1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * linux/drivers/char/serial_core.h
4 *
5 * Copyright (C) 2000 Deep Blue Solutions Ltd.
6 */
7 #ifndef LINUX_SERIAL_CORE_H
8 #define LINUX_SERIAL_CORE_H
9
10 #include <linux/bitops.h>
11 #include <linux/compiler.h>
12 #include <linux/console.h>
13 #include <linux/interrupt.h>
14 #include <linux/spinlock.h>
15 #include <linux/sched.h>
16 #include <linux/tty.h>
17 #include <linux/mutex.h>
18 #include <linux/sysrq.h>
19 #include <uapi/linux/serial_core.h>
20
21 #ifdef CONFIG_SERIAL_CORE_CONSOLE
22 #define uart_console(port) \
23 ((port)->cons && (port)->cons->index == (port)->line)
24 #else
25 #define uart_console(port) ({ (void)port; 0; })
26 #endif
27
28 struct uart_port;
29 struct serial_struct;
30 struct serial_port_device;
31 struct device;
32 struct gpio_desc;
33
34 /**
35 * struct uart_ops -- interface between serial_core and the driver
36 *
37 * This structure describes all the operations that can be done on the
38 * physical hardware.
39 *
40 * @tx_empty: ``unsigned int ()(struct uart_port *port)``
41 *
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.
46 *
47 * Locking: none.
48 * Interrupts: caller dependent.
49 * This call must not sleep
50 *
51 * @set_mctrl: ``void ()(struct uart_port *port, unsigned int mctrl)``
52 *
53 * This function sets the modem control lines for @port to the state
54 * described by @mctrl. The relevant bits of @mctrl are:
55 *
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.
61 *
62 * If the appropriate bit is set, the signal should be driven
63 * active. If the bit is clear, the signal should be driven
64 * inactive.
65 *
66 * Locking: @port->lock taken.
67 * Interrupts: locally disabled.
68 * This call must not sleep
69 *
70 * @get_mctrl: ``unsigned int ()(struct uart_port *port)``
71 *
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:
75 *
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
80 *
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.
85 *
86 * Locking: @port->lock taken.
87 * Interrupts: locally disabled.
88 * This call must not sleep
89 *
90 * @stop_tx: ``void ()(struct uart_port *port)``
91 *
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.
95 *
96 * The driver should stop transmitting characters as soon as possible.
97 *
98 * Locking: @port->lock taken.
99 * Interrupts: locally disabled.
100 * This call must not sleep
101 *
102 * @start_tx: ``void ()(struct uart_port *port)``
103 *
104 * Start transmitting characters.
105 *
106 * Locking: @port->lock taken.
107 * Interrupts: locally disabled.
108 * This call must not sleep
109 *
110 * @throttle: ``void ()(struct uart_port *port)``
111 *
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.
116 *
117 * Locking: serialized with @unthrottle() and termios modification by the
118 * tty layer.
119 *
120 * @unthrottle: ``void ()(struct uart_port *port)``
121 *
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
124 * disciplines.
125 *
126 * This will be called only if hardware assisted flow control is enabled.
127 *
128 * Locking: serialized with @throttle() and termios modification by the
129 * tty layer.
130 *
131 * @send_xchar: ``void ()(struct uart_port *port, char ch)``
132 *
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.
138 *
139 * Do not transmit if @ch == '\0' (%__DISABLED_CHAR).
140 *
141 * Locking: none.
142 * Interrupts: caller dependent.
143 *
144 * @start_rx: ``void ()(struct uart_port *port)``
145 *
146 * Start receiving characters.
147 *
148 * Locking: @port->lock taken.
149 * Interrupts: locally disabled.
150 * This call must not sleep
151 *
152 * @stop_rx: ``void ()(struct uart_port *port)``
153 *
154 * Stop receiving characters; the @port is in the process of being closed.
155 *
156 * Locking: @port->lock taken.
157 * Interrupts: locally disabled.
158 * This call must not sleep
159 *
160 * @enable_ms: ``void ()(struct uart_port *port)``
161 *
162 * Enable the modem status interrupts.
163 *
164 * This method may be called multiple times. Modem status interrupts
165 * should be disabled when the @shutdown() method is called.
166 *
167 * Locking: @port->lock taken.
168 * Interrupts: locally disabled.
169 * This call must not sleep
170 *
171 * @break_ctl: ``void ()(struct uart_port *port, int ctl)``
172 *
173 * Control the transmission of a break signal. If @ctl is nonzero, the
174 * break signal should be transmitted. The signal should be terminated
175 * when another call is made with a zero @ctl.
176 *
177 * Locking: caller holds tty_port->mutex
178 *
179 * @startup: ``int ()(struct uart_port *port)``
180 *
181 * Grab any interrupt resources and initialise any low level driver state.
182 * Enable the port for reception. It should not activate RTS nor DTR;
183 * this will be done via a separate call to @set_mctrl().
184 *
185 * This method will only be called when the port is initially opened.
186 *
187 * Locking: port_sem taken.
188 * Interrupts: globally disabled.
