[deliverable/linux.git] / include / linux / tty_ldisc.h

#ifndef _LINUX_TTY_LDISC_H
#define _LINUX_TTY_LDISC_H

/*
 * This structure defines the interface between the tty line discipline
 * implementation and the tty routines.  The following routines can be
 * defined; unless noted otherwise, they are optional, and can be
 * filled in with a null pointer.
 *
 * int	(*open)(struct tty_struct *);
 *
 *	This function is called when the line discipline is associated
 *	with the tty.  The line discipline can use this as an
 *	opportunity to initialize any state needed by the ldisc routines.
 *
 * void	(*close)(struct tty_struct *);
 *
 *	This function is called when the line discipline is being
 *	shutdown, either because the tty is being closed or because
 *	the tty is being changed to use a new line discipline
 *
 * void	(*flush_buffer)(struct tty_struct *tty);
 *
 *	This function instructs the line discipline to clear its
 *	buffers of any input characters it may have queued to be
 *	delivered to the user mode process.
 *
 * ssize_t (*chars_in_buffer)(struct tty_struct *tty);
 *
 *	This function returns the number of input characters the line
 *	discipline may have queued up to be delivered to the user mode
 *	process.
 *
 * ssize_t (*read)(struct tty_struct * tty, struct file * file,
 *		   unsigned char * buf, size_t nr);
 *
 *	This function is called when the user requests to read from
 *	the tty.  The line discipline will return whatever characters
 *	it has buffered up for the user.  If this function is not
 *	defined, the user will receive an EIO error.
 *
 * ssize_t (*write)(struct tty_struct * tty, struct file * file,
 *		    const unsigned char * buf, size_t nr);
 *
 *	This function is called when the user requests to write to the
 *	tty.  The line discipline will deliver the characters to the
 *	low-level tty device for transmission, optionally performing
 *	some processing on the characters first.  If this function is
 *	not defined, the user will receive an EIO error.
 *
 * int	(*ioctl)(struct tty_struct * tty, struct file * file,
 *		 unsigned int cmd, unsigned long arg);
 *
 *	This function is called when the user requests an ioctl which
 *	is not handled by the tty layer or the low-level tty driver.
 *	It is intended for ioctls which affect line discpline
 *	operation.  Note that the search order for ioctls is (1) tty
 *	layer, (2) tty low-level driver, (3) line discpline.  So a
 *	low-level driver can "grab" an ioctl request before the line
 *	discpline has a chance to see it.
 *
 * long	(*compat_ioctl)(struct tty_struct * tty, struct file * file,
 *		        unsigned int cmd, unsigned long arg);
 *
 *	Process ioctl calls from 32-bit process on 64-bit system
 *
 * void	(*set_termios)(struct tty_struct *tty, struct ktermios * old);
 *
 *	This function notifies the line discpline that a change has
 *	been made to the termios structure.
 *
 * int	(*poll)(struct tty_struct * tty, struct file * file,
 *		  poll_table *wait);
 *
 *	This function is called when a user attempts to select/poll on a
 *	tty device.  It is solely the responsibility of the line
 *	discipline to handle poll requests.
 *
 * void	(*receive_buf)(struct tty_struct *, const unsigned char *cp,
 *		       char *fp, int count);
 *
 *	This function is called by the low-level tty driver to send
 *	characters received by the hardware to the line discpline for
 *	processing.  <cp> is a pointer to the buffer of input
 *	character received by the device.  <fp> is a pointer to a
 *	pointer of flag bytes which indicate whether a character was
 *	received with a parity error, etc. <fp> may be NULL to indicate
 *	all data received is TTY_NORMAL.
 *
 * void	(*write_wakeup)(struct tty_struct *);
 *
 *	This function is called by the low-level tty driver to signal
 *	that line discpline should try to send more characters to the
 *	low-level driver for transmission.  If the line discpline does
 *	not have any more data to send, it can just return.
 *
 * int (*hangup)(struct tty_struct *)
 *
 *	Called on a hangup. Tells the discipline that it should
 *	cease I/O to the tty driver. Can sleep. The driver should
 *	seek to perform this action quickly but should wait until
 *	any pending driver I/O is completed.
 *
 * void (*fasync)(struct tty_struct *, int on)
 *
 *	Notify line discipline when signal-driven I/O is enabled or
 *	disabled.
 *
 * void (*dcd_change)(struct tty_struct *tty, unsigned int status)
 *
 *	Tells the discipline that the DCD pin has changed its status.
 *	Used exclusively by the N_PPS (Pulse-Per-Second) line discipline.
 *
 * int	(*receive_buf2)(struct tty_struct *, const unsigned char *cp,
 *			char *fp, int count);
 *
 *	This function is called by the low-level tty driver to send
 *	characters received by the hardware to the line discpline for
 *	processing.  <cp> is a pointer to the buffer of input
 *	character received by the device.  <fp> is a pointer to a
 *	pointer of flag bytes which indicate whether a character was
 *	received with a parity error, etc. <fp> may be NULL to indicate
 *	all data received is TTY_NORMAL.
 *	If assigned, prefer this function for automatic flow control.
 */

