out_desc.bEndpointAddress;

	status = usb_assign_descriptors(f, fs_function, hs_function, NULL,
	NULL);
	if (status)
	goto fail;

	dev_dbg(&cdev->gadget->dev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
	obex->port_num,
	gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
	obex->port.in->name, obex->port.out->name);

	return 0;

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

	return status;
	}

	static inline struct f_serial_opts to_f_serial_opts(struct config_item item)
	{
	return container_of(to_config_group(item), struct f_serial_opts,
	func_inst.group);
	}

	static void obex_attr_release(struct config_item *item)
	{
	struct f_serial_opts *opts = to_f_serial_opts(item);

	usb_put_function_instance(&opts->func_inst);
	}

	static struct configfs_item_operations obex_item_ops = {
	.release = obex_attr_release,
	};

	static ssize_t f_obex_port_num_show(struct config_item item, char page)
	{
	return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
	}

	CONFIGFS_ATTR_RO(f_obex_, port_num);

	static struct configfs_attribute *acm_attrs[] = {
	&f_obex_attr_port_num,
	NULL,
	};

	static const struct config_item_type obex_func_type = {
	.ct_item_ops = &obex_item_ops,
	.ct_attrs = acm_attrs,
	.ct_owner = THIS_MODULE,
	};

	static void obex_free_inst(struct usb_function_instance *f)
	{
	struct f_serial_opts *opts;

	opts = container_of(f, struct f_serial_opts, func_inst);
	gserial_free_line(opts->port_num);
	kfree(opts);
	}

	static struct usb_function_instance *obex_alloc_inst(void)
	{
	struct f_serial_opts *opts;
	int ret;

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

	opts->func_inst.free_func_inst = obex_free_inst;
	ret = gserial_alloc_line_no_console(&opts->port_num);
	if (ret) {
	kfree(opts);
	return ERR_PTR(ret);
	}
	config_group_init_type_name(&opts->func_inst.group, "",
	&obex_func_type);

	return &opts->func_inst;
	}

	static void obex_free(struct usb_function *f)
	{
	struct f_obex *obex;

	obex = func_to_obex(f);
	kfree(obex);
	}

	static void obex_unbind(struct usb_configuration c, struct usb_function f)
	{
	usb_free_all_descriptors(f);
	}

	static struct usb_function obex_alloc(struct usb_function_instance fi)
	{
	struct f_obex *obex;
	struct f_serial_opts *opts;

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

	opts = container_of(fi, struct f_serial_opts, func_inst);

	obex->port_num = opts->port_num;

	obex->port.connect = obex_connect;
	obex->port.disconnect = obex_disconnect;

	obex->port.func.name = "obex";
	/* descriptors are per-instance copies */
	obex->port.func.bind = obex_bind;
	obex->port.func.unbind = obex_unbind;
	obex->port.func.set_alt = obex_set_alt;
	obex->port.func.get_alt = obex_get_alt;
	obex->port.func.disable = obex_disable;
	obex->port.func.free_func = obex_free;
	obex->port.func.bind_deactivated = true;

	return &obex->port.func;
	}

	DECLARE_USB_FUNCTION_INIT(obex, obex_alloc_inst, obex_alloc);
	MODULE_AUTHOR("Felipe Balbi");
	MODULE_LICENSE("GPL");