[net-next-2.6.git] / include / net / irda / irda_device.h

/*********************************************************************
 *                
 * Filename:      irda_device.h
 * Version:       0.9
 * Description:   Contains various declarations used by the drivers
 * Status:        Experimental.
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Tue Apr 14 12:41:42 1998
 * Modified at:   Mon Mar 20 09:08:57 2000
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 * 
 *     Copyright (c) 1999-2000 Dag Brattli, All Rights Reserved.
 *     Copyright (c) 1998 Thomas Davis, <ratbert@radiks.net>,
 *     Copyright (c) 2000-2002 Jean Tourrilhes <jt@hpl.hp.com>
 *
 *     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
 *     
 ********************************************************************/

/*
 * This header contains all the IrDA definitions a driver really
 * needs, and therefore the driver should not need to include
 * any other IrDA headers - Jean II
 */

#ifndef IRDA_DEVICE_H
#define IRDA_DEVICE_H

#include <linux/tty.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <linux/skbuff.h>		/* struct sk_buff */
#include <linux/irda.h>
#include <linux/types.h>

#include <net/pkt_sched.h>
#include <net/irda/irda.h>
#include <net/irda/qos.h>		/* struct qos_info */
#include <net/irda/irqueue.h>		/* irda_queue_t */

/* A few forward declarations (to make compiler happy) */
struct irlap_cb;

/* Some non-standard interface flags (should not conflict with any in if.h) */
#define IFF_SIR 	0x0001 /* Supports SIR speeds */
#define IFF_MIR 	0x0002 /* Supports MIR speeds */
#define IFF_FIR 	0x0004 /* Supports FIR speeds */
#define IFF_VFIR        0x0008 /* Supports VFIR speeds */
#define IFF_PIO   	0x0010 /* Supports PIO transfer of data */
#define IFF_DMA		0x0020 /* Supports DMA transfer of data */
#define IFF_SHM         0x0040 /* Supports shared memory data transfers */
#define IFF_DONGLE      0x0080 /* Interface has a dongle attached */
#define IFF_AIR         0x0100 /* Supports Advanced IR (AIR) standards */

#define IO_XMIT 0x01
#define IO_RECV 0x02

typedef enum {
	IRDA_IRLAP, /* IrDA mode, and deliver to IrLAP */
	IRDA_RAW,   /* IrDA mode */
	SHARP_ASK,
	TV_REMOTE,  /* Also known as Consumer Electronics IR */
} INFRARED_MODE;

typedef enum {
	IRDA_TASK_INIT,        /* All tasks are initialized with this state */
	IRDA_TASK_DONE,        /* Signals that the task is finished */
	IRDA_TASK_WAIT,
	IRDA_TASK_WAIT1,
	IRDA_TASK_WAIT2,
	IRDA_TASK_WAIT3,
	IRDA_TASK_CHILD_INIT,  /* Initializing child task */
	IRDA_TASK_CHILD_WAIT,  /* Waiting for child task to finish */
	IRDA_TASK_CHILD_DONE   /* Child task is finished */
} IRDA_TASK_STATE;

struct irda_task;
typedef int (*IRDA_TASK_CALLBACK) (struct irda_task *task);

struct irda_task {
	irda_queue_t q;
	magic_t magic;

	IRDA_TASK_STATE state;
	IRDA_TASK_CALLBACK function;
	IRDA_TASK_CALLBACK finished;

	struct irda_task *parent;
	struct timer_list timer;

	void *instance; /* Instance being called */
	void *param;    /* Parameter to be used by instance */
};

/* Dongle info */
struct dongle_reg;
typedef struct {
	struct dongle_reg *issue;     /* Registration info */
	struct net_device *dev;           /* Device we are attached to */
	struct irda_task *speed_task; /* Task handling speed change */
	struct irda_task *reset_task; /* Task handling reset */
	__u32 speed;                  /* Current speed */

	/* Callbacks to the IrDA device driver */
	int (*set_mode)(struct net_device *, int mode);
	int (*read)(struct net_device *dev, __u8 *buf, int len);
	int (*write)(struct net_device *dev, __u8 *buf, int len);
	int (*set_dtr_rts)(struct net_device *dev, int dtr, int rts);
} dongle_t;