#include <linux/fs.h>
#include <linux/wait.h>
#include <linux/wait.h>


/*
 * the semaphore definition
 */
struct ld_semaphore {
	long			count;
	raw_spinlock_t		wait_lock;
	unsigned int		wait_readers;
	struct list_head	read_wait;
	struct list_head	write_wait;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	struct lockdep_map	dep_map;
#endif
};

extern void __init_ldsem(struct ld_semaphore *sem, const char *name,
			 struct lock_class_key *key);

#define init_ldsem(sem)						\
do {								\
	static struct lock_class_key __key;			\
								\
	__init_ldsem((sem), #sem, &__key);			\
} while (0)


extern int ldsem_down_read(struct ld_semaphore *sem, long timeout);
extern int ldsem_down_read_trylock(struct ld_semaphore *sem);
extern int ldsem_down_write(struct ld_semaphore *sem, long timeout);
extern int ldsem_down_write_trylock(struct ld_semaphore *sem);
extern void ldsem_up_read(struct ld_semaphore *sem);
extern void ldsem_up_write(struct ld_semaphore *sem);

#ifdef CONFIG_DEBUG_LOCK_ALLOC
extern int ldsem_down_read_nested(struct ld_semaphore *sem, int subclass,
				  long timeout);
extern int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
				   long timeout);
#else
# define ldsem_down_read_nested(sem, subclass, timeout)		\
		ldsem_down_read(sem, timeout)
# define ldsem_down_write_nested(sem, subclass, timeout)	\
		ldsem_down_write(sem, timeout)
#endif


struct tty_ldisc_ops {
	int	magic;
	char	*name;
	int	num;
	int	flags;

	/*
	 * The following routines are called from above.
	 */
	int	(*open)(struct tty_struct *);
	void	(*close)(struct tty_struct *);
	void	(*flush_buffer)(struct tty_struct *tty);
	ssize_t	(*chars_in_buffer)(struct tty_struct *tty);
	ssize_t	(*read)(struct tty_struct *tty, struct file *file,
			unsigned char __user *buf, size_t nr);
	ssize_t	(*write)(struct tty_struct *tty, struct file *file,
			 const unsigned char *buf, size_t nr);
	int	(*ioctl)(struct tty_struct *tty, struct file *file,
			 unsigned int cmd, unsigned long arg);
	long	(*compat_ioctl)(struct tty_struct *tty, struct file *file,
				unsigned int cmd, unsigned long arg);
	void	(*set_termios)(struct tty_struct *tty, struct ktermios *old);
	unsigned int (*poll)(struct tty_struct *, struct file *,
			     struct poll_table_struct *);
	int	(*hangup)(struct tty_struct *tty);

