hso.c

/******************************************************************************
 *
 * Driver for Option High Speed Mobile Devices.
 *
 *  Copyright (C) 2008 Option International
 *                     Filip Aben <f.aben@option.com>
 *                     Denis Joseph Barrow <d.barow@option.com>
 *                     Jan Dumon <j.dumon@option.com>
 *  Copyright (C) 2007 Andrew Bird (Sphere Systems Ltd)
 *  			<ajb@spheresystems.co.uk>
 *  Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
 *  Copyright (C) 2008 Novell, Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 *  USA
 *
 *
 *****************************************************************************/

/******************************************************************************
 *
 * Description of the device:
 *
 * Interface 0:	Contains the IP network interface on the bulk end points.
 *		The multiplexed serial ports are using the interrupt and
 *		control endpoints.
 *		Interrupt contains a bitmap telling which multiplexed
 *		serialport needs servicing.
 *
 * Interface 1:	Diagnostics port, uses bulk only, do not submit urbs until the
 *		port is opened, as this have a huge impact on the network port
 *		throughput.
 *
 * Interface 2:	Standard modem interface - circuit switched interface, this
 *		can be used to make a standard ppp connection however it
 *              should not be used in conjunction with the IP network interface
 *              enabled for USB performance reasons i.e. if using this set
 *              ideally disable_net=1.
 *
 *****************************************************************************/

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/module.h>
#include <linux/ethtool.h>
#include <linux/usb.h>
#include <linux/timer.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/kmod.h>
#include <linux/rfkill.h>
#include <linux/ip.h>
#include <linux/uaccess.h>
#include <linux/usb/cdc.h>
#include <net/arp.h>
#include <asm/byteorder.h>
#include <linux/serial_core.h>
#include <linux/serial.h>


#define MOD_AUTHOR			"Option Wireless"
#define MOD_DESCRIPTION			"USB High Speed Option driver"
#define MOD_LICENSE			"GPL"

#define HSO_MAX_NET_DEVICES		10
#define HSO__MAX_MTU			2048
#define DEFAULT_MTU			1500
#define DEFAULT_MRU			1500

#define CTRL_URB_RX_SIZE		1024
#define CTRL_URB_TX_SIZE		64

#define BULK_URB_RX_SIZE		4096
#define BULK_URB_TX_SIZE		8192

#define MUX_BULK_RX_BUF_SIZE		HSO__MAX_MTU
#define MUX_BULK_TX_BUF_SIZE		HSO__MAX_MTU
#define MUX_BULK_RX_BUF_COUNT		4
#define USB_TYPE_OPTION_VENDOR		0x20

/* These definitions are used with the struct hso_net flags element */
/* - use *_bit operations on it. (bit indices not values.) */
#define HSO_NET_RUNNING			0

#define	HSO_NET_TX_TIMEOUT		(HZ*10)

#define HSO_SERIAL_MAGIC		0x48534f31

/* Number of ttys to handle */
#define HSO_SERIAL_TTY_MINORS		256

#define MAX_RX_URBS			2

static inline struct hso_serial *get_serial_by_tty(struct tty_struct *tty)
{
	if (tty)
		return tty->driver_data;
	return NULL;
}

/*****************************************************************************/
/* Debugging functions                                                       */
/*****************************************************************************/
#define D__(lvl_, fmt, arg...)				\
	do {						\
		printk(lvl_ "[%d:%s]: " fmt "\n",	\
		       __LINE__, __func__, ## arg);	\
	} while (0)

#define D_(lvl, args...)				\
	do {						\
		if (lvl & debug)			\
			D__(KERN_INFO, args);		\
	} while (0)

#define D1(args...)	D_(0x01, ##args)
#define D2(args...)	D_(0x02, ##args)
#define D3(args...)	D_(0x04, ##args)
#define D4(args...)	D_(0x08, ##args)
#define D5(args...)	D_(0x10, ##args)

/*****************************************************************************/
/* Enumerators                                                               */
/*****************************************************************************/
enum pkt_parse_state {
	WAIT_IP,
	WAIT_DATA,
	WAIT_SYNC
};

