diff options
Diffstat (limited to 'include/linux/tty_port.h')
| -rw-r--r-- | include/linux/tty_port.h | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/include/linux/tty_port.h b/include/linux/tty_port.h new file mode 100644 index 000000000000..6e86e9e118b6 --- /dev/null +++ b/include/linux/tty_port.h @@ -0,0 +1,208 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_TTY_PORT_H +#define _LINUX_TTY_PORT_H + +#include <linux/kref.h> +#include <linux/mutex.h> +#include <linux/tty_buffer.h> +#include <linux/wait.h> + +/* + * Port level information. Each device keeps its own port level information + * so provide a common structure for those ports wanting to use common support + * routines. + * + * The tty port has a different lifetime to the tty so must be kept apart. + * In addition be careful as tty -> port mappings are valid for the life + * of the tty object but in many cases port -> tty mappings are valid only + * until a hangup so don't use the wrong path. + */ + +struct attribute_group; +struct tty_driver; +struct tty_port; +struct tty_struct; + +struct tty_port_operations { + /* Return 1 if the carrier is raised */ + int (*carrier_raised)(struct tty_port *port); + /* Control the DTR line */ + void (*dtr_rts)(struct tty_port *port, int raise); + /* Called when the last close completes or a hangup finishes + IFF the port was initialized. Do not use to free resources. Called + under the port mutex to serialize against activate/shutdowns */ + void (*shutdown)(struct tty_port *port); + /* Called under the port mutex from tty_port_open, serialized using + the port mutex */ + /* FIXME: long term getting the tty argument *out* of this would be + good for consoles */ + int (*activate)(struct tty_port *port, struct tty_struct *tty); + /* Called on the final put of a port */ + void (*destruct)(struct tty_port *port); +}; + +struct tty_port_client_operations { + int (*receive_buf)(struct tty_port *port, const unsigned char *, const unsigned char *, size_t); + void (*write_wakeup)(struct tty_port *port); +}; + +extern const struct tty_port_client_operations tty_port_default_client_ops; + +struct tty_port { + struct tty_bufhead buf; /* Locked internally */ + struct tty_struct *tty; /* Back pointer */ + struct tty_struct *itty; /* internal back ptr */ + const struct tty_port_operations *ops; /* Port operations */ + const struct tty_port_client_operations *client_ops; /* Port client operations */ + spinlock_t lock; /* Lock protecting tty field */ + int blocked_open; /* Waiting to open */ + int count; /* Usage count */ + wait_queue_head_t open_wait; /* Open waiters */ + wait_queue_head_t delta_msr_wait; /* Modem status change */ + unsigned long flags; /* User TTY flags ASYNC_ */ + unsigned long iflags; /* Internal flags TTY_PORT_ */ + unsigned char console:1; /* port is a console */ + struct mutex mutex; /* Locking */ + struct mutex buf_mutex; /* Buffer alloc lock */ + unsigned char *xmit_buf; /* Optional buffer */ + unsigned int close_delay; /* Close port delay */ + unsigned int closing_wait; /* Delay for output */ + int drain_delay; /* Set to zero if no pure time + based drain is needed else + set to size of fifo */ + struct kref kref; /* Ref counter */ + void *client_data; +}; + +/* tty_port::iflags bits -- use atomic bit ops */ +#define TTY_PORT_INITIALIZED 0 /* device is initialized */ +#define TTY_PORT_SUSPENDED 1 /* device is suspended */ +#define TTY_PORT_ACTIVE 2 /* device is open */ + +/* + * uart drivers: use the uart_port::status field and the UPSTAT_* defines + * for s/w-based flow control steering and carrier detection status + */ +#define TTY_PORT_CTS_FLOW 3 /* h/w flow control enabled */ +#define TTY_PORT_CHECK_CD 4 /* carrier detect enabled */ +#define TTY_PORT_KOPENED 5 /* device exclusively opened by + kernel */ + +void tty_port_init(struct tty_port *port); +void tty_port_link_device(struct tty_port *port, struct tty_driver *driver, + unsigned index); +struct device *tty_port_register_device(struct tty_port *port, + struct tty_driver *driver, unsigned index, + struct device *device); +struct device *tty_port_register_device_attr(struct tty_port *port, + struct tty_driver *driver, unsigned index, + struct device *device, void *drvdata, + const struct attribute_group **attr_grp); +struct device *tty_port_register_device_serdev(struct tty_port *port, + struct tty_driver *driver, unsigned index, + struct device *device); +struct device *tty_port_register_device_attr_serdev(struct tty_port *port, + struct tty_driver *driver, unsigned index, + struct device *device, void *drvdata, + const struct attribute_group **attr_grp); +void tty_port_unregister_device(struct tty_port *port, + struct tty_driver *driver, unsigned index); +int tty_port_alloc_xmit_buf(struct tty_port *port); +void tty_port_free_xmit_buf(struct tty_port *port); +void tty_port_destroy(struct tty_port *port); +void tty_port_put(struct tty_port *port); + +static inline struct tty_port *tty_port_get(struct tty_port *port) +{ + if (port && kref_get_unless_zero(&port->kref)) + return port; + return NULL; +} + +/* If the cts flow control is enabled, return true. */ +static inline bool tty_port_cts_enabled(const struct tty_port *port) +{ + return test_bit(TTY_PORT_CTS_FLOW, &port->iflags); +} + +static inline void tty_port_set_cts_flow(struct tty_port *port, bool val) +{ + assign_bit(TTY_PORT_CTS_FLOW, &port->iflags, val); +} + +static inline bool tty_port_active(const struct tty_port *port) +{ + return test_bit(TTY_PORT_ACTIVE, &port->iflags); +} + +static inline void tty_port_set_active(struct tty_port *port, bool val) +{ + assign_bit(TTY_PORT_ACTIVE, &port->iflags, val); +} + +static inline bool tty_port_check_carrier(const struct tty_port *port) +{ + return test_bit(TTY_PORT_CHECK_CD, &port->iflags); +} + +static inline void tty_port_set_check_carrier(struct tty_port *port, bool val) +{ + assign_bit(TTY_PORT_CHECK_CD, &port->iflags, val); +} + +static inline bool tty_port_suspended(const struct tty_port *port) +{ + return test_bit(TTY_PORT_SUSPENDED, &port->iflags); +} + +static inline void tty_port_set_suspended(struct tty_port *port, bool val) +{ + assign_bit(TTY_PORT_SUSPENDED, &port->iflags, val); +} + +static inline bool tty_port_initialized(const struct tty_port *port) +{ + return test_bit(TTY_PORT_INITIALIZED, &port->iflags); +} + +static inline void tty_port_set_initialized(struct tty_port *port, bool val) +{ + assign_bit(TTY_PORT_INITIALIZED, &port->iflags, val); +} + +static inline bool tty_port_kopened(const struct tty_port *port) +{ + return test_bit(TTY_PORT_KOPENED, &port->iflags); +} + +static inline void tty_port_set_kopened(struct tty_port *port, bool val) +{ + assign_bit(TTY_PORT_KOPENED, &port->iflags, val); +} + +struct tty_struct *tty_port_tty_get(struct tty_port *port); +void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty); +int tty_port_carrier_raised(struct tty_port *port); +void tty_port_raise_dtr_rts(struct tty_port *port); +void tty_port_lower_dtr_rts(struct tty_port *port); +void tty_port_hangup(struct tty_port *port); +void tty_port_tty_hangup(struct tty_port *port, bool check_clocal); +void tty_port_tty_wakeup(struct tty_port *port); +int tty_port_block_til_ready(struct tty_port *port, struct tty_struct *tty, + struct file *filp); +int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, + struct file *filp); +void tty_port_close_end(struct tty_port *port, struct tty_struct *tty); +void tty_port_close(struct tty_port *port, struct tty_struct *tty, + struct file *filp); +int tty_port_install(struct tty_port *port, struct tty_driver *driver, + struct tty_struct *tty); +int tty_port_open(struct tty_port *port, struct tty_struct *tty, + struct file *filp); + +static inline int tty_port_users(struct tty_port *port) +{ + return port->count + port->blocked_open; +} + +#endif |