1 /* SPDX-License-Identifier: GPL-2.0-or-later */
3 * linux/drivers/char/serial_core.h
5 * Copyright (C) 2000 Deep Blue Solutions Ltd.
7 #ifndef LINUX_SERIAL_CORE_H
8 #define LINUX_SERIAL_CORE_H
10 #include <linux/bitops.h>
11 #include <linux/compiler.h>
12 #include <linux/console.h>
13 #include <linux/interrupt.h>
14 #include <linux/circ_buf.h>
15 #include <linux/spinlock.h>
16 #include <linux/sched.h>
17 #include <linux/tty.h>
18 #include <linux/mutex.h>
19 #include <linux/sysrq.h>
20 #include <uapi/linux/serial_core.h>
22 #ifdef CONFIG_SERIAL_CORE_CONSOLE
23 #define uart_console(port) \
24 ((port)->cons && (port)->cons->index == (port)->line)
26 #define uart_console(port) ({ (void)port; 0; })
35 * struct uart_ops -- interface between serial_core and the driver
37 * This structure describes all the operations that can be done on the
40 * @tx_empty: ``unsigned int ()(struct uart_port *port)``
42 * This function tests whether the transmitter fifo and shifter for the
43 * @port is empty. If it is empty, this function should return
44 * %TIOCSER_TEMT, otherwise return 0. If the port does not support this
45 * operation, then it should return %TIOCSER_TEMT.
48 * Interrupts: caller dependent.
49 * This call must not sleep
51 * @set_mctrl: ``void ()(struct uart_port *port, unsigned int mctrl)``
53 * This function sets the modem control lines for @port to the state
54 * described by @mctrl. The relevant bits of @mctrl are:
56 * - %TIOCM_RTS RTS signal.
57 * - %TIOCM_DTR DTR signal.
58 * - %TIOCM_OUT1 OUT1 signal.
59 * - %TIOCM_OUT2 OUT2 signal.
60 * - %TIOCM_LOOP Set the port into loopback mode.
62 * If the appropriate bit is set, the signal should be driven
63 * active. If the bit is clear, the signal should be driven
66 * Locking: @port->lock taken.
67 * Interrupts: locally disabled.
68 * This call must not sleep
70 * @get_mctrl: ``unsigned int ()(struct uart_port *port)``
72 * Returns the current state of modem control inputs of @port. The state
73 * of the outputs should not be returned, since the core keeps track of
74 * their state. The state information should include:
76 * - %TIOCM_CAR state of DCD signal
77 * - %TIOCM_CTS state of CTS signal
78 * - %TIOCM_DSR state of DSR signal
79 * - %TIOCM_RI state of RI signal
81 * The bit is set if the signal is currently driven active. If
82 * the port does not support CTS, DCD or DSR, the driver should
83 * indicate that the signal is permanently active. If RI is
84 * not available, the signal should not be indicated as active.
86 * Locking: @port->lock taken.
87 * Interrupts: locally disabled.
88 * This call must not sleep
90 * @stop_tx: ``void ()(struct uart_port *port)``
92 * Stop transmitting characters. This might be due to the CTS line
93 * becoming inactive or the tty layer indicating we want to stop
94 * transmission due to an %XOFF character.
96 * The driver should stop transmitting characters as soon as possible.
98 * Locking: @port->lock taken.
99 * Interrupts: locally disabled.
100 * This call must not sleep
102 * @start_tx: ``void ()(struct uart_port *port)``
104 * Start transmitting characters.
106 * Locking: @port->lock taken.
107 * Interrupts: locally disabled.
108 * This call must not sleep
110 * @throttle: ``void ()(struct uart_port *port)``
112 * Notify the serial driver that input buffers for the line discipline are
113 * close to full, and it should somehow signal that no more characters
114 * should be sent to the serial port.
115 * This will be called only if hardware assisted flow control is enabled.
117 * Locking: serialized with @unthrottle() and termios modification by the
120 * @unthrottle: ``void ()(struct uart_port *port)``
122 * Notify the serial driver that characters can now be sent to the serial
123 * port without fear of overrunning the input buffers of the line
126 * This will be called only if hardware assisted flow control is enabled.
128 * Locking: serialized with @throttle() and termios modification by the
131 * @send_xchar: ``void ()(struct uart_port *port, char ch)``
133 * Transmit a high priority character, even if the port is stopped. This
134 * is used to implement XON/XOFF flow control and tcflow(). If the serial
135 * driver does not implement this function, the tty core will append the
136 * character to the circular buffer and then call start_tx() / stop_tx()
137 * to flush the data out.