/*****************************************************************************/
/* Structs                                                                   */
/*****************************************************************************/

struct hso_shared_int {
	struct usb_endpoint_descriptor *intr_endp;
	void *shared_intr_buf;
	struct urb *shared_intr_urb;
	struct usb_device *usb;
	int use_count;
	int ref_count;
	struct mutex shared_int_lock;
};

struct hso_net {
	struct hso_device *parent;
	struct net_device *net;
	struct rfkill *rfkill;

	struct usb_endpoint_descriptor *in_endp;
	struct usb_endpoint_descriptor *out_endp;

	struct urb *mux_bulk_rx_urb_pool[MUX_BULK_RX_BUF_COUNT];
	struct urb *mux_bulk_tx_urb;
	void *mux_bulk_rx_buf_pool[MUX_BULK_RX_BUF_COUNT];
	void *mux_bulk_tx_buf;

	struct sk_buff *skb_rx_buf;
	struct sk_buff *skb_tx_buf;

	enum pkt_parse_state rx_parse_state;
	spinlock_t net_lock;

	unsigned short rx_buf_size;
	unsigned short rx_buf_missing;
	struct iphdr rx_ip_hdr;

	unsigned long flags;
};

enum rx_ctrl_state{
	RX_IDLE,
	RX_SENT,
	RX_PENDING
};

#define BM_REQUEST_TYPE (0xa1)
#define B_NOTIFICATION  (0x20)
#define W_VALUE         (0x0)
#define W_INDEX         (0x2)
#define W_LENGTH        (0x2)

#define B_OVERRUN       (0x1<<6)
#define B_PARITY        (0x1<<5)
#define B_FRAMING       (0x1<<4)
#define B_RING_SIGNAL   (0x1<<3)
#define B_BREAK         (0x1<<2)
#define B_TX_CARRIER    (0x1<<1)
#define B_RX_CARRIER    (0x1<<0)

struct hso_serial_state_notification {
	u8 bmRequestType;
	u8 bNotification;
	u16 wValue;
	u16 wIndex;
	u16 wLength;
	u16 UART_state_bitmap;
} __packed;

struct hso_tiocmget {
	struct mutex mutex;
	wait_queue_head_t waitq;
	int    intr_completed;
	struct usb_endpoint_descriptor *endp;
	struct urb *urb;
	struct hso_serial_state_notification serial_state_notification;
	u16    prev_UART_state_bitmap;
	struct uart_icount icount;
};


struct hso_serial {
	struct hso_device *parent;
	int magic;
	u8 minor;

	struct hso_shared_int *shared_int;

	/* rx/tx urb could be either a bulk urb or a control urb depending
	   on which serial port it is used on. */
	struct urb *rx_urb[MAX_RX_URBS];
	u8 num_rx_urbs;
	u8 *rx_data[MAX_RX_URBS];
	u16 rx_data_length;	/* should contain allocated length */

	struct urb *tx_urb;
	u8 *tx_data;
	u8 *tx_buffer;
	u16 tx_data_length;	/* should contain allocated length */
	u16 tx_data_count;
	u16 tx_buffer_count;
	struct usb_ctrlrequest ctrl_req_tx;
	struct usb_ctrlrequest ctrl_req_rx;

	struct usb_endpoint_descriptor *in_endp;
	struct usb_endpoint_descriptor *out_endp;

	enum rx_ctrl_state rx_state;
	u8 rts_state;
	u8 dtr_state;
	unsigned tx_urb_used:1;

	/* from usb_serial_port */
	struct tty_struct *tty;
	int open_count;
	spinlock_t serial_lock;

	int (*write_data) (struct hso_serial *serial);
	struct hso_tiocmget  *tiocmget;
	/* Hacks required to get flow control
	 * working on the serial receive buffers
	 * so as not to drop characters on the floor.
	 */
	int  curr_rx_urb_idx;
	u16  curr_rx_urb_offset;
	u8   rx_urb_filled[MAX_RX_URBS];
	struct tasklet_struct unthrottle_tasklet;
	struct work_struct    retry_unthrottle_workqueue;
};

struct hso_device {
	union {
		struct hso_serial *dev_serial;
		struct hso_net *dev_net;
	} port_data;

	u32 port_spec;

	u8 is_active;
	u8 usb_gone;
	struct work_struct async_get_intf;
	struct work_struct async_put_intf;
	struct work_struct reset_device;

	struct usb_device *usb;
	struct usb_interface *interface;

	struct device *dev;
	struct kref ref;
	struct mutex mutex;
};