189 *
190 * @shutdown: ``void ()(struct uart_port *port)``
191 *
192 * Disable the @port, disable any break condition that may be in effect,
193 * and free any interrupt resources. It should not disable RTS nor DTR;
194 * this will have already been done via a separate call to @set_mctrl().
195 *
196 * Drivers must not access @port->state once this call has completed.
197 *
198 * This method will only be called when there are no more users of this
199 * @port.
200 *
201 * Locking: port_sem taken.
202 * Interrupts: caller dependent.
203 *
204 * @flush_buffer: ``void ()(struct uart_port *port)``
205 *
206 * Flush any write buffers, reset any DMA state and stop any ongoing DMA
207 * transfers.
208 *
209 * This will be called whenever the @port->state->xmit circular buffer is
210 * cleared.
211 *
212 * Locking: @port->lock taken.
213 * Interrupts: locally disabled.
214 * This call must not sleep
215 *
216 * @set_termios: ``void ()(struct uart_port *port, struct ktermios *new,
217 * struct ktermios *old)``
218 *
219 * Change the @port parameters, including word length, parity, stop bits.
220 * Update @port->read_status_mask and @port->ignore_status_mask to
221 * indicate the types of events we are interested in receiving. Relevant
222 * ktermios::c_cflag bits are:
223 *
224 * - %CSIZE - word size
225 * - %CSTOPB - 2 stop bits
226 * - %PARENB - parity enable
227 * - %PARODD - odd parity (when %PARENB is in force)
228 * - %ADDRB - address bit (changed through uart_port::rs485_config()).
229 * - %CREAD - enable reception of characters (if not set, still receive
230 * characters from the port, but throw them away).
231 * - %CRTSCTS - if set, enable CTS status change reporting.
232 * - %CLOCAL - if not set, enable modem status change reporting.
233 *
234 * Relevant ktermios::c_iflag bits are:
235 *
236 * - %INPCK - enable frame and parity error events to be passed to the TTY
237 * layer.
238 * - %BRKINT / %PARMRK - both of these enable break events to be passed to
239 * the TTY layer.
240 * - %IGNPAR - ignore parity and framing errors.
241 * - %IGNBRK - ignore break errors. If %IGNPAR is also set, ignore overrun
242 * errors as well.
243 *
244 * The interaction of the ktermios::c_iflag bits is as follows (parity
245 * error given as an example):
246 *
247 * ============ ======= ======= =========================================
248 * Parity error INPCK IGNPAR
249 * ============ ======= ======= =========================================
250 * n/a 0 n/a character received, marked as %TTY_NORMAL
251 * None 1 n/a character received, marked as %TTY_NORMAL
252 * Yes 1 0 character received, marked as %TTY_PARITY
253 * Yes 1 1 character discarded
254 * ============ ======= ======= =========================================
255 *
256 * Other flags may be used (eg, xon/xoff characters) if your hardware
257 * supports hardware "soft" flow control.
258 *
259 * Locking: caller holds tty_port->mutex
260 * Interrupts: caller dependent.
261 * This call must not sleep
262 *
263 * @set_ldisc: ``void ()(struct uart_port *port, struct ktermios *termios)``
264 *
265 * Notifier for discipline change. See
266 * Documentation/driver-api/tty/tty_ldisc.rst.
267 *
268 * Locking: caller holds tty_port->mutex
269 *
270 * @pm: ``void ()(struct uart_port *port, unsigned int state,
271 * unsigned int oldstate)``
272 *
273 * Perform any power management related activities on the specified @port.
274 * @state indicates the new state (defined by enum uart_pm_state),
275 * @oldstate indicates the previous state.
276 *
277 * This function should not be used to grab any resources.
278 *
279 * This will be called when the @port is initially opened and finally
280 * closed, except when the @port is also the system console. This will
281 * occur even if %CONFIG_PM is not set.
282 *
283 * Locking: none.
284 * Interrupts: caller dependent.
285 *
286 * @type: ``const char *()(struct uart_port *port)``
287 *
288 * Return a pointer to a string constant describing the specified @port,
289 * or return %NULL, in which case the string 'unknown' is substituted.
290 *
291 * Locking: none.
292 * Interrupts: caller dependent.
293 *
294 * @release_port: ``void ()(struct uart_port *port)``
295 *
296 * Release any memory and IO region resources currently in use by the
297 * @port.
298 *
299 * Locking: none.
300 * Interrupts: caller dependent.
301 *
302 * @request_port: ``int ()(struct uart_port *port)``
303 *
304 * Request any memory and IO region resources required by the port. If any
305 * fail, no resources should be registered when this function returns, and
306 * it should return -%EBUSY on failure.
307 *
308 * Locking: none.
309 * Interrupts: caller dependent.
310 *
311 * @config_port: ``void ()(struct uart_port *port, int type)``
312 *
313 * Perform any autoconfiguration steps required for the @port. @type
314 * contains a bit mask of the required configuration. %UART_CONFIG_TYPE
315 * indicates that the port requires detection and identification.
316 * @port->type should be set to the type found, or %PORT_UNKNOWN if no
317 * port was detected.
