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/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> |
21 | |
22 | #ifdef CONFIG_SERIAL_CORE_CONSOLE |
23 | #define uart_console(port) \ |
24 | ((port)->cons && (port)->cons->index == (port)->line) |
25 | #else |
26 | #define uart_console(port) ({ (void)port; 0; }) |
27 | #endif |
28 | |
29 | struct uart_port; |
30 | struct serial_struct; |
31 | struct serial_port_device; |
32 | struct device; |
33 | struct gpio_desc; |
34 | |
35 | /** |
36 | * struct uart_ops -- interface between serial_core and the driver |
37 | * |
38 | * This structure describes all the operations that can be done on the |
39 | * physical hardware. |
40 | * |
41 | * @tx_empty: ``unsigned int ()(struct uart_port *port)`` |
42 | * |
43 | * This function tests whether the transmitter fifo and shifter for the |
44 | * @port is empty. If it is empty, this function should return |
45 | * %TIOCSER_TEMT, otherwise return 0. If the port does not support this |
46 | * operation, then it should return %TIOCSER_TEMT. |
47 | * |
48 | * Locking: none. |
49 | * Interrupts: caller dependent. |
50 | * This call must not sleep |
51 | * |
52 | * @set_mctrl: ``void ()(struct uart_port *port, unsigned int mctrl)`` |
53 | * |
54 | * This function sets the modem control lines for @port to the state |
55 | * described by @mctrl. The relevant bits of @mctrl are: |
56 | * |
57 | * - %TIOCM_RTS RTS signal. |
58 | * - %TIOCM_DTR DTR signal. |
59 | * - %TIOCM_OUT1 OUT1 signal. |
60 | * - %TIOCM_OUT2 OUT2 signal. |
61 | * - %TIOCM_LOOP Set the port into loopback mode. |
62 | * |
63 | * If the appropriate bit is set, the signal should be driven |
64 | * active. If the bit is clear, the signal should be driven |
65 | * inactive. |
66 | * |
67 | * Locking: @port->lock taken. |
68 | * Interrupts: locally disabled. |
69 | * This call must not sleep |
70 | * |
71 | * @get_mctrl: ``unsigned int ()(struct uart_port *port)`` |
72 | * |
73 | * Returns the current state of modem control inputs of @port. The state |
74 | * of the outputs should not be returned, since the core keeps track of |
75 | * their state. The state information should include: |
76 | * |
77 | * - %TIOCM_CAR state of DCD signal |
78 | * - %TIOCM_CTS state of CTS signal |
79 | * - %TIOCM_DSR state of DSR signal |
80 | * - %TIOCM_RI state of RI signal |
81 | * |
82 | * The bit is set if the signal is currently driven active. If |
83 | * the port does not support CTS, DCD or DSR, the driver should |
84 | * indicate that the signal is permanently active. If RI is |
85 | * not available, the signal should not be indicated as active. |
86 | * |
87 | * Locking: @port->lock taken. |
88 | * Interrupts: locally disabled. |
89 | * This call must not sleep |
90 | * |
91 | * @stop_tx: ``void ()(struct uart_port *port)`` |
92 | * |
93 | * Stop transmitting characters. This might be due to the CTS line |
94 | * becoming inactive or the tty layer indicating we want to stop |
95 | * transmission due to an %XOFF character. |
96 | * |
97 | * The driver should stop transmitting characters as soon as possible. |
98 | * |
99 | * Locking: @port->lock taken. |
100 | * Interrupts: locally disabled. |
101 | * This call must not sleep |
102 | * |
103 | * @start_tx: ``void ()(struct uart_port *port)`` |
104 | * |
105 | * Start transmitting characters. |
106 | * |
107 | * Locking: @port->lock taken. |
108 | * Interrupts: locally disabled. |
109 | * This call must not sleep |
110 | * |
111 | * @throttle: ``void ()(struct uart_port *port)`` |
112 | * |
113 | * Notify the serial driver that input buffers for the line discipline are |
114 | * close to full, and it should somehow signal that no more characters |
115 | * should be sent to the serial port. |
116 | * This will be called only if hardware assisted flow control is enabled. |
117 | * |
118 | * Locking: serialized with @unthrottle() and termios modification by the |
119 | * tty layer. |
120 | * |
121 | * @unthrottle: ``void ()(struct uart_port *port)`` |
122 | * |
123 | * Notify the serial driver that characters can now be sent to the serial |
124 | * port without fear of overrunning the input buffers of the line |
125 | * disciplines. |
126 | * |
127 | * This will be called only if hardware assisted flow control is enabled. |
128 | * |
129 | * Locking: serialized with @throttle() and termios modification by the |
130 | * tty layer. |
131 | * |
132 | * @send_xchar: ``void ()(struct uart_port *port, char ch)`` |
133 | * |
134 | * Transmit a high priority character, even if the port is stopped. This |
135 | * is used to implement XON/XOFF flow control and tcflow(). If the serial |
136 | * driver does not implement this function, the tty core will append the |
137 | * character to the circular buffer and then call start_tx() / stop_tx() |
138 | * to flush the data out. |
139 | * |
140 | * Do not transmit if @ch == '\0' (%__DISABLED_CHAR). |
141 | * |
142 | * Locking: none. |
143 | * Interrupts: caller dependent. |
144 | * |
145 | * @start_rx: ``void ()(struct uart_port *port)`` |
146 | * |
147 | * Start receiving characters. |
148 | * |
149 | * Locking: @port->lock taken. |
150 | * Interrupts: locally disabled. |
151 | * This call must not sleep |
152 | * |