/* Type of interface */
#define HSO_INTF_MASK		0xFF00
#define	HSO_INTF_MUX		0x0100
#define	HSO_INTF_BULK   	0x0200

/* Type of port */
#define HSO_PORT_MASK		0xFF
#define HSO_PORT_NO_PORT	0x0
#define	HSO_PORT_CONTROL	0x1
#define	HSO_PORT_APP		0x2
#define	HSO_PORT_GPS		0x3
#define	HSO_PORT_PCSC		0x4
#define	HSO_PORT_APP2		0x5
#define HSO_PORT_GPS_CONTROL	0x6
#define HSO_PORT_MSD		0x7
#define HSO_PORT_VOICE		0x8
#define HSO_PORT_DIAG2		0x9
#define	HSO_PORT_DIAG		0x10
#define	HSO_PORT_MODEM		0x11
#define	HSO_PORT_NETWORK	0x12

/* Additional device info */
#define HSO_INFO_MASK		0xFF000000
#define HSO_INFO_CRC_BUG	0x01000000

/*****************************************************************************/
/* Prototypes                                                                */
/*****************************************************************************/
/* Serial driver functions */
static int hso_serial_tiocmset(struct tty_struct *tty,
			       unsigned int set, unsigned int clear);
static void ctrl_callback(struct urb *urb);
static int put_rxbuf_data(struct urb *urb, struct hso_serial *serial);
static void hso_kick_transmit(struct hso_serial *serial);
/* Helper functions */
static int hso_mux_submit_intr_urb(struct hso_shared_int *mux_int,
				   struct usb_device *usb, gfp_t gfp);
static void handle_usb_error(int status, const char *function,
			     struct hso_device *hso_dev);
static struct usb_endpoint_descriptor *hso_get_ep(struct usb_interface *intf,
						  int type, int dir);
static int hso_get_mux_ports(struct usb_interface *intf, unsigned char *ports);
static void hso_free_interface(struct usb_interface *intf);
static int hso_start_serial_device(struct hso_device *hso_dev, gfp_t flags);
static int hso_stop_serial_device(struct hso_device *hso_dev);
static int hso_start_net_device(struct hso_device *hso_dev);
static void hso_free_shared_int(struct hso_shared_int *shared_int);
static int hso_stop_net_device(struct hso_device *hso_dev);
static void hso_serial_ref_free(struct kref *ref);
static void hso_std_serial_read_bulk_callback(struct urb *urb);
static int hso_mux_serial_read(struct hso_serial *serial);
static void async_get_intf(struct work_struct *data);
static void async_put_intf(struct work_struct *data);
static int hso_put_activity(struct hso_device *hso_dev);
static int hso_get_activity(struct hso_device *hso_dev);
static void tiocmget_intr_callback(struct urb *urb);
static void reset_device(struct work_struct *data);
/*****************************************************************************/
/* Helping functions                                                         */
/*****************************************************************************/

/* #define DEBUG */

static inline struct hso_net *dev2net(struct hso_device *hso_dev)
{
	return hso_dev->port_data.dev_net;
}

static inline struct hso_serial *dev2ser(struct hso_device *hso_dev)
{
	return hso_dev->port_data.dev_serial;
}

/* Debugging functions */
#ifdef DEBUG
static void dbg_dump(int line_count, const char *func_name, unsigned char *buf,
		     unsigned int len)
{
	static char name[255];

	sprintf(name, "hso[%d:%s]", line_count, func_name);
	print_hex_dump_bytes(name, DUMP_PREFIX_NONE, buf, len);
}

#define DUMP(buf_, len_)	\
	dbg_dump(__LINE__, __func__, (unsigned char *)buf_, len_)

