/*
 * f_serial.c - generic USB serial function driver
 *
 * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
 * Copyright (C) 2008 by David Brownell
 * Copyright (C) 2008 by Nokia Corporation
 *
 * This software is distributed under the terms of the GNU General
 * Public License ("GPL") as published by the Free Software Foundation,
 * either version 2 of that License or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/usb/android_composite.h>

#include "u_serial.h"
#include "gadget_chips.h"

#define CONFIG_MODEM_SUPPORT
/*
 * This function packages a simple "generic serial" port with no real
 * control mechanisms, just raw data transfer over two bulk endpoints.
 *
 * Because it's not standardized, this isn't as interoperable as the
 * CDC ACM driver.  However, for many purposes it's just as functional
 * if you can arrange appropriate host side drivers.
 */

struct gser_descs {
	struct usb_endpoint_descriptor	*in;
	struct usb_endpoint_descriptor	*out;
#ifdef CONFIG_MODEM_SUPPORT
	struct usb_endpoint_descriptor	*notify;
#endif
};

struct f_gser {
	struct gserial			port;
	u8				data_id;
	u8				port_num;
	u8				disabled;
	u8				configured;

	struct gser_descs		fs;
	struct gser_descs		hs;
	u8				online;
#ifdef CONFIG_MODEM_SUPPORT
	u8				pending;
	spinlock_t			lock;
	struct usb_ep			*notify;
	struct usb_endpoint_descriptor	*notify_desc;
	struct usb_request		*notify_req;

	struct usb_cdc_line_coding	port_line_coding;

	/* SetControlLineState request */
	u16				port_handshake_bits;
#define ACM_CTRL_RTS	(1 << 1)	/* unused with full duplex */
#define ACM_CTRL_DTR	(1 << 0)	/* host is ready for data r/w */

	/* SerialState notification */
	u16				serial_state;
#define ACM_CTRL_OVERRUN	(1 << 6)
#define ACM_CTRL_PARITY		(1 << 5)
#define ACM_CTRL_FRAMING	(1 << 4)
#define ACM_CTRL_RI		(1 << 3)
#define ACM_CTRL_BRK		(1 << 2)
#define ACM_CTRL_DSR		(1 << 1)
#define ACM_CTRL_DCD		(1 << 0)
#endif
};
static struct usb_function *modem_function;
static struct usb_function *serial_function;

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

#ifdef CONFIG_MODEM_SUPPORT
static inline struct f_gser *port_to_gser(struct gserial *p)
{
	return container_of(p, struct f_gser, port);
}
#define GS_LOG2_NOTIFY_INTERVAL		5	/* 1 << 5 == 32 msec */
#define GS_NOTIFY_MAXPACKET		10	/* notification + 2 bytes */
#endif
/*-------------------------------------------------------------------------*/

/* interface descriptor: */

static struct usb_interface_descriptor gser_interface_desc = {
	.bLength =		USB_DT_INTERFACE_SIZE,
	.bDescriptorType =	USB_DT_INTERFACE,
	/* .bInterfaceNumber = DYNAMIC */
#ifdef CONFIG_MODEM_SUPPORT
	.bNumEndpoints =	3,
#else
	.bNumEndpoints =	2,
#endif
	.bInterfaceClass =	USB_CLASS_VENDOR_SPEC,
	.bInterfaceSubClass =	0,
	.bInterfaceProtocol =	0,
	/* .iInterface = DYNAMIC */
};
#ifdef CONFIG_MODEM_SUPPORT
static struct usb_cdc_header_desc gser_header_desc  = {
	.bLength =		sizeof(gser_header_desc),
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
	.bcdCDC =		__constant_cpu_to_le16(0x0110),
};

static struct usb_cdc_call_mgmt_descriptor
gser_call_mgmt_descriptor  = {
	.bLength =		sizeof(gser_call_mgmt_descriptor),
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubType =	USB_CDC_CALL_MANAGEMENT_TYPE,
	.bmCapabilities =	0,
	/* .bDataInterface = DYNAMIC */
};

static struct usb_cdc_acm_descriptor gser_descriptor  = {
	.bLength =		sizeof(gser_descriptor),
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubType =	USB_CDC_ACM_TYPE,
	.bmCapabilities =	USB_CDC_CAP_LINE,
};

