xref: /linux-6.15/include/linux/serial_core.h (revision facb4edc)
1 /*
2  *  linux/drivers/char/serial_core.h
3  *
4  *  Copyright (C) 2000 Deep Blue Solutions Ltd.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20 #ifndef LINUX_SERIAL_CORE_H
21 #define LINUX_SERIAL_CORE_H
22 
23 #include <linux/serial.h>
24 
25 /*
26  * The type definitions.  These are from Ted Ts'o's serial.h
27  */
28 #define PORT_UNKNOWN	0
29 #define PORT_8250	1
30 #define PORT_16450	2
31 #define PORT_16550	3
32 #define PORT_16550A	4
33 #define PORT_CIRRUS	5
34 #define PORT_16650	6
35 #define PORT_16650V2	7
36 #define PORT_16750	8
37 #define PORT_STARTECH	9
38 #define PORT_16C950	10
39 #define PORT_16654	11
40 #define PORT_16850	12
41 #define PORT_RSA	13
42 #define PORT_NS16550A	14
43 #define PORT_XSCALE	15
44 #define PORT_RM9000	16	/* PMC-Sierra RM9xxx internal UART */
45 #define PORT_OCTEON	17	/* Cavium OCTEON internal UART */
46 #define PORT_AR7	18	/* Texas Instruments AR7 internal UART */
47 #define PORT_U6_16550A	19	/* ST-Ericsson U6xxx internal UART */
48 #define PORT_MAX_8250	19	/* max port ID */
49 
50 /*
51  * ARM specific type numbers.  These are not currently guaranteed
52  * to be implemented, and will change in the future.  These are
53  * separate so any additions to the old serial.c that occur before
54  * we are merged can be easily merged here.
55  */
56 #define PORT_PXA	31
57 #define PORT_AMBA	32
58 #define PORT_CLPS711X	33
59 #define PORT_SA1100	34
60 #define PORT_UART00	35
61 #define PORT_21285	37
62 
63 /* Sparc type numbers.  */
64 #define PORT_SUNZILOG	38
65 #define PORT_SUNSAB	39
66 
67 /* DEC */
68 #define PORT_DZ		46
69 #define PORT_ZS		47
70 
71 /* Parisc type numbers. */
72 #define PORT_MUX	48
73 
74 /* Atmel AT91 / AT32 SoC */
75 #define PORT_ATMEL	49
76 
77 /* Macintosh Zilog type numbers */
78 #define PORT_MAC_ZILOG	50	/* m68k : not yet implemented */
79 #define PORT_PMAC_ZILOG	51
80 
81 /* SH-SCI */
82 #define PORT_SCI	52
83 #define PORT_SCIF	53
84 #define PORT_IRDA	54
85 
86 /* Samsung S3C2410 SoC and derivatives thereof */
87 #define PORT_S3C2410    55
88 
89 /* SGI IP22 aka Indy / Challenge S / Indigo 2 */
90 #define PORT_IP22ZILOG	56
91 
92 /* Sharp LH7a40x -- an ARM9 SoC series */
93 #define PORT_LH7A40X	57
94 
95 /* PPC CPM type number */
96 #define PORT_CPM        58
97 
98 /* MPC52xx (and MPC512x) type numbers */
99 #define PORT_MPC52xx	59
100 
101 /* IBM icom */
102 #define PORT_ICOM	60
103 
104 /* Samsung S3C2440 SoC */
105 #define PORT_S3C2440	61
106 
107 /* Motorola i.MX SoC */
108 #define PORT_IMX	62
109 
110 /* Marvell MPSC */
111 #define PORT_MPSC	63
112 
113 /* TXX9 type number */
114 #define PORT_TXX9	64
115 
116 /* NEC VR4100 series SIU/DSIU */
117 #define PORT_VR41XX_SIU		65
118 #define PORT_VR41XX_DSIU	66
119 
120 /* Samsung S3C2400 SoC */
121 #define PORT_S3C2400	67
122 
123 /* M32R SIO */
124 #define PORT_M32R_SIO	68
125 
126 /*Digi jsm */
127 #define PORT_JSM        69
128 
129 #define PORT_PNX8XXX	70
130 
131 /* Hilscher netx */
132 #define PORT_NETX	71
133 
134 /* SUN4V Hypervisor Console */
135 #define PORT_SUNHV	72
