xref: /linux-6.15/include/linux/serial_core.h (revision ecba1060)
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 /*
24  * The type definitions.  These are from Ted Ts'o's serial.h
25  */
26 #define PORT_UNKNOWN	0
27 #define PORT_8250	1
28 #define PORT_16450	2
29 #define PORT_16550	3
30 #define PORT_16550A	4
31 #define PORT_CIRRUS	5
32 #define PORT_16650	6
33 #define PORT_16650V2	7
34 #define PORT_16750	8
35 #define PORT_STARTECH	9
36 #define PORT_16C950	10
37 #define PORT_16654	11
38 #define PORT_16850	12
39 #define PORT_RSA	13
40 #define PORT_NS16550A	14
41 #define PORT_XSCALE	15
42 #define PORT_RM9000	16	/* PMC-Sierra RM9xxx internal UART */
43 #define PORT_OCTEON	17	/* Cavium OCTEON internal UART */
44 #define PORT_AR7	18	/* Texas Instruments AR7 internal UART */
45 #define PORT_MAX_8250	18	/* max port ID */
46 
47 /*
48  * ARM specific type numbers.  These are not currently guaranteed
49  * to be implemented, and will change in the future.  These are
50  * separate so any additions to the old serial.c that occur before
51  * we are merged can be easily merged here.
52  */
53 #define PORT_PXA	31
54 #define PORT_AMBA	32
55 #define PORT_CLPS711X	33
56 #define PORT_SA1100	34
57 #define PORT_UART00	35
58 #define PORT_21285	37
59 
60 /* Sparc type numbers.  */
61 #define PORT_SUNZILOG	38
62 #define PORT_SUNSAB	39
63 
64 /* DEC */
65 #define PORT_DZ		46
66 #define PORT_ZS		47
67 
68 /* Parisc type numbers. */
69 #define PORT_MUX	48
70 
71 /* Atmel AT91 / AT32 SoC */
72 #define PORT_ATMEL	49
73 
74 /* Macintosh Zilog type numbers */
75 #define PORT_MAC_ZILOG	50	/* m68k : not yet implemented */
76 #define PORT_PMAC_ZILOG	51
77 
78 /* SH-SCI */
79 #define PORT_SCI	52
80 #define PORT_SCIF	53
81 #define PORT_IRDA	54
82 
83 /* Samsung S3C2410 SoC and derivatives thereof */
84 #define PORT_S3C2410    55
85 
86 /* SGI IP22 aka Indy / Challenge S / Indigo 2 */
87 #define PORT_IP22ZILOG	56
88 
89 /* Sharp LH7a40x -- an ARM9 SoC series */
90 #define PORT_LH7A40X	57
91 
92 /* PPC CPM type number */
93 #define PORT_CPM        58
94 
95 /* MPC52xx type numbers */
96 #define PORT_MPC52xx	59
97 
98 /* IBM icom */
99 #define PORT_ICOM	60
100 
101 /* Samsung S3C2440 SoC */
102 #define PORT_S3C2440	61
103 
104 /* Motorola i.MX SoC */
105 #define PORT_IMX	62
106 
107 /* Marvell MPSC */
108 #define PORT_MPSC	63
109 
110 /* TXX9 type number */
111 #define PORT_TXX9	64
112 
113 /* NEC VR4100 series SIU/DSIU */
114 #define PORT_VR41XX_SIU		65
115 #define PORT_VR41XX_DSIU	66
116 
117 /* Samsung S3C2400 SoC */
118 #define PORT_S3C2400	67
119 
120 /* M32R SIO */
121 #define PORT_M32R_SIO	68
122 
123 /*Digi jsm */
124 #define PORT_JSM        69
125 
126 #define PORT_PNX8XXX	70
127 
128 /* Hilscher netx */
129 #define PORT_NETX	71
130 
131 /* SUN4V Hypervisor Console */
132 #define PORT_SUNHV	72
133 
134 #define PORT_S3C2412	73
135 
136 /* Xilinx uartlite */
137 #define PORT_UARTLITE	74
138 
139 /* Blackfin bf5xx */
140 #define PORT_BFIN	75
141 
142 /* Micrel KS8695 */
143 #define PORT_KS8695	76
144 
145 /* Broadcom SB1250, etc. SOC */
146 #define PORT_SB1250_DUART	77
147 
148 /* Freescale ColdFire */
149 #define PORT_MCF	78
150 
151 /* Blackfin SPORT */
152 #define PORT_BFIN_SPORT		79
153 
154 /* MN10300 on-chip UART numbers */
155 #define PORT_MN10300		80
156 #define PORT_MN10300_CTS	81
157 
158 #define PORT_SC26XX	82
159 
160 /* SH-SCI */
161 #define PORT_SCIFA	83
162 
163 #define PORT_S3C6400	84
164 
165 /* NWPSERIAL */
166 #define PORT_NWPSERIAL	85
167 
168 /* MAX3100 */
169 #define PORT_MAX3100    86
170 
171 /* Timberdale UART */
172 #define PORT_TIMBUART	87
173 
174 /* Qualcomm MSM SoCs */
175 #define PORT_MSM	88
176 
177 #ifdef __KERNEL__
178 
179 #include <linux/compiler.h>
180 #include <linux/interrupt.h>
181 #include <linux/circ_buf.h>
182 #include <linux/spinlock.h>
183 #include <linux/sched.h>
184 #include <linux/tty.h>
185 #include <linux/mutex.h>
186 #include <linux/sysrq.h>
187 
188 struct uart_port;
189 struct uart_info;
190 struct serial_struct;
191 struct device;
192 
193 /*
194  * This structure describes all the operations that can be
195  * done on the physical hardware.