318 *
319 * %UART_CONFIG_IRQ indicates autoconfiguration of the interrupt signal,
320 * which should be probed using standard kernel autoprobing techniques.
321 * This is not necessary on platforms where ports have interrupts
322 * internally hard wired (eg, system on a chip implementations).
323 *
324 * Locking: none.
325 * Interrupts: caller dependent.
326 *
327 * @verify_port: ``int ()(struct uart_port *port,
328 * struct serial_struct *serinfo)``
329 *
330 * Verify the new serial port information contained within @serinfo is
331 * suitable for this port type.
332 *
333 * Locking: none.
334 * Interrupts: caller dependent.
335 *
336 * @ioctl: ``int ()(struct uart_port *port, unsigned int cmd,
337 * unsigned long arg)``
338 *
339 * Perform any port specific IOCTLs. IOCTL commands must be defined using
340 * the standard numbering system found in <asm/ioctl.h>.
341 *
342 * Locking: none.
343 * Interrupts: caller dependent.
344 *
345 * @poll_init: ``int ()(struct uart_port *port)``
346 *
347 * Called by kgdb to perform the minimal hardware initialization needed to
348 * support @poll_put_char() and @poll_get_char(). Unlike @startup(), this
349 * should not request interrupts.
350 *
351 * Locking: %tty_mutex and tty_port->mutex taken.
352 * Interrupts: n/a.
353 *
354 * @poll_put_char: ``void ()(struct uart_port *port, unsigned char ch)``
355 *
356 * Called by kgdb to write a single character @ch directly to the serial
357 * @port. It can and should block until there is space in the TX FIFO.
358 *
359 * Locking: none.
360 * Interrupts: caller dependent.
361 * This call must not sleep
362 *
363 * @poll_get_char: ``int ()(struct uart_port *port)``
364 *
365 * Called by kgdb to read a single character directly from the serial
366 * port. If data is available, it should be returned; otherwise the
367 * function should return %NO_POLL_CHAR immediately.
368 *
369 * Locking: none.
370 * Interrupts: caller dependent.
371 * This call must not sleep
372 */
373 struct uart_ops {
374 unsigned int (*tx_empty)(struct uart_port *);
375 void (*set_mctrl)(struct uart_port *, unsigned int mctrl);
376 unsigned int (*get_mctrl)(struct uart_port *);
377 void (*stop_tx)(struct uart_port *);
378 void (*start_tx)(struct uart_port *);
379 void (*throttle)(struct uart_port *);
380 void (*unthrottle)(struct uart_port *);
381 void (*send_xchar)(struct uart_port *, char ch);
382 void (*stop_rx)(struct uart_port *);
383 void (*start_rx)(struct uart_port *);
384 void (*enable_ms)(struct uart_port *);
385 void (*break_ctl)(struct uart_port *, int ctl);
386 int (*startup)(struct uart_port *);
387 void (*shutdown)(struct uart_port *);
388 void (*flush_buffer)(struct uart_port *);
389 void (*set_termios)(struct uart_port *, struct ktermios *new,
390 const struct ktermios *old);
391 void (*set_ldisc)(struct uart_port *, struct ktermios *);
392 void (*pm)(struct uart_port *, unsigned int state,
393 unsigned int oldstate);
394 const char *(*type)(struct uart_port *);
395 void (*release_port)(struct uart_port *);
396 int (*request_port)(struct uart_port *);
397 void (*config_port)(struct uart_port *, int);
398 int (*verify_port)(struct uart_port *, struct serial_struct *);
399 int (*ioctl)(struct uart_port *, unsigned int, unsigned long);
400 #ifdef CONFIG_CONSOLE_POLL
401 int (*poll_init)(struct uart_port *);
402 void (*poll_put_char)(struct uart_port *, unsigned char);
403 int (*poll_get_char)(struct uart_port *);
404 #endif
405 };
406
407 #define NO_POLL_CHAR 0x00ff0000
408 #define UART_CONFIG_TYPE (1 << 0)
409 #define UART_CONFIG_IRQ (1 << 1)
410
411 struct uart_icount {
412 __u32 cts;
413 __u32 dsr;
414 __u32 rng;
415 __u32 dcd;
416 __u32 rx;
417 __u32 tx;
418 __u32 frame;
419 __u32 overrun;
420 __u32 parity;
421 __u32 brk;
422 __u32 buf_overrun;
423 };
424
425 typedef u64 __bitwise upf_t;
426 typedef unsigned int __bitwise upstat_t;
427
428 struct uart_port {
429 spinlock_t lock; /* port lock */
430 unsigned long iobase; /* in/out[bwl] */
431 unsigned char __iomem *membase; /* read/write[bwl] */
432 unsigned int (*serial_in)(struct uart_port *, int);
433 void (*serial_out)(struct uart_port *, int, int);
434 void (*set_termios)(struct uart_port *,
435 struct ktermios *new,
436 const struct ktermios *old);
437 void (*set_ldisc)(struct uart_port *,
438 struct ktermios *);
439 unsigned int (*get_mctrl)(struct uart_port *);
440 void (*set_mctrl)(struct uart_port *, unsigned int);
441 unsigned int (*get_divisor)(struct uart_port *,
442 unsigned int baud,
443 unsigned int *frac);
444 void (*set_divisor)(struct uart_port *,
445 unsigned int baud,
446 unsigned int quot,
447 unsigned int quot_frac);
448 int (*startup)(struct uart_port *port);