static struct usb_cdc_union_desc gser_union_desc  = {
	.bLength =		sizeof(gser_union_desc),
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
	/* .bMasterInterface0 =	DYNAMIC */
	/* .bSlaveInterface0 =	DYNAMIC */
};
#endif
/* full speed support: */
#ifdef CONFIG_MODEM_SUPPORT
static struct usb_endpoint_descriptor gser_fs_notify_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,
	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_INT,
	.wMaxPacketSize =	__constant_cpu_to_le16(GS_NOTIFY_MAXPACKET),
	.bInterval =		1 << GS_LOG2_NOTIFY_INTERVAL,
};
#endif

static struct usb_endpoint_descriptor gser_fs_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 gser_fs_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 *gser_fs_function[] = {
	(struct usb_descriptor_header *) &gser_interface_desc,
#ifdef CONFIG_MODEM_SUPPORT
	(struct usb_descriptor_header *) &gser_header_desc,
	(struct usb_descriptor_header *) &gser_call_mgmt_descriptor,
	(struct usb_descriptor_header *) &gser_descriptor,
	(struct usb_descriptor_header *) &gser_union_desc,
	(struct usb_descriptor_header *) &gser_fs_notify_desc,
#endif
	(struct usb_descriptor_header *) &gser_fs_in_desc,
	(struct usb_descriptor_header *) &gser_fs_out_desc,
	NULL,
};

/* high speed support: */
#ifdef CONFIG_MODEM_SUPPORT
static struct usb_endpoint_descriptor gser_hs_notify_desc  = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,
	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_INT,
	.wMaxPacketSize =	__constant_cpu_to_le16(GS_NOTIFY_MAXPACKET),
	.bInterval =		GS_LOG2_NOTIFY_INTERVAL+4,
};
#endif

static struct usb_endpoint_descriptor gser_hs_in_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	__constant_cpu_to_le16(512),
};

static struct usb_endpoint_descriptor gser_hs_out_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	__constant_cpu_to_le16(512),
};

static struct usb_descriptor_header *gser_hs_function[] = {
	(struct usb_descriptor_header *) &gser_interface_desc,
#ifdef CONFIG_MODEM_SUPPORT
	(struct usb_descriptor_header *) &gser_header_desc,
	(struct usb_descriptor_header *) &gser_call_mgmt_descriptor,
	(struct usb_descriptor_header *) &gser_descriptor,
	(struct usb_descriptor_header *) &gser_union_desc,
	(struct usb_descriptor_header *) &gser_hs_notify_desc,
#endif
	(struct usb_descriptor_header *) &gser_hs_in_desc,
	(struct usb_descriptor_header *) &gser_hs_out_desc,
	NULL,
};

/* string descriptors: */

static struct usb_string modem_string_defs[] = {
	[0].s = "HTC Modem",
	{  } /* end of list */
};

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

static struct usb_gadget_strings *modem_strings[] = {
	&modem_string_table,
	NULL,
};

static struct usb_string serial_string_defs[] = {
	[0].s = "HTC Serial",
	{  } /* end of list */
};

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

static struct usb_gadget_strings *serial_strings[] = {
	&serial_string_table,
	NULL,
};
#ifdef CONFIG_MODEM_SUPPORT
static void gser_complete_set_line_coding(struct usb_ep *ep,
		struct usb_request *req)
{
	struct f_gser            *gser = ep->driver_data;
	struct usb_composite_dev *cdev = gser->port.func.config->cdev;

	if (req->status != 0) {
		DBG(cdev, "gser ttyGS%d completion, err %d\n",
				gser->port_num, req->status);
		return;
	}

	/* normal completion */
	if (req->actual != sizeof(gser->port_line_coding)) {
		DBG(cdev, "gser ttyGS%d short resp, len %d\n",
				gser->port_num, req->actual);
		usb_ep_set_halt(ep);
	} else {
		struct usb_cdc_line_coding	*value = req->buf;
		gser->port_line_coding = *value;
	}
}
/*-------------------------------------------------------------------------*/
static int
gser_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
{
	struct f_gser            *gser = func_to_gser(f);
	struct usb_composite_dev *cdev = f->config->cdev;
	struct usb_request	 *req = cdev->req;
	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);