#define DUMP1(buf_, len_)			\
	do {					\
		if (0x01 & debug)		\
			DUMP(buf_, len_);	\
	} while (0)
#else
#define DUMP(buf_, len_)
#define DUMP1(buf_, len_)
#endif

/* module parameters */
static int debug;
static int tty_major;
static int disable_net;

/* driver info */
static const char driver_name[] = "hso";
static const char tty_filename[] = "ttyHS";
static const char *version = __FILE__ ": " MOD_AUTHOR;
/* the usb driver itself (registered in hso_init) */
static struct usb_driver hso_driver;
/* serial structures */
static struct tty_driver *tty_drv;
static struct hso_device *serial_table[HSO_SERIAL_TTY_MINORS];
static struct hso_device *network_table[HSO_MAX_NET_DEVICES];
static spinlock_t serial_table_lock;

static const s32 default_port_spec[] = {
	HSO_INTF_MUX | HSO_PORT_NETWORK,
	HSO_INTF_BULK | HSO_PORT_DIAG,
	HSO_INTF_BULK | HSO_PORT_MODEM,
	0
};

static const s32 icon321_port_spec[] = {
	HSO_INTF_MUX | HSO_PORT_NETWORK,
	HSO_INTF_BULK | HSO_PORT_DIAG2,
	HSO_INTF_BULK | HSO_PORT_MODEM,
	HSO_INTF_BULK | HSO_PORT_DIAG,
	0
};

#define default_port_device(vendor, product)	\
	USB_DEVICE(vendor, product),	\
		.driver_info = (kernel_ulong_t)default_port_spec

#define icon321_port_device(vendor, product)	\
	USB_DEVICE(vendor, product),	\
		.driver_info = (kernel_ulong_t)icon321_port_spec

/* list of devices we support */
static const struct usb_device_id hso_ids[] = {
	{default_port_device(0x0af0, 0x6711)},
	{default_port_device(0x0af0, 0x6731)},
	{default_port_device(0x0af0, 0x6751)},
	{default_port_device(0x0af0, 0x6771)},
	{default_port_device(0x0af0, 0x6791)},
	{default_port_device(0x0af0, 0x6811)},
	{default_port_device(0x0af0, 0x6911)},
	{default_port_device(0x0af0, 0x6951)},
	{default_port_device(0x0af0, 0x6971)},
	{default_port_device(0x0af0, 0x7011)},
	{default_port_device(0x0af0, 0x7031)},
	{default_port_device(0x0af0, 0x7051)},
	{default_port_device(0x0af0, 0x7071)},
	{default_port_device(0x0af0, 0x7111)},
	{default_port_device(0x0af0, 0x7211)},
	{default_port_device(0x0af0, 0x7251)},
	{default_port_device(0x0af0, 0x7271)},
	{default_port_device(0x0af0, 0x7311)},
	{default_port_device(0x0af0, 0xc031)},	/* Icon-Edge */
	{icon321_port_device(0x0af0, 0xd013)},	/* Module HSxPA */
	{icon321_port_device(0x0af0, 0xd031)},	/* Icon-321 */
	{icon321_port_device(0x0af0, 0xd033)},	/* Icon-322 */
	{USB_DEVICE(0x0af0, 0x7301)},		/* GE40x */
	{USB_DEVICE(0x0af0, 0x7361)},		/* GE40x */
	{USB_DEVICE(0x0af0, 0x7381)},		/* GE40x */
	{USB_DEVICE(0x0af0, 0x7401)},		/* GI 0401 */
	{USB_DEVICE(0x0af0, 0x7501)},		/* GTM 382 */
	{USB_DEVICE(0x0af0, 0x7601)},		/* GE40x */
	{USB_DEVICE(0x0af0, 0x7701)},
	{USB_DEVICE(0x0af0, 0x7706)},
	{USB_DEVICE(0x0af0, 0x7801)},
	{USB_DEVICE(0x0af0, 0x7901)},
	{USB_DEVICE(0x0af0, 0x7A01)},
	{USB_DEVICE(0x0af0, 0x7A05)},
	{USB_DEVICE(0x0af0, 0x8200)},
	{USB_DEVICE(0x0af0, 0x8201)},
	{USB_DEVICE(0x0af0, 0x8300)},
	{USB_DEVICE(0x0af0, 0x8302)},
	{USB_DEVICE(0x0af0, 0x8304)},
	{USB_DEVICE(0x0af0, 0x8400)},
	{USB_DEVICE(0x0af0, 0x8600)},
	{USB_DEVICE(0x0af0, 0x8800)},
	{USB_DEVICE(0x0af0, 0x8900)},
	{USB_DEVICE(0x0af0, 0x9000)},
	{USB_DEVICE(0x0af0, 0xd035)},
	{USB_DEVICE(0x0af0, 0xd055)},
	{USB_DEVICE(0x0af0, 0xd155)},
	{USB_DEVICE(0x0af0, 0xd255)},
	{USB_DEVICE(0x0af0, 0xd057)},
	{USB_DEVICE(0x0af0, 0xd157)},
	{USB_DEVICE(0x0af0, 0xd257)},
	{USB_DEVICE(0x0af0, 0xd357)},
	{USB_DEVICE(0x0af0, 0xd058)},
	{USB_DEVICE(0x0af0, 0xc100)},
	{}
};
MODULE_DEVICE_TABLE(usb, hso_ids);