449 void (*shutdown)(struct uart_port *port);
450 void (*throttle)(struct uart_port *port);
451 void (*unthrottle)(struct uart_port *port);
452 int (*handle_irq)(struct uart_port *);
453 void (*pm)(struct uart_port *, unsigned int state,
454 unsigned int old);
455 void (*handle_break)(struct uart_port *);
456 int (*rs485_config)(struct uart_port *,
457 struct ktermios *termios,
458 struct serial_rs485 *rs485);
459 int (*iso7816_config)(struct uart_port *,
460 struct serial_iso7816 *iso7816);
461 unsigned int ctrl_id; /* optional serial core controller id */
462 unsigned int port_id; /* optional serial core port id */
463 unsigned int irq; /* irq number */
464 unsigned long irqflags; /* irq flags */
465 unsigned int uartclk; /* base uart clock */
466 unsigned int fifosize; /* tx fifo size */
467 unsigned char x_char; /* xon/xoff char */
468 unsigned char regshift; /* reg offset shift */
469
470 unsigned char iotype; /* io access style */
471
472 #define UPIO_UNKNOWN ((unsigned char)~0U) /* UCHAR_MAX */
473 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
474 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
475 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */
476 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */
477 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */
478 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */
479 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */
480 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */
481
482 unsigned char quirks; /* internal quirks */
483
484 /* internal quirks must be updated while holding port mutex */
485 #define UPQ_NO_TXEN_TEST BIT(0)
486
487 unsigned int read_status_mask; /* driver specific */
488 unsigned int ignore_status_mask; /* driver specific */
489 struct uart_state *state; /* pointer to parent state */
490 struct uart_icount icount; /* statistics */
491
492 struct console *cons; /* struct console, if any */
493 /* flags must be updated while holding port mutex */
494 upf_t flags;
495
496 /*
497 * These flags must be equivalent to the flags defined in
498 * include/uapi/linux/tty_flags.h which are the userspace definitions
499 * assigned from the serial_struct flags in uart_set_info()
500 * [for bit definitions in the UPF_CHANGE_MASK]
501 *
502 * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable
503 * The remaining bits are serial-core specific and not modifiable by
504 * userspace.
505 */
506 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ )
507 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ )
508 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ )
509 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ )
510 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ )
511 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ )
512 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ )
513 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ )
514 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ )
515 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ )
516 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ )
517 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ )
518 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ )
519 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
520
521 #define UPF_NO_THRE_TEST ((__force upf_t) BIT_ULL(19))
522 /* Port has hardware-assisted h/w flow control */
523 #define UPF_AUTO_CTS ((__force upf_t) BIT_ULL(20))
524 #define UPF_AUTO_RTS ((__force upf_t) BIT_ULL(21))
525 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
526 /* Port has hardware-assisted s/w flow control */
527 #define UPF_SOFT_FLOW ((__force upf_t) BIT_ULL(22))
528 #define UPF_CONS_FLOW ((__force upf_t) BIT_ULL(23))
529 #define UPF_SHARE_IRQ ((__force upf_t) BIT_ULL(24))
530 #define UPF_EXAR_EFR ((__force upf_t) BIT_ULL(25))
531 #define UPF_BUG_THRE ((__force upf_t) BIT_ULL(26))
532 /* The exact UART type is known and should not be probed. */
533 #define UPF_FIXED_TYPE ((__force upf_t) BIT_ULL(27))
534 #define UPF_BOOT_AUTOCONF ((__force upf_t) BIT_ULL(28))
535 #define UPF_FIXED_PORT ((__force upf_t) BIT_ULL(29))
536 #define UPF_DEAD ((__force upf_t) BIT_ULL(30))
537 #define UPF_IOREMAP ((__force upf_t) BIT_ULL(31))
538 #define UPF_FULL_PROBE ((__force upf_t) BIT_ULL(32))
539
540 #define __UPF_CHANGE_MASK 0x17fff
541 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK)
542 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
543
544 #if __UPF_CHANGE_MASK > ASYNC_FLAGS
545 #error Change mask not equivalent to userspace-visible bit defines
546 #endif
547
548 /*
549 * Must hold termios_rwsem, port mutex and port lock to change;
550 * can hold any one lock to read.
