* defined; unless noted otherwise, they are optional, and can be
* filled in with a null pointer.
*
+ * struct tty_struct * (*lookup)(struct tty_driver *self, int idx)
+ *
+ * Return the tty device corresponding to idx, NULL if there is not
+ * one currently in use and an ERR_PTR value on error. Called under
+ * tty_mutex (for now!)
+ *
+ * Optional method. Default behaviour is to use the ttys array
+ *
+ * int (*install)(struct tty_driver *self, struct tty_struct *tty)
+ *
+ * Install a new tty into the tty driver internal tables. Used in
+ * conjunction with lookup and remove methods.
+ *
+ * Optional method. Default behaviour is to use the ttys array
+ *
+ * void (*remove)(struct tty_driver *self, struct tty_struct *tty)
+ *
+ * Remove a closed tty from the tty driver internal tables. Used in
+ * conjunction with lookup and remove methods.
+ *
+ * Optional method. Default behaviour is to use the ttys array
+ *
* int (*open)(struct tty_struct * tty, struct file * filp);
*
* This routine is called when a particular tty device is opened.
* This routine is mandatory; if this routine is not filled in,
* the attempted open will fail with ENODEV.
+ *
+ * Required method.
*
* void (*close)(struct tty_struct * tty, struct file * filp);
*
* This routine is called when a particular tty device is closed.
*
+ * Required method.
+ *
+ * void (*shutdown)(struct tty_struct * tty);
+ *
+ * This routine is called when a particular tty device is closed for
+ * the last time freeing up the resources.
+ *
* int (*write)(struct tty_struct * tty,
* const unsigned char *buf, int count);
*
* This routine is called by the kernel to write a series of
* characters to the tty device. The characters may come from
* user space or kernel space. This routine will return the
- * number of characters actually accepted for writing. This
- * routine is mandatory.
+ * number of characters actually accepted for writing.
+ *
+ * Optional: Required for writable devices.
*
- * void (*put_char)(struct tty_struct *tty, unsigned char ch);
+ * int (*put_char)(struct tty_struct *tty, unsigned char ch);
*
* This routine is called by the kernel to write a single
* character to the tty device. If the kernel uses this routine,
* done stuffing characters into the driver. If there is no room
* in the queue, the character is ignored.
*
+ * Optional: Kernel will use the write method if not provided.
+ *
+ * Note: Do not call this function directly, call tty_put_char
+ *
* void (*flush_chars)(struct tty_struct *tty);
*
* This routine is called by the kernel after it has written a
* series of characters to the tty device using put_char().
+ *
+ * Optional:
+ *
+ * Note: Do not call this function directly, call tty_driver_flush_chars
*
* int (*write_room)(struct tty_struct *tty);
*
* will accept for queuing to be written. This number is subject
* to change as output buffers get emptied, or if the output flow
* control is acted.
+ *
+ * Required if write method is provided else not needed.
+ *
+ * Note: Do not call this function directly, call tty_write_room
*
* int (*ioctl)(struct tty_struct *tty, struct file * file,
* unsigned int cmd, unsigned long arg);
* device-specific ioctl's. If the ioctl number passed in cmd
* is not recognized by the driver, it should return ENOIOCTLCMD.
*
+ * Optional
+ *
* long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
* unsigned int cmd, unsigned long arg);
*
* implement ioctl processing for 32 bit process on 64 bit system
+ *
+ * Optional
*
* void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
*
* This routine allows the tty driver to be notified when
- * device's termios settings have changed. Note that a
- * well-designed tty driver should be prepared to accept the case
- * where old == NULL, and try to do something rational.
+ * device's termios settings have changed.
+ *
+ * Optional: Called under the termios lock
+ *
*
* void (*set_ldisc)(struct tty_struct *tty);
*
* This routine allows the tty driver to be notified when the
* device's termios settings have changed.
+ *
+ * Optional: Called under BKL (currently)
*
* void (*throttle)(struct tty_struct * tty);
*
* This routine notifies the tty driver that input buffers for
* the line discipline are close to full, and it should somehow
* signal that no more characters should be sent to the tty.
+ *
+ * Optional: Always invoke via tty_throttle();
*
* void (*unthrottle)(struct tty_struct * tty);
*
* that characters can now be sent to the tty without fear of
* overrunning the input buffers of the line disciplines.