139 * Do not transmit if @ch == '\0' (%__DISABLED_CHAR).
142 * Interrupts: caller dependent.
144 * @stop_rx: ``void ()(struct uart_port *port)``
146 * Stop receiving characters; the @port is in the process of being closed.
148 * Locking: @port->lock taken.
149 * Interrupts: locally disabled.
150 * This call must not sleep
152 * @enable_ms: ``void ()(struct uart_port *port)``
154 * Enable the modem status interrupts.
156 * This method may be called multiple times. Modem status interrupts
157 * should be disabled when the @shutdown() method is called.
159 * Locking: @port->lock taken.
160 * Interrupts: locally disabled.
161 * This call must not sleep
163 * @break_ctl: ``void ()(struct uart_port *port, int ctl)``
165 * Control the transmission of a break signal. If @ctl is nonzero, the
166 * break signal should be transmitted. The signal should be terminated
167 * when another call is made with a zero @ctl.
169 * Locking: caller holds tty_port->mutex
171 * @startup: ``int ()(struct uart_port *port)``
173 * Grab any interrupt resources and initialise any low level driver state.
174 * Enable the port for reception. It should not activate RTS nor DTR;
175 * this will be done via a separate call to @set_mctrl().
177 * This method will only be called when the port is initially opened.
179 * Locking: port_sem taken.
180 * Interrupts: globally disabled.
182 * @shutdown: ``void ()(struct uart_port *port)``
184 * Disable the @port, disable any break condition that may be in effect,
185 * and free any interrupt resources. It should not disable RTS nor DTR;
186 * this will have already been done via a separate call to @set_mctrl().
188 * Drivers must not access @port->state once this call has completed.
190 * This method will only be called when there are no more users of this
193 * Locking: port_sem taken.
194 * Interrupts: caller dependent.
196 * @flush_buffer: ``void ()(struct uart_port *port)``
198 * Flush any write buffers, reset any DMA state and stop any ongoing DMA
201 * This will be called whenever the @port->state->xmit circular buffer is
204 * Locking: @port->lock taken.
205 * Interrupts: locally disabled.
206 * This call must not sleep
208 * @set_termios: ``void ()(struct uart_port *port, struct ktermios *new,
209 * struct ktermios *old)``
211 * Change the @port parameters, including word length, parity, stop bits.
212 * Update @port->read_status_mask and @port->ignore_status_mask to
213 * indicate the types of events we are interested in receiving. Relevant
214 * ktermios::c_cflag bits are:
216 * - %CSIZE - word size
217 * - %CSTOPB - 2 stop bits
218 * - %PARENB - parity enable
219 * - %PARODD - odd parity (when %PARENB is in force)
220 * - %ADDRB - address bit (changed through uart_port::rs485_config()).
221 * - %CREAD - enable reception of characters (if not set, still receive
222 * characters from the port, but throw them away).
223 * - %CRTSCTS - if set, enable CTS status change reporting.
224 * - %CLOCAL - if not set, enable modem status change reporting.
226 * Relevant ktermios::c_iflag bits are:
228 * - %INPCK - enable frame and parity error events to be passed to the TTY
230 * - %BRKINT / %PARMRK - both of these enable break events to be passed to
232 * - %IGNPAR - ignore parity and framing errors.
233 * - %IGNBRK - ignore break errors. If %IGNPAR is also set, ignore overrun
236 * The interaction of the ktermios::c_iflag bits is as follows (parity
237 * error given as an example):
239 * ============ ======= ======= =========================================
240 * Parity error INPCK IGNPAR
241 * ============ ======= ======= =========================================
242 * n/a 0 n/a character received, marked as %TTY_NORMAL
243 * None 1 n/a character received, marked as %TTY_NORMAL
244 * Yes 1 0 character received, marked as %TTY_PARITY
245 * Yes 1 1 character discarded
246 * ============ ======= ======= =========================================
248 * Other flags may be used (eg, xon/xoff characters) if your hardware
249 * supports hardware "soft" flow control.
251 * Locking: caller holds tty_port->mutex
252 * Interrupts: caller dependent.
253 * This call must not sleep
255 * @set_ldisc: ``void ()(struct uart_port *port, struct ktermios *termios)``
257 * Notifier for discipline change. See
258 * Documentation/driver-api/tty/tty_ldisc.rst.