153 | * @stop_rx: ``void ()(struct uart_port *port)`` |
154 | * |
155 | * Stop receiving characters; the @port is in the process of being closed. |
156 | * |
157 | * Locking: @port->lock taken. |
158 | * Interrupts: locally disabled. |
159 | * This call must not sleep |
160 | * |
161 | * @enable_ms: ``void ()(struct uart_port *port)`` |
162 | * |
163 | * Enable the modem status interrupts. |
164 | * |
165 | * This method may be called multiple times. Modem status interrupts |
166 | * should be disabled when the @shutdown() method is called. |
167 | * |
168 | * Locking: @port->lock taken. |
169 | * Interrupts: locally disabled. |
170 | * This call must not sleep |
171 | * |
172 | * @break_ctl: ``void ()(struct uart_port *port, int ctl)`` |
173 | * |
174 | * Control the transmission of a break signal. If @ctl is nonzero, the |
175 | * break signal should be transmitted. The signal should be terminated |
176 | * when another call is made with a zero @ctl. |
177 | * |
178 | * Locking: caller holds tty_port->mutex |
179 | * |
180 | * @startup: ``int ()(struct uart_port *port)`` |
181 | * |
182 | * Grab any interrupt resources and initialise any low level driver state. |
183 | * Enable the port for reception. It should not activate RTS nor DTR; |
184 | * this will be done via a separate call to @set_mctrl(). |
185 | * |
186 | * This method will only be called when the port is initially opened. |
187 | * |
188 | * Locking: port_sem taken. |
189 | * Interrupts: globally disabled. |
190 | * |
191 | * @shutdown: ``void ()(struct uart_port *port)`` |
192 | * |
193 | * Disable the @port, disable any break condition that may be in effect, |
194 | * and free any interrupt resources. It should not disable RTS nor DTR; |
195 | * this will have already been done via a separate call to @set_mctrl(). |
196 | * |
197 | * Drivers must not access @port->state once this call has completed. |
198 | * |
199 | * This method will only be called when there are no more users of this |
200 | * @port. |
201 | * |
202 | * Locking: port_sem taken. |
203 | * Interrupts: caller dependent. |
204 | * |
205 | * @flush_buffer: ``void ()(struct uart_port *port)`` |
206 | * |
207 | * Flush any write buffers, reset any DMA state and stop any ongoing DMA |
208 | * transfers. |
209 | * |
210 | * This will be called whenever the @port->state->xmit circular buffer is |
211 | * cleared. |
212 | * |
213 | * Locking: @port->lock taken. |
214 | * Interrupts: locally disabled. |
215 | * This call must not sleep |
216 | * |
217 | * @set_termios: ``void ()(struct uart_port *port, struct ktermios *new, |
218 | * struct ktermios *old)`` |
219 | * |
220 | * Change the @port parameters, including word length, parity, stop bits. |
221 | * Update @port->read_status_mask and @port->ignore_status_mask to |
222 | * indicate the types of events we are interested in receiving. Relevant |
223 | * ktermios::c_cflag bits are: |
224 | * |
225 | * - %CSIZE - word size |
226 | * - %CSTOPB - 2 stop bits |
227 | * - %PARENB - parity enable |
228 | * - %PARODD - odd parity (when %PARENB is in force) |
229 | * - %ADDRB - address bit (changed through uart_port::rs485_config()). |
230 | * - %CREAD - enable reception of characters (if not set, still receive |
231 | * characters from the port, but throw them away). |
232 | * - %CRTSCTS - if set, enable CTS status change reporting. |
233 | * - %CLOCAL - if not set, enable modem status change reporting. |
234 | * |
235 | * Relevant ktermios::c_iflag bits are: |
236 | * |
237 | * - %INPCK - enable frame and parity error events to be passed to the TTY |
238 | * layer. |
239 | * - %BRKINT / %PARMRK - both of these enable break events to be passed to |
240 | * the TTY layer. |
241 | * - %IGNPAR - ignore parity and framing errors. |
242 | * - %IGNBRK - ignore break errors. If %IGNPAR is also set, ignore overrun |
243 | * errors as well. |
244 | * |
245 | * The interaction of the ktermios::c_iflag bits is as follows (parity |
246 | * error given as an example): |
247 | * |
248 | * ============ ======= ======= ========================================= |
249 | * Parity error INPCK IGNPAR |
250 | * ============ ======= ======= ========================================= |
251 | * n/a 0 n/a character received, marked as %TTY_NORMAL |
252 | * None 1 n/a character received, marked as %TTY_NORMAL |
253 | * Yes 1 0 character received, marked as %TTY_PARITY |
254 | * Yes 1 1 character discarded |
255 | * ============ ======= ======= ========================================= |
256 | * |
257 | * Other flags may be used (eg, xon/xoff characters) if your hardware |
258 | * supports hardware "soft" flow control. |
259 | * |
260 | * Locking: caller holds tty_port->mutex |
261 | * Interrupts: caller dependent. |
262 | * This call must not sleep |
263 | * |
264 | * @set_ldisc: ``void ()(struct uart_port *port, struct ktermios *termios)`` |
265 | * |
266 | * Notifier for discipline change. See |
267 | * Documentation/driver-api/tty/tty_ldisc.rst. |
268 | * |
269 | * Locking: caller holds tty_port->mutex |
270 | * |
271 | * @pm: ``void ()(struct uart_port *port, unsigned int state, |
272 | * unsigned int oldstate)`` |
273 | * |
274 | * Perform any power management related activities on the specified @port. |