*
+ * Optional: Always invoke via tty_unthrottle();
+ *
* void (*stop)(struct tty_struct *tty);
*
* This routine notifies the tty driver that it should stop
* outputting characters to the tty device.
+ *
+ * Optional:
+ *
+ * Note: Call stop_tty not this method.
*
* void (*start)(struct tty_struct *tty);
*
* This routine notifies the tty driver that it resume sending
* characters to the tty device.
+ *
+ * Optional:
+ *
+ * Note: Call start_tty not this method.
*
* void (*hangup)(struct tty_struct *tty);
*
* This routine notifies the tty driver that it should hangup the
* tty device.
*
- * void (*break_ctl)(struct tty_stuct *tty, int state);
+ * Optional:
+ *
+ * int (*break_ctl)(struct tty_stuct *tty, int state);
*
* This optional routine requests the tty driver to turn on or
* off BREAK status on the RS-232 port. If state is -1,
*
* If this routine is implemented, the high-level tty driver will
* handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK,
- * TIOCCBRK. Otherwise, these ioctls will be passed down to the
- * driver to handle.
+ * TIOCCBRK.
+ *
+ * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface
+ * will also be called with actual times and the hardware is expected
+ * to do the delay work itself. 0 and -1 are still used for on/off.
+ *
+ * Optional: Required for TCSBRK/BRKP/etc handling.
*
* void (*wait_until_sent)(struct tty_struct *tty, int timeout);
*
* This routine waits until the device has written out all of the
* characters in its transmitter FIFO.
*
+ * Optional: If not provided the device is assumed to have no FIFO
+ *
+ * Note: Usually correct to call tty_wait_until_sent
+ *
* void (*send_xchar)(struct tty_struct *tty, char ch);
*
* This routine is used to send a high-priority XON/XOFF
* character to the device.
+ *
+ * Optional: If not provided then the write method is called under
+ * the atomic write lock to keep it serialized with the ldisc.
+ *
+ * int (*resize)(struct tty_struct *tty, struct winsize *ws)
+ *
+ * Called when a termios request is issued which changes the
+ * requested terminal geometry.
+ *
+ * Optional: the default action is to update the termios structure
+ * without error. This is usually the correct behaviour. Drivers should
+ * not force errors here if they are not resizable objects (eg a serial
+ * line). See tty_do_resize() if you need to wrap the standard method
+ * in your own logic - the usual case.
+ *
+ * void (*set_termiox)(struct tty_struct *tty, struct termiox *new);
+ *
+ * Called when the device receives a termiox based ioctl. Passes down
+ * the requested data from user space. This method will not be invoked
+ * unless the tty also has a valid tty->termiox pointer.
+ *
+ * Optional: Called under the termios lock
*/
#include <linux/fs.h>
#include <linux/cdev.h>
struct tty_struct;
+struct tty_driver;
struct tty_operations {
+ struct tty_struct * (*lookup)(struct tty_driver *driver,
+ struct inode *inode, int idx);
+ int (*install)(struct tty_driver *driver, struct tty_struct *tty);
+ void (*remove)(struct tty_driver *driver, struct tty_struct *tty);
int (*open)(struct tty_struct * tty, struct file * filp);
void (*close)(struct tty_struct * tty, struct file * filp);
+ void (*shutdown)(struct tty_struct *tty);
int (*write)(struct tty_struct * tty,
const unsigned char *buf, int count);
- void (*put_char)(struct tty_struct *tty, unsigned char ch);
+ int (*put_char)(struct tty_struct *tty, unsigned char ch);
void (*flush_chars)(struct tty_struct *tty);
int (*write_room)(struct tty_struct *tty);
int (*chars_in_buffer)(struct tty_struct *tty);
void (*stop)(struct tty_struct *tty);
void (*start)(struct tty_struct *tty);
void (*hangup)(struct tty_struct *tty);
- void (*break_ctl)(struct tty_struct *tty, int state);
+ int (*break_ctl)(struct tty_struct *tty, int state);
void (*flush_buffer)(struct tty_struct *tty);
void (*set_ldisc)(struct tty_struct *tty);
void (*wait_until_sent)(struct tty_struct *tty, int timeout);
void (*send_xchar)(struct tty_struct *tty, char ch);
- int (*read_proc)(char *page, char **start, off_t off,
- int count, int *eof, void *data);