	/*
	 * The following routines are called from below.
	 */
	void	(*receive_buf)(struct tty_struct *, const unsigned char *cp,
			       char *fp, int count);
	void	(*write_wakeup)(struct tty_struct *);
	void	(*dcd_change)(struct tty_struct *, unsigned int);
	void	(*fasync)(struct tty_struct *tty, int on);
	int	(*receive_buf2)(struct tty_struct *, const unsigned char *cp,
				char *fp, int count);

	struct  module *owner;

	int refcount;
};

struct tty_ldisc {
	struct tty_ldisc_ops *ops;
	struct tty_struct *tty;
};

#define TTY_LDISC_MAGIC	0x5403

#define LDISC_FLAG_DEFINED	0x00000001

#define MODULE_ALIAS_LDISC(ldisc) \
	MODULE_ALIAS("tty-ldisc-" __stringify(ldisc))

#endif /* _LINUX_TTY_LDISC_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_TTY_LDISC_H
	2	#define _LINUX_TTY_LDISC_H
	3
	4	/*
	5	* This structure defines the interface between the tty line discipline
	6	* implementation and the tty routines. The following routines can be
	7	* defined; unless noted otherwise, they are optional, and can be
	8	* filled in with a null pointer.
	9	*
	10	* int (open)(struct tty_struct );
	11	*
6be06e72 PH	12	* This function is called when the line discipline is associated
	13	* with the tty. The line discipline can use this as an
	14	* opportunity to initialize any state needed by the ldisc routines.
	15	*
1da177e4 LT	16	* void (close)(struct tty_struct );
	17	*
	18	* This function is called when the line discipline is being
6be06e72 PH	19	* shutdown, either because the tty is being closed or because
	20	* the tty is being changed to use a new line discipline
	21	*
1da177e4 LT	22	* void (flush_buffer)(struct tty_struct tty);
1da177e4 LT	23	*
6be06e72 PH	24	* This function instructs the line discipline to clear its
	25	* buffers of any input characters it may have queued to be
	26	* delivered to the user mode process.
	27	*
1da177e4 LT	28	* ssize_t (chars_in_buffer)(struct tty_struct tty);
1da177e4 LT	29	*
6be06e72	30	* This function returns the number of input characters the line
1da177e4 LT	31	* discipline may have queued up to be delivered to the user mode
1da177e4 LT	32	* process.
6be06e72	33	*
1da177e4 LT	34	* ssize_t (read)(struct tty_struct tty, struct file * file,
	35	* unsigned char * buf, size_t nr);
	36	*
6be06e72 PH	37	* This function is called when the user requests to read from
	38	* the tty. The line discipline will return whatever characters
	39	* it has buffered up for the user. If this function is not
	40	* defined, the user will receive an EIO error.
	41	*
1da177e4	42	* ssize_t (write)(struct tty_struct tty, struct file * file,
6be06e72 PH	43	* const unsigned char * buf, size_t nr);
	44	*
	45	* This function is called when the user requests to write to the
	46	* tty. The line discipline will deliver the characters to the
	47	* low-level tty device for transmission, optionally performing
	48	* some processing on the characters first. If this function is
	49	* not defined, the user will receive an EIO error.
	50	*
1da177e4	51	* int (ioctl)(struct tty_struct tty, struct file * file,
6be06e72	52	* unsigned int cmd, unsigned long arg);
1da177e4 LT	53	*
1da177e4 LT	54	* This function is called when the user requests an ioctl which
6be06e72 PH	55	* is not handled by the tty layer or the low-level tty driver.
	56	* It is intended for ioctls which affect line discpline
	57	* operation. Note that the search order for ioctls is (1) tty
	58	* layer, (2) tty low-level driver, (3) line discpline. So a