551 */
552 upstat_t status;
553
554 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0))
555 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1))
556 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2))
557 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3))
558 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4))
559 #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5))
560
561 bool hw_stopped; /* sw-assisted CTS flow state */
562 unsigned int mctrl; /* current modem ctrl settings */
563 unsigned int frame_time; /* frame timing in ns */
564 unsigned int type; /* port type */
565 const struct uart_ops *ops;
566 unsigned int custom_divisor;
567 unsigned int line; /* port index */
568 unsigned int minor;
569 resource_size_t mapbase; /* for ioremap */
570 resource_size_t mapsize;
571 struct device *dev; /* serial port physical parent device */
572 struct serial_port_device *port_dev; /* serial core port device */
573
574 unsigned long sysrq; /* sysrq timeout */
575 u8 sysrq_ch; /* char for sysrq */
576 unsigned char has_sysrq;
577 unsigned char sysrq_seq; /* index in sysrq_toggle_seq */
578
579 unsigned char hub6; /* this should be in the 8250 driver */
580 unsigned char suspended;
581 unsigned char console_reinit;
582 const char *name; /* port name */
583 struct attribute_group *attr_group; /* port specific attributes */
584 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */
585 struct serial_rs485 rs485;
586 struct serial_rs485 rs485_supported; /* Supported mask for serial_rs485 */
587 struct gpio_desc *rs485_term_gpio; /* enable RS485 bus termination */
588 struct gpio_desc *rs485_rx_during_tx_gpio; /* Output GPIO that sets the state of RS485 RX during TX */
589 struct serial_iso7816 iso7816;
590 void *private_data; /* generic platform data pointer */
591 };
592
593 /**
594 * uart_port_lock - Lock the UART port
595 * @up: Pointer to UART port structure
596 */
597 static inline void uart_port_lock(struct uart_port *up)
598 {
599 spin_lock(&up->lock);
600 }
601
602 /**
603 * uart_port_lock_irq - Lock the UART port and disable interrupts
604 * @up: Pointer to UART port structure
605 */
606 static inline void uart_port_lock_irq(struct uart_port *up)
607 {
608 spin_lock_irq(&up->lock);
609 }
610
611 /**
612 * uart_port_lock_irqsave - Lock the UART port, save and disable interrupts
613 * @up: Pointer to UART port structure
614 * @flags: Pointer to interrupt flags storage
615 */
616 static inline void uart_port_lock_irqsave(struct uart_port *up, unsigned long *flags)
617 {
618 spin_lock_irqsave(&up->lock, *flags);
619 }
620
621 /**
622 * uart_port_trylock - Try to lock the UART port
623 * @up: Pointer to UART port structure
624 *
625 * Returns: True if lock was acquired, false otherwise
626 */
627 static inline bool uart_port_trylock(struct uart_port *up)
628 {
629 return spin_trylock(&up->lock);
630 }
631
632 /**
633 * uart_port_trylock_irqsave - Try to lock the UART port, save and disable interrupts
634 * @up: Pointer to UART port structure
635 * @flags: Pointer to interrupt flags storage
636 *
637 * Returns: True if lock was acquired, false otherwise
638 */
639 static inline bool uart_port_trylock_irqsave(struct uart_port *up, unsigned long *flags)
640 {
641 return spin_trylock_irqsave(&up->lock, *flags);
642 }
643
644 /**
645 * uart_port_unlock - Unlock the UART port
646 * @up: Pointer to UART port structure
647 */
648 static inline void uart_port_unlock(struct uart_port *up)
649 {
650 spin_unlock(&up->lock);
651 }
652
653 /**
654 * uart_port_unlock_irq - Unlock the UART port and re-enable interrupts
655 * @up: Pointer to UART port structure
656 */
657 static inline void uart_port_unlock_irq(struct uart_port *up)
658 {
659 spin_unlock_irq(&up->lock);
660 }
661
662 /**
663 * uart_port_unlock_irqrestore - Unlock the UART port, restore interrupts
664 * @up: Pointer to UART port structure
665 * @flags: The saved interrupt flags for restore
666 */
667 static inline void uart_port_unlock_irqrestore(struct uart_port *up, unsigned long flags)
668 {
669 spin_unlock_irqrestore(&up->lock, flags);
670 }
671
672 static inline int serial_port_in(struct uart_port *up, int offset)
673 {
674 return up->serial_in(up, offset);
675 }
676
677 static inline void serial_port_out(struct uart_port *up, int offset, int value)
678 {
679 up->serial_out(up, offset, value);
680 }
681
682 /**
683 * enum uart_pm_state - power states for UARTs
684 * @UART_PM_STATE_ON: UART is powered, up and operational
685 * @UART_PM_STATE_OFF: UART is powered off
686 * @UART_PM_STATE_UNDEFINED: sentinel
687 */
688 enum uart_pm_state {
689 UART_PM_STATE_ON = 0,
690 UART_PM_STATE_OFF = 3, /* number taken from ACPI */
691 UART_PM_STATE_UNDEFINED,
692 };
693
694 /*
695 * This is the state information which is persistent across opens.
696 */
697 struct uart_state {
698 struct tty_port port;
699
700 enum uart_pm_state pm_state;
701
702 atomic_t refcount;
703 wait_queue_head_t remove_wait;
704 struct uart_port *uart_port;
705 };
706
707 #define UART_XMIT_SIZE PAGE_SIZE
708
709
710 /* number of characters left in xmit buffer before we ask for more */
711 #define WAKEUP_CHARS 256
712
713 /**
714 * uart_xmit_advance - Advance xmit buffer and account Tx'ed chars
715 * @up: uart_port structure describing the port
716 * @chars: number of characters sent
717 *
718 * This function advances the tail of circular xmit buffer by the number of
719 * @chars transmitted and handles accounting of transmitted bytes (into
720 * @up's icount.tx).