/* Dongle registration info */
struct dongle_reg {
	irda_queue_t q;         /* Must be first */
	IRDA_DONGLE type;

	void (*open)(dongle_t *dongle, struct qos_info *qos);
	void (*close)(dongle_t *dongle);
	int  (*reset)(struct irda_task *task);
	int  (*change_speed)(struct irda_task *task);
	struct module *owner;
};

/* 
 * Per-packet information we need to hide inside sk_buff 
 * (must not exceed 48 bytes, check with struct sk_buff) 
 */
struct irda_skb_cb {
	magic_t magic;       /* Be sure that we can trust the information */
	__u32   next_speed;  /* The Speed to be set *after* this frame */
	__u16   mtt;         /* Minimum turn around time */
	__u16   xbofs;       /* Number of xbofs required, used by SIR mode */
	__u16   next_xbofs;  /* Number of xbofs required *after* this frame */
	void    *context;    /* May be used by drivers */
	void    (*destructor)(struct sk_buff *skb); /* Used for flow control */
	__u16   xbofs_delay; /* Number of xbofs used for generating the mtt */
	__u8    line;        /* Used by IrCOMM in IrLPT mode */
};

/* Chip specific info */
typedef struct {
	int cfg_base;         /* Config register IO base */
        int sir_base;         /* SIR IO base */
	int fir_base;         /* FIR IO base */
	int mem_base;         /* Shared memory base */
        int sir_ext;          /* Length of SIR iobase */
	int fir_ext;          /* Length of FIR iobase */
        int irq, irq2;        /* Interrupts used */
        int dma, dma2;        /* DMA channel(s) used */
        int fifo_size;        /* FIFO size */
        int irqflags;         /* interrupt flags (ie, IRQF_SHARED|IRQF_DISABLED) */
	int direction;        /* Link direction, used by some FIR drivers */
	int enabled;          /* Powered on? */
	int suspended;        /* Suspended by APM */
	__u32 speed;          /* Currently used speed */
	__u32 new_speed;      /* Speed we must change to when Tx is finished */
	int dongle_id;        /* Dongle or transceiver currently used */
} chipio_t;

/* IO buffer specific info (inspired by struct sk_buff) */
typedef struct {
	int state;            /* Receiving state (transmit state not used) */
	int in_frame;         /* True if receiving frame */

	__u8 *head;	      /* start of buffer */
	__u8 *data;	      /* start of data in buffer */

	int len;	      /* current length of data */
	int truesize;	      /* total allocated size of buffer */
	__u16 fcs;

	struct sk_buff *skb;	/* ZeroCopy Rx in async_unwrap_char() */
} iobuff_t;

/* Maximum SIR frame (skb) that we expect to receive *unwrapped*.
 * Max LAP MTU (I field) is 2048 bytes max (IrLAP 1.1, chapt 6.6.5, p40).
 * Max LAP header is 2 bytes (for now).
 * Max CRC is 2 bytes at SIR, 4 bytes at FIR. 
 * Need 1 byte for skb_reserve() to align IP header for IrLAN.
 * Add a few extra bytes just to be safe (buffer is power of two anyway)
 * Jean II */
#define IRDA_SKB_MAX_MTU	2064
/* Maximum SIR frame that we expect to send, wrapped (i.e. with XBOFS
 * and escaped characters on top of above). */
#define IRDA_SIR_MAX_FRAME	4269

/* The SIR unwrapper async_unwrap_char() will use a Rx-copy-break mechanism
 * when using the optional ZeroCopy Rx, where only small frames are memcpy
 * to a smaller skb to save memory. This is the threshold under which copy
 * will happen (and over which it won't happen).
 * Some FIR drivers may use this #define as well...
 * This is the same value as various Ethernet drivers. - Jean II */
#define IRDA_RX_COPY_THRESHOLD  256

/* Function prototypes */
int  irda_device_init(void);
void irda_device_cleanup(void);

/* IrLAP entry points used by the drivers.
 * We declare them here to avoid the driver pulling a whole bunch stack
 * headers they don't really need - Jean II */
struct irlap_cb *irlap_open(struct net_device *dev, struct qos_info *qos,
			    const char *hw_name);
void irlap_close(struct irlap_cb *self);