/* Sysfs attribute */
static ssize_t hso_sysfs_show_porttype(struct device *dev,
				       struct device_attribute *attr,
				       char *buf)
{
	struct hso_device *hso_dev = dev_get_drvdata(dev);
	char *port_name;

	if (!hso_dev)
		return 0;

	switch (hso_dev->port_spec & HSO_PORT_MASK) {
	case HSO_PORT_CONTROL:
		port_name = "Control";
		break;
	case HSO_PORT_APP:
		port_name = "Application";
		break;
	case HSO_PORT_APP2:
		port_name = "Application2";
		break;
	case HSO_PORT_GPS:
		port_name = "GPS";
		break;
	case HSO_PORT_GPS_CONTROL:
		port_name = "GPS Control";
		break;
	case HSO_PORT_PCSC:
		port_name = "PCSC";
		break;
	case HSO_PORT_DIAG:
		port_name = "Diagnostic";
		break;
	case HSO_PORT_DIAG2:
		port_name = "Diagnostic2";
		break;
	case HSO_PORT_MODEM:
		port_name = "Modem";
		break;
	case HSO_PORT_NETWORK:
		port_name = "Network";
		break;
	default:
		port_name = "Unknown";
		break;
	}

	return sprintf(buf, "%s\n", port_name);
}
static DEVICE_ATTR(hsotype, S_IRUGO, hso_sysfs_show_porttype, NULL);

static int hso_urb_to_index(struct hso_serial *serial, struct urb *urb)
{
	int idx;

	for (idx = 0; idx < serial->num_rx_urbs; idx++)
		if (serial->rx_urb[idx] == urb)
			return idx;
	dev_err(serial->parent->dev, "hso_urb_to_index failed\n");
	return -1;
}

/* converts mux value to a port spec value */
static u32 hso_mux_to_port(int mux)
{
	u32 result;

	switch (mux) {
	case 0x1:
		result = HSO_PORT_CONTROL;
		break;
	case 0x2:
		result = HSO_PORT_APP;
		break;
	case 0x4:
		result = HSO_PORT_PCSC;
		break;
	case 0x8:
		result = HSO_PORT_GPS;
		break;
	case 0x10:
		result = HSO_PORT_APP2;
		break;
	default:
		result = HSO_PORT_NO_PORT;
	}
	return result;
}

