xref: /linux-6.15/include/linux/serial_core.h (revision 2d6ffcca)
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_MAX_8250	16	/* max port ID */
44 
45 /*
46  * ARM specific type numbers.  These are not currently guaranteed
47  * to be implemented, and will change in the future.  These are
48  * separate so any additions to the old serial.c that occur before
49  * we are merged can be easily merged here.
50  */
51 #define PORT_PXA	31
52 #define PORT_AMBA	32
53 #define PORT_CLPS711X	33
54 #define PORT_SA1100	34
55 #define PORT_UART00	35
56 #define PORT_21285	37
57 
58 /* Sparc type numbers.  */
59 #define PORT_SUNZILOG	38
60 #define PORT_SUNSAB	39
61 
62 /* DEC */
63 #define PORT_DZ		46
64 #define PORT_ZS		47
65 
66 /* Parisc type numbers. */
67 #define PORT_MUX	48
68 
69 /* Atmel AT91 / AT32 SoC */
70 #define PORT_ATMEL	49
71 
72 /* Macintosh Zilog type numbers */
73 #define PORT_MAC_ZILOG	50	/* m68k : not yet implemented */
74 #define PORT_PMAC_ZILOG	51
75 
76 /* SH-SCI */
77 #define PORT_SCI	52
78 #define PORT_SCIF	53
79 #define PORT_IRDA	54
80 
81 /* Samsung S3C2410 SoC and derivatives thereof */
82 #define PORT_S3C2410    55
83 
84 /* SGI IP22 aka Indy / Challenge S / Indigo 2 */
85 #define PORT_IP22ZILOG	56
86 
87 /* Sharp LH7a40x -- an ARM9 SoC series */
88 #define PORT_LH7A40X	57
89 
90 /* PPC CPM type number */
91 #define PORT_CPM        58
92 
93 /* MPC52xx type numbers */
94 #define PORT_MPC52xx	59
95 
96 /* IBM icom */
97 #define PORT_ICOM	60
98 
99 /* Samsung S3C2440 SoC */
100 #define PORT_S3C2440	61
101 
102 /* Motorola i.MX SoC */
103 #define PORT_IMX	62
104 
105 /* Marvell MPSC */
106 #define PORT_MPSC	63
107 
108 /* TXX9 type number */
109 #define PORT_TXX9	64
110 
111 /* NEC VR4100 series SIU/DSIU */
112 #define PORT_VR41XX_SIU		65
113 #define PORT_VR41XX_DSIU	66
114 
115 /* Samsung S3C2400 SoC */
116 #define PORT_S3C2400	67
117 
118 /* M32R SIO */
119 #define PORT_M32R_SIO	68
120 
121 /*Digi jsm */
122 #define PORT_JSM        69
123 
124 #define PORT_PNX8XXX	70
125 
126 /* Hilscher netx */
127 #define PORT_NETX	71
128 
129 /* SUN4V Hypervisor Console */
130 #define PORT_SUNHV	72
131 
132 #define PORT_S3C2412	73
133 
134 /* Xilinx uartlite */
135 #define PORT_UARTLITE	74
136 
137 /* Blackfin bf5xx */
138 #define PORT_BFIN	75
139 
140 /* Micrel KS8695 */
141 #define PORT_KS8695	76
142 
143 /* Broadcom SB1250, etc. SOC */
144 #define PORT_SB1250_DUART	77
145 
146 /* Freescale ColdFire */
147 #define PORT_MCF	78
148 
149 /* Blackfin SPORT */
150 #define PORT_BFIN_SPORT		79
151 
152 /* MN10300 on-chip UART numbers */
153 #define PORT_MN10300		80
154 #define PORT_MN10300_CTS	81
155 
156 #define PORT_SC26XX	82
157 
158 #ifdef __KERNEL__
159 
160 #include <linux/compiler.h>
161 #include <linux/interrupt.h>
162 #include <linux/circ_buf.h>
163 #include <linux/spinlock.h>
164 #include <linux/sched.h>
165 #include <linux/tty.h>
166 #include <linux/mutex.h>
167 #include <linux/sysrq.h>
168 
169 struct uart_port;
170 struct uart_info;
171 struct serial_struct;
172 struct device;
173 
174 /*
175  * This structure describes all the operations that can be
176  * done on the physical hardware.