136 
137 #define PORT_S3C2412	73
138 
139 /* Xilinx uartlite */
140 #define PORT_UARTLITE	74
141 
142 /* Blackfin bf5xx */
143 #define PORT_BFIN	75
144 
145 /* Micrel KS8695 */
146 #define PORT_KS8695	76
147 
148 /* Broadcom SB1250, etc. SOC */
149 #define PORT_SB1250_DUART	77
150 
151 /* Freescale ColdFire */
152 #define PORT_MCF	78
153 
154 /* Blackfin SPORT */
155 #define PORT_BFIN_SPORT		79
156 
157 /* MN10300 on-chip UART numbers */
158 #define PORT_MN10300		80
159 #define PORT_MN10300_CTS	81
160 
161 #define PORT_SC26XX	82
162 
163 /* SH-SCI */
164 #define PORT_SCIFA	83
165 
166 #define PORT_S3C6400	84
167 
168 /* NWPSERIAL */
169 #define PORT_NWPSERIAL	85
170 
171 /* MAX3100 */
172 #define PORT_MAX3100    86
173 
174 /* Timberdale UART */
175 #define PORT_TIMBUART	87
176 
177 /* Qualcomm MSM SoCs */
178 #define PORT_MSM	88
179 
180 /* BCM63xx family SoCs */
181 #define PORT_BCM63XX	89
182 
183 /* Aeroflex Gaisler GRLIB APBUART */
184 #define PORT_APBUART    90
185 
186 /* Altera UARTs */
187 #define PORT_ALTERA_JTAGUART	91
188 #define PORT_ALTERA_UART	92
189 
190 /* SH-SCI */
191 #define PORT_SCIFB	93
192 
193 /* MAX3107 */
194 #define PORT_MAX3107	94
195 
196 /* High Speed UART for Medfield */
197 #define PORT_MFD	95
198 
199 /* TI OMAP-UART */
200 #define PORT_OMAP	96
201 
202 /* VIA VT8500 SoC */
203 #define PORT_VT8500	97
204 
205 #ifdef __KERNEL__
206 
207 #include <linux/compiler.h>
208 #include <linux/interrupt.h>
209 #include <linux/circ_buf.h>
210 #include <linux/spinlock.h>
211 #include <linux/sched.h>
212 #include <linux/tty.h>
213 #include <linux/mutex.h>
214 #include <linux/sysrq.h>
215 
216 struct uart_port;
217 struct serial_struct;
218 struct device;
219 
220 /*
221  * This structure describes all the operations that can be
222  * done on the physical hardware.
223  */
224 struct uart_ops {
225 	unsigned int	(*tx_empty)(struct uart_port *);
226 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
227 	unsigned int	(*get_mctrl)(struct uart_port *);
228 	void		(*stop_tx)(struct uart_port *);
229 	void		(*start_tx)(struct uart_port *);
230 	void		(*send_xchar)(struct uart_port *, char ch);
231 	void		(*stop_rx)(struct uart_port *);
232 	void		(*enable_ms)(struct uart_port *);
233 	void		(*break_ctl)(struct uart_port *, int ctl);
234 	int		(*startup)(struct uart_port *);
235 	void		(*shutdown)(struct uart_port *);
236 	void		(*flush_buffer)(struct uart_port *);
237 	void		(*set_termios)(struct uart_port *, struct ktermios *new,
238 				       struct ktermios *old);
239 	void		(*set_ldisc)(struct uart_port *, int new);
240 	void		(*pm)(struct uart_port *, unsigned int state,
241 			      unsigned int oldstate);
242 	int		(*set_wake)(struct uart_port *, unsigned int state);
243 
244 	/*
245 	 * Return a string describing the type of the port
246 	 */
247 	const char *(*type)(struct uart_port *);
248 
249 	/*
250 	 * Release IO and memory resources used by the port.
251 	 * This includes iounmap if necessary.
252 	 */
253 	void		(*release_port)(struct uart_port *);
254 
255 	/*
256 	 * Request IO and memory resources used by the port.