260 * Locking: caller holds tty_port->mutex
262 * @pm: ``void ()(struct uart_port *port, unsigned int state,
263 * unsigned int oldstate)``
265 * Perform any power management related activities on the specified @port.
266 * @state indicates the new state (defined by enum uart_pm_state),
267 * @oldstate indicates the previous state.
269 * This function should not be used to grab any resources.
271 * This will be called when the @port is initially opened and finally
272 * closed, except when the @port is also the system console. This will
273 * occur even if %CONFIG_PM is not set.
276 * Interrupts: caller dependent.
278 * @type: ``const char *()(struct uart_port *port)``
280 * Return a pointer to a string constant describing the specified @port,
281 * or return %NULL, in which case the string 'unknown' is substituted.
284 * Interrupts: caller dependent.
286 * @release_port: ``void ()(struct uart_port *port)``
288 * Release any memory and IO region resources currently in use by the
292 * Interrupts: caller dependent.
294 * @request_port: ``int ()(struct uart_port *port)``
296 * Request any memory and IO region resources required by the port. If any
297 * fail, no resources should be registered when this function returns, and
298 * it should return -%EBUSY on failure.
301 * Interrupts: caller dependent.
303 * @config_port: ``void ()(struct uart_port *port, int type)``
305 * Perform any autoconfiguration steps required for the @port. @type
306 * contains a bit mask of the required configuration. %UART_CONFIG_TYPE
307 * indicates that the port requires detection and identification.
308 * @port->type should be set to the type found, or %PORT_UNKNOWN if no
311 * %UART_CONFIG_IRQ indicates autoconfiguration of the interrupt signal,
312 * which should be probed using standard kernel autoprobing techniques.
313 * This is not necessary on platforms where ports have interrupts
314 * internally hard wired (eg, system on a chip implementations).
317 * Interrupts: caller dependent.
319 * @verify_port: ``int ()(struct uart_port *port,
320 * struct serial_struct *serinfo)``
322 * Verify the new serial port information contained within @serinfo is
323 * suitable for this port type.
326 * Interrupts: caller dependent.
328 * @ioctl: ``int ()(struct uart_port *port, unsigned int cmd,
329 * unsigned long arg)``
331 * Perform any port specific IOCTLs. IOCTL commands must be defined using
332 * the standard numbering system found in <asm/ioctl.h>.
335 * Interrupts: caller dependent.
337 * @poll_init: ``int ()(struct uart_port *port)``
339 * Called by kgdb to perform the minimal hardware initialization needed to
340 * support @poll_put_char() and @poll_get_char(). Unlike @startup(), this
341 * should not request interrupts.
343 * Locking: %tty_mutex and tty_port->mutex taken.
346 * @poll_put_char: ``void ()(struct uart_port *port, unsigned char ch)``
348 * Called by kgdb to write a single character @ch directly to the serial
349 * @port. It can and should block until there is space in the TX FIFO.
352 * Interrupts: caller dependent.
353 * This call must not sleep
355 * @poll_get_char: ``int ()(struct uart_port *port)``
357 * Called by kgdb to read a single character directly from the serial
358 * port. If data is available, it should be returned; otherwise the
359 * function should return %NO_POLL_CHAR immediately.
362 * Interrupts: caller dependent.
