258 lines
9.2 KiB
C
258 lines
9.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_TTY_PORT_H
|
|
#define _LINUX_TTY_PORT_H
|
|
|
|
#include <linux/kfifo.h>
|
|
#include <linux/kref.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/tty_buffer.h>
|
|
#include <linux/wait.h>
|
|
|
|
struct attribute_group;
|
|
struct tty_driver;
|
|
struct tty_port;
|
|
struct tty_struct;
|
|
|
|
/**
|
|
* struct tty_port_operations -- operations on tty_port
|
|
* @carrier_raised: return true if the carrier is raised on @port
|
|
* @dtr_rts: raise the DTR line if @active is true, otherwise lower DTR
|
|
* @shutdown: called when the last close completes or a hangup finishes IFF the
|
|
* port was initialized. Do not use to free resources. Turn off the device
|
|
* only. Called under the port mutex to serialize against @activate and
|
|
* @shutdown.
|
|
* @activate: called under the port mutex from tty_port_open(), serialized using
|
|
* the port mutex. Supposed to turn on the device.
|
|
*
|
|
* FIXME: long term getting the tty argument *out* of this would be good
|
|
* for consoles.
|
|
*
|
|
* @destruct: called on the final put of a port. Free resources, possibly incl.
|
|
* the port itself.
|
|
*/
|
|
struct tty_port_operations {
|
|
bool (*carrier_raised)(struct tty_port *port);
|
|
void (*dtr_rts)(struct tty_port *port, bool active);
|
|
void (*shutdown)(struct tty_port *port);
|
|
int (*activate)(struct tty_port *port, struct tty_struct *tty);
|
|
void (*destruct)(struct tty_port *port);
|
|
};
|
|
|
|
struct tty_port_client_operations {
|
|
size_t (*receive_buf)(struct tty_port *port, const u8 *cp, const u8 *fp,
|
|
size_t count);
|
|
void (*lookahead_buf)(struct tty_port *port, const u8 *cp,
|
|
const u8 *fp, size_t count);
|
|
void (*write_wakeup)(struct tty_port *port);
|
|
};
|
|
|
|
extern const struct tty_port_client_operations tty_port_default_client_ops;
|
|
|
|
/**
|
|
* struct tty_port -- port level information
|
|
*
|
|
* @buf: buffer for this port, locked internally
|
|
* @tty: back pointer to &struct tty_struct, valid only if the tty is open. Use
|
|
* tty_port_tty_get() to obtain it (and tty_kref_put() to release).
|
|
* @itty: internal back pointer to &struct tty_struct. Avoid this. It should be
|
|
* eliminated in the long term.
|
|
* @ops: tty port operations (like activate, shutdown), see &struct
|
|
* tty_port_operations
|
|
* @client_ops: tty port client operations (like receive_buf, write_wakeup).
|
|
* By default, tty_port_default_client_ops is used.
|
|
* @lock: lock protecting @tty
|
|
* @blocked_open: # of procs waiting for open in tty_port_block_til_ready()
|
|
* @count: usage count
|
|
* @open_wait: open waiters queue (waiting e.g. for a carrier)
|
|
* @delta_msr_wait: modem status change queue (waiting for MSR changes)
|
|
* @flags: user TTY flags (%ASYNC_)
|
|
* @iflags: internal flags (%TTY_PORT_)
|
|
* @console: when set, the port is a console
|
|
* @mutex: locking, for open, shutdown and other port operations
|
|
* @buf_mutex: @xmit_buf alloc lock
|
|
* @xmit_buf: optional xmit buffer used by some drivers
|
|
* @xmit_fifo: optional xmit buffer used by some drivers
|
|
* @close_delay: delay in jiffies to wait when closing the port
|
|
* @closing_wait: delay in jiffies for output to be sent before closing
|
|
* @drain_delay: set to zero if no pure time based drain is needed else set to
|
|
* size of fifo
|
|
* @kref: references counter. Reaching zero calls @ops->destruct() if non-%NULL
|
|
* or frees the port otherwise.
|
|
* @client_data: pointer to private data, for @client_ops
|
|
*
|
|
* Each device keeps its own port level information. &struct tty_port was
|
|
* introduced as a common structure for such information. As every TTY device
|
|
* shall have a backing tty_port structure, every driver can use these members.
|
|
*
|
|
* 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.
|
|
*
|
|
* Tty port shall be initialized by tty_port_init() and shut down either by
|
|
* tty_port_destroy() (refcounting not used), or tty_port_put() (refcounting).
|
|
*
|
|
* There is a lot of helpers around &struct tty_port too. To name the most
|
|
* significant ones: tty_port_open(), tty_port_close() (or
|
|
* tty_port_close_start() and tty_port_close_end() separately if need be), and
|
|
* tty_port_hangup(). These call @ops->activate() and @ops->shutdown() as
|
|
* needed.
|
|
*/
|
|
struct tty_port {
|
|
struct tty_bufhead buf;
|
|
struct tty_struct *tty;
|
|
struct tty_struct *itty;
|
|
const struct tty_port_operations *ops;
|
|
const struct tty_port_client_operations *client_ops;
|
|
spinlock_t lock;
|
|
int blocked_open;
|
|
int count;
|
|
wait_queue_head_t open_wait;
|
|
wait_queue_head_t delta_msr_wait;
|
|
unsigned long flags;
|
|
unsigned long iflags;
|
|
unsigned char console:1;
|
|
struct mutex mutex;
|
|
struct mutex buf_mutex;
|
|
unsigned char *xmit_buf;
|
|
DECLARE_KFIFO_PTR(xmit_fifo, unsigned char);
|
|
unsigned int close_delay;
|
|
unsigned int closing_wait;
|
|
int drain_delay;
|
|
struct kref kref;
|
|
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);
|
|
bool 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
|