275 | * @state indicates the new state (defined by enum uart_pm_state), |
276 | * @oldstate indicates the previous state. |
277 | * |
278 | * This function should not be used to grab any resources. |
279 | * |
280 | * This will be called when the @port is initially opened and finally |
281 | * closed, except when the @port is also the system console. This will |
282 | * occur even if %CONFIG_PM is not set. |
283 | * |
284 | * Locking: none. |
285 | * Interrupts: caller dependent. |
286 | * |
287 | * @type: ``const char *()(struct uart_port *port)`` |
288 | * |
289 | * Return a pointer to a string constant describing the specified @port, |
290 | * or return %NULL, in which case the string 'unknown' is substituted. |
291 | * |
292 | * Locking: none. |
293 | * Interrupts: caller dependent. |
294 | * |
295 | * @release_port: ``void ()(struct uart_port *port)`` |
296 | * |
297 | * Release any memory and IO region resources currently in use by the |
298 | * @port. |
299 | * |
300 | * Locking: none. |
301 | * Interrupts: caller dependent. |
302 | * |
303 | * @request_port: ``int ()(struct uart_port *port)`` |
304 | * |
305 | * Request any memory and IO region resources required by the port. If any |
306 | * fail, no resources should be registered when this function returns, and |
307 | * it should return -%EBUSY on failure. |
308 | * |
309 | * Locking: none. |
310 | * Interrupts: caller dependent. |
311 | * |
312 | * @config_port: ``void ()(struct uart_port *port, int type)`` |
313 | * |
314 | * Perform any autoconfiguration steps required for the @port. @type |
315 | * contains a bit mask of the required configuration. %UART_CONFIG_TYPE |
316 | * indicates that the port requires detection and identification. |
317 | * @port->type should be set to the type found, or %PORT_UNKNOWN if no |
318 | * port was detected. |
319 | * |
320 | * %UART_CONFIG_IRQ indicates autoconfiguration of the interrupt signal, |
321 | * which should be probed using standard kernel autoprobing techniques. |
322 | * This is not necessary on platforms where ports have interrupts |
323 | * internally hard wired (eg, system on a chip implementations). |
324 | * |
325 | * Locking: none. |
326 | * Interrupts: caller dependent. |
327 | * |
328 | * @verify_port: ``int ()(struct uart_port *port, |
329 | * struct serial_struct *serinfo)`` |
330 | * |
331 | * Verify the new serial port information contained within @serinfo is |
332 | * suitable for this port type. |
333 | * |
334 | * Locking: none. |
335 | * Interrupts: caller dependent. |
336 | * |
337 | * @ioctl: ``int ()(struct uart_port *port, unsigned int cmd, |
338 | * unsigned long arg)`` |
339 | * |
340 | * Perform any port specific IOCTLs. IOCTL commands must be defined using |
341 | * the standard numbering system found in <asm/ioctl.h>. |
342 | * |
343 | * Locking: none. |
344 | * Interrupts: caller dependent. |
345 | * |
346 | * @poll_init: ``int ()(struct uart_port *port)`` |
347 | * |
348 | * Called by kgdb to perform the minimal hardware initialization needed to |
349 | * support @poll_put_char() and @poll_get_char(). Unlike @startup(), this |
350 | * should not request interrupts. |
351 | * |
352 | * Locking: %tty_mutex and tty_port->mutex taken. |
353 | * Interrupts: n/a. |
354 | * |
355 | * @poll_put_char: ``void ()(struct uart_port *port, unsigned char ch)`` |
356 | * |
357 | * Called by kgdb to write a single character @ch directly to the serial |
358 | * @port. It can and should block until there is space in the TX FIFO. |
359 | * |
360 | * Locking: none. |
361 | * Interrupts: caller dependent. |
362 | * This call must not sleep |
363 | * |
364 | * @poll_get_char: ``int ()(struct uart_port *port)`` |
365 | * |
366 | * Called by kgdb to read a single character directly from the serial |
367 | * port. If data is available, it should be returned; otherwise the |
368 | * function should return %NO_POLL_CHAR immediately. |
369 | * |
370 | * Locking: none. |
371 | * Interrupts: caller dependent. |
372 | * This call must not sleep |
373 | */ |
374 | struct uart_ops { |
375 | unsigned int (*tx_empty)(struct uart_port *); |
376 | void (*set_mctrl)(struct uart_port *, unsigned int mctrl); |
377 | unsigned int (*get_mctrl)(struct uart_port *); |
378 | void (*stop_tx)(struct uart_port *); |
379 | void (*start_tx)(struct uart_port *); |
380 | void (*throttle)(struct uart_port *); |
381 | void (*unthrottle)(struct uart_port *); |
382 | void (*send_xchar)(struct uart_port *, char ch); |
383 | void (*stop_rx)(struct uart_port *); |
384 | void (*start_rx)(struct uart_port *); |
385 | void (*enable_ms)(struct uart_port *); |
386 | void (*break_ctl)(struct uart_port *, int ctl); |
387 | int (*startup)(struct uart_port *); |
388 | void (*shutdown)(struct uart_port *); |
389 | void (*flush_buffer)(struct uart_port *); |
390 | void (*set_termios)(struct uart_port *, struct ktermios *new, |
391 | const struct ktermios *old); |
392 | void (*set_ldisc)(struct uart_port *, struct ktermios *); |
393 | void (*pm)(struct uart_port *, unsigned int state, |
394 | unsigned int oldstate); |
395 | const char *(*type)(struct uart_port *); |
396 | void (*release_port)(struct uart_port *); |
397 | int (*request_port)(struct uart_port *); |
398 | void (*config_port)(struct uart_port *, int); |
399 | int (*verify_port)(struct uart_port *, struct serial_struct *); |
400 | int (*ioctl)(struct uart_port *, unsigned int, unsigned long); |
401 | #ifdef CONFIG_CONSOLE_POLL |
402 | int (*poll_init)(struct uart_port *); |
403 | void (*poll_put_char)(struct uart_port *, unsigned char); |
404 | int (*poll_get_char)(struct uart_port *); |
405 | #endif |
406 | }; |
407 | |
408 | #define NO_POLL_CHAR 0x00ff0000 |
409 | #define UART_CONFIG_TYPE (1 << 0) |
410 | #define UART_CONFIG_IRQ (1 << 1) |
411 | |
412 | struct uart_icount { |
413 | __u32 cts; |
414 | __u32 dsr; |
415 | __u32 rng; |
416 | __u32 dcd; |
417 | __u32 rx; |
418 | __u32 tx; |
419 | __u32 frame; |
420 | __u32 overrun; |
421 | __u32 parity; |
422 | __u32 brk; |
423 | __u32 buf_overrun; |
424 | }; |
425 | |
426 | typedef u64 __bitwise upf_t; |
427 | typedef unsigned int __bitwise upstat_t; |
428 | |
429 | struct uart_port { |
430 | spinlock_t lock; /* port lock */ |
431 | unsigned long iobase; /* in/out[bwl] */ |
432 | unsigned char __iomem *membase; /* read/write[bwl] */ |
433 | unsigned int (*serial_in)(struct uart_port *, int); |
434 | void (*serial_out)(struct uart_port *, int, int); |
435 | void (*set_termios)(struct uart_port *, |
436 | struct ktermios *new, |
437 | const struct ktermios *old); |
438 | void (*set_ldisc)(struct uart_port *, |
439 | struct ktermios *); |
440 | unsigned int (*get_mctrl)(struct uart_port *); |
441 | void (*set_mctrl)(struct uart_port *, unsigned int); |
442 | unsigned int (*get_divisor)(struct uart_port *, |
443 | unsigned int baud, |
444 | unsigned int *frac); |
445 | void (*set_divisor)(struct uart_port *, |
446 | unsigned int baud, |
447 | unsigned int quot, |
448 | unsigned int quot_frac); |
449 | int (*startup)(struct uart_port *port); |
450 | void (*shutdown)(struct uart_port *port); |
451 | void (*throttle)(struct uart_port *port); |
452 | void (*unthrottle)(struct uart_port *port); |
453 | int (*handle_irq)(struct uart_port *); |
454 | void (*pm)(struct uart_port *, unsigned int state, |
455 | unsigned int old); |
456 | void (*handle_break)(struct uart_port *); |
457 | int (*rs485_config)(struct uart_port *, |
458 | struct ktermios *termios, |
459 | struct serial_rs485 *rs485); |
460 | int (*iso7816_config)(struct uart_port *, |
461 | struct serial_iso7816 *iso7816); |
462 | unsigned int ctrl_id; /* optional serial core controller id */ |
463 | unsigned int port_id; /* optional serial core port id */ |
464 | unsigned int irq; /* irq number */ |
465 | unsigned long irqflags; /* irq flags */ |
466 | unsigned int uartclk; /* base uart clock */ |
467 | unsigned int fifosize; /* tx fifo size */ |
468 | unsigned char x_char; /* xon/xoff char */ |
469 | unsigned char regshift; /* reg offset shift */ |
470 | unsigned char iotype; /* io access style */ |
471 | unsigned char quirks; /* internal quirks */ |
472 | |
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 | /* quirks must be updated while holding port mutex */ |
483 | #define UPQ_NO_TXEN_TEST BIT(0) |
484 | |
485 | unsigned int read_status_mask; /* driver specific */ |
486 | unsigned int ignore_status_mask; /* driver specific */ |
487 | struct uart_state *state; /* pointer to parent state */ |
488 | struct uart_icount icount; /* statistics */ |
489 | |
490 | struct console *cons; /* struct console, if any */ |
491 | /* flags must be updated while holding port mutex */ |
492 | upf_t flags; |
493 | |
494 | /* |
495 | * These flags must be equivalent to the flags defined in |
496 | * include/uapi/linux/tty_flags.h which are the userspace definitions |
497 | * assigned from the serial_struct flags in uart_set_info() |
498 | * [for bit definitions in the UPF_CHANGE_MASK] |
499 | * |
500 | * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable |
501 | * The remaining bits are serial-core specific and not modifiable by |
502 | * userspace. |
503 | */ |
504 | #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ ) |
505 | #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ ) |
506 | #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ ) |
507 | #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ ) |
508 | #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ ) |
509 | #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ ) |
510 | #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ ) |
511 | #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ ) |
512 | #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ ) |
513 | #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ ) |
514 | #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ ) |
515 | #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ ) |
516 | #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ ) |
517 | #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ ) |
518 | |
519 | #define UPF_NO_THRE_TEST ((__force upf_t) BIT_ULL(19)) |
520 | /* Port has hardware-assisted h/w flow control */ |
521 | #define UPF_AUTO_CTS ((__force upf_t) BIT_ULL(20)) |
522 | #define UPF_AUTO_RTS ((__force upf_t) BIT_ULL(21)) |
523 | #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS)) |
524 | /* Port has hardware-assisted s/w flow control */ |
525 | #define UPF_SOFT_FLOW ((__force upf_t) BIT_ULL(22)) |