196  */
197 struct uart_ops {
198 	unsigned int	(*tx_empty)(struct uart_port *);
199 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
200 	unsigned int	(*get_mctrl)(struct uart_port *);
201 	void		(*stop_tx)(struct uart_port *);
202 	void		(*start_tx)(struct uart_port *);
203 	void		(*send_xchar)(struct uart_port *, char ch);
204 	void		(*stop_rx)(struct uart_port *);
205 	void		(*enable_ms)(struct uart_port *);
206 	void		(*break_ctl)(struct uart_port *, int ctl);
207 	int		(*startup)(struct uart_port *);
208 	void		(*shutdown)(struct uart_port *);
209 	void		(*flush_buffer)(struct uart_port *);
210 	void		(*set_termios)(struct uart_port *, struct ktermios *new,
211 				       struct ktermios *old);
212 	void		(*set_ldisc)(struct uart_port *);
213 	void		(*pm)(struct uart_port *, unsigned int state,
214 			      unsigned int oldstate);
215 	int		(*set_wake)(struct uart_port *, unsigned int state);
216 
217 	/*
218 	 * Return a string describing the type of the port
219 	 */
220 	const char *(*type)(struct uart_port *);
221 
222 	/*
223 	 * Release IO and memory resources used by the port.
224 	 * This includes iounmap if necessary.
225 	 */
226 	void		(*release_port)(struct uart_port *);
227 
228 	/*
229 	 * Request IO and memory resources used by the port.
230 	 * This includes iomapping the port if necessary.
231 	 */
232 	int		(*request_port)(struct uart_port *);
233 	void		(*config_port)(struct uart_port *, int);
234 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
235 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
236 #ifdef CONFIG_CONSOLE_POLL
237 	void	(*poll_put_char)(struct uart_port *, unsigned char);
238 	int		(*poll_get_char)(struct uart_port *);
239 #endif
240 };
241 
242 #define UART_CONFIG_TYPE	(1 << 0)
243 #define UART_CONFIG_IRQ		(1 << 1)
244 
245 struct uart_icount {
246 	__u32	cts;
247 	__u32	dsr;
248 	__u32	rng;
249 	__u32	dcd;
250 	__u32	rx;
251 	__u32	tx;
252 	__u32	frame;
253 	__u32	overrun;
254 	__u32	parity;
255 	__u32	brk;
256 	__u32	buf_overrun;
257 };
258 
259 typedef unsigned int __bitwise__ upf_t;
260 
261 struct uart_port {
262 	spinlock_t		lock;			/* port lock */
263 	unsigned long		iobase;			/* in/out[bwl] */
264 	unsigned char __iomem	*membase;		/* read/write[bwl] */
265 	unsigned int		(*serial_in)(struct uart_port *, int);
266 	void			(*serial_out)(struct uart_port *, int, int);
267 	unsigned int		irq;			/* irq number */
268 	unsigned int		uartclk;		/* base uart clock */
269 	unsigned int		fifosize;		/* tx fifo size */
270 	unsigned char		x_char;			/* xon/xoff char */
271 	unsigned char		regshift;		/* reg offset shift */
272 	unsigned char		iotype;			/* io access style */
273 	unsigned char		unused1;
274 
275 #define UPIO_PORT		(0)
276 #define UPIO_HUB6		(1)
277 #define UPIO_MEM		(2)
278 #define UPIO_MEM32		(3)
279 #define UPIO_AU			(4)			/* Au1x00 type IO */
280 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
281 #define UPIO_DWAPB		(6)			/* DesignWare APB UART */
282 #define UPIO_RM9000		(7)			/* RM9000 type IO */
283 
284 	unsigned int		read_status_mask;	/* driver specific */
285 	unsigned int		ignore_status_mask;	/* driver specific */
286 	struct uart_info	*info;			/* pointer to parent info */
287 	struct uart_icount	icount;			/* statistics */
288 
289 	struct console		*cons;			/* struct console, if any */
290 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
291 	unsigned long		sysrq;			/* sysrq timeout */
292 #endif
293 
294 	upf_t			flags;
295 
296 #define UPF_FOURPORT		((__force upf_t) (1 << 1))