721 */
722 static inline void uart_xmit_advance(struct uart_port *up, unsigned int chars)
723 {
724 struct tty_port *tport = &up->state->port;
725
726 kfifo_skip_count(&tport->xmit_fifo, chars);
727 up->icount.tx += chars;
728 }
729
730 static inline unsigned int uart_fifo_out(struct uart_port *up,
731 unsigned char *buf, unsigned int chars)
732 {
733 struct tty_port *tport = &up->state->port;
734
735 chars = kfifo_out(&tport->xmit_fifo, buf, chars);
736 up->icount.tx += chars;
737
738 return chars;
739 }
740
741 static inline unsigned int uart_fifo_get(struct uart_port *up,
742 unsigned char *ch)
743 {
744 struct tty_port *tport = &up->state->port;
745 unsigned int chars;
746
747 chars = kfifo_get(&tport->xmit_fifo, ch);
748 up->icount.tx += chars;
749
750 return chars;
751 }
752
753 struct module;
754 struct tty_driver;
755
756 struct uart_driver {
757 struct module *owner;
758 const char *driver_name;
759 const char *dev_name;
760 int major;
761 int minor;
762 int nr;
763 struct console *cons;
764
765 /*
766 * these are private; the low level driver should not
767 * touch these; they should be initialised to NULL
768 */
769 struct uart_state *state;
770 struct tty_driver *tty_driver;
771 };
772
773 void uart_write_wakeup(struct uart_port *port);
774
775 /**
776 * enum UART_TX_FLAGS -- flags for uart_port_tx_flags()
777 *
778 * @UART_TX_NOSTOP: don't call port->ops->stop_tx() on empty buffer
779 */
780 enum UART_TX_FLAGS {
781 UART_TX_NOSTOP = BIT(0),
782 };
783
784 #define __uart_port_tx(uport, ch, flags, tx_ready, put_char, tx_done, \
785 for_test, for_post) \
786 ({ \
787 struct uart_port *__port = (uport); \
788 struct tty_port *__tport = &__port->state->port; \
789 unsigned int pending; \
790 \
791 for (; (for_test) && (tx_ready); (for_post), __port->icount.tx++) { \
792 if (__port->x_char) { \
793 (ch) = __port->x_char; \
794 (put_char); \
795 __port->x_char = 0; \
796 continue; \
797 } \
798 \
799 if (uart_tx_stopped(__port)) \
800 break; \
801 \
802 if (!kfifo_get(&__tport->xmit_fifo, &(ch))) \
803 break; \
804 \
805 (put_char); \
806 } \
807 \
808 (tx_done); \
809 \
810 pending = kfifo_len(&__tport->xmit_fifo); \
811 if (pending < WAKEUP_CHARS) { \
812 uart_write_wakeup(__port); \
813 \
814 if (!((flags) & UART_TX_NOSTOP) && pending == 0) \
815 __port->ops->stop_tx(__port); \
816 } \
817 \
818 pending; \
819 })
820
821 /**
822 * uart_port_tx_limited -- transmit helper for uart_port with count limiting
823 * @port: uart port
824 * @ch: variable to store a character to be written to the HW
825 * @count: a limit of characters to send
826 * @tx_ready: can HW accept more data function
827 * @put_char: function to write a character
828 * @tx_done: function to call after the loop is done
829 *
830 * This helper transmits characters from the xmit buffer to the hardware using
831 * @put_char(). It does so until @count characters are sent and while @tx_ready
832 * evaluates to true.
833 *
834 * Returns: the number of characters in the xmit buffer when done.
835 *
836 * The expression in macro parameters shall be designed as follows:
837 * * **tx_ready:** should evaluate to true if the HW can accept more data to
838 * be sent. This parameter can be %true, which means the HW is always ready.
839 * * **put_char:** shall write @ch to the device of @port.
840 * * **tx_done:** when the write loop is done, this can perform arbitrary
841 * action before potential invocation of ops->stop_tx() happens. If the
842 * driver does not need to do anything, use e.g. ({}).
843 *
844 * For all of them, @port->lock is held, interrupts are locally disabled and
845 * the expressions must not sleep.
846 */
847 #define uart_port_tx_limited(port, ch, count, tx_ready, put_char, tx_done) ({ \
848 unsigned int __count = (count); \
849 __uart_port_tx(port, ch, 0, tx_ready, put_char, tx_done, __count, \
850 __count--); \
851 })
852
853 /**
854 * uart_port_tx_limited_flags -- transmit helper for uart_port with count limiting with flags
855 * @port: uart port
856 * @ch: variable to store a character to be written to the HW
857 * @flags: %UART_TX_NOSTOP or similar
858 * @count: a limit of characters to send
859 * @tx_ready: can HW accept more data function
860 * @put_char: function to write a character
861 * @tx_done: function to call after the loop is done
862 *
863 * See uart_port_tx_limited() for more details.
