| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _LINUX_TTY_DRIVER_H |
| #define _LINUX_TTY_DRIVER_H |
| |
| /* |
| * This structure defines the interface between the low-level tty |
| * driver 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. |
| * |
| * struct tty_struct * (*lookup)(struct tty_driver *self, struct file *, 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. Called with tty lock held. |
| * |
| * void (*close)(struct tty_struct * tty, struct file * filp); |
| * |
| * This routine is called when a particular tty device is closed. |
| * Note: called even if the corresponding open() failed. |
| * |
| * Required method. Called with tty lock held. |
| * |
| * void (*shutdown)(struct tty_struct * tty); |
| * |
| * This routine is called under the tty lock when a particular tty device |
| * is closed for the last time. It executes before the tty resources |
| * are freed so may execute while another function holds a tty kref. |
| * |
| * void (*cleanup)(struct tty_struct * tty); |
| * |
| * This routine is called asynchronously when a particular tty device |
| * is closed for the last time freeing up the resources. This is |
| * actually the second part of shutdown for routines that might sleep. |
| * |
| * |
| * 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. |
| * |
| * Optional: Required for writable devices. |
| * |
| * 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, |
| * it must call the flush_chars() routine (if defined) when it is |
| * 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 |
| * |
| * unsigned int (*write_room)(struct tty_struct *tty); |
| * |
| * This routine returns the numbers of characters the tty driver |
| * 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, unsigned int cmd, unsigned long arg); |
| * |
| * This routine allows the tty driver to implement |
| * device-specific ioctls. 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,, |
| * 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. |
| * |
| * 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_safe(), called under the |
| * termios lock. |
| * |
| * void (*unthrottle)(struct tty_struct * tty); |
| * |
| * This routine notifies the tty drivers that it should signals |
| * 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(), called under the |
| * termios lock. |
| * |
| * void (*stop)(struct tty_struct *tty); |
| * |
| * This routine notifies the tty driver that it should stop |
| * outputting characters to the tty device. |
| * |
| * Called with ->flow.lock held. Serialized with start() method. |
| * |
| * 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. |
| * |
| * Called with ->flow.lock held. Serialized with stop() method. |
| * |
| * Optional: |
| * |
| * Note: Call start_tty not this method. |
| * |
| * void (*hangup)(struct tty_struct *tty); |
| * |
| * This routine notifies the tty driver that it should hang up the |
| * tty device. |
| * |
| * Optional: |
| * |
| * Called with tty lock held. |
| * |
| * int (*break_ctl)(struct tty_struct *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, |
| * then the BREAK status should be turned on; if state is 0, then |
| * BREAK should be turned off. |
| * |
| * If this routine is implemented, the high-level tty driver will |
| * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK, |
| * 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. |
| * |
| * int (*get_icount)(struct tty_struct *tty, struct serial_icounter *icount); |
| * |
| * Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel |
| * structure to complete. This method is optional and will only be called |
| * if provided (otherwise ENOTTY will be returned). |
| */ |
| |
| #include <linux/export.h> |
| #include <linux/fs.h> |
| #include <linux/kref.h> |
| #include <linux/list.h> |
| #include <linux/cdev.h> |
| #include <linux/termios.h> |
| #include <linux/seq_file.h> |
| |
| struct tty_struct; |
| struct tty_driver; |
| struct serial_icounter_struct; |
| struct serial_struct; |
| |
| struct tty_operations { |
| struct tty_struct * (*lookup)(struct tty_driver *driver, |
| struct file *filp, 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); |
| void (*cleanup)(struct tty_struct *tty); |
| int (*write)(struct tty_struct * tty, |
| const unsigned char *buf, int count); |
| int (*put_char)(struct tty_struct *tty, unsigned char ch); |
| void (*flush_chars)(struct tty_struct *tty); |
| unsigned int (*write_room)(struct tty_struct *tty); |
| unsigned int (*chars_in_buffer)(struct tty_struct *tty); |
| int (*ioctl)(struct tty_struct *tty, |
| unsigned int cmd, unsigned long arg); |
| long (*compat_ioctl)(struct tty_struct *tty, |
| 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); |
| 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 (*tiocmget)(struct tty_struct *tty); |
| int (*tiocmset)(struct tty_struct *tty, |
| unsigned int set, unsigned int clear); |
| int (*resize)(struct tty_struct *tty, struct winsize *ws); |
| int (*get_icount)(struct tty_struct *tty, |
| struct serial_icounter_struct *icount); |
| int (*get_serial)(struct tty_struct *tty, struct serial_struct *p); |
| int (*set_serial)(struct tty_struct *tty, struct serial_struct *p); |
| void (*show_fdinfo)(struct tty_struct *tty, struct seq_file *m); |
| #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 |