177  */
178 struct uart_ops {
179 	unsigned int	(*tx_empty)(struct uart_port *);
180 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
181 	unsigned int	(*get_mctrl)(struct uart_port *);
182 	void		(*stop_tx)(struct uart_port *);
183 	void		(*start_tx)(struct uart_port *);
184 	void		(*send_xchar)(struct uart_port *, char ch);
185 	void		(*stop_rx)(struct uart_port *);
186 	void		(*enable_ms)(struct uart_port *);
187 	void		(*break_ctl)(struct uart_port *, int ctl);
188 	int		(*startup)(struct uart_port *);
189 	void		(*shutdown)(struct uart_port *);
190 	void		(*flush_buffer)(struct uart_port *);
191 	void		(*set_termios)(struct uart_port *, struct ktermios *new,
192 				       struct ktermios *old);
193 	void		(*set_ldisc)(struct uart_port *);
194 	void		(*pm)(struct uart_port *, unsigned int state,
195 			      unsigned int oldstate);
196 	int		(*set_wake)(struct uart_port *, unsigned int state);
197 
198 	/*
199 	 * Return a string describing the type of the port
200 	 */
201 	const char *(*type)(struct uart_port *);
202 
203 	/*
204 	 * Release IO and memory resources used by the port.
205 	 * This includes iounmap if necessary.
206 	 */
207 	void		(*release_port)(struct uart_port *);
208 
209 	/*
210 	 * Request IO and memory resources used by the port.
211 	 * This includes iomapping the port if necessary.
212 	 */
213 	int		(*request_port)(struct uart_port *);
214 	void		(*config_port)(struct uart_port *, int);
215 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
216 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
217 #ifdef CONFIG_CONSOLE_POLL
218 	void	(*poll_put_char)(struct uart_port *, unsigned char);
219 	int		(*poll_get_char)(struct uart_port *);
220 #endif
221 };
222 
223 #define UART_CONFIG_TYPE	(1 << 0)
224 #define UART_CONFIG_IRQ		(1 << 1)
225 
226 struct uart_icount {
227 	__u32	cts;
228 	__u32	dsr;
229 	__u32	rng;
230 	__u32	dcd;
231 	__u32	rx;
232 	__u32	tx;
233 	__u32	frame;
234 	__u32	overrun;
235 	__u32	parity;
236 	__u32	brk;
237 	__u32	buf_overrun;
238 };
239 
240 typedef unsigned int __bitwise__ upf_t;
241 
242 struct uart_port {
243 	spinlock_t		lock;			/* port lock */
244 	unsigned int		iobase;			/* in/out[bwl] */
245 	unsigned char __iomem	*membase;		/* read/write[bwl] */
246 	unsigned int		irq;			/* irq number */
247 	unsigned int		uartclk;		/* base uart clock */
248 	unsigned int		fifosize;		/* tx fifo size */
249 	unsigned char		x_char;			/* xon/xoff char */
250 	unsigned char		regshift;		/* reg offset shift */
251 	unsigned char		iotype;			/* io access style */
252 	unsigned char		unused1;
253 
254 #define UPIO_PORT		(0)
255 #define UPIO_HUB6		(1)
256 #define UPIO_MEM		(2)
257 #define UPIO_MEM32		(3)
258 #define UPIO_AU			(4)			/* Au1x00 type IO */
259 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
260 #define UPIO_DWAPB		(6)			/* DesignWare APB UART */
261 #define UPIO_RM9000		(7)			/* RM9000 type IO */
262 
263 	unsigned int		read_status_mask;	/* driver specific */
264 	unsigned int		ignore_status_mask;	/* driver specific */
265 	struct uart_info	*info;			/* pointer to parent info */
266 	struct uart_icount	icount;			/* statistics */
267 
268 	struct console		*cons;			/* struct console, if any */
269 #ifdef CONFIG_SERIAL_CORE_CONSOLE
270 	unsigned long		sysrq;			/* sysrq timeout */
271 #endif
272 
273 	upf_t			flags;
274 
275 #define UPF_FOURPORT		((__force upf_t) (1 << 1))
276 #define UPF_SAK			((__force upf_t) (1 << 2))
277 #define UPF_SPD_MASK		((__force upf_t) (0x1030))
278 #define UPF_SPD_HI		((__force upf_t) (0x0010))
279 #define UPF_SPD_VHI		((__force upf_t) (0x0020))
280 #define UPF_SPD_CUST		((__force upf_t) (0x0030))
281 #define UPF_SPD_SHI		((__force upf_t) (0x1000))
282 #define UPF_SPD_WARP		((__force upf_t) (0x1010))
283 #define UPF_SKIP_TEST		((__force upf_t) (1 << 6))