	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {

	/* SET_LINE_CODING ... just read and save what the host sends */
	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
			| USB_CDC_REQ_SET_LINE_CODING:
		if (w_length != sizeof(struct usb_cdc_line_coding)
				|| w_index != gser->data_id)
			goto invalid;
		value = w_length;
		cdev->gadget->ep0->driver_data = gser;
		req->complete = gser_complete_set_line_coding;
		break;

	/* GET_LINE_CODING ... return what host sent, or initial value */
	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
			| USB_CDC_REQ_GET_LINE_CODING:
		if (w_index != gser->data_id)
			goto invalid;

		value = min_t(unsigned, w_length,
				sizeof(struct usb_cdc_line_coding));
		memcpy(req->buf, &gser->port_line_coding, value);
		break;

	/* SET_CONTROL_LINE_STATE ... save what the host sent */
	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
			| USB_CDC_REQ_SET_CONTROL_LINE_STATE:
		if (w_index != gser->data_id)
			goto invalid;

		value = 0;
		gser->port_handshake_bits = w_value;
		break;

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

	/* respond with data transfer or status phase? */
	if (value >= 0) {
		DBG(cdev, "gser ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
			gser->port_num, ctrl->bRequestType, ctrl->bRequest,
			w_value, w_index, w_length);
		req->zero = 0;
		req->length = value;
		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
		if (value < 0)
			ERROR(cdev, "gser response on ttyGS%d, err %d\n",
					gser->port_num, value);
	}

	/* device either stalls (value < 0) or reports success */
	return value;
}
#endif
static int gser_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
{
	struct f_gser		 *gser = func_to_gser(f);
	struct usb_composite_dev *cdev = f->config->cdev;
	struct usb_interface_descriptor *desc;

	/* we know alt == 0, so this is an activation or a reset */
	if (cdev->gadget->speed == USB_SPEED_HIGH)
		desc = (struct usb_interface_descriptor *) *(f->hs_descriptors);
	else
		desc = (struct usb_interface_descriptor *) *(f->descriptors);
	gser->data_id = desc->bInterfaceNumber;

#ifdef CONFIG_MODEM_SUPPORT
#if 0
	if (gser->notify->driver_data) {
		DBG(cdev, "reset generic ttyGS%d\n", gser->port_num);
		usb_ep_disable(gser->notify);
	}
#endif
	gser->notify_desc = ep_choose(cdev->gadget,
			gser->hs.notify,
			gser->fs.notify);
	usb_ep_enable(gser->notify, gser->notify_desc);
	gser->notify->driver_data = gser;
#endif
#if 0
	if (gser->port.in->driver_data) {
		DBG(cdev, "reset generic ttyGS%d\n", gser->port_num);
		gserial_disconnect(&gser->port);
	} else {
		DBG(cdev, "activate generic ttyGS%d\n", gser->port_num);
	}
#endif
	gser->port.in_desc = ep_choose(cdev->gadget,
			gser->hs.in, gser->fs.in);
	gser->port.out_desc = ep_choose(cdev->gadget,
			gser->hs.out, gser->fs.out);
	gserial_connect(&gser->port, gser->port_num);
	gser->online = 1;
	return 0;
}

static void gser_disable(struct usb_function *f)
{
	struct f_gser	         *gser = func_to_gser(f);
	struct usb_composite_dev *cdev = f->config->cdev;

	DBG(cdev, "generic ttyGS%d deactivated\n", gser->port_num);
	gserial_disconnect(&gser->port);
#if 0
	/* disable endpoints, aborting down any active I/O */
	usb_ep_fifo_flush(gser->port.out);
	usb_ep_disable(gser->port.out);
	gser->port.out->driver_data = NULL;

	usb_ep_fifo_flush(gser->port.in);
	usb_ep_disable(gser->port.in);
	gser->port.in->driver_data = NULL;
#endif
#ifdef CONFIG_MODEM_SUPPORT
	usb_ep_fifo_flush(gser->notify);
	usb_ep_disable(gser->notify);
	gser->notify->driver_data = NULL;
#endif
	gser->online = 0;
}
#ifdef CONFIG_MODEM_SUPPORT
static int gser_notify(struct f_gser *gser, u8 type, u16 value,
		void *data, unsigned length)
{
	struct usb_ep			*ep = gser->notify;
	struct usb_request		*req;
	struct usb_cdc_notification	*notify;
	const unsigned			len = sizeof(*notify) + length;
	void				*buf;
	int				status;
	struct usb_composite_dev *cdev = gser->port.func.config->cdev;