	59	* low-level driver can "grab" an ioctl request before the line
	60	* discpline has a chance to see it.
	61	*
e10cc1df	62	* long (compat_ioctl)(struct tty_struct tty, struct file * file,
6be06e72	63	* unsigned int cmd, unsigned long arg);
e10cc1df	64	*
6be06e72	65	* Process ioctl calls from 32-bit process on 64-bit system
e10cc1df	66	*
edc6afc5	67	* void (set_termios)(struct tty_struct tty, struct ktermios * old);
1da177e4	68	*
6be06e72 PH	69	* This function notifies the line discpline that a change has
	70	* been made to the termios structure.
	71	*
1da177e4	72	* int (poll)(struct tty_struct tty, struct file * file,
6be06e72	73	* poll_table *wait);
1da177e4	74	*
6be06e72 PH	75	* This function is called when a user attempts to select/poll on a
	76	* tty device. It is solely the responsibility of the line
	77	* discipline to handle poll requests.
1da177e4	78	*
55db4c64	79	* void (receive_buf)(struct tty_struct , const unsigned char *cp,
6be06e72 PH	80	* char *fp, int count);
	81	*
	82	* This function is called by the low-level tty driver to send
	83	* characters received by the hardware to the line discpline for
	84	* processing. <cp> is a pointer to the buffer of input
	85	* character received by the device. <fp> is a pointer to a
	86	* pointer of flag bytes which indicate whether a character was
82f91fe0 PH	87	* received with a parity error, etc. <fp> may be NULL to indicate
82f91fe0 PH	88	* all data received is TTY_NORMAL.
6be06e72	89	*
1da177e4 LT	90	* void (write_wakeup)(struct tty_struct );
1da177e4 LT	91	*
6be06e72 PH	92	* This function is called by the low-level tty driver to signal
	93	* that line discpline should try to send more characters to the
	94	* low-level driver for transmission. If the line discpline does
	95	* not have any more data to send, it can just return.
1da177e4 LT	96	*
	97	* int (hangup)(struct tty_struct )
	98	*
	99	* Called on a hangup. Tells the discipline that it should
	100	* cease I/O to the tty driver. Can sleep. The driver should
	101	* seek to perform this action quickly but should wait until
	102	* any pending driver I/O is completed.
b3e63afe	103	*
f6c8dbe6 PH	104	* void (fasync)(struct tty_struct , int on)
	105	*
	106	* Notify line discipline when signal-driven I/O is enabled or
	107	* disabled.
	108	*
593fb1ae	109	* void (dcd_change)(struct tty_struct tty, unsigned int status)
b3e63afe	110	*
593fb1ae GS	111	* Tells the discipline that the DCD pin has changed its status.
593fb1ae GS	112	* Used exclusively by the N_PPS (Pulse-Per-Second) line discipline.
24a89d1c PH	113	*
	114	* int (receive_buf2)(struct tty_struct , const unsigned char *cp,
	115	* char *fp, int count);
	116	*
	117	* This function is called by the low-level tty driver to send
	118	* characters received by the hardware to the line discpline for
	119	* processing. <cp> is a pointer to the buffer of input
	120	* character received by the device. <fp> is a pointer to a
	121	* pointer of flag bytes which indicate whether a character was
82f91fe0 PH	122	* received with a parity error, etc. <fp> may be NULL to indicate
82f91fe0 PH	123	* all data received is TTY_NORMAL.
24a89d1c	124	* If assigned, prefer this function for automatic flow control.
1da177e4 LT	125	*/
	126
	127	#include <linux/fs.h>
	128	#include <linux/wait.h>
1541f845	129	#include <linux/wait.h>
1da177e4	130
4898e640 PH	131
	132	/*
	133	* the semaphore definition
	134	*/
	135	struct ld_semaphore {
	136	long count;