/* Interface to be uses by IrLAP */
void irda_device_set_media_busy(struct net_device *dev, int status);
int  irda_device_is_media_busy(struct net_device *dev);
int  irda_device_is_receiving(struct net_device *dev);

/* Interface for internal use */
static inline int irda_device_txqueue_empty(const struct net_device *dev)
{
	return skb_queue_empty(&dev->qdisc->q);
}
int  irda_device_set_raw_mode(struct net_device* self, int status);
struct net_device *alloc_irdadev(int sizeof_priv);

/* Dongle interface */
void irda_device_unregister_dongle(struct dongle_reg *dongle);
int  irda_device_register_dongle(struct dongle_reg *dongle);
dongle_t *irda_device_dongle_init(struct net_device *dev, int type);
int irda_device_dongle_cleanup(dongle_t *dongle);

void irda_setup_dma(int channel, dma_addr_t buffer, int count, int mode);

void irda_task_delete(struct irda_task *task);
struct irda_task *irda_task_execute(void *instance, 
				    IRDA_TASK_CALLBACK function, 
				    IRDA_TASK_CALLBACK finished, 
				    struct irda_task *parent, void *param);
void irda_task_next_state(struct irda_task *task, IRDA_TASK_STATE state);

/*
 * Function irda_get_mtt (skb)
 *
 *    Utility function for getting the minimum turnaround time out of 
 *    the skb, where it has been hidden in the cb field.
 */
static inline __u16 irda_get_mtt(const struct sk_buff *skb)
{
	const struct irda_skb_cb *cb = (const struct irda_skb_cb *) skb->cb;
	return (cb->magic == LAP_MAGIC) ? cb->mtt : 10000;
}

/*
 * Function irda_get_next_speed (skb)
 *
 *    Extract the speed that should be set *after* this frame from the skb
 *
 * Note : return -1 for user space frames
 */
static inline __u32 irda_get_next_speed(const struct sk_buff *skb)
{
	const struct irda_skb_cb *cb = (const struct irda_skb_cb *) skb->cb;
	return (cb->magic == LAP_MAGIC) ? cb->next_speed : -1;
}

/*
 * Function irda_get_next_xbofs (skb)
 *
 *    Extract the xbofs that should be set for this frame from the skb
 *
 * Note : default to 10 for user space frames
 */
static inline __u16 irda_get_xbofs(const struct sk_buff *skb)
{
	const struct irda_skb_cb *cb = (const struct irda_skb_cb *) skb->cb;
	return (cb->magic == LAP_MAGIC) ? cb->xbofs : 10;
}