526 | #define UPF_CONS_FLOW ((__force upf_t) BIT_ULL(23)) |
527 | #define UPF_SHARE_IRQ ((__force upf_t) BIT_ULL(24)) |
528 | #define UPF_EXAR_EFR ((__force upf_t) BIT_ULL(25)) |
529 | #define UPF_BUG_THRE ((__force upf_t) BIT_ULL(26)) |
530 | /* The exact UART type is known and should not be probed. */ |
531 | #define UPF_FIXED_TYPE ((__force upf_t) BIT_ULL(27)) |
532 | #define UPF_BOOT_AUTOCONF ((__force upf_t) BIT_ULL(28)) |
533 | #define UPF_FIXED_PORT ((__force upf_t) BIT_ULL(29)) |
534 | #define UPF_DEAD ((__force upf_t) BIT_ULL(30)) |
535 | #define UPF_IOREMAP ((__force upf_t) BIT_ULL(31)) |
536 | #define UPF_FULL_PROBE ((__force upf_t) BIT_ULL(32)) |
537 | |
538 | #define __UPF_CHANGE_MASK 0x17fff |
539 | #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK) |
540 | #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY)) |
541 | |
542 | #if __UPF_CHANGE_MASK > ASYNC_FLAGS |
543 | #error Change mask not equivalent to userspace-visible bit defines |
544 | #endif |
545 | |
546 | /* |
547 | * Must hold termios_rwsem, port mutex and port lock to change; |
548 | * can hold any one lock to read. |
549 | */ |
550 | upstat_t status; |
551 | |
552 | #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0)) |
553 | #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1)) |
554 | #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2)) |
555 | #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3)) |
556 | #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4)) |
557 | #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5)) |
558 | |
559 | bool hw_stopped; /* sw-assisted CTS flow state */ |
560 | unsigned int mctrl; /* current modem ctrl settings */ |
561 | unsigned int frame_time; /* frame timing in ns */ |
562 | unsigned int type; /* port type */ |
563 | const struct uart_ops *ops; |
564 | unsigned int custom_divisor; |
565 | unsigned int line; /* port index */ |
566 | unsigned int minor; |
567 | resource_size_t mapbase; /* for ioremap */ |
568 | resource_size_t mapsize; |
569 | struct device *dev; /* serial port physical parent device */ |
570 | struct serial_port_device *port_dev; /* serial core port device */ |
571 | |
572 | unsigned long sysrq; /* sysrq timeout */ |
573 | u8 sysrq_ch; /* char for sysrq */ |
574 | unsigned char has_sysrq; |
575 | unsigned char sysrq_seq; /* index in sysrq_toggle_seq */ |
576 | |
577 | unsigned char hub6; /* this should be in the 8250 driver */ |
578 | unsigned char suspended; |
579 | unsigned char console_reinit; |
580 | const char *name; /* port name */ |
581 | struct attribute_group *attr_group; /* port specific attributes */ |
582 | const struct attribute_group **tty_groups; /* all attributes (serial core use only) */ |
583 | struct serial_rs485 rs485; |
584 | struct serial_rs485 rs485_supported; /* Supported mask for serial_rs485 */ |
585 | struct gpio_desc *rs485_term_gpio; /* enable RS485 bus termination */ |
586 | struct gpio_desc *rs485_rx_during_tx_gpio; /* Output GPIO that sets the state of RS485 RX during TX */ |
587 | struct serial_iso7816 iso7816; |
588 | void *private_data; /* generic platform data pointer */ |
589 | }; |
590 | |
591 | /** |
592 | * uart_port_lock - Lock the UART port |
593 | * @up: Pointer to UART port structure |
594 | */ |
595 | static inline void uart_port_lock(struct uart_port *up) |
596 | { |
597 | spin_lock(lock: &up->lock); |
598 | } |
599 | |
600 | /** |
601 | * uart_port_lock_irq - Lock the UART port and disable interrupts |
602 | * @up: Pointer to UART port structure |
603 | */ |
604 | static inline void uart_port_lock_irq(struct uart_port *up) |
605 | { |
606 | spin_lock_irq(lock: &up->lock); |
607 | } |
608 | |
609 | /** |
610 | * uart_port_lock_irqsave - Lock the UART port, save and disable interrupts |
611 | * @up: Pointer to UART port structure |
612 | * @flags: Pointer to interrupt flags storage |
613 | */ |
614 | static inline void uart_port_lock_irqsave(struct uart_port *up, unsigned long *flags) |
615 | { |
616 | spin_lock_irqsave(&up->lock, *flags); |
617 | } |
618 | |
619 | /** |
620 | * uart_port_trylock - Try to lock the UART port |
621 | * @up: Pointer to UART port structure |
622 | * |
623 | * Returns: True if lock was acquired, false otherwise |
624 | */ |
625 | static inline bool uart_port_trylock(struct uart_port *up) |
626 | { |
627 | return spin_trylock(lock: &up->lock); |
628 | } |
629 | |
630 | /** |
631 | * uart_port_trylock_irqsave - Try to lock the UART port, save and disable interrupts |
632 | * @up: Pointer to UART port structure |
633 | * @flags: Pointer to interrupt flags storage |
634 | * |
635 | * Returns: True if lock was acquired, false otherwise |
636 | */ |
637 | static inline bool uart_port_trylock_irqsave(struct uart_port *up, unsigned long *flags) |
638 | { |
639 | return spin_trylock_irqsave(&up->lock, *flags); |
640 | } |
641 | |
642 | /** |
643 | * uart_port_unlock - Unlock the UART port |
644 | * @up: Pointer to UART port structure |
645 | */ |
646 | static inline void uart_port_unlock(struct uart_port *up) |
647 | { |
648 | spin_unlock(lock: &up->lock); |
649 | } |
650 | |
651 | /** |
652 | * uart_port_unlock_irq - Unlock the UART port and re-enable interrupts |
653 | * @up: Pointer to UART port structure |
654 | */ |
655 | static inline void uart_port_unlock_irq(struct uart_port *up) |
656 | { |
657 | spin_unlock_irq(lock: &up->lock); |
658 | } |
659 | |
660 | /** |
661 | * uart_port_unlock_irqrestore - Unlock the UART port, restore interrupts |
662 | * @up: Pointer to UART port structure |
663 | * @flags: The saved interrupt flags for restore |
664 | */ |
665 | static inline void uart_port_unlock_irqrestore(struct uart_port *up, unsigned long flags) |
666 | { |
667 | spin_unlock_irqrestore(lock: &up->lock, flags); |
668 | } |
669 | |
670 | static inline int serial_port_in(struct uart_port *up, int offset) |
671 | { |
672 | return up->serial_in(up, offset); |
673 | } |
674 | |
675 | static inline void serial_port_out(struct uart_port *up, int offset, int value) |
676 | { |
677 | up->serial_out(up, offset, value); |
678 | } |
679 | |
680 | /** |
681 | * enum uart_pm_state - power states for UARTs |
682 | * @UART_PM_STATE_ON: UART is powered, up and operational |
683 | * @UART_PM_STATE_OFF: UART is powered off |
684 | * @UART_PM_STATE_UNDEFINED: sentinel |
685 | */ |
686 | enum uart_pm_state { |
687 | UART_PM_STATE_ON = 0, |
688 | UART_PM_STATE_OFF = 3, /* number taken from ACPI */ |
689 | UART_PM_STATE_UNDEFINED, |
690 | }; |
691 | |
692 | /* |
693 | * This is the state information which is persistent across opens. |
694 | */ |
695 | struct uart_state { |
696 | struct tty_port port; |
697 | |
698 | enum uart_pm_state pm_state; |
699 | struct circ_buf xmit; |
700 | |
701 | atomic_t refcount; |
702 | wait_queue_head_t remove_wait; |
703 | struct uart_port *uart_port; |
704 | }; |
705 | |
706 | #define UART_XMIT_SIZE PAGE_SIZE |
707 | |
708 | |
709 | /* number of characters left in xmit buffer before we ask for more */ |
710 | #define WAKEUP_CHARS 256 |
711 | |
712 | /** |
713 | * uart_xmit_advance - Advance xmit buffer and account Tx'ed chars |
714 | * @up: uart_port structure describing the port |
715 | * @chars: number of characters sent |
716 | * |
717 | * This function advances the tail of circular xmit buffer by the number of |
718 | * @chars transmitted and handles accounting of transmitted bytes (into |
719 | * @up's icount.tx). |
720 | */ |
721 | static inline void uart_xmit_advance(struct uart_port *up, unsigned int chars) |
722 | { |
723 | struct circ_buf *xmit = &up->state->xmit; |
724 | |
725 | xmit->tail = (xmit->tail + chars) & (UART_XMIT_SIZE - 1); |
726 | up->icount.tx += chars; |
727 | } |
728 | |
729 | struct module; |
730 | struct tty_driver; |
731 | |
732 | struct uart_driver { |
733 | struct module *owner; |
734 | const char *driver_name; |
735 | const char *dev_name; |
736 | int major; |
737 | int minor; |
738 | int nr; |
739 | struct console *cons; |
740 | |
741 | /* |
742 | * these are private; the low level driver should not |
743 | * touch these; they should be initialised to NULL |
744 | */ |
745 | struct uart_state *state; |
746 | struct tty_driver *tty_driver; |
747 | }; |
748 | |
749 | void uart_write_wakeup(struct uart_port *port); |
750 | |
751 | #define __uart_port_tx(uport, ch, tx_ready, put_char, tx_done, for_test, \ |
752 | for_post) \ |
753 | ({ \ |
754 | struct uart_port *__port = (uport); \ |
755 | struct circ_buf *xmit = &__port->state->xmit; \ |
756 | unsigned int pending; \ |
757 | \ |
758 | for (; (for_test) && (tx_ready); (for_post), __port->icount.tx++) { \ |
759 | if (__port->x_char) { \ |
760 | (ch) = __port->x_char; \ |
761 | (put_char); \ |
762 | __port->x_char = 0; \ |
763 | continue; \ |
764 | } \ |
765 | \ |
766 | if (uart_circ_empty(xmit) || uart_tx_stopped(__port)) \ |
767 | break; \ |
768 | \ |
769 | (ch) = xmit->buf[xmit->tail]; \ |
770 | (put_char); \ |
771 | xmit->tail = (xmit->tail + 1) % UART_XMIT_SIZE; \ |
772 | } \ |
773 | \ |
774 | (tx_done); \ |
775 | \ |
776 | pending = uart_circ_chars_pending(xmit); \ |
777 | if (pending < WAKEUP_CHARS) { \ |
778 | uart_write_wakeup(__port); \ |
779 | \ |
780 | if (pending == 0) \ |
781 | __port->ops->stop_tx(__port); \ |
782 | } \ |
783 | \ |
784 | pending; \ |
785 | }) |
786 | |
787 | /** |
788 | * uart_port_tx_limited -- transmit helper for uart_port with count limiting |
789 | * @port: uart port |
790 | * @ch: variable to store a character to be written to the HW |
791 | * @count: a limit of characters to send |
792 | * @tx_ready: can HW accept more data function |
793 | * @put_char: function to write a character |
794 | * @tx_done: function to call after the loop is done |
795 | * |
796 | * This helper transmits characters from the xmit buffer to the hardware using |
797 | * @put_char(). It does so until @count characters are sent and while @tx_ready |
798 | * evaluates to true. |
799 | * |
800 | * Returns: the number of characters in the xmit buffer when done. |
801 | * |
802 | * The expression in macro parameters shall be designed as follows: |
803 | * * **tx_ready:** should evaluate to true if the HW can accept more data to |
804 | * be sent. This parameter can be %true, which means the HW is always ready. |
805 | * * **put_char:** shall write @ch to the device of @port. |
806 | * * **tx_done:** when the write loop is done, this can perform arbitrary |
807 | * action before potential invocation of ops->stop_tx() happens. If the |
808 | * driver does not need to do anything, use e.g. ({}). |
809 | * |
810 | * For all of them, @port->lock is held, interrupts are locally disabled and |
811 | * the expressions must not sleep. |
812 | */ |
813 | #define uart_port_tx_limited(port, ch, count, tx_ready, put_char, tx_done) ({ \ |
814 | unsigned int __count = (count); \ |
815 | __uart_port_tx(port, ch, tx_ready, put_char, tx_done, __count, \ |
816 | __count--); \ |
817 | }) |
818 | |
819 | /** |
820 | * uart_port_tx -- transmit helper for uart_port |
821 | * @port: uart port |
822 | * @ch: variable to store a character to be written to the HW |
823 | * @tx_ready: can HW accept more data function |
824 | * @put_char: function to write a character |
825 | * |
826 | * See uart_port_tx_limited() for more details. |
827 | */ |
828 | #define uart_port_tx(port, ch, tx_ready, put_char) \ |
829 | __uart_port_tx(port, ch, tx_ready, put_char, ({}), true, ({})) |
830 | |
831 | /* |
832 | * Baud rate helpers. |
833 | */ |
834 | void uart_update_timeout(struct uart_port *port, unsigned int cflag, |
835 | unsigned int baud); |
836 | unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, |
837 | const struct ktermios *old, unsigned int min, |
838 | unsigned int max); |
839 | unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud); |
840 | |
841 | /* |
842 | * Calculates FIFO drain time. |
843 | */ |
844 | static inline unsigned long uart_fifo_timeout(struct uart_port *port) |
845 | { |
846 | u64 fifo_timeout = (u64)READ_ONCE(port->frame_time) * port->fifosize; |
847 | |
848 | /* Add .02 seconds of slop */ |
849 | fifo_timeout += 20 * NSEC_PER_MSEC; |
850 | |
851 | return max(nsecs_to_jiffies(fifo_timeout), 1UL); |
852 | } |
853 | |
854 | /* Base timer interval for polling */ |
855 | static inline int uart_poll_timeout(struct uart_port *port) |
856 | { |
857 | int timeout = uart_fifo_timeout(port); |
858 | |
859 | return timeout > 6 ? (timeout / 2 - 2) : 1; |
860 | } |
861 | |
862 | /* |
863 | * Console helpers. |
864 | */ |
865 | struct earlycon_device { |
866 | struct console *con; |
867 | struct uart_port port; |
868 | char options[32]; /* e.g., 115200n8 */ |
869 | unsigned int baud; |
870 | }; |
871 | |
872 | struct earlycon_id { |
873 | char name[15]; |
874 | char name_term; /* In case compiler didn't '\0' term name */ |
875 | char compatible[128]; |
876 | int (*setup)(struct earlycon_device *, const char *options); |
877 | }; |
878 | |
879 | extern const struct earlycon_id __earlycon_table[]; |
880 | extern const struct earlycon_id __earlycon_table_end[]; |
881 | |
882 | #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE) |
883 | #define EARLYCON_USED_OR_UNUSED __used |
884 | #else |
885 | #define EARLYCON_USED_OR_UNUSED __maybe_unused |
886 | #endif |
887 | |
888 | #define OF_EARLYCON_DECLARE(_name, compat, fn) \ |
889 | static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \ |
890 | EARLYCON_USED_OR_UNUSED __section("__earlycon_table") \ |
891 | __aligned(__alignof__(struct earlycon_id)) \ |
892 | = { .name = __stringify(_name), \ |
893 | .compatible = compat, \ |
894 | .setup = fn } |
895 | |
896 | #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) |
897 | |
898 | int of_setup_earlycon(const struct earlycon_id *match, unsigned long node, |
899 | const char *options); |
900 | |
901 | #ifdef CONFIG_SERIAL_EARLYCON |
902 | extern bool earlycon_acpi_spcr_enable __initdata; |
903 | int setup_earlycon(char *buf); |
904 | #else |
905 | static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED; |
906 | static inline int setup_earlycon(char *buf) { return 0; } |
907 | #endif |
908 | |
909 | /* Variant of uart_console_registered() when the console_list_lock is held. */ |
910 | static inline bool uart_console_registered_locked(struct uart_port *port) |
911 | { |
912 | return uart_console(port) && console_is_registered_locked(con: port->cons); |
913 | } |
914 | |
915 | static inline bool uart_console_registered(struct uart_port *port) |
916 | { |
917 | return uart_console(port) && console_is_registered(con: port->cons); |
918 | } |
919 | |
920 | struct uart_port *uart_get_console(struct uart_port *ports, int nr, |
921 | struct console *c); |
922 | int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, |
923 | char **options); |
924 | void uart_parse_options(const char *options, int *baud, int *parity, int *bits, |
925 | int *flow); |
926 | int uart_set_options(struct uart_port *port, struct console *co, int baud, |
927 | int parity, int bits, int flow); |
928 | struct tty_driver *uart_console_device(struct console *co, int *index); |
929 | void uart_console_write(struct uart_port *port, const char *s, |
930 | unsigned int count, |
931 | void (*putchar)(struct uart_port *, unsigned char)); |
932 | |
933 | /* |
934 | * Port/driver registration/removal |
935 | */ |
936 | int uart_register_driver(struct uart_driver *uart); |
937 | void uart_unregister_driver(struct uart_driver *uart); |
938 | int uart_add_one_port(struct uart_driver *reg, struct uart_port *port); |
939 | void uart_remove_one_port(struct uart_driver *reg, struct uart_port *port); |
940 | bool uart_match_port(const struct uart_port *port1, |
941 | const struct uart_port *port2); |
942 | |
943 | /* |
944 | * Power Management |
945 | */ |