363 * This call must not sleep
366 unsigned int (*tx_empty)(struct uart_port *);
367 void (*set_mctrl)(struct uart_port *, unsigned int mctrl);
368 unsigned int (*get_mctrl)(struct uart_port *);
369 void (*stop_tx)(struct uart_port *);
370 void (*start_tx)(struct uart_port *);
371 void (*throttle)(struct uart_port *);
372 void (*unthrottle)(struct uart_port *);
373 void (*send_xchar)(struct uart_port *, char ch);
374 void (*stop_rx)(struct uart_port *);
375 void (*start_rx)(struct uart_port *);
376 void (*enable_ms)(struct uart_port *);
377 void (*break_ctl)(struct uart_port *, int ctl);
378 int (*startup)(struct uart_port *);
379 void (*shutdown)(struct uart_port *);
380 void (*flush_buffer)(struct uart_port *);
381 void (*set_termios)(struct uart_port *, struct ktermios *new,
382 struct ktermios *old);
383 void (*set_ldisc)(struct uart_port *, struct ktermios *);
384 void (*pm)(struct uart_port *, unsigned int state,
385 unsigned int oldstate);
386 const char *(*type)(struct uart_port *);
387 void (*release_port)(struct uart_port *);
388 int (*request_port)(struct uart_port *);
389 void (*config_port)(struct uart_port *, int);
390 int (*verify_port)(struct uart_port *, struct serial_struct *);
391 int (*ioctl)(struct uart_port *, unsigned int, unsigned long);
392 #ifdef CONFIG_CONSOLE_POLL
393 int (*poll_init)(struct uart_port *);
394 void (*poll_put_char)(struct uart_port *, unsigned char);
395 int (*poll_get_char)(struct uart_port *);
399 #define NO_POLL_CHAR 0x00ff0000
400 #define UART_CONFIG_TYPE (1 << 0)
401 #define UART_CONFIG_IRQ (1 << 1)
417 typedef unsigned int __bitwise upf_t;
418 typedef unsigned int __bitwise upstat_t;
421 spinlock_t lock; /* port lock */
422 unsigned long iobase; /* in/out[bwl] */
423 unsigned char __iomem *membase; /* read/write[bwl] */
424 unsigned int (*serial_in)(struct uart_port *, int);
425 void (*serial_out)(struct uart_port *, int, int);
426 void (*set_termios)(struct uart_port *,
427 struct ktermios *new,
428 struct ktermios *old);
429 void (*set_ldisc)(struct uart_port *,
431 unsigned int (*get_mctrl)(struct uart_port *);
432 void (*set_mctrl)(struct uart_port *, unsigned int);
433 unsigned int (*get_divisor)(struct uart_port *,
436 void (*set_divisor)(struct uart_port *,
439 unsigned int quot_frac);
440 int (*startup)(struct uart_port *port);
441 void (*shutdown)(struct uart_port *port);
442 void (*throttle)(struct uart_port *port);
443 void (*unthrottle)(struct uart_port *port);
444 int (*handle_irq)(struct uart_port *);
445 void (*pm)(struct uart_port *, unsigned int state,
447 void (*handle_break)(struct uart_port *);
448 int (*rs485_config)(struct uart_port *,
449 struct ktermios *termios,
450 struct serial_rs485 *rs485);
451 int (*iso7816_config)(struct uart_port *,
452 struct serial_iso7816 *iso7816);
453 unsigned int irq; /* irq number */
454 unsigned long irqflags; /* irq flags */
455 unsigned int uartclk; /* base uart clock */
456 unsigned int fifosize; /* tx fifo size */
457 unsigned char x_char; /* xon/xoff char */
458 unsigned char regshift; /* reg offset shift */
459 unsigned char iotype; /* io access style */
460 unsigned char quirks; /* internal quirks */
462 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
463 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
464 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */
465 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */
466 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */
467 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */
468 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */
469 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */
471 /* quirks must be updated while holding port mutex */
472 #define UPQ_NO_TXEN_TEST BIT(0)
474 unsigned int read_status_mask; /* driver specific */
475 unsigned int ignore_status_mask; /* driver specific */
476 struct uart_state *state; /* pointer to parent state */
477 struct uart_icount icount; /* statistics */
479 struct console *cons; /* struct console, if any */
480 /* flags must be updated while holding port mutex */
484 * These flags must be equivalent to the flags defined in
485 * include/uapi/linux/tty_flags.h which are the userspace definitions
486 * assigned from the serial_struct flags in uart_set_info()
487 * [for bit definitions in the UPF_CHANGE_MASK]
489 * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable
490 * The remaining bits are serial-core specific and not modifiable by
493 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ )
494 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ )
495 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ )
496 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ )
497 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ )
498 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ )
499 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ )
500 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ )
501 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ )
502 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ )
503 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ )
504 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ )
505 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ )
506 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
508 #define UPF_NO_THRE_TEST ((__force upf_t) (1 << 19))
509 /* Port has hardware-assisted h/w flow control */
510 #define UPF_AUTO_CTS ((__force upf_t) (1 << 20))
511 #define UPF_AUTO_RTS ((__force upf_t) (1 << 21))
512 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
513 /* Port has hardware-assisted s/w flow control */
514 #define UPF_SOFT_FLOW ((__force upf_t) (1 << 22))
515 #define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
516 #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
517 #define UPF_EXAR_EFR ((__force upf_t) (1 << 25))
518 #define UPF_BUG_THRE ((__force upf_t) (1 << 26))
519 /* The exact UART type is known and should not be probed. */
520 #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
521 #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
522 #define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
523 #define UPF_DEAD ((__force upf_t) (1 << 30))
524 #define UPF_IOREMAP ((__force upf_t) (1 << 31))
526 #define __UPF_CHANGE_MASK 0x17fff
527 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK)
528 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
530 #if __UPF_CHANGE_MASK > ASYNC_FLAGS
531 #error Change mask not equivalent to userspace-visible bit defines
535 * Must hold termios_rwsem, port mutex and port lock to change;
536 * can hold any one lock to read.