/*
 * Function irda_get_next_xbofs (skb)
 *
 *    Extract the xbofs that should be set *after* this frame from the skb
 *
 * Note : return -1 for user space frames
 */
static inline __u16 irda_get_next_xbofs(const struct sk_buff *skb)
{
	const struct irda_skb_cb *cb = (const struct irda_skb_cb *) skb->cb;
	return (cb->magic == LAP_MAGIC) ? cb->next_xbofs : -1;
}
#endif /* IRDA_DEVICE_H */
Commit	Line	Data
1da177e4 LT	1	/*********************************************************************
	2	*
	3	* Filename: irda_device.h
	4	* Version: 0.9
	5	* Description: Contains various declarations used by the drivers
	6	* Status: Experimental.
	7	* Author: Dag Brattli <dagb@cs.uit.no>
	8	* Created at: Tue Apr 14 12:41:42 1998
	9	* Modified at: Mon Mar 20 09:08:57 2000
	10	* Modified by: Dag Brattli <dagb@cs.uit.no>
	11	*
	12	* Copyright (c) 1999-2000 Dag Brattli, All Rights Reserved.
	13	* Copyright (c) 1998 Thomas Davis, <ratbert@radiks.net>,
	14	* Copyright (c) 2000-2002 Jean Tourrilhes <jt@hpl.hp.com>
	15	*
	16	* This program is free software; you can redistribute it and/or
	17	* modify it under the terms of the GNU General Public License as
	18	* published by the Free Software Foundation; either version 2 of
	19	* the License, or (at your option) any later version.
	20	*
	21	* This program is distributed in the hope that it will be useful,
	22	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	23	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	24	* GNU General Public License for more details.
	25	*
	26	* You should have received a copy of the GNU General Public License
	27	* along with this program; if not, write to the Free Software
	28	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	29	* MA 02111-1307 USA
	30	*
	31	********************************************************************/
	32
	33	/*
	34	* This header contains all the IrDA definitions a driver really
	35	* needs, and therefore the driver should not need to include
	36	* any other IrDA headers - Jean II
	37	*/
	38
	39	#ifndef IRDA_DEVICE_H
	40	#define IRDA_DEVICE_H
	41
1da177e4 LT	42	#include <linux/tty.h>
	43	#include <linux/netdevice.h>
	44	#include <linux/spinlock.h>
	45	#include <linux/skbuff.h> /* struct sk_buff */
	46	#include <linux/irda.h>
	47	#include <linux/types.h>
	48
	49	#include <net/pkt_sched.h>
	50	#include <net/irda/irda.h>
	51	#include <net/irda/qos.h> /* struct qos_info */
	52	#include <net/irda/irqueue.h> /* irda_queue_t */
	53
	54	/* A few forward declarations (to make compiler happy) */
	55	struct irlap_cb;
	56
	57	/* Some non-standard interface flags (should not conflict with any in if.h) */
	58	#define IFF_SIR 0x0001 /* Supports SIR speeds */
	59	#define IFF_MIR 0x0002 /* Supports MIR speeds */
	60	#define IFF_FIR 0x0004 /* Supports FIR speeds */
	61	#define IFF_VFIR 0x0008 /* Supports VFIR speeds */
	62	#define IFF_PIO 0x0010 /* Supports PIO transfer of data */
	63	#define IFF_DMA 0x0020 /* Supports DMA transfer of data */
	64	#define IFF_SHM 0x0040 /* Supports shared memory data transfers */
	65	#define IFF_DONGLE 0x0080 /* Interface has a dongle attached */
	66	#define IFF_AIR 0x0100 /* Supports Advanced IR (AIR) standards */
	67
	68	#define IO_XMIT 0x01
	69	#define IO_RECV 0x02
	70
	71	typedef enum {
	72	IRDA_IRLAP, /* IrDA mode, and deliver to IrLAP */
	73	IRDA_RAW, /* IrDA mode */
	74	SHARP_ASK,
	75	TV_REMOTE, /* Also known as Consumer Electronics IR */
	76	} INFRARED_MODE;
	77
	78	typedef enum {
	79	IRDA_TASK_INIT, /* All tasks are initialized with this state */
	80	IRDA_TASK_DONE, /* Signals that the task is finished */
	81	IRDA_TASK_WAIT,
	82	IRDA_TASK_WAIT1,
	83	IRDA_TASK_WAIT2,
	84	IRDA_TASK_WAIT3,
	85	IRDA_TASK_CHILD_INIT, /* Initializing child task */
	86	IRDA_TASK_CHILD_WAIT, /* Waiting for child task to finish */
	87	IRDA_TASK_CHILD_DONE /* Child task is finished */
	88	} IRDA_TASK_STATE;
	89
	90	struct irda_task;
	91	typedef int (IRDA_TASK_CALLBACK) (struct irda_task task);