- int (*write_proc)(struct file *file, const char __user *buffer,
- unsigned long count, void *data);
int (*tiocmget)(struct tty_struct *tty, struct file *file);
int (*tiocmset)(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear);
+ int (*resize)(struct tty_struct *tty, struct winsize *ws);
+ int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew);
+#ifdef CONFIG_CONSOLE_POLL
+ int (*poll_init)(struct tty_driver *driver, int line, char *options);
+ int (*poll_get_char)(struct tty_driver *driver, int line);
+ void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
+#endif
+ const struct file_operations *proc_fops;
};
struct tty_driver {
int magic; /* magic number for this structure */
+ struct kref kref; /* Reference management */
struct cdev cdev;
struct module *owner;
const char *driver_name;
short subtype; /* subtype of tty driver */
struct ktermios init_termios; /* Initial termios */
int flags; /* tty driver flags */
- int refcount; /* for loadable tty drivers */
struct proc_dir_entry *proc_entry; /* /proc fs entry */
struct tty_driver *other; /* only used for the PTY driver */
struct tty_struct **ttys;
struct ktermios **termios;
struct ktermios **termios_locked;
- void *driver_state; /* only used for the PTY driver */
-
+ void *driver_state;
+
/*
- * Interface routines from the upper tty layer to the tty
- * driver. Will be replaced with struct tty_operations.
+ * Driver methods
*/
- int (*open)(struct tty_struct * tty, struct file * filp);
- void (*close)(struct tty_struct * tty, struct file * filp);
- int (*write)(struct tty_struct * tty,
- const unsigned char *buf, int count);
- void (*put_char)(struct tty_struct *tty, unsigned char ch);
- void (*flush_chars)(struct tty_struct *tty);
- int (*write_room)(struct tty_struct *tty);
- int (*chars_in_buffer)(struct tty_struct *tty);
- 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);
- void (*throttle)(struct tty_struct * tty);
- void (*unthrottle)(struct tty_struct * tty);
- void (*stop)(struct tty_struct *tty);
- void (*start)(struct tty_struct *tty);
- void (*hangup)(struct tty_struct *tty);
- void (*break_ctl)(struct tty_struct *tty, int state);
- void (*flush_buffer)(struct tty_struct *tty);
- void (*set_ldisc)(struct tty_struct *tty);
- void (*wait_until_sent)(struct tty_struct *tty, int timeout);
- void (*send_xchar)(struct tty_struct *tty, char ch);
- int (*read_proc)(char *page, char **start, off_t off,
- int count, int *eof, void *data);
- int (*write_proc)(struct file *file, const char __user *buffer,
- unsigned long count, void *data);
- int (*tiocmget)(struct tty_struct *tty, struct file *file);
- int (*tiocmset)(struct tty_struct *tty, struct file *file,
- unsigned int set, unsigned int clear);
+ const struct tty_operations *ops;
struct list_head tty_drivers;
};
extern struct list_head tty_drivers;
-struct tty_driver *alloc_tty_driver(int lines);
-void put_tty_driver(struct tty_driver *driver);
-void tty_set_operations(struct tty_driver *driver,
+extern struct tty_driver *alloc_tty_driver(int lines);
+extern void put_tty_driver(struct tty_driver *driver);
+extern void tty_set_operations(struct tty_driver *driver,
const struct tty_operations *op);
+extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
+
+extern void tty_driver_kref_put(struct tty_driver *driver);
+extern inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d)
+{
+ kref_get(&d->kref);
+ return d;
+}
/* tty driver magic number */
#define TTY_DRIVER_MAGIC 0x5402
* TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
* use dynamic memory keyed through the devpts filesystem. This
* is only applicable to the pty driver.
+ *
+ * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass
+ * the requested timeout to the caller instead of using a simple
+ * on/off interface.
+ *
*/
#define TTY_DRIVER_INSTALLED 0x0001
#define TTY_DRIVER_RESET_TERMIOS 0x0002
#define TTY_DRIVER_REAL_RAW 0x0004
#define TTY_DRIVER_DYNAMIC_DEV 0x0008
#define TTY_DRIVER_DEVPTS_MEM 0x0010
+#define TTY_DRIVER_HARDWARE_BREAK 0x0020
/* tty driver types */
#define TTY_DRIVER_TYPE_SYSTEM 0x0001
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff