xref: /linux-6.15/include/linux/serial_core.h (revision a8b0ca17)
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_TEGRA	20	/* NVIDIA Tegra internal UART */
49 #define PORT_MAX_8250	20	/* max port ID */
50 
51 /*
52  * ARM specific type numbers.  These are not currently guaranteed
53  * to be implemented, and will change in the future.  These are
54  * separate so any additions to the old serial.c that occur before
55  * we are merged can be easily merged here.
56  */
57 #define PORT_PXA	31
58 #define PORT_AMBA	32
59 #define PORT_CLPS711X	33
60 #define PORT_SA1100	34
61 #define PORT_UART00	35
62 #define PORT_21285	37
63 
64 /* Sparc type numbers.  */
65 #define PORT_SUNZILOG	38
66 #define PORT_SUNSAB	39
67 
68 /* DEC */
69 #define PORT_DZ		46
70 #define PORT_ZS		47
71 
72 /* Parisc type numbers. */
73 #define PORT_MUX	48
74 
75 /* Atmel AT91 / AT32 SoC */
76 #define PORT_ATMEL	49
77 
78 /* Macintosh Zilog type numbers */
79 #define PORT_MAC_ZILOG	50	/* m68k : not yet implemented */
80 #define PORT_PMAC_ZILOG	51
81 
82 /* SH-SCI */
83 #define PORT_SCI	52
84 #define PORT_SCIF	53
85 #define PORT_IRDA	54
86 
87 /* Samsung S3C2410 SoC and derivatives thereof */
88 #define PORT_S3C2410    55
89 
90 /* SGI IP22 aka Indy / Challenge S / Indigo 2 */
91 #define PORT_IP22ZILOG	56
92 
93 /* Sharp LH7a40x -- an ARM9 SoC series */
94 #define PORT_LH7A40X	57
95 
96 /* PPC CPM type number */
97 #define PORT_CPM        58
98 
99 /* MPC52xx (and MPC512x) type numbers */
100 #define PORT_MPC52xx	59
101 
102 /* IBM icom */
103 #define PORT_ICOM	60
104 
105 /* Samsung S3C2440 SoC */
106 #define PORT_S3C2440	61
107 
108 /* Motorola i.MX SoC */
109 #define PORT_IMX	62
110 
111 /* Marvell MPSC */
112 #define PORT_MPSC	63
113 
114 /* TXX9 type number */
115 #define PORT_TXX9	64
116 
117 /* NEC VR4100 series SIU/DSIU */
118 #define PORT_VR41XX_SIU		65
119 #define PORT_VR41XX_DSIU	66
120 
121 /* Samsung S3C2400 SoC */
122 #define PORT_S3C2400	67
123 
124 /* M32R SIO */
125 #define PORT_M32R_SIO	68
126 
127 /*Digi jsm */
128 #define PORT_JSM        69
129 
130 #define PORT_PNX8XXX	70
131 
132 /* Hilscher netx */
133 #define PORT_NETX	71
134 
135 /* SUN4V Hypervisor Console */
136 #define PORT_SUNHV	72
137 
138 #define PORT_S3C2412	73
139 
140 /* Xilinx uartlite */
141 #define PORT_UARTLITE	74
142 
143 /* Blackfin bf5xx */
144 #define PORT_BFIN	75
145 
146 /* Micrel KS8695 */
147 #define PORT_KS8695	76
148 
149 /* Broadcom SB1250, etc. SOC */
150 #define PORT_SB1250_DUART	77
151 
152 /* Freescale ColdFire */
153 #define PORT_MCF	78
154 
155 /* Blackfin SPORT */
156 #define PORT_BFIN_SPORT		79
157 
158 /* MN10300 on-chip UART numbers */
159 #define PORT_MN10300		80
160 #define PORT_MN10300_CTS	81
161 
162 #define PORT_SC26XX	82
163 
164 /* SH-SCI */
165 #define PORT_SCIFA	83
166 
167 #define PORT_S3C6400	84
168 
169 /* NWPSERIAL */
170 #define PORT_NWPSERIAL	85
171 
172 /* MAX3100 */
173 #define PORT_MAX3100    86
174 
175 /* Timberdale UART */
176 #define PORT_TIMBUART	87
177 
178 /* Qualcomm MSM SoCs */
179 #define PORT_MSM	88
180 
181 /* BCM63xx family SoCs */
182 #define PORT_BCM63XX	89
183 
184 /* Aeroflex Gaisler GRLIB APBUART */
185 #define PORT_APBUART    90
186 
187 /* Altera UARTs */
188 #define PORT_ALTERA_JTAGUART	91
189 #define PORT_ALTERA_UART	92
190 
191 /* SH-SCI */
192 #define PORT_SCIFB	93
193 
194 /* MAX3107 */
195 #define PORT_MAX3107	94
196 
197 /* High Speed UART for Medfield */
198 #define PORT_MFD	95
199 
200 /* TI OMAP-UART */
201 #define PORT_OMAP	96
202 
203 /* VIA VT8500 SoC */
204 #define PORT_VT8500	97
205 
206 /* Xilinx PSS UART */
207 #define PORT_XUARTPS	98
208 
209 #ifdef __KERNEL__
210 
211 #include <linux/compiler.h>
212 #include <linux/interrupt.h>
213 #include <linux/circ_buf.h>
214 #include <linux/spinlock.h>
215 #include <linux/sched.h>
216 #include <linux/tty.h>
217 #include <linux/mutex.h>
218 #include <linux/sysrq.h>
219 #include <linux/pps_kernel.h>
220 
221 struct uart_port;
222 struct serial_struct;
223 struct device;
224 
225 /*
226  * This structure describes all the operations that can be
227  * done on the physical hardware.