	92
	93	struct irda_task {
	94	irda_queue_t q;
	95	magic_t magic;
	96
	97	IRDA_TASK_STATE state;
	98	IRDA_TASK_CALLBACK function;
	99	IRDA_TASK_CALLBACK finished;
	100
	101	struct irda_task *parent;
	102	struct timer_list timer;
	103
	104	void instance; / Instance being called */
	105	void param; / Parameter to be used by instance */
106	};
107
108	/* Dongle info */
109	struct dongle_reg;
110	typedef struct {
111	struct dongle_reg issue; / Registration info */
112	struct net_device dev; / Device we are attached to */
113	struct irda_task speed_task; / Task handling speed change */
114	struct irda_task reset_task; / Task handling reset */
115	__u32 speed; /* Current speed */
116
117	/* Callbacks to the IrDA device driver */
118	int (set_mode)(struct net_device , int mode);
119	int (read)(struct net_device dev, __u8 *buf, int len);
120	int (write)(struct net_device dev, __u8 *buf, int len);
121	int (set_dtr_rts)(struct net_device dev, int dtr, int rts);
122	} dongle_t;
123
124	/* Dongle registration info */
125	struct dongle_reg {
126	irda_queue_t q; /* Must be first */
127	IRDA_DONGLE type;
128
129	void (open)(dongle_t dongle, struct qos_info *qos);
130	void (close)(dongle_t dongle);
131	int (reset)(struct irda_task task);
132	int (change_speed)(struct irda_task task);
133	struct module *owner;
134	};
135
136	/*
137	* Per-packet information we need to hide inside sk_buff
138	* (must not exceed 48 bytes, check with struct sk_buff)
139	*/
140	struct irda_skb_cb {
141	magic_t magic; /* Be sure that we can trust the information */
142	__u32 next_speed; /* The Speed to be set after this frame */
143	__u16 mtt; /* Minimum turn around time */
144	__u16 xbofs; /* Number of xbofs required, used by SIR mode */
145	__u16 next_xbofs; /* Number of xbofs required after this frame */
146	void context; / May be used by drivers */
147	void (destructor)(struct sk_buff skb); /* Used for flow control */
148	__u16 xbofs_delay; /* Number of xbofs used for generating the mtt */
149	__u8 line; /* Used by IrCOMM in IrLPT mode */
150	};
151
152	/* Chip specific info */
153	typedef struct {
154	int cfg_base; /* Config register IO base */
155	int sir_base; /* SIR IO base */
156	int fir_base; /* FIR IO base */
157	int mem_base; /* Shared memory base */
158	int sir_ext; /* Length of SIR iobase */
159	int fir_ext; /* Length of FIR iobase */
160	int irq, irq2; /* Interrupts used */
161	int dma, dma2; /* DMA channel(s) used */
162	int fifo_size; /* FIFO size */
1fb9df5d	163	int irqflags; /* interrupt flags (ie, IRQF_SHARED\|IRQF_DISABLED) */
1da177e4 LT	164	int direction; /* Link direction, used by some FIR drivers */
	165	int enabled; /* Powered on? */
	166	int suspended; /* Suspended by APM */
	167	__u32 speed; /* Currently used speed */
	168	__u32 new_speed; /* Speed we must change to when Tx is finished */
	169	int dongle_id; /* Dongle or transceiver currently used */
	170	} chipio_t;
	171
	172	/* IO buffer specific info (inspired by struct sk_buff) */
	173	typedef struct {
	174	int state; /* Receiving state (transmit state not used) */
	175	int in_frame; /* True if receiving frame */
	176
	177	__u8 head; / start of buffer */
	178	__u8 data; / start of data in buffer */
	179
	180	int len; /* current length of data */
	181	int truesize; /* total allocated size of buffer */
	182	__u16 fcs;
	183
	184	struct sk_buff skb; / ZeroCopy Rx in async_unwrap_char() */
	185	} iobuff_t;
	186
	187	/* Maximum SIR frame (skb) that we expect to receive unwrapped.
	188	* Max LAP MTU (I field) is 2048 bytes max (IrLAP 1.1, chapt 6.6.5, p40).
	189	* Max LAP header is 2 bytes (for now).
	190	* Max CRC is 2 bytes at SIR, 4 bytes at FIR.
	191	* Need 1 byte for skb_reserve() to align IP header for IrLAN.
	192	* Add a few extra bytes just to be safe (buffer is power of two anyway)
	193	* Jean II */
	194	#define IRDA_SKB_MAX_MTU 2064
	195	/* Maximum SIR frame that we expect to send, wrapped (i.e. with XBOFS