864 */
865 #define uart_port_tx_limited_flags(port, ch, flags, count, tx_ready, put_char, tx_done) ({ \
866 unsigned int __count = (count); \
867 __uart_port_tx(port, ch, flags, tx_ready, put_char, tx_done, __count, \
868 __count--); \
869 })
870
871 /**
872 * uart_port_tx -- transmit helper for uart_port
873 * @port: uart port
874 * @ch: variable to store a character to be written to the HW
875 * @tx_ready: can HW accept more data function
876 * @put_char: function to write a character
877 *
878 * See uart_port_tx_limited() for more details.
879 */
880 #define uart_port_tx(port, ch, tx_ready, put_char) \
881 __uart_port_tx(port, ch, 0, tx_ready, put_char, ({}), true, ({}))
882
883
884 /**
885 * uart_port_tx_flags -- transmit helper for uart_port with flags
886 * @port: uart port
887 * @ch: variable to store a character to be written to the HW
888 * @flags: %UART_TX_NOSTOP or similar
889 * @tx_ready: can HW accept more data function
890 * @put_char: function to write a character
891 *
892 * See uart_port_tx_limited() for more details.
893 */
894 #define uart_port_tx_flags(port, ch, flags, tx_ready, put_char) \
895 __uart_port_tx(port, ch, flags, tx_ready, put_char, ({}), true, ({}))
896 /*
897 * Baud rate helpers.
898 */
899 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
900 unsigned int baud);
901 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
902 const struct ktermios *old, unsigned int min,
903 unsigned int max);
904 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
905
906 /*
907 * Calculates FIFO drain time.
908 */
909 static inline unsigned long uart_fifo_timeout(struct uart_port *port)
910 {
911 u64 fifo_timeout = (u64)READ_ONCE(port->frame_time) * port->fifosize;
912
913 /* Add .02 seconds of slop */
914 fifo_timeout += 20 * NSEC_PER_MSEC;
915
916 return max(nsecs_to_jiffies(fifo_timeout), 1UL);
917 }
918
919 /* Base timer interval for polling */
920 static inline unsigned long uart_poll_timeout(struct uart_port *port)
921 {
922 unsigned long timeout = uart_fifo_timeout(port);
923
924 return timeout > 6 ? (timeout / 2 - 2) : 1;
925 }
926
927 /*
928 * Console helpers.
929 */
930 struct earlycon_device {
931 struct console *con;
932 struct uart_port port;
933 char options[32]; /* e.g., 115200n8 */
934 unsigned int baud;
935 };
936
937 struct earlycon_id {
938 char name[15];
939 char name_term; /* In case compiler didn't '\0' term name */
940 char compatible[128];
941 int (*setup)(struct earlycon_device *, const char *options);
942 };
943
944 extern const struct earlycon_id __earlycon_table[];
945 extern const struct earlycon_id __earlycon_table_end[];
946
947 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE)
948 #define EARLYCON_USED_OR_UNUSED __used
949 #else
950 #define EARLYCON_USED_OR_UNUSED __maybe_unused
951 #endif
952
953 #define OF_EARLYCON_DECLARE(_name, compat, fn) \
954 static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \
955 EARLYCON_USED_OR_UNUSED __section("__earlycon_table") \
956 __aligned(__alignof__(struct earlycon_id)) \
957 = { .name = __stringify(_name), \
958 .compatible = compat, \
959 .setup = fn }
960
961 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn)
962
963 int of_setup_earlycon(const struct earlycon_id *match, unsigned long node,
964 const char *options);
965
966 #ifdef CONFIG_SERIAL_EARLYCON
967 extern bool earlycon_acpi_spcr_enable __initdata;
968 int setup_earlycon(char *buf);
969 #else
970 static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED;
971 static inline int setup_earlycon(char *buf) { return 0; }
972 #endif
973
974 /* Variant of uart_console_registered() when the console_list_lock is held. */
975 static inline bool uart_console_registered_locked(struct uart_port *port)
976 {
977 return uart_console(port) && console_is_registered_locked(port->cons);
978 }
979
980 static inline bool uart_console_registered(struct uart_port *port)
981 {
982 return uart_console(port) && console_is_registered(port->cons);
983 }
984
985 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
986 struct console *c);
987 int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
988 char **options);
989 void uart_parse_options(const char *options, int *baud, int *parity, int *bits,
990 int *flow);
991 int uart_set_options(struct uart_port *port, struct console *co, int baud,
992 int parity, int bits, int flow);
993 struct tty_driver *uart_console_device(struct console *co, int *index);
994 void uart_console_write(struct uart_port *port, const char *s,
995 unsigned int count,
996 void (*putchar)(struct uart_port *, unsigned char));
997
998 /*
999 * Port/driver registration/removal
1000 */
1001 int uart_register_driver(struct uart_driver *uart);
1002 void uart_unregister_driver(struct uart_driver *uart);
1003 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
1004 void uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
1005 int uart_read_port_properties(struct uart_port *port);
1006 int uart_read_and_validate_port_properties(struct uart_port *port);
1007 bool uart_match_port(const struct uart_port *port1,
1008 const struct uart_port *port2);
1009
1010 /*
1011 * Power Management
1012 */
1013 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
1014 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
1015
1016 static inline int uart_tx_stopped(struct uart_port *port)
1017 {
1018 struct tty_struct *tty = port->state->port.tty;
1019 if ((tty && tty->flow.stopped) || port->hw_stopped)
1020 return 1;
1021 return 0;
1022 }
1023
1024 static inline bool uart_cts_enabled(struct uart_port *uport)
1025 {
1026 return !!(uport->status & UPSTAT_CTS_ENABLE);
1027 }
1028
1029 static inline bool uart_softcts_mode(struct uart_port *uport)
1030 {
1031 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS;
1032
1033 return ((uport->status & mask) == UPSTAT_CTS_ENABLE);
1034 }
1035
1036 /*
1037 * The following are helper functions for the low level drivers.