284 #define UPF_AUTO_IRQ		((__force upf_t) (1 << 7))
285 #define UPF_HARDPPS_CD		((__force upf_t) (1 << 11))
286 #define UPF_LOW_LATENCY		((__force upf_t) (1 << 13))
287 #define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
288 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
289 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
290 #define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
291 #define UPF_BOOT_AUTOCONF	((__force upf_t) (1 << 28))
292 #define UPF_FIXED_PORT		((__force upf_t) (1 << 29))
293 #define UPF_DEAD		((__force upf_t) (1 << 30))
294 #define UPF_IOREMAP		((__force upf_t) (1 << 31))
295 
296 #define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
297 #define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
298 
299 	unsigned int		mctrl;			/* current modem ctrl settings */
300 	unsigned int		timeout;		/* character-based timeout */
301 	unsigned int		type;			/* port type */
302 	const struct uart_ops	*ops;
303 	unsigned int		custom_divisor;
304 	unsigned int		line;			/* port index */
305 	resource_size_t		mapbase;		/* for ioremap */
306 	struct device		*dev;			/* parent device */
307 	unsigned char		hub6;			/* this should be in the 8250 driver */
308 	unsigned char		suspended;
309 	unsigned char		unused[2];
310 	void			*private_data;		/* generic platform data pointer */
311 };
312 
313 /*
314  * This is the state information which is persistent across opens.
315  * The low level driver must not to touch any elements contained
316  * within.
317  */
318 struct uart_state {
319 	unsigned int		close_delay;		/* msec */
320 	unsigned int		closing_wait;		/* msec */
321 
322 #define USF_CLOSING_WAIT_INF	(0)
323 #define USF_CLOSING_WAIT_NONE	(~0U)
324 
325 	int			count;
326 	int			pm_state;
327 	struct uart_info	*info;
328 	struct uart_port	*port;
329 
330 	struct mutex		mutex;
331 };
332 
333 #define UART_XMIT_SIZE	PAGE_SIZE
334 
335 typedef unsigned int __bitwise__ uif_t;
336 
337 /*
338  * This is the state information which is only valid when the port
339  * is open; it may be freed by 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 struct uart_info {
344 	struct tty_port		port;
345 	struct circ_buf		xmit;
346 	uif_t			flags;
347 
348 /*
349  * Definitions for info->flags.  These are _private_ to serial_core, and
350  * are specific to this structure.  They may be queried by low level drivers.
351  *
352  * FIXME: use the ASY_ definitions
353  */
354 #define UIF_CHECK_CD		((__force uif_t) (1 << 25))
355 #define UIF_CTS_FLOW		((__force uif_t) (1 << 26))
356 #define UIF_NORMAL_ACTIVE	((__force uif_t) (1 << 29))
357 #define UIF_INITIALIZED		((__force uif_t) (1 << 31))
358 #define UIF_SUSPENDED		((__force uif_t) (1 << 30))
359 
360 	struct tasklet_struct	tlet;
361 	wait_queue_head_t	delta_msr_wait;
362 };
363 
364 /* number of characters left in xmit buffer before we ask for more */
365 #define WAKEUP_CHARS		256
366 
367 struct module;
368 struct tty_driver;
369 
370 struct uart_driver {
371 	struct module		*owner;
372 	const char		*driver_name;
373 	const char		*dev_name;
374 	int			 major;
375 	int			 minor;
376 	int			 nr;
377 	struct console		*cons;
378 
379 	/*
380 	 * these are private; the low level driver should not
381 	 * touch these; they should be initialised to NULL
382 	 */
383 	struct uart_state	*state;
384 	struct tty_driver	*tty_driver;
385 };
386 
387 void uart_write_wakeup(struct uart_port *port);
388 
389 /*
390  * Baud rate helpers.
391  */
392 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
393 			 unsigned int baud);
394 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
395 				struct ktermios *old, unsigned int min,
396 				unsigned int max);
397 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
398 
399 /*
400  * Console helpers.