/* converts port spec value to a mux value */
static u32 hso_port_to_mux(int port)
{
	u32 result;

	switch (port & HSO_PORT_MASK) {
	case HSO_PORT_CONTROL:
		result = 0x0;
		break;
	case HSO_PORT_APP:
		result = 0x1;
		break;
	case HSO_PORT_PCSC:
		result = 0x2;
		break;
	case HSO_PORT_GPS:
		result = 0x3;
		break;
	case HSO_PORT_APP2:
		result = 0x4;
		break;
	default:
		result = 0x0;
	}
	return result;
}

static struct hso_serial *get_serial_by_shared_int_and_type(
					struct hso_shared_int *shared_int,
					int mux)
{
	int i, port;

	port = hso_mux_to_port(mux);

	for (i = 0; i < HSO_SERIAL_TTY_MINORS; i++) {
		if (serial_table[i] &&
		    (dev2ser(serial_table[i])->shared_int == shared_int) &&
		    ((serial_table[i]->port_spec & HSO_PORT_MASK) == port)) {
			return dev2ser(serial_table[i]);
		}
	}

	return NULL;
}

static struct hso_serial *get_serial_by_index(unsigned index)
{
	struct hso_serial *serial = NULL;
	unsigned long flags;

	spin_lock_irqsave(&serial_table_lock, flags);
	if (serial_table[index])
		serial = dev2ser(serial_table[index]);
	spin_unlock_irqrestore(&serial_table_lock, flags);

	return serial;
}

static int get_free_serial_index(void)
{
	int index;
	unsigned long flags;

	spin_lock_irqsave(&serial_table_lock, flags);
	for (index = 0; index < HSO_SERIAL_TTY_MINORS; index++) {
		if (serial_table[index] == NULL) {
			spin_unlock_irqrestore(&serial_table_lock, flags);
			return index;
		}
	}
	spin_unlock_irqrestore(&serial_table_lock, flags);

	printk(KERN_ERR "%s: no free serial devices in table\n", __func__);
	return -1;
}

static void set_serial_by_index(unsigned index, struct hso_serial *serial)
{
	unsigned long flags;

	spin_lock_irqsave(&serial_table_lock, flags);
	if (serial)
		serial_table[index] = serial->parent;
	else
		serial_table[index] = NULL;
	spin_unlock_irqrestore(&serial_table_lock, flags);
}

static void handle_usb_error(int status, const char *function,
			     struct hso_device *hso_dev)
{
	char *explanation;

	switch (status) {
	case -ENODEV:
		explanation = "no device";
		break;
	case -ENOENT:
		explanation = "endpoint not enabled";
		break;
	case -EPIPE:
		explanation = "endpoint stalled";
		break;
	case -ENOSPC:
		explanation = "not enough bandwidth";
		break;
	case -ESHUTDOWN:
		explanation = "device disabled";
		break;
	case -EHOSTUNREACH:
		explanation = "device suspended";
		break;
	case -EINVAL:
	case -EAGAIN:
	case -EFBIG:
	case -EMSGSIZE:
		explanation = "internal error";
		break;
	case -EILSEQ:
	case -EPROTO:
	case -ETIME:
	case -ETIMEDOUT:
		explanation = "protocol error";
		if (hso_dev)
			schedule_work(&hso_dev->reset_device);
		break;
	default:
		explanation = "unknown status";
		break;
	}

	/* log a meaningful explanation of an USB status */
	D1("%s: received USB status - %s (%d)", function, explanation, status);
}

/* Network interface functions */

/* called when net interface is brought up by ifconfig */
static int hso_net_open(struct net_device *net)
{
	struct hso_net *odev = netdev_priv(net);
	unsigned long flags = 0;

	if (!odev) {
		dev_err(&net->dev, "No net device !\n");
		return -ENODEV;
	}

	odev->skb_tx_buf = NULL;

	/* setup environment */
	spin_lock_irqsave(&odev->net_lock, flags);
	odev->rx_parse_state = WAIT_IP;
	odev->rx_buf_size = 0;
	odev->rx_buf_missing = sizeof(struct iphdr);
	spin_unlock_irqrestore(&odev->net_lock, flags);

	/* We are up and running. */
	set_bit(HSO_NET_RUNNING, &odev->flags);
	hso_start_net_device(odev->parent);

	/* Tell the kernel we are ready to start receiving from it */
	netif_start_queue(net);

	return 0;
}

/* called when interface is brought down by ifconfig */
static int hso_net_close(struct net_device *net)
{
	struct hso_net *odev = netdev_priv(net);