228  */
229 struct uart_ops {
230 	unsigned int	(*tx_empty)(struct uart_port *);
231 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
232 	unsigned int	(*get_mctrl)(struct uart_port *);
233 	void		(*stop_tx)(struct uart_port *);
234 	void		(*start_tx)(struct uart_port *);
235 	void		(*send_xchar)(struct uart_port *, char ch);
236 	void		(*stop_rx)(struct uart_port *);
237 	void		(*enable_ms)(struct uart_port *);
238 	void		(*break_ctl)(struct uart_port *, int ctl);
239 	int		(*startup)(struct uart_port *);
240 	void		(*shutdown)(struct uart_port *);
241 	void		(*flush_buffer)(struct uart_port *);
242 	void		(*set_termios)(struct uart_port *, struct ktermios *new,
243 				       struct ktermios *old);
244 	void		(*set_ldisc)(struct uart_port *, int new);
245 	void		(*pm)(struct uart_port *, unsigned int state,
246 			      unsigned int oldstate);
247 	int		(*set_wake)(struct uart_port *, unsigned int state);
248 
249 	/*
250 	 * Return a string describing the type of the port
251 	 */
252 	const char *(*type)(struct uart_port *);
253 
254 	/*
255 	 * Release IO and memory resources used by the port.
256 	 * This includes iounmap if necessary.
257 	 */
258 	void		(*release_port)(struct uart_port *);
259 
260 	/*
261 	 * Request IO and memory resources used by the port.
262 	 * This includes iomapping the port if necessary.
263 	 */
264 	int		(*request_port)(struct uart_port *);
265 	void		(*config_port)(struct uart_port *, int);
266 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
267 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
268 #ifdef CONFIG_CONSOLE_POLL
269 	void	(*poll_put_char)(struct uart_port *, unsigned char);
270 	int		(*poll_get_char)(struct uart_port *);
271 #endif
272 };
273 
274 #define NO_POLL_CHAR		0x00ff0000
275 #define UART_CONFIG_TYPE	(1 << 0)
276 #define UART_CONFIG_IRQ		(1 << 1)
277 
278 struct uart_icount {
279 	__u32	cts;
280 	__u32	dsr;
281 	__u32	rng;
282 	__u32	dcd;
283 	__u32	rx;
284 	__u32	tx;
285 	__u32	frame;
286 	__u32	overrun;
287 	__u32	parity;
288 	__u32	brk;
289 	__u32	buf_overrun;
290 };
291 
292 typedef unsigned int __bitwise__ upf_t;
293 
294 struct uart_port {
295 	spinlock_t		lock;			/* port lock */
296 	unsigned long		iobase;			/* in/out[bwl] */
297 	unsigned char __iomem	*membase;		/* read/write[bwl] */
298 	unsigned int		(*serial_in)(struct uart_port *, int);
299 	void			(*serial_out)(struct uart_port *, int, int);
300 	void			(*set_termios)(struct uart_port *,
301 				               struct ktermios *new,
302 				               struct ktermios *old);
303 	void			(*pm)(struct uart_port *, unsigned int state,
304 				      unsigned int old);
305 	unsigned int		irq;			/* irq number */
306 	unsigned long		irqflags;		/* irq flags  */
307 	unsigned int		uartclk;		/* base uart clock */
308 	unsigned int		fifosize;		/* tx fifo size */
309 	unsigned char		x_char;			/* xon/xoff char */
310 	unsigned char		regshift;		/* reg offset shift */
311 	unsigned char		iotype;			/* io access style */
312 	unsigned char		unused1;
313 
314 #define UPIO_PORT		(0)
315 #define UPIO_HUB6		(1)
316 #define UPIO_MEM		(2)
317 #define UPIO_MEM32		(3)
318 #define UPIO_AU			(4)			/* Au1x00 type IO */
319 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
320 #define UPIO_DWAPB		(6)			/* DesignWare APB UART */
321 #define UPIO_RM9000		(7)			/* RM9000 type IO */
322 #define UPIO_DWAPB32		(8)			/* DesignWare APB UART (32 bit accesses) */
323 
324 	unsigned int		read_status_mask;	/* driver specific */
325 	unsigned int		ignore_status_mask;	/* driver specific */
326 	struct uart_state	*state;			/* pointer to parent state */