257 	 * This includes iomapping the port if necessary.
258 	 */
259 	int		(*request_port)(struct uart_port *);
260 	void		(*config_port)(struct uart_port *, int);
261 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
262 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
263 #ifdef CONFIG_CONSOLE_POLL
264 	void	(*poll_put_char)(struct uart_port *, unsigned char);
265 	int		(*poll_get_char)(struct uart_port *);
266 #endif
267 };
268 
269 #define NO_POLL_CHAR		0x00ff0000
270 #define UART_CONFIG_TYPE	(1 << 0)
271 #define UART_CONFIG_IRQ		(1 << 1)
272 
273 struct uart_icount {
274 	__u32	cts;
275 	__u32	dsr;
276 	__u32	rng;
277 	__u32	dcd;
278 	__u32	rx;
279 	__u32	tx;
280 	__u32	frame;
281 	__u32	overrun;
282 	__u32	parity;
283 	__u32	brk;
284 	__u32	buf_overrun;
285 };
286 
287 typedef unsigned int __bitwise__ upf_t;
288 
289 struct uart_port {
290 	spinlock_t		lock;			/* port lock */
291 	unsigned long		iobase;			/* in/out[bwl] */
292 	unsigned char __iomem	*membase;		/* read/write[bwl] */
293 	unsigned int		(*serial_in)(struct uart_port *, int);
294 	void			(*serial_out)(struct uart_port *, int, int);
295 	void			(*set_termios)(struct uart_port *,
296 				               struct ktermios *new,
297 				               struct ktermios *old);
298 	void			(*pm)(struct uart_port *, unsigned int state,
299 				      unsigned int old);
300 	unsigned int		irq;			/* irq number */
301 	unsigned long		irqflags;		/* irq flags  */
302 	unsigned int		uartclk;		/* base uart clock */
303 	unsigned int		fifosize;		/* tx fifo size */
304 	unsigned char		x_char;			/* xon/xoff char */
305 	unsigned char		regshift;		/* reg offset shift */
306 	unsigned char		iotype;			/* io access style */
307 	unsigned char		unused1;
308 
309 #define UPIO_PORT		(0)
310 #define UPIO_HUB6		(1)
311 #define UPIO_MEM		(2)
312 #define UPIO_MEM32		(3)
313 #define UPIO_AU			(4)			/* Au1x00 type IO */
314 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
315 #define UPIO_DWAPB		(6)			/* DesignWare APB UART */
316 #define UPIO_RM9000		(7)			/* RM9000 type IO */
317 #define UPIO_DWAPB32		(8)			/* DesignWare APB UART (32 bit accesses) */
318 
319 	unsigned int		read_status_mask;	/* driver specific */
320 	unsigned int		ignore_status_mask;	/* driver specific */
321 	struct uart_state	*state;			/* pointer to parent state */
322 	struct uart_icount	icount;			/* statistics */
323 
324 	struct console		*cons;			/* struct console, if any */
325 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
326 	unsigned long		sysrq;			/* sysrq timeout */
327 #endif
328 
329 	upf_t			flags;
330 
331 #define UPF_FOURPORT		((__force upf_t) (1 << 1))
332 #define UPF_SAK			((__force upf_t) (1 << 2))
333 #define UPF_SPD_MASK		((__force upf_t) (0x1030))
334 #define UPF_SPD_HI		((__force upf_t) (0x0010))
335 #define UPF_SPD_VHI		((__force upf_t) (0x0020))
336 #define UPF_SPD_CUST		((__force upf_t) (0x0030))
337 #define UPF_SPD_SHI		((__force upf_t) (0x1000))
338 #define UPF_SPD_WARP		((__force upf_t) (0x1010))
339 #define UPF_SKIP_TEST		((__force upf_t) (1 << 6))
340 #define UPF_AUTO_IRQ		((__force upf_t) (1 << 7))
341 #define UPF_HARDPPS_CD		((__force upf_t) (1 << 11))
342 #define UPF_LOW_LATENCY		((__force upf_t) (1 << 13))
343 #define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
344 #define UPF_NO_TXEN_TEST	((__force upf_t) (1 << 15))
345 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
346 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
347 #define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
348 /* The exact UART type is known and should not be probed.  */
349 #define UPF_FIXED_TYPE		((__force upf_t) (1 << 27))
350 #define UPF_BOOT_AUTOCONF	((__force upf_t) (1 << 28))
351 #define UPF_FIXED_PORT		((__force upf_t) (1 << 29))
352 #define UPF_DEAD		((__force upf_t) (1 << 30))
353 #define UPF_IOREMAP		((__force upf_t) (1 << 31))
354 