| int (*proc_show)(struct seq_file *, void *); |
| } __randomize_layout; |
| |
| struct tty_driver { |
| int magic; /* magic number for this structure */ |
| struct kref kref; /* Reference management */ |
| struct cdev **cdevs; |
| struct module *owner; |
| const char *driver_name; |
| const char *name; |
| int name_base; /* offset of printed name */ |
| int major; /* major device number */ |
| int minor_start; /* start of minor device number */ |
| unsigned int num; /* number of devices allocated */ |
| short type; /* type of tty driver */ |
| short subtype; /* subtype of tty driver */ |
| struct ktermios init_termios; /* Initial termios */ |
| unsigned long flags; /* tty driver flags */ |
| struct proc_dir_entry *proc_entry; /* /proc fs entry */ |
| struct tty_driver *other; /* only used for the PTY driver */ |
| |
| /* |
| * Pointer to the tty data structures |
| */ |
| struct tty_struct **ttys; |
| struct tty_port **ports; |
| struct ktermios **termios; |
| void *driver_state; |
| |
| /* |
| * Driver methods |
| */ |
| |
| const struct tty_operations *ops; |
| struct list_head tty_drivers; |
| } __randomize_layout; |
| |
| extern struct list_head tty_drivers; |
| |
| struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, |
| unsigned long flags); |
| struct tty_driver *tty_find_polling_driver(char *name, int *line); |
| |
| void tty_driver_kref_put(struct tty_driver *driver); |
| |
| /* Use TTY_DRIVER_* flags below */ |
| #define tty_alloc_driver(lines, flags) \ |
| __tty_alloc_driver(lines, THIS_MODULE, flags) |
| |
| static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d) |
| { |
| kref_get(&d->kref); |
| return d; |
| } |
| |
| static inline void tty_set_operations(struct tty_driver *driver, |
| const struct tty_operations *op) |
| { |
| driver->ops = op; |
| } |
| |
| /* tty driver magic number */ |
| #define TTY_DRIVER_MAGIC 0x5402 |
| |
| /* |
| * tty driver flags |
| * |
| * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the |
| * termios setting when the last process has closed the device. |
| * Used for PTY's, in particular. |
| * |
| * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will |
| * guarantee never to set any special character handling |
| * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || |
| * !INPCK)). That is, if there is no reason for the driver to |
| * send notifications of parity and break characters up to the |
| * line driver, it won't do so. This allows the line driver to |
| * optimize for this case if this flag is set. (Note that there |
| * is also a promise, if the above case is true, not to signal |
| * overruns, either.) |
| * |
| * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need |
| * to be registered with a call to tty_register_device() when the |
| * device is found in the system and unregistered with a call to |
| * tty_unregister_device() so the devices will be show up |
| * properly in sysfs. If not set, driver->num entries will be |
| * created by the tty core in sysfs when tty_register_driver() is |
| * called. This is to be used by drivers that have tty devices |
| * that can appear and disappear while the main tty driver is |
| * registered with the tty core. |
| * |
| * 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. |
| * |
| * TTY_DRIVER_DYNAMIC_ALLOC -- do not allocate structures which are |
| * needed per line for this driver as it would waste memory. |
| * The driver will take care. |
| * |
| * TTY_DRIVER_UNNUMBERED_NODE -- do not create numbered /dev nodes. In |
| * other words create /dev/ttyprintk and not /dev/ttyprintk0. |
| * Applicable only when a driver for a single tty device is |
| * being allocated. |
| */ |
| #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 |
| #define TTY_DRIVER_DYNAMIC_ALLOC 0x0040 |
| #define TTY_DRIVER_UNNUMBERED_NODE 0x0080 |
| |
| /* tty driver types */ |
| #define TTY_DRIVER_TYPE_SYSTEM 0x0001 |
| #define TTY_DRIVER_TYPE_CONSOLE 0x0002 |
| #define TTY_DRIVER_TYPE_SERIAL 0x0003 |
| #define TTY_DRIVER_TYPE_PTY 0x0004 |
| #define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */ |
| #define TTY_DRIVER_TYPE_SYSCONS 0x0006 |
| |
| /* system subtypes (magic, used by tty_io.c) */ |
| #define SYSTEM_TYPE_TTY 0x0001 |
| #define SYSTEM_TYPE_CONSOLE 0x0002 |
| #define SYSTEM_TYPE_SYSCONS 0x0003 |
| #define SYSTEM_TYPE_SYSPTMX 0x0004 |
| |
| /* pty subtypes (magic, used by tty_io.c) */ |
| #define PTY_TYPE_MASTER 0x0001 |
| #define PTY_TYPE_SLAVE 0x0002 |
| |
| /* serial subtype definitions */ |
| #define SERIAL_TYPE_NORMAL 1 |
| |
| int tty_register_driver(struct tty_driver *driver); |
| void tty_unregister_driver(struct tty_driver *driver); |
| struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
| struct device *dev); |
| struct device *tty_register_device_attr(struct tty_driver *driver, |
| unsigned index, struct device *device, void *drvdata, |
| const struct attribute_group **attr_grp); |
| void tty_unregister_device(struct tty_driver *driver, unsigned index); |
| |
| #ifdef CONFIG_PROC_FS |
| void proc_tty_register_driver(struct tty_driver *); |
| void proc_tty_unregister_driver(struct tty_driver *); |
| #else |
| static inline void proc_tty_register_driver(struct tty_driver *d) {} |
| static inline void proc_tty_unregister_driver(struct tty_driver *d) {} |
| #endif |
| |
| #endif /* #ifdef _LINUX_TTY_DRIVER_H */ |