	req = gser->notify_req;
	gser->notify_req = NULL;
	gser->pending = false;

	req->length = len;
	notify = req->buf;
	buf = notify + 1;

	notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
			| USB_RECIP_INTERFACE;
	notify->bNotificationType = type;
	notify->wValue = cpu_to_le16(value);
	notify->wIndex = cpu_to_le16(gser->data_id);
	notify->wLength = cpu_to_le16(length);
	memcpy(buf, data, length);

	status = usb_ep_queue(ep, req, GFP_ATOMIC);
	if (status < 0) {
		ERROR(cdev, "gser ttyGS%d can't notify serial state, %d\n",
				gser->port_num, status);
		gser->notify_req = req;
	}

	return status;
}

static int gser_notify_serial_state(struct f_gser *gser)
{
	int			 status;
	unsigned long flags;
	struct usb_composite_dev *cdev = gser->port.func.config->cdev;
	if (gser->disabled)
		return 0;

	spin_lock_irqsave(&gser->lock, flags);
	if (gser->notify_req) {
		DBG(cdev, "gser ttyGS%d serial state %04x\n",
				gser->port_num, gser->serial_state);
		status = gser_notify(gser, USB_CDC_NOTIFY_SERIAL_STATE,
				0, &gser->serial_state,
					sizeof(gser->serial_state));
	} else {
		gser->pending = true;
		status = 0;
	}
	spin_unlock_irqrestore(&gser->lock, flags);
	return status;
}

static void gser_notify_complete(struct usb_ep *ep, struct usb_request *req)
{
	struct f_gser *gser = req->context;
	u8	      doit = false;
	unsigned long flags;

	/* on this call path we do NOT hold the port spinlock,
	 * which is why ACM needs its own spinlock
	 */
	spin_lock_irqsave(&gser->lock, flags);
	if (req->status != -ESHUTDOWN)
		doit = gser->pending;
	gser->notify_req = req;
	spin_unlock_irqrestore(&gser->lock, flags);

	if (doit && gser->online)
		gser_notify_serial_state(gser);
}
static void gser_connect(struct gserial *port)
{
	struct f_gser *gser = port_to_gser(port);

	gser->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
	gser_notify_serial_state(gser);
}

unsigned int gser_get_dtr(struct gserial *port)
{
	struct f_gser *gser = port_to_gser(port);

	if (gser->port_handshake_bits & ACM_CTRL_DTR)
		return 1;
	else
		return 0;
}

unsigned int gser_get_rts(struct gserial *port)
{
	struct f_gser *gser = port_to_gser(port);

	if (gser->port_handshake_bits & ACM_CTRL_RTS)
		return 1;
	else
		return 0;
}

unsigned int gser_send_carrier_detect(struct gserial *port, unsigned int yes)
{
	struct f_gser *gser = port_to_gser(port);
	u16			state;

	state = gser->serial_state;
	state &= ~ACM_CTRL_DCD;
	if (yes)
		state |= ACM_CTRL_DCD;

	gser->serial_state = state;
	return gser_notify_serial_state(gser);

}

unsigned int gser_send_ring_indicator(struct gserial *port, unsigned int yes)
{
	struct f_gser *gser = port_to_gser(port);
	u16			state;

	state = gser->serial_state;
	state &= ~ACM_CTRL_RI;
	if (yes)
		state |= ACM_CTRL_RI;

	gser->serial_state = state;
	return gser_notify_serial_state(gser);

}
static void gser_disconnect(struct gserial *port)
{
	struct f_gser *gser = port_to_gser(port);

	gser->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
	gser_notify_serial_state(gser);
}

static int gser_send_break(struct gserial *port, int duration)
{
	struct f_gser *gser = port_to_gser(port);
	u16			state;

	state = gser->serial_state;
	state &= ~ACM_CTRL_BRK;
	if (duration)
		state |= ACM_CTRL_BRK;

	gser->serial_state = state;
	return gser_notify_serial_state(gser);
}
#endif
/*-------------------------------------------------------------------------*/

/* serial function driver setup/binding */

static int
gser_bind(struct usb_configuration *c, struct usb_function *f)
{
	struct usb_composite_dev *cdev = c->cdev;
	struct f_gser            *gser = func_to_gser(f);
	int			 status;
	struct usb_ep		 *ep;
	struct usb_gadget_strings	*s;