540 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0))
541 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1))
542 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2))
543 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3))
544 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4))
545 #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5))
547 int hw_stopped; /* sw-assisted CTS flow state */
548 unsigned int mctrl; /* current modem ctrl settings */
549 unsigned int frame_time; /* frame timing in ns */
550 unsigned int type; /* port type */
551 const struct uart_ops *ops;
552 unsigned int custom_divisor;
553 unsigned int line; /* port index */
555 resource_size_t mapbase; /* for ioremap */
556 resource_size_t mapsize;
557 struct device *dev; /* parent device */
559 unsigned long sysrq; /* sysrq timeout */
560 unsigned int sysrq_ch; /* char for sysrq */
561 unsigned char has_sysrq;
562 unsigned char sysrq_seq; /* index in sysrq_toggle_seq */
564 unsigned char hub6; /* this should be in the 8250 driver */
565 unsigned char suspended;
566 unsigned char console_reinit;
567 const char *name; /* port name */
568 struct attribute_group *attr_group; /* port specific attributes */
569 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */
570 struct serial_rs485 rs485;
571 struct serial_rs485 rs485_supported; /* Supported mask for serial_rs485 */
572 struct gpio_desc *rs485_term_gpio; /* enable RS485 bus termination */
573 struct serial_iso7816 iso7816;
574 void *private_data; /* generic platform data pointer */
577 static inline int serial_port_in(struct uart_port *up, int offset)
579 return up->serial_in(up, offset);
582 static inline void serial_port_out(struct uart_port *up, int offset, int value)
584 up->serial_out(up, offset, value);
588 * enum uart_pm_state - power states for UARTs
589 * @UART_PM_STATE_ON: UART is powered, up and operational
590 * @UART_PM_STATE_OFF: UART is powered off
591 * @UART_PM_STATE_UNDEFINED: sentinel
594 UART_PM_STATE_ON = 0,
595 UART_PM_STATE_OFF = 3, /* number taken from ACPI */
596 UART_PM_STATE_UNDEFINED,
600 * This is the state information which is persistent across opens.
603 struct tty_port port;
605 enum uart_pm_state pm_state;
606 struct circ_buf xmit;
609 wait_queue_head_t remove_wait;
610 struct uart_port *uart_port;
613 #define UART_XMIT_SIZE PAGE_SIZE
616 /* number of characters left in xmit buffer before we ask for more */
617 #define WAKEUP_CHARS 256
623 struct module *owner;
624 const char *driver_name;
625 const char *dev_name;
629 struct console *cons;
632 * these are private; the low level driver should not
633 * touch these; they should be initialised to NULL
635 struct uart_state *state;
636 struct tty_driver *tty_driver;
639 void uart_write_wakeup(struct uart_port *port);
644 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
646 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
647 struct ktermios *old, unsigned int min,
649 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
652 * Calculates FIFO drain time.