401  */
402 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
403 				   struct console *c);
404 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
405 			int *flow);
406 int uart_set_options(struct uart_port *port, struct console *co, int baud,
407 		     int parity, int bits, int flow);
408 struct tty_driver *uart_console_device(struct console *co, int *index);
409 void uart_console_write(struct uart_port *port, const char *s,
410 			unsigned int count,
411 			void (*putchar)(struct uart_port *, int));
412 
413 /*
414  * Port/driver registration/removal
415  */
416 int uart_register_driver(struct uart_driver *uart);
417 void uart_unregister_driver(struct uart_driver *uart);
418 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
419 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
420 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
421 
422 /*
423  * Power Management
424  */
425 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
426 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
427 
428 #define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
429 #define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)
430 
431 #define uart_circ_chars_pending(circ)	\
432 	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
433 
434 #define uart_circ_chars_free(circ)	\
435 	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
436 
437 #define uart_tx_stopped(portp)		\
438 	((portp)->info->port.tty->stopped || (portp)->info->port.tty->hw_stopped)
439 
440 /*
441  * The following are helper functions for the low level drivers.
442  */
443 static inline int
444 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
445 {
446 #ifdef SUPPORT_SYSRQ
447 	if (port->sysrq) {
448 		if (ch && time_before(jiffies, port->sysrq)) {
449 			handle_sysrq(ch, port->info ? port->info->port.tty : NULL);
450 			port->sysrq = 0;
451 			return 1;
452 		}
453 		port->sysrq = 0;
454 	}
455 #endif
456 	return 0;
457 }
458 #ifndef SUPPORT_SYSRQ
459 #define uart_handle_sysrq_char(port,ch) uart_handle_sysrq_char(port, 0)
460 #endif
461 
462 /*
463  * We do the SysRQ and SAK checking like this...
464  */
465 static inline int uart_handle_break(struct uart_port *port)
466 {
467 	struct uart_info *info = port->info;
468 #ifdef SUPPORT_SYSRQ
469 	if (port->cons && port->cons->index == port->line) {
470 		if (!port->sysrq) {
471 			port->sysrq = jiffies + HZ*5;
472 			return 1;
473 		}
474 		port->sysrq = 0;
475 	}
476 #endif
477 	if (port->flags & UPF_SAK)
478 		do_SAK(info->port.tty);
479 	return 0;
480 }
481 
482 /**
483  *	uart_handle_dcd_change - handle a change of carrier detect state
484  *	@port: uart_port structure for the open port
485  *	@status: new carrier detect status, nonzero if active
486  */
487 static inline void
488 uart_handle_dcd_change(struct uart_port *port, unsigned int status)
489 {
490 	struct uart_info *info = port->info;
491 
492 	port->icount.dcd++;
493 
494 #ifdef CONFIG_HARD_PPS
495 	if ((port->flags & UPF_HARDPPS_CD) && status)
496 		hardpps();
497 #endif
498 
499 	if (info->flags & UIF_CHECK_CD) {
500 		if (status)
501 			wake_up_interruptible(&info->port.open_wait);
502 		else if (info->port.tty)
503 			tty_hangup(info->port.tty);
504 	}
505 }
506 
507 /**
508  *	uart_handle_cts_change - handle a change of clear-to-send state
509  *	@port: uart_port structure for the open port
510  *	@status: new clear to send status, nonzero if active
511  */
512 static inline void
513 uart_handle_cts_change(struct uart_port *port, unsigned int status)
514 {
515 	struct uart_info *info = port->info;
516 	struct tty_struct *tty = info->port.tty;
517 
518 	port->icount.cts++;
519 
520 	if (info->flags & UIF_CTS_FLOW) {
521 		if (tty->hw_stopped) {
522 			if (status) {
523 				tty->hw_stopped = 0;
524 				port->ops->start_tx(port);
525 				uart_write_wakeup(port);
526 			}
527 		} else {
528 			if (!status) {
529 				tty->hw_stopped = 1;
530 				port->ops->stop_tx(port);
531 			}
532 		}
533 	}
534 }
535 
536 #include <linux/tty_flip.h>
537 
538 static inline void
539 uart_insert_char(struct uart_port *port, unsigned int status,
540 		 unsigned int overrun, unsigned int ch, unsigned int flag)
541 {
542 	struct tty_struct *tty = port->info->port.tty;
543 
544 	if ((status & port->ignore_status_mask & ~overrun) == 0)
545 		tty_insert_flip_char(tty, ch, flag);
546 
547 	/*
548 	 * Overrun is special.  Since it's reported immediately,
549 	 * it doesn't affect the current character.
550 	 */
551 	if (status & ~port->ignore_status_mask & overrun)
552 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
553 }
554 
555 /*
556  *	UART_ENABLE_MS - determine if port should enable modem status irqs
557  */
558 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
559 					 (cflag) & CRTSCTS || \
560 					 !((cflag) & CLOCAL))
561 
562 #endif
563 
564 #endif /* LINUX_SERIAL_CORE_H */
565