	/* we don't need the queue anymore */
	netif_stop_queue(net);
	/* no longer running */
	clear_bit(HSO_NET_RUNNING, &odev->flags);

	hso_stop_net_device(odev->parent);

	/* done */
	return 0;
}

/* USB tells is xmit done, we should start the netqueue again */
static void write_bulk_callback(struct urb *urb)
{
	struct hso_net *odev = urb->context;
	int status = urb->status;

	/* Sanity check */
	if (!odev || !test_bit(HSO_NET_RUNNING, &odev->flags)) {
		dev_err(&urb->dev->dev, "%s: device not running\n", __func__);
		return;
	}

	/* Do we still have a valid kernel network device? */
	if (!netif_device_present(odev->net)) {
		dev_err(&urb->dev->dev, "%s: net device not present\n",
			__func__);
		return;
	}

	/* log status, but don't act on it, we don't need to resubmit anything
	 * anyhow */
	if (status)
		handle_usb_error(status, __func__, odev->parent);

	hso_put_activity(odev->parent);

	/* Tell the network interface we are ready for another frame */
	netif_wake_queue(odev->net);
}

/* called by kernel when we need to transmit a packet */
static netdev_tx_t hso_net_start_xmit(struct sk_buff *skb,
					    struct net_device *net)
{
	struct hso_net *odev = netdev_priv(net);
	int result;

	/* Tell the kernel, "No more frames 'til we are done with this one." */
	netif_stop_queue(net);
	if (hso_get_activity(odev->parent) == -EAGAIN) {
		odev->skb_tx_buf = skb;
		return NETDEV_TX_OK;
	}

	/* log if asked */
	DUMP1(skb->data, skb->len);
	/* Copy it from kernel memory to OUR memory */
	memcpy(odev->mux_bulk_tx_buf, skb->data, skb->len);
	D1("len: %d/%d", skb->len, MUX_BULK_TX_BUF_SIZE);

	/* Fill in the URB for shipping it out. */
	usb_fill_bulk_urb(odev->mux_bulk_tx_urb,
			  odev->parent->usb,
			  usb_sndbulkpipe(odev->parent->usb,
					  odev->out_endp->
					  bEndpointAddress & 0x7F),
			  odev->mux_bulk_tx_buf, skb->len, write_bulk_callback,
			  odev);

	/* Deal with the Zero Length packet problem, I hope */
	odev->mux_bulk_tx_urb->transfer_flags |= URB_ZERO_PACKET;

	/* Send the URB on its merry way. */
	result = usb_submit_urb(odev->mux_bulk_tx_urb, GFP_ATOMIC);
	if (result) {
		dev_warn(&odev->parent->interface->dev,
			"failed mux_bulk_tx_urb %d\n", result);
		net->stats.tx_errors++;
		netif_start_queue(net);
	} else {
		net->stats.tx_packets++;
		net->stats.tx_bytes += skb->len;
	}
	dev_kfree_skb(skb);
	/* we're done */
	return NETDEV_TX_OK;
}

static const struct ethtool_ops ops = {
	.get_link = ethtool_op_get_link
};

/* called when a packet did not ack after watchdogtimeout */
static void hso_net_tx_timeout(struct net_device *net)
{
	struct hso_net *odev = netdev_priv(net);

	if (!odev)
		return;

	/* Tell syslog we are hosed. */
	dev_warn(&net->dev, "Tx timed out.\n");

	/* Tear the waiting frame off the list */
	if (odev->mux_bulk_tx_urb &&
	    (odev->mux_bulk_tx_urb->status == -EINPROGRESS))
		usb_unlink_urb(odev->mux_bulk_tx_urb);

	/* Update statistics */
	net->stats.tx_errors++;
}

/* make a real packet from the received USB buffer */
static void packetizeRx(struct hso_net *odev, unsigned char *ip_pkt,
			unsigned int count, unsigned char is_eop)
{
	unsigned short temp_bytes;
	unsigned short buffer_offset = 0;
	unsigned short frame_len;
	unsigned char *tmp_rx_buf;