	137	raw_spinlock_t wait_lock;
	138	unsigned int wait_readers;
	139	struct list_head read_wait;
	140	struct list_head write_wait;
	141	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	142	struct lockdep_map dep_map;
	143	#endif
	144	};
	145
	146	extern void __init_ldsem(struct ld_semaphore sem, const char name,
	147	struct lock_class_key *key);
	148
	149	#define init_ldsem(sem) \
	150	do { \
	151	static struct lock_class_key __key; \
	152	\
	153	__init_ldsem((sem), #sem, &__key); \
	154	} while (0)
	155
	156
	157	extern int ldsem_down_read(struct ld_semaphore *sem, long timeout);
	158	extern int ldsem_down_read_trylock(struct ld_semaphore *sem);
	159	extern int ldsem_down_write(struct ld_semaphore *sem, long timeout);
	160	extern int ldsem_down_write_trylock(struct ld_semaphore *sem);
	161	extern void ldsem_up_read(struct ld_semaphore *sem);
	162	extern void ldsem_up_write(struct ld_semaphore *sem);
	163
	164	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	165	extern int ldsem_down_read_nested(struct ld_semaphore *sem, int subclass,
	166	long timeout);
	167	extern int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
	168	long timeout);
	169	#else
	170	# define ldsem_down_read_nested(sem, subclass, timeout) \
	171	ldsem_down_read(sem, timeout)
	172	# define ldsem_down_write_nested(sem, subclass, timeout) \
	173	ldsem_down_write(sem, timeout)
	174	#endif
	175
	176
a352def2	177	struct tty_ldisc_ops {
1da177e4 LT	178	int magic;
	179	char *name;
	180	int num;
	181	int flags;
6be06e72	182
1da177e4 LT	183	/*
	184	* The following routines are called from above.
	185	*/
	186	int (open)(struct tty_struct );
	187	void (close)(struct tty_struct );
	188	void (flush_buffer)(struct tty_struct tty);
	189	ssize_t (chars_in_buffer)(struct tty_struct tty);
6be06e72 PH	190	ssize_t (read)(struct tty_struct tty, struct file *file,
	191	unsigned char __user *buf, size_t nr);
	192	ssize_t (write)(struct tty_struct tty, struct file *file,
	193	const unsigned char *buf, size_t nr);
	194	int (ioctl)(struct tty_struct tty, struct file *file,
1da177e4	195	unsigned int cmd, unsigned long arg);
6be06e72	196	long (compat_ioctl)(struct tty_struct tty, struct file *file,
e10cc1df	197	unsigned int cmd, unsigned long arg);
6be06e72	198	void (set_termios)(struct tty_struct tty, struct ktermios *old);
1da177e4 LT	199	unsigned int (poll)(struct tty_struct , struct file *,
	200	struct poll_table_struct *);
	201	int (hangup)(struct tty_struct tty);
6be06e72	202
1da177e4 LT	203	/*
	204	* The following routines are called from below.
	205	*/
55db4c64 LT	206	void (receive_buf)(struct tty_struct , const unsigned char *cp,
55db4c64 LT	207	char *fp, int count);
1da177e4	208	void (write_wakeup)(struct tty_struct );
593fb1ae	209	void (dcd_change)(struct tty_struct , unsigned int);
f6c8dbe6	210	void (fasync)(struct tty_struct tty, int on);
24a89d1c PH	211	int (receive_buf2)(struct tty_struct , const unsigned char *cp,
24a89d1c PH	212	char *fp, int count);
1da177e4 LT	213
1da177e4 LT	214	struct module *owner;
6be06e72	215
1da177e4 LT	216	int refcount;
	217	};
	218
a352def2 AC	219	struct tty_ldisc {
a352def2 AC	220	struct tty_ldisc_ops *ops;
36697529	221	struct tty_struct *tty;
a352def2 AC	222	};
a352def2 AC	223
1da177e4 LT	224	#define TTY_LDISC_MAGIC 0x5403
	225
	226	#define LDISC_FLAG_DEFINED 0x00000001
	227
	228	#define MODULE_ALIAS_LDISC(ldisc) \
	229	MODULE_ALIAS("tty-ldisc-" __stringify(ldisc))
	230
	231	#endif /* _LINUX_TTY_LDISC_H */