	196	* and escaped characters on top of above). */
	197	#define IRDA_SIR_MAX_FRAME 4269
	198
	199	/* The SIR unwrapper async_unwrap_char() will use a Rx-copy-break mechanism
	200	* when using the optional ZeroCopy Rx, where only small frames are memcpy
	201	* to a smaller skb to save memory. This is the threshold under which copy
	202	* will happen (and over which it won't happen).
	203	* Some FIR drivers may use this #define as well...
	204	* This is the same value as various Ethernet drivers. - Jean II */
	205	#define IRDA_RX_COPY_THRESHOLD 256
	206
	207	/* Function prototypes */
	208	int irda_device_init(void);
	209	void irda_device_cleanup(void);
	210
	211	/* IrLAP entry points used by the drivers.
	212	* We declare them here to avoid the driver pulling a whole bunch stack
	213	* headers they don't really need - Jean II */
	214	struct irlap_cb irlap_open(struct net_device dev, struct qos_info *qos,
	215	const char *hw_name);
	216	void irlap_close(struct irlap_cb *self);
	217
	218	/* Interface to be uses by IrLAP */
	219	void irda_device_set_media_busy(struct net_device *dev, int status);
	220	int irda_device_is_media_busy(struct net_device *dev);
	221	int irda_device_is_receiving(struct net_device *dev);
	222
	223	/* Interface for internal use */
	224	static inline int irda_device_txqueue_empty(const struct net_device *dev)
	225	{
b03efcfb	226	return skb_queue_empty(&dev->qdisc->q);
1da177e4 LT	227	}
	228	int irda_device_set_raw_mode(struct net_device* self, int status);
	229	struct net_device *alloc_irdadev(int sizeof_priv);
	230
	231	/* Dongle interface */
	232	void irda_device_unregister_dongle(struct dongle_reg *dongle);
	233	int irda_device_register_dongle(struct dongle_reg *dongle);
	234	dongle_t irda_device_dongle_init(struct net_device dev, int type);
	235	int irda_device_dongle_cleanup(dongle_t *dongle);
	236
1da177e4	237	void irda_setup_dma(int channel, dma_addr_t buffer, int count, int mode);
1da177e4 LT	238
	239	void irda_task_delete(struct irda_task *task);
	240	struct irda_task irda_task_execute(void instance,
	241	IRDA_TASK_CALLBACK function,
	242	IRDA_TASK_CALLBACK finished,
	243	struct irda_task parent, void param);
	244	void irda_task_next_state(struct irda_task *task, IRDA_TASK_STATE state);
	245
	246	/*
	247	* Function irda_get_mtt (skb)
	248	*
	249	* Utility function for getting the minimum turnaround time out of
	250	* the skb, where it has been hidden in the cb field.
	251	*/
	252	static inline __u16 irda_get_mtt(const struct sk_buff *skb)
	253	{
	254	const struct irda_skb_cb cb = (const struct irda_skb_cb ) skb->cb;
	255	return (cb->magic == LAP_MAGIC) ? cb->mtt : 10000;
	256	}
	257
	258	/*
	259	* Function irda_get_next_speed (skb)
	260	*
	261	* Extract the speed that should be set after this frame from the skb
	262	*
	263	* Note : return -1 for user space frames
	264	*/
	265	static inline __u32 irda_get_next_speed(const struct sk_buff *skb)
	266	{
	267	const struct irda_skb_cb cb = (const struct irda_skb_cb ) skb->cb;
	268	return (cb->magic == LAP_MAGIC) ? cb->next_speed : -1;
	269	}
	270
	271	/*
	272	* Function irda_get_next_xbofs (skb)
	273	*
	274	* Extract the xbofs that should be set for this frame from the skb
	275	*
	276	* Note : default to 10 for user space frames
	277	*/
	278	static inline __u16 irda_get_xbofs(const struct sk_buff *skb)
	279	{
	280	const struct irda_skb_cb cb = (const struct irda_skb_cb ) skb->cb;
	281	return (cb->magic == LAP_MAGIC) ? cb->xbofs : 10;
	282	}
	283
	284	/*
	285	* Function irda_get_next_xbofs (skb)
	286	*
	287	* Extract the xbofs that should be set after this frame from the skb
	288	*
	289	* Note : return -1 for user space frames
	290	*/
	291	static inline __u16 irda_get_next_xbofs(const struct sk_buff *skb)
	292	{
	293	const struct irda_skb_cb cb = (const struct irda_skb_cb ) skb->cb;
	294	return (cb->magic == LAP_MAGIC) ? cb->next_xbofs : -1;
	295	}
	296	#endif /* IRDA_DEVICE_H */
	297
	298