297 #define UPF_SAK			((__force upf_t) (1 << 2))
298 #define UPF_SPD_MASK		((__force upf_t) (0x1030))
299 #define UPF_SPD_HI		((__force upf_t) (0x0010))
300 #define UPF_SPD_VHI		((__force upf_t) (0x0020))
301 #define UPF_SPD_CUST		((__force upf_t) (0x0030))
302 #define UPF_SPD_SHI		((__force upf_t) (0x1000))
303 #define UPF_SPD_WARP		((__force upf_t) (0x1010))
304 #define UPF_SKIP_TEST		((__force upf_t) (1 << 6))
305 #define UPF_AUTO_IRQ		((__force upf_t) (1 << 7))
306 #define UPF_HARDPPS_CD		((__force upf_t) (1 << 11))
307 #define UPF_LOW_LATENCY		((__force upf_t) (1 << 13))
308 #define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
309 #define UPF_NO_TXEN_TEST	((__force upf_t) (1 << 15))
310 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
311 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
312 #define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
313 /* The exact UART type is known and should not be probed.  */
314 #define UPF_FIXED_TYPE		((__force upf_t) (1 << 27))
315 #define UPF_BOOT_AUTOCONF	((__force upf_t) (1 << 28))
316 #define UPF_FIXED_PORT		((__force upf_t) (1 << 29))
317 #define UPF_DEAD		((__force upf_t) (1 << 30))
318 #define UPF_IOREMAP		((__force upf_t) (1 << 31))
319 
320 #define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
321 #define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
322 
323 	unsigned int		mctrl;			/* current modem ctrl settings */
324 	unsigned int		timeout;		/* character-based timeout */
325 	unsigned int		type;			/* port type */
326 	const struct uart_ops	*ops;
327 	unsigned int		custom_divisor;
328 	unsigned int		line;			/* port index */
329 	resource_size_t		mapbase;		/* for ioremap */
330 	struct device		*dev;			/* parent device */
331 	unsigned char		hub6;			/* this should be in the 8250 driver */
332 	unsigned char		suspended;
333 	unsigned char		unused[2];
334 	void			*private_data;		/* generic platform data pointer */
335 };
336 
337 /*
338  * This is the state information which is only valid when the port
339  * is open; it may be cleared the core driver once the device has
340  * been closed.  Either the low level driver or the core can modify
341  * stuff here.
342  */
343 typedef unsigned int __bitwise__ uif_t;
344 
345 struct uart_info {
346 	struct tty_port		port;
347 	struct circ_buf		xmit;
348 	uif_t			flags;
349 
350 /*
351  * Definitions for info->flags.  These are _private_ to serial_core, and
352  * are specific to this structure.  They may be queried by low level drivers.
353  *
354  * FIXME: use the ASY_ definitions
355  */
356 #define UIF_CHECK_CD		((__force uif_t) (1 << 25))
357 #define UIF_CTS_FLOW		((__force uif_t) (1 << 26))
358 #define UIF_NORMAL_ACTIVE	((__force uif_t) (1 << 29))
359 #define UIF_INITIALIZED		((__force uif_t) (1 << 31))
360 #define UIF_SUSPENDED		((__force uif_t) (1 << 30))
361 
362 	struct tasklet_struct	tlet;
363 	wait_queue_head_t	delta_msr_wait;
364 };
365 
366 /*
367  * This is the state information which is persistent across opens.
368  * The low level driver must not to touch any elements contained
369  * within.
370  */
371 struct uart_state {
372 	unsigned int		close_delay;		/* msec */
373 	unsigned int		closing_wait;		/* msec */
374 
375 #define USF_CLOSING_WAIT_INF	(0)
376 #define USF_CLOSING_WAIT_NONE	(~0U)
377 
378 	int			count;
379 	int			pm_state;
380 	struct uart_info	info;
381 	struct uart_port	*port;
382 
383 	struct mutex		mutex;
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 /*
425  * Console helpers.