355 #define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
356 #define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
357 
358 	unsigned int		mctrl;			/* current modem ctrl settings */
359 	unsigned int		timeout;		/* character-based timeout */
360 	unsigned int		type;			/* port type */
361 	const struct uart_ops	*ops;
362 	unsigned int		custom_divisor;
363 	unsigned int		line;			/* port index */
364 	resource_size_t		mapbase;		/* for ioremap */
365 	struct device		*dev;			/* parent device */
366 	unsigned char		hub6;			/* this should be in the 8250 driver */
367 	unsigned char		suspended;
368 	unsigned char		irq_wake;
369 	unsigned char		unused[2];
370 	void			*private_data;		/* generic platform data pointer */
371 };
372 
373 /*
374  * This is the state information which is persistent across opens.
375  */
376 struct uart_state {
377 	struct tty_port		port;
378 
379 	int			pm_state;
380 	struct circ_buf		xmit;
381 
382 	struct tasklet_struct	tlet;
383 	struct uart_port	*uart_port;
384 };
385 
386 #define UART_XMIT_SIZE	PAGE_SIZE
387 
388 
389 /* number of characters left in xmit buffer before we ask for more */
390 #define WAKEUP_CHARS		256
391 
392 struct module;
393 struct tty_driver;
394 
395 struct uart_driver {
396 	struct module		*owner;
397 	const char		*driver_name;
398 	const char		*dev_name;
399 	int			 major;
400 	int			 minor;
401 	int			 nr;
402 	struct console		*cons;
403 
404 	/*
405 	 * these are private; the low level driver should not
406 	 * touch these; they should be initialised to NULL
407 	 */
408 	struct uart_state	*state;
409 	struct tty_driver	*tty_driver;
410 };
411 
412 void uart_write_wakeup(struct uart_port *port);
413 
414 /*
415  * Baud rate helpers.
416  */
417 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
418 			 unsigned int baud);
419 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
420 				struct ktermios *old, unsigned int min,
421 				unsigned int max);
422 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
423 
424 /* Base timer interval for polling */
425 static inline int uart_poll_timeout(struct uart_port *port)
426 {
427 	int timeout = port->timeout;
428 
429 	return timeout > 6 ? (timeout / 2 - 2) : 1;
430 }
431 
432 /*
433  * Console helpers.
434  */
435 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
436 				   struct console *c);
437 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
438 			int *flow);
439 int uart_set_options(struct uart_port *port, struct console *co, int baud,
440 		     int parity, int bits, int flow);
441 struct tty_driver *uart_console_device(struct console *co, int *index);
442 void uart_console_write(struct uart_port *port, const char *s,
443 			unsigned int count,
444 			void (*putchar)(struct uart_port *, int));
445 
446 /*
447  * Port/driver registration/removal
448  */
449 int uart_register_driver(struct uart_driver *uart);
450 void uart_unregister_driver(struct uart_driver *uart);
451 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
452 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
453 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
454 
455 /*
456  * Power Management
457  */
458 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
459 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
460 
461 #define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
462 #define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)
463 
464 #define uart_circ_chars_pending(circ)	\
465 	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
466 
467 #define uart_circ_chars_free(circ)	\
468 	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
469 
470 static inline int uart_tx_stopped(struct uart_port *port)
471 {
472 	struct tty_struct *tty = port->state->port.tty;
473 	if(tty->stopped || tty->hw_stopped)
474 		return 1;
475 	return 0;
476 }
477 
478 /*
479  * The following are helper functions for the low level drivers.