654 static inline unsigned long uart_fifo_timeout(struct uart_port *port)
656 u64 fifo_timeout = (u64)READ_ONCE(port->frame_time) * port->fifosize;
658 /* Add .02 seconds of slop */
659 fifo_timeout += 20 * NSEC_PER_MSEC;
661 return max(nsecs_to_jiffies(fifo_timeout), 1UL);
664 /* Base timer interval for polling */
665 static inline int uart_poll_timeout(struct uart_port *port)
667 int timeout = uart_fifo_timeout(port);
669 return timeout > 6 ? (timeout / 2 - 2) : 1;
675 struct earlycon_device {
677 struct uart_port port;
678 char options[16]; /* e.g., 115200n8 */
684 char name_term; /* In case compiler didn't '\0' term name */
685 char compatible[128];
686 int (*setup)(struct earlycon_device *, const char *options);
689 extern const struct earlycon_id __earlycon_table[];
690 extern const struct earlycon_id __earlycon_table_end[];
692 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE)
693 #define EARLYCON_USED_OR_UNUSED __used
695 #define EARLYCON_USED_OR_UNUSED __maybe_unused
698 #define OF_EARLYCON_DECLARE(_name, compat, fn) \
699 static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \
700 EARLYCON_USED_OR_UNUSED __section("__earlycon_table") \
701 __aligned(__alignof__(struct earlycon_id)) \
702 = { .name = __stringify(_name), \
703 .compatible = compat, \
706 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn)
708 extern int of_setup_earlycon(const struct earlycon_id *match,
710 const char *options);
712 #ifdef CONFIG_SERIAL_EARLYCON
713 extern bool earlycon_acpi_spcr_enable __initdata;
714 int setup_earlycon(char *buf);
716 static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED;
717 static inline int setup_earlycon(char *buf) { return 0; }
720 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
722 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
724 void uart_parse_options(const char *options, int *baud, int *parity, int *bits,
726 int uart_set_options(struct uart_port *port, struct console *co, int baud,
727 int parity, int bits, int flow);
728 struct tty_driver *uart_console_device(struct console *co, int *index);
729 void uart_console_write(struct uart_port *port, const char *s,
731 void (*putchar)(struct uart_port *, unsigned char));
734 * Port/driver registration/removal
736 int uart_register_driver(struct uart_driver *uart);
737 void uart_unregister_driver(struct uart_driver *uart);
738 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
739 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
740 bool uart_match_port(const struct uart_port *port1,
741 const struct uart_port *port2);
746 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
747 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
749 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail)
750 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0)
752 #define uart_circ_chars_pending(circ) \
753 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
755 #define uart_circ_chars_free(circ) \
756 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
758 static inline int uart_tx_stopped(struct uart_port *port)
760 struct tty_struct *tty = port->state->port.tty;
761 if ((tty && tty->flow.stopped) || port->hw_stopped)
766 static inline bool uart_cts_enabled(struct uart_port *uport)
768 return !!(uport->status & UPSTAT_CTS_ENABLE);
771 static inline bool uart_softcts_mode(struct uart_port *uport)
773 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS;
775 return ((uport->status & mask) == UPSTAT_CTS_ENABLE);
779 * The following are helper functions for the low level drivers.
782 extern void uart_handle_dcd_change(struct uart_port *uport,
783 unsigned int status);
784 extern void uart_handle_cts_change(struct uart_port *uport,
785 unsigned int status);
787 extern void uart_insert_char(struct uart_port *port, unsigned int status,
788 unsigned int overrun, unsigned int ch, unsigned int flag);
790 void uart_xchar_out(struct uart_port *uport, int offset);
792 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL
793 #define SYSRQ_TIMEOUT (HZ * 5)
795 bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch);
797 static inline int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
802 if (ch && time_before(jiffies, port->sysrq)) {
808 if (uart_try_toggle_sysrq(port, ch))
816 static inline int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch)
821 if (ch && time_before(jiffies, port->sysrq)) {
827 if (uart_try_toggle_sysrq(port, ch))
835 static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
839 if (!port->has_sysrq) {
840 spin_unlock(&port->lock);
844 sysrq_ch = port->sysrq_ch;
847 spin_unlock(&port->lock);
850 handle_sysrq(sysrq_ch);
853 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port,
858 if (!port->has_sysrq) {
859 spin_unlock_irqrestore(&port->lock, flags);
863 sysrq_ch = port->sysrq_ch;
866 spin_unlock_irqrestore(&port->lock, flags);
869 handle_sysrq(sysrq_ch);
871 #else /* CONFIG_MAGIC_SYSRQ_SERIAL */
872 static inline int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
876 static inline int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch)
880 static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
882 spin_unlock(&port->lock);
884 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port,
887 spin_unlock_irqrestore(&port->lock, flags);
889 #endif /* CONFIG_MAGIC_SYSRQ_SERIAL */
892 * We do the SysRQ and SAK checking like this...
894 static inline int uart_handle_break(struct uart_port *port)
896 struct uart_state *state = port->state;
898 if (port->handle_break)
899 port->handle_break(port);
901 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL
902 if (port->has_sysrq && uart_console(port)) {
904 port->sysrq = jiffies + SYSRQ_TIMEOUT;
910 if (port->flags & UPF_SAK)
911 do_SAK(state->port.tty);
916 * UART_ENABLE_MS - determine if port should enable modem status irqs
918 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \
919 (cflag) & CRTSCTS || \
922 int uart_get_rs485_mode(struct uart_port *port);
923 int uart_rs485_config(struct uart_port *port);
924 #endif /* LINUX_SERIAL_CORE_H */