	/* allocate instance-specific interface IDs */
	status = usb_interface_id(c, f);
	if (status < 0)
		goto fail;
	gser->data_id = status;
	gser_interface_desc.bInterfaceNumber = status;
	if (f->strings) {
		s = *(f->strings);
		gser_interface_desc.iInterface = s->strings[0].id;
	}

	status = -ENODEV;

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

	ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_out_desc);
	if (!ep)
		goto fail;
	gser->port.out = ep;
	ep->driver_data = gser;	/* claim */

#ifdef CONFIG_MODEM_SUPPORT
	ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_notify_desc);
	if (!ep)
		goto fail;
	gser->notify = ep;
	ep->driver_data = gser;	/* claim */
	/* allocate notification */
	gser->notify_req = gs_alloc_req(ep,
			sizeof(struct usb_cdc_notification) + 2,
			GFP_KERNEL);
	if (!gser->notify_req)
		goto fail;

	gser->notify_req->complete = gser_notify_complete;
	gser->notify_req->context = gser;
#endif

	/* copy descriptors, and track endpoint copies */
	f->descriptors = usb_copy_descriptors(gser_fs_function);

	gser->fs.in = usb_find_endpoint(gser_fs_function,
			f->descriptors, &gser_fs_in_desc);
	gser->fs.out = usb_find_endpoint(gser_fs_function,
			f->descriptors, &gser_fs_out_desc);
#ifdef CONFIG_MODEM_SUPPORT
	gser->fs.notify = usb_find_endpoint(gser_fs_function,
			f->descriptors, &gser_fs_notify_desc);
#endif


	/* 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)) {
		gser_hs_in_desc.bEndpointAddress =
				gser_fs_in_desc.bEndpointAddress;
		gser_hs_out_desc.bEndpointAddress =
				gser_fs_out_desc.bEndpointAddress;
#ifdef CONFIG_MODEM_SUPPORT
		gser_hs_notify_desc.bEndpointAddress =
				gser_fs_notify_desc.bEndpointAddress;
#endif

		/* copy descriptors, and track endpoint copies */
		f->hs_descriptors = usb_copy_descriptors(gser_hs_function);

		gser->hs.in = usb_find_endpoint(gser_hs_function,
				f->hs_descriptors, &gser_hs_in_desc);
		gser->hs.out = usb_find_endpoint(gser_hs_function,
				f->hs_descriptors, &gser_hs_out_desc);
#ifdef CONFIG_MODEM_SUPPORT
		gser->hs.notify = usb_find_endpoint(gser_hs_function,
				f->hs_descriptors, &gser_hs_notify_desc);
#endif
	}

	DBG(cdev, "generic ttyGS%d: %s speed IN/%s OUT/%s\n",
			gser->port_num,
			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
			gser->port.in->name, gser->port.out->name);
	return 0;

fail:
#ifdef CONFIG_MODEM_SUPPORT
	if (gser->notify_req)
		gs_free_req(gser->notify, gser->notify_req);

	/* we might as well release our claims on endpoints */
	if (gser->notify)
		gser->notify->driver_data = NULL;
#endif
	/* we might as well release our claims on endpoints */
	if (gser->port.out)
		gser->port.out->driver_data = NULL;
	if (gser->port.in)
		gser->port.in->driver_data = NULL;

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

	return status;
}

static void
gser_unbind(struct usb_configuration *c, struct usb_function *f)
{
#ifdef CONFIG_MODEM_SUPPORT
	struct f_gser *gser = func_to_gser(f);
#endif
	if (gadget_is_dualspeed(c->cdev->gadget))
		usb_free_descriptors(f->hs_descriptors);
	usb_free_descriptors(f->descriptors);
#ifdef CONFIG_MODEM_SUPPORT
	gs_free_req(gser->notify, gser->notify_req);
#endif
	kfree(func_to_gser(f));
}

/**
 * gser_bind_config - add a generic serial function to a configuration
 * @c: the configuration to support the serial instance
 * @port_num: /dev/ttyGS* port this interface will use
 * Context: single threaded during gadget setup
 *
 * Returns zero on success, else negative errno.
 *
 * Caller must have called @gserial_setup() with enough ports to
 * handle all the ones it binds.  Caller is also responsible
 * for calling @gserial_cleanup() before module unload.
 */
int gser_bind_config(struct usb_configuration *c, u8 port_num)
{
	struct f_gser *gser;
	int		status;

	/* REVISIT might want instance-specific strings to help
	 * distinguish instances ...
	 */

	/* maybe allocate device-global string ID */
	if (modem_string_defs[0].id == 0 && port_num == 0) {
		status = usb_string_id(c->cdev);
		if (status < 0) {
			printk(KERN_ERR "%s: return %d\n", __func__, status);
			return status;
		}
		modem_string_defs[0].id = status;
	}
	if (serial_string_defs[0].id == 0 && port_num == 2) {
		status = usb_string_id(c->cdev);
		if (status < 0) {
			printk(KERN_ERR "%s: return %d\n", __func__, status);
			return status;
		}
		serial_string_defs[0].id = status;
	}
	/* allocate and initialize one new instance */
	gser = kzalloc(sizeof *gser, GFP_KERNEL);
	if (!gser)
		return -ENOMEM;

#ifdef CONFIG_MODEM_SUPPORT
	spin_lock_init(&gser->lock);
#endif
	gser->port_num = port_num;

	if (port_num == 0) {
		gser->port.func.name = "modem";
		gser->port.func.strings = modem_strings;
		modem_function = &gser->port.func;
	} else if (port_num == 2) {
		gser->port.func.name = "serial";
		gser->port.func.strings = serial_strings;
		serial_function = &gser->port.func;
	}
	gser->port.func.bind = gser_bind;
	gser->port.func.unbind = gser_unbind;
	gser->port.func.set_alt = gser_set_alt;
	gser->port.func.disable = gser_disable;
#ifdef CONFIG_MODEM_SUPPORT
	gser->port.func.setup = gser_setup;
	gser->port.connect = gser_connect;
	gser->port.get_dtr = gser_get_dtr;
	gser->port.get_rts = gser_get_rts;
	gser->port.send_carrier_detect = gser_send_carrier_detect;
	gser->port.send_ring_indicator = gser_send_ring_indicator;
	gser->port.disconnect = gser_disconnect;
	gser->port.send_break = gser_send_break;
#endif
	gser->port.func.hidden = 1;
	gser->disabled = 1;

	status = usb_add_function(c, &gser->port.func);
	if (status)
		kfree(gser);
	return status;
}

static int modem_set_enabled(const char *val, struct kernel_param *kp)
{
	struct f_gser *gser;
	int enabled = simple_strtol(val, NULL, 0);
	printk(KERN_INFO "%s: %d\n", __func__, enabled);
	gser = func_to_gser(modem_function);
	if (!gser)
		return 0;
	gser->disabled = !enabled;
	android_enable_function(modem_function, enabled);
	return 0;
}

static int modem_get_enabled(char *buffer, struct kernel_param *kp)
{
	buffer[0] = '0' + !modem_function->hidden;
	printk(KERN_INFO "%s: %d\n", __func__, buffer[0] - '0');
	return 1;
}
module_param_call(modem_enabled, modem_set_enabled, modem_get_enabled, NULL, 0664);

static int serial_set_enabled(const char *val, struct kernel_param *kp)
{
	struct f_gser *gser;
	int enabled = simple_strtol(val, NULL, 0);
	printk(KERN_INFO "%s: %d\n", __func__, enabled);
	gser = func_to_gser(serial_function);
	if (!gser)
		return 0;
	gser->disabled = !enabled;
	android_enable_function(serial_function, enabled);
	return 0;
}

static int serial_get_enabled(char *buffer, struct kernel_param *kp)
{
	buffer[0] = '0' + !serial_function->hidden;
	printk(KERN_INFO "%s: %d\n", __func__, buffer[0] - '0');
	return 1;
}
module_param_call(serial_enabled, serial_set_enabled, serial_get_enabled, NULL, 0664);

static int serial_bind_config(struct usb_configuration *c)
{
	int ret;

	printk(KERN_INFO "serial_bind_config\n");
	ret = gser_bind_config(c, 0);
	if (ret)
		return ret;
	ret = gser_bind_config(c, 2);
	if (ret == 0)
		gserial_setup(c->cdev->gadget, 3);
	return ret;
}

static struct android_usb_function android_serial_function = {
	.name = "serial",
	.bind_config = serial_bind_config,
};

static int __init init(void)
{
	printk(KERN_INFO "serial init\n");
	android_register_function(&android_serial_function);
	return 0;
}
module_init(init);