480  */
481 static inline int
482 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
483 {
484 #ifdef SUPPORT_SYSRQ
485 	if (port->sysrq) {
486 		if (ch && time_before(jiffies, port->sysrq)) {
487 			handle_sysrq(ch);
488 			port->sysrq = 0;
489 			return 1;
490 		}
491 		port->sysrq = 0;
492 	}
493 #endif
494 	return 0;
495 }
496 #ifndef SUPPORT_SYSRQ
497 #define uart_handle_sysrq_char(port,ch) uart_handle_sysrq_char(port, 0)
498 #endif
499 
500 /*
501  * We do the SysRQ and SAK checking like this...
502  */
503 static inline int uart_handle_break(struct uart_port *port)
504 {
505 	struct uart_state *state = port->state;
506 #ifdef SUPPORT_SYSRQ
507 	if (port->cons && port->cons->index == port->line) {
508 		if (!port->sysrq) {
509 			port->sysrq = jiffies + HZ*5;
510 			return 1;
511 		}
512 		port->sysrq = 0;
513 	}
514 #endif
515 	if (port->flags & UPF_SAK)
516 		do_SAK(state->port.tty);
517 	return 0;
518 }
519 
520 /**
521  *	uart_handle_dcd_change - handle a change of carrier detect state
522  *	@uport: uart_port structure for the open port
523  *	@status: new carrier detect status, nonzero if active
524  */
525 static inline void
526 uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
527 {
528 	struct uart_state *state = uport->state;
529 	struct tty_port *port = &state->port;
530 	struct tty_ldisc *ld = tty_ldisc_ref(port->tty);
531 	struct timespec ts;
532 
533 	if (ld && ld->ops->dcd_change)
534 		getnstimeofday(&ts);
535 
536 	uport->icount.dcd++;
537 #ifdef CONFIG_HARD_PPS
538 	if ((uport->flags & UPF_HARDPPS_CD) && status)
539 		hardpps();
540 #endif
541 
542 	if (port->flags & ASYNC_CHECK_CD) {
543 		if (status)
544 			wake_up_interruptible(&port->open_wait);
545 		else if (port->tty)
546 			tty_hangup(port->tty);
547 	}
548 
549 	if (ld && ld->ops->dcd_change)
550 		ld->ops->dcd_change(port->tty, status, &ts);
551 	if (ld)
552 		tty_ldisc_deref(ld);
553 }
554 
555 /**
556  *	uart_handle_cts_change - handle a change of clear-to-send state
557  *	@uport: uart_port structure for the open port
558  *	@status: new clear to send status, nonzero if active
559  */
560 static inline void
561 uart_handle_cts_change(struct uart_port *uport, unsigned int status)
562 {
563 	struct tty_port *port = &uport->state->port;
564 	struct tty_struct *tty = port->tty;
565 
566 	uport->icount.cts++;
567 
568 	if (port->flags & ASYNC_CTS_FLOW) {
569 		if (tty->hw_stopped) {
570 			if (status) {
571 				tty->hw_stopped = 0;
572 				uport->ops->start_tx(uport);
573 				uart_write_wakeup(uport);
574 			}
575 		} else {
576 			if (!status) {
577 				tty->hw_stopped = 1;
578 				uport->ops->stop_tx(uport);
579 			}
580 		}
581 	}
582 }
583 
584 #include <linux/tty_flip.h>
585 
586 static inline void
587 uart_insert_char(struct uart_port *port, unsigned int status,
588 		 unsigned int overrun, unsigned int ch, unsigned int flag)
589 {
590 	struct tty_struct *tty = port->state->port.tty;
591 
592 	if ((status & port->ignore_status_mask & ~overrun) == 0)
593 		tty_insert_flip_char(tty, ch, flag);
594 
595 	/*
596 	 * Overrun is special.  Since it's reported immediately,
597 	 * it doesn't affect the current character.
598 	 */
599 	if (status & ~port->ignore_status_mask & overrun)
600 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
601 }
602 
603 /*
604  *	UART_ENABLE_MS - determine if port should enable modem status irqs
605  */
606 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
607 					 (cflag) & CRTSCTS || \
608 					 !((cflag) & CLOCAL))
609 
610 #endif
611 
612 #endif /* LINUX_SERIAL_CORE_H */
613