426  */
427 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
428 				   struct console *c);
429 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
430 			int *flow);
431 int uart_set_options(struct uart_port *port, struct console *co, int baud,
432 		     int parity, int bits, int flow);
433 struct tty_driver *uart_console_device(struct console *co, int *index);
434 void uart_console_write(struct uart_port *port, const char *s,
435 			unsigned int count,
436 			void (*putchar)(struct uart_port *, int));
437 
438 /*
439  * Port/driver registration/removal
440  */
441 int uart_register_driver(struct uart_driver *uart);
442 void uart_unregister_driver(struct uart_driver *uart);
443 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
444 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
445 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
446 
447 /*
448  * Power Management
449  */
450 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
451 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
452 
453 #define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
454 #define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)
455 
456 #define uart_circ_chars_pending(circ)	\
457 	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
458 
459 #define uart_circ_chars_free(circ)	\
460 	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
461 
462 static inline int uart_tx_stopped(struct uart_port *port)
463 {
464 	struct tty_struct *tty = port->info->port.tty;
465 	if(tty->stopped || tty->hw_stopped)
466 		return 1;
467 	return 0;
468 }
469 
470 /*
471  * The following are helper functions for the low level drivers.
472  */
473 static inline int
474 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
475 {
476 #ifdef SUPPORT_SYSRQ
477 	if (port->sysrq) {
478 		if (ch && time_before(jiffies, port->sysrq)) {
479 			handle_sysrq(ch, port->info->port.tty);
480 			port->sysrq = 0;
481 			return 1;
482 		}
483 		port->sysrq = 0;
484 	}
485 #endif
486 	return 0;
487 }
488 #ifndef SUPPORT_SYSRQ
489 #define uart_handle_sysrq_char(port,ch) uart_handle_sysrq_char(port, 0)
490 #endif
491 
492 /*
493  * We do the SysRQ and SAK checking like this...
494  */
495 static inline int uart_handle_break(struct uart_port *port)
496 {
497 	struct uart_info *info = port->info;
498 #ifdef SUPPORT_SYSRQ
499 	if (port->cons && port->cons->index == port->line) {
500 		if (!port->sysrq) {
501 			port->sysrq = jiffies + HZ*5;
502 			return 1;
503 		}
504 		port->sysrq = 0;
505 	}
506 #endif
507 	if (port->flags & UPF_SAK)
508 		do_SAK(info->port.tty);
509 	return 0;
510 }
511 
512 /**
513  *	uart_handle_dcd_change - handle a change of carrier detect state
514  *	@port: uart_port structure for the open port
515  *	@status: new carrier detect status, nonzero if active
516  */
517 static inline void
518 uart_handle_dcd_change(struct uart_port *port, unsigned int status)
519 {
520 	struct uart_info *info = port->info;
521 
522 	port->icount.dcd++;
523 
524 #ifdef CONFIG_HARD_PPS
525 	if ((port->flags & UPF_HARDPPS_CD) && status)
526 		hardpps();
527 #endif
528 
529 	if (info->flags & UIF_CHECK_CD) {
530 		if (status)
531 			wake_up_interruptible(&info->port.open_wait);
532 		else if (info->port.tty)
533 			tty_hangup(info->port.tty);
534 	}
535 }
536 
537 /**
538  *	uart_handle_cts_change - handle a change of clear-to-send state
539  *	@port: uart_port structure for the open port
540  *	@status: new clear to send status, nonzero if active
541  */
542 static inline void
543 uart_handle_cts_change(struct uart_port *port, unsigned int status)
544 {
545 	struct uart_info *info = port->info;
546 	struct tty_struct *tty = info->port.tty;
547 
548 	port->icount.cts++;
549 
550 	if (info->flags & UIF_CTS_FLOW) {
551 		if (tty->hw_stopped) {
552 			if (status) {
553 				tty->hw_stopped = 0;
554 				port->ops->start_tx(port);
555 				uart_write_wakeup(port);
556 			}
557 		} else {
558 			if (!status) {
559 				tty->hw_stopped = 1;
560 				port->ops->stop_tx(port);
561 			}
562 		}
563 	}
564 }
565 
566 #include <linux/tty_flip.h>
567 
568 static inline void
569 uart_insert_char(struct uart_port *port, unsigned int status,
570 		 unsigned int overrun, unsigned int ch, unsigned int flag)
571 {
572 	struct tty_struct *tty = port->info->port.tty;
573 
574 	if ((status & port->ignore_status_mask & ~overrun) == 0)
575 		tty_insert_flip_char(tty, ch, flag);
576 
577 	/*
578 	 * Overrun is special.  Since it's reported immediately,
579 	 * it doesn't affect the current character.
580 	 */
581 	if (status & ~port->ignore_status_mask & overrun)
582 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
583 }
584 
585 /*
586  *	UART_ENABLE_MS - determine if port should enable modem status irqs
587  */
588 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
589 					 (cflag) & CRTSCTS || \
590 					 !((cflag) & CLOCAL))
591 
592 #endif
593 
594 #endif /* LINUX_SERIAL_CORE_H */
595