946 | int uart_suspend_port(struct uart_driver *reg, struct uart_port *port); |
947 | int uart_resume_port(struct uart_driver *reg, struct uart_port *port); |
948 | |
949 | #define uart_circ_empty(circ) ((circ)->head == (circ)->tail) |
950 | #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0) |
951 | |
952 | #define uart_circ_chars_pending(circ) \ |
953 | (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE)) |
954 | |
955 | #define uart_circ_chars_free(circ) \ |
956 | (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE)) |
957 | |
958 | static inline int uart_tx_stopped(struct uart_port *port) |
959 | { |
960 | struct tty_struct *tty = port->state->port.tty; |
961 | if ((tty && tty->flow.stopped) || port->hw_stopped) |
962 | return 1; |
963 | return 0; |
964 | } |
965 | |
966 | static inline bool uart_cts_enabled(struct uart_port *uport) |
967 | { |
968 | return !!(uport->status & UPSTAT_CTS_ENABLE); |
969 | } |
970 | |
971 | static inline bool uart_softcts_mode(struct uart_port *uport) |
972 | { |
973 | upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS; |
974 | |
975 | return ((uport->status & mask) == UPSTAT_CTS_ENABLE); |
976 | } |
977 | |
978 | /* |
979 | * The following are helper functions for the low level drivers. |
980 | */ |
981 | |
982 | void uart_handle_dcd_change(struct uart_port *uport, bool active); |
983 | void uart_handle_cts_change(struct uart_port *uport, bool active); |
984 | |
985 | void uart_insert_char(struct uart_port *port, unsigned int status, |
986 | unsigned int overrun, u8 ch, u8 flag); |
987 | |
988 | void uart_xchar_out(struct uart_port *uport, int offset); |
989 | |
990 | #ifdef CONFIG_MAGIC_SYSRQ_SERIAL |
991 | #define SYSRQ_TIMEOUT (HZ * 5) |
992 | |
993 | bool uart_try_toggle_sysrq(struct uart_port *port, u8 ch); |
994 | |
995 | static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch) |
996 | { |
997 | if (!port->sysrq) |
998 | return 0; |
999 | |
1000 | if (ch && time_before(jiffies, port->sysrq)) { |
1001 | if (sysrq_mask()) { |
1002 | handle_sysrq(key: ch); |
1003 | port->sysrq = 0; |
1004 | return 1; |
1005 | } |
1006 | if (uart_try_toggle_sysrq(port, ch)) |
1007 | return 1; |
1008 | } |
1009 | port->sysrq = 0; |
1010 | |
1011 | return 0; |
1012 | } |
1013 | |
1014 | static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch) |
1015 | { |
1016 | if (!port->sysrq) |
1017 | return 0; |
1018 | |
1019 | if (ch && time_before(jiffies, port->sysrq)) { |
1020 | if (sysrq_mask()) { |
1021 | port->sysrq_ch = ch; |
1022 | port->sysrq = 0; |
1023 | return 1; |
1024 | } |
1025 | if (uart_try_toggle_sysrq(port, ch)) |
1026 | return 1; |
1027 | } |
1028 | port->sysrq = 0; |
1029 | |
1030 | return 0; |
1031 | } |
1032 | |
1033 | static inline void uart_unlock_and_check_sysrq(struct uart_port *port) |
1034 | { |
1035 | u8 sysrq_ch; |
1036 | |
1037 | if (!port->has_sysrq) { |
1038 | uart_port_unlock(up: port); |
1039 | return; |
1040 | } |
1041 | |
1042 | sysrq_ch = port->sysrq_ch; |
1043 | port->sysrq_ch = 0; |
1044 | |
1045 | uart_port_unlock(up: port); |
1046 | |
1047 | if (sysrq_ch) |
1048 | handle_sysrq(key: sysrq_ch); |
1049 | } |
1050 | |
1051 | static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, |
1052 | unsigned long flags) |
1053 | { |
1054 | u8 sysrq_ch; |
1055 | |
1056 | if (!port->has_sysrq) { |
1057 | uart_port_unlock_irqrestore(up: port, flags); |
1058 | return; |
1059 | } |
1060 | |
1061 | sysrq_ch = port->sysrq_ch; |
1062 | port->sysrq_ch = 0; |
1063 | |
1064 | uart_port_unlock_irqrestore(up: port, flags); |
1065 | |
1066 | if (sysrq_ch) |
1067 | handle_sysrq(key: sysrq_ch); |
1068 | } |
1069 | #else /* CONFIG_MAGIC_SYSRQ_SERIAL */ |
1070 | static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch) |
1071 | { |
1072 | return 0; |
1073 | } |
1074 | static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch) |
1075 | { |
1076 | return 0; |
1077 | } |
1078 | static inline void uart_unlock_and_check_sysrq(struct uart_port *port) |
1079 | { |
1080 | uart_port_unlock(port); |
1081 | } |
1082 | static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, |
1083 | unsigned long flags) |
1084 | { |
1085 | uart_port_unlock_irqrestore(port, flags); |
1086 | } |
1087 | #endif /* CONFIG_MAGIC_SYSRQ_SERIAL */ |
1088 | |
1089 | /* |
1090 | * We do the SysRQ and SAK checking like this... |
1091 | */ |
1092 | static inline int uart_handle_break(struct uart_port *port) |
1093 | { |
1094 | struct uart_state *state = port->state; |
1095 | |
1096 | if (port->handle_break) |
1097 | port->handle_break(port); |
1098 | |
1099 | #ifdef CONFIG_MAGIC_SYSRQ_SERIAL |
1100 | if (port->has_sysrq && uart_console(port)) { |
1101 | if (!port->sysrq) { |
1102 | port->sysrq = jiffies + SYSRQ_TIMEOUT; |
1103 | return 1; |
1104 | } |
1105 | port->sysrq = 0; |
1106 | } |
1107 | #endif |
1108 | if (port->flags & UPF_SAK) |
1109 | do_SAK(tty: state->port.tty); |
1110 | return 0; |
1111 | } |
1112 | |
1113 | /* |
1114 | * UART_ENABLE_MS - determine if port should enable modem status irqs |
1115 | */ |
1116 | #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \ |
1117 | (cflag) & CRTSCTS || \ |
1118 | !((cflag) & CLOCAL)) |
1119 | |
1120 | int uart_get_rs485_mode(struct uart_port *port); |
1121 | #endif /* LINUX_SERIAL_CORE_H */ |
1122 | |