	/* log if needed */
	D1("Rx %d bytes", count);
	DUMP(ip_pkt, min(128, (int)count));

	while (count) {
		switch (odev->rx_parse_state) {
		case WAIT_IP:
			/* waiting for IP header. */
			/* wanted bytes - size of ip header */
			temp_bytes =
			    (count <
			     odev->rx_buf_missing) ? count : odev->
			    rx_buf_missing;

			memcpy(((unsigned char *)(&odev->rx_ip_hdr)) +
			       odev->rx_buf_size, ip_pkt + buffer_offset,
			       temp_bytes);

			odev->rx_buf_size += temp_bytes;
			buffer_offset += temp_bytes;
			odev->rx_buf_missing -= temp_bytes;
			count -= temp_bytes;

			if (!odev->rx_buf_missing) {
				/* header is complete allocate an sk_buffer and
				 * continue to WAIT_DATA */
				frame_len = ntohs(odev->rx_ip_hdr.tot_len);

				if ((frame_len > DEFAULT_MRU) ||
				    (frame_len < sizeof(struct iphdr))) {
					dev_err(&odev->net->dev,
						"Invalid frame (%d) length\n",
						frame_len);
					odev->rx_parse_state = WAIT_SYNC;
					continue;
				}
				/* Allocate an sk_buff */
				odev->skb_rx_buf = netdev_alloc_skb(odev->net,
								    frame_len);
				if (!odev->skb_rx_buf) {
					/* We got no receive buffer. */
					D1("could not allocate memory");
					odev->rx_parse_state = WAIT_SYNC;
					return;
				}

				/* Copy what we got so far. make room for iphdr
				 * after tail. */
				tmp_rx_buf =
				    skb_put(odev->skb_rx_buf,
					    sizeof(struct iphdr));
				memcpy(tmp_rx_buf, (char *)&(odev->rx_ip_hdr),
				       sizeof(struct iphdr));

				/* ETH_HLEN */
				odev->rx_buf_size = sizeof(struct iphdr);

				/* Filip actually use .tot_len */
				odev->rx_buf_missing =
				    frame_len - sizeof(struct iphdr);
				odev->rx_parse_state = WAIT_DATA;
			}
			break;

		case WAIT_DATA:
			temp_bytes = (count < odev->rx_buf_missing)
					? count : odev->rx_buf_missing;

			/* Copy the rest of the bytes that are left in the
			 * buffer into the waiting sk_buf. */
			/* Make room for temp_bytes after tail. */
			tmp_rx_buf = skb_put(odev->skb_rx_buf, temp_bytes);
			memcpy(tmp_rx_buf, ip_pkt + buffer_offset, temp_bytes);

			odev->rx_buf_missing -= temp_bytes;
			count -= temp_bytes;
			buffer_offset += temp_bytes;
			odev->rx_buf_size += temp_bytes;
			if (!odev->rx_buf_missing) {
				/* Packet is complete. Inject into stack. */
				/* We have IP packet here */
				odev->skb_rx_buf->protocol = cpu_to_be16(ETH_P_IP);
				skb_reset_mac_header(odev->skb_rx_buf);

				/* Ship it off to the kernel */
				netif_rx(odev->skb_rx_buf);
				/* No longer our buffer. */
				odev->skb_rx_buf = NULL;

				/* update out statistics */
				odev->net->stats.rx_packets++;

				odev->net->stats.rx_bytes += odev->rx_buf_size;

				odev->rx_buf_size = 0;
				odev->rx_buf_missing = sizeof(struct iphdr);
				odev->rx_parse_state = WAIT_IP;
			}
			break;

		case WAIT_SYNC:
			D1(" W_S");
			count = 0;
			break;
		default:
			D1(" ");
			count--;
			break;
		}
	}

	/* Recovery mechanism for WAIT_SYNC state. */
	if (is_eop) {
		if (odev->rx_parse_state == WAIT_SYNC) {
			odev->rx_parse_state = WAIT_IP;
			odev->rx_buf_size = 0;
			odev->rx_buf_missing = sizeof(struct iphdr);
		}
	}
}

static void fix_crc_bug(struct urb *urb, __le16 max_packet_size)