1038 */
1039
1040 void uart_handle_dcd_change(struct uart_port *uport, bool active);
1041 void uart_handle_cts_change(struct uart_port *uport, bool active);
1042
1043 void uart_insert_char(struct uart_port *port, unsigned int status,
1044 unsigned int overrun, u8 ch, u8 flag);
1045
1046 void uart_xchar_out(struct uart_port *uport, int offset);
1047
1048 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL
1049 #define SYSRQ_TIMEOUT (HZ * 5)
1050
1051 bool uart_try_toggle_sysrq(struct uart_port *port, u8 ch);
1052
1053 static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch)
1054 {
1055 if (!port->sysrq)
1056 return 0;
1057
1058 if (ch && time_before(jiffies, port->sysrq)) {
1059 if (sysrq_mask()) {
1060 handle_sysrq(ch);
1061 port->sysrq = 0;
1062 return 1;
1063 }
1064 if (uart_try_toggle_sysrq(port, ch))
1065 return 1;
1066 }
1067 port->sysrq = 0;
1068
1069 return 0;
1070 }
1071
1072 static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch)
1073 {
1074 if (!port->sysrq)
1075 return 0;
1076
1077 if (ch && time_before(jiffies, port->sysrq)) {
1078 if (sysrq_mask()) {
1079 port->sysrq_ch = ch;
1080 port->sysrq = 0;
1081 return 1;
1082 }
1083 if (uart_try_toggle_sysrq(port, ch))
1084 return 1;
1085 }
1086 port->sysrq = 0;
1087
1088 return 0;
1089 }
1090
1091 static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
1092 {
1093 u8 sysrq_ch;
1094
1095 if (!port->has_sysrq) {
1096 uart_port_unlock(port);
1097 return;
1098 }
1099
1100 sysrq_ch = port->sysrq_ch;
1101 port->sysrq_ch = 0;
1102
1103 uart_port_unlock(port);
1104
1105 if (sysrq_ch)
1106 handle_sysrq(sysrq_ch);
1107 }
1108
1109 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port,
1110 unsigned long flags)
1111 {
1112 u8 sysrq_ch;
1113
1114 if (!port->has_sysrq) {
1115 uart_port_unlock_irqrestore(port, flags);
1116 return;
1117 }
1118
1119 sysrq_ch = port->sysrq_ch;
1120 port->sysrq_ch = 0;
1121
1122 uart_port_unlock_irqrestore(port, flags);
1123
1124 if (sysrq_ch)
1125 handle_sysrq(sysrq_ch);
1126 }
1127 #else /* CONFIG_MAGIC_SYSRQ_SERIAL */
1128 static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch)
1129 {
1130 return 0;
1131 }
1132 static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch)
1133 {
1134 return 0;
1135 }
1136 static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
1137 {
1138 uart_port_unlock(port);
1139 }
1140 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port,
1141 unsigned long flags)
1142 {
1143 uart_port_unlock_irqrestore(port, flags);
1144 }
1145 #endif /* CONFIG_MAGIC_SYSRQ_SERIAL */
1146
1147 /*
1148 * We do the SysRQ and SAK checking like this...
1149 */
1150 static inline int uart_handle_break(struct uart_port *port)
1151 {
1152 struct uart_state *state = port->state;
1153
1154 if (port->handle_break)
1155 port->handle_break(port);
1156
1157 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL
1158 if (port->has_sysrq && uart_console(port)) {
1159 if (!port->sysrq) {
1160 port->sysrq = jiffies + SYSRQ_TIMEOUT;
1161 return 1;
1162 }
1163 port->sysrq = 0;
1164 }
1165 #endif
1166 if (port->flags & UPF_SAK)
1167 do_SAK(state->port.tty);
1168 return 0;
1169 }
1170
1171 /*
1172 * UART_ENABLE_MS - determine if port should enable modem status irqs
1173 */
1174 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \
1175 (cflag) & CRTSCTS || \
1176 !((cflag) & CLOCAL))
1177
1178 int uart_get_rs485_mode(struct uart_port *port);
1179 #endif /* LINUX_SERIAL_CORE_H */
1180
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