327 	struct uart_icount	icount;			/* statistics */
328 
329 	struct console		*cons;			/* struct console, if any */
330 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
331 	unsigned long		sysrq;			/* sysrq timeout */
332 #endif
333 
334 	upf_t			flags;
335 
336 #define UPF_FOURPORT		((__force upf_t) (1 << 1))
337 #define UPF_SAK			((__force upf_t) (1 << 2))
338 #define UPF_SPD_MASK		((__force upf_t) (0x1030))
339 #define UPF_SPD_HI		((__force upf_t) (0x0010))
340 #define UPF_SPD_VHI		((__force upf_t) (0x0020))
341 #define UPF_SPD_CUST		((__force upf_t) (0x0030))
342 #define UPF_SPD_SHI		((__force upf_t) (0x1000))
343 #define UPF_SPD_WARP		((__force upf_t) (0x1010))
344 #define UPF_SKIP_TEST		((__force upf_t) (1 << 6))
345 #define UPF_AUTO_IRQ		((__force upf_t) (1 << 7))
346 #define UPF_HARDPPS_CD		((__force upf_t) (1 << 11))
347 #define UPF_LOW_LATENCY		((__force upf_t) (1 << 13))
348 #define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
349 #define UPF_NO_TXEN_TEST	((__force upf_t) (1 << 15))
350 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
351 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
352 #define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
353 /* The exact UART type is known and should not be probed.  */
354 #define UPF_FIXED_TYPE		((__force upf_t) (1 << 27))
355 #define UPF_BOOT_AUTOCONF	((__force upf_t) (1 << 28))
356 #define UPF_FIXED_PORT		((__force upf_t) (1 << 29))
357 #define UPF_DEAD		((__force upf_t) (1 << 30))
358 #define UPF_IOREMAP		((__force upf_t) (1 << 31))
359 
360 #define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
361 #define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
362 
363 	unsigned int		mctrl;			/* current modem ctrl settings */
364 	unsigned int		timeout;		/* character-based timeout */
365 	unsigned int		type;			/* port type */
366 	const struct uart_ops	*ops;
367 	unsigned int		custom_divisor;
368 	unsigned int		line;			/* port index */
369 	resource_size_t		mapbase;		/* for ioremap */
370 	struct device		*dev;			/* parent device */
371 	unsigned char		hub6;			/* this should be in the 8250 driver */
372 	unsigned char		suspended;
373 	unsigned char		irq_wake;
374 	unsigned char		unused[2];
375 	void			*private_data;		/* generic platform data pointer */
376 };
377 
378 /*
379  * This is the state information which is persistent across opens.
380  */
381 struct uart_state {
382 	struct tty_port		port;
383 
384 	int			pm_state;
385 	struct circ_buf		xmit;
386 
387 	struct tasklet_struct	tlet;
388 	struct uart_port	*uart_port;
389 };
390 
391 #define UART_XMIT_SIZE	PAGE_SIZE
392 
393 
394 /* number of characters left in xmit buffer before we ask for more */
395 #define WAKEUP_CHARS		256
396 
397 struct module;
398 struct tty_driver;
399 
400 struct uart_driver {
401 	struct module		*owner;
402 	const char		*driver_name;
403 	const char		*dev_name;
404 	int			 major;
405 	int			 minor;
406 	int			 nr;
407 	struct console		*cons;
408 
409 	/*
410 	 * these are private; the low level driver should not
411 	 * touch these; they should be initialised to NULL
412 	 */
413 	struct uart_state	*state;
414 	struct tty_driver	*tty_driver;
415 };
416 
417 void uart_write_wakeup(struct uart_port *port);
418 
419 /*
420  * Baud rate helpers.
421  */
422 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
423 			 unsigned int baud);
424 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
425 				struct ktermios *old, unsigned int min,
426 				unsigned int max);
427 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
428 
429 /* Base timer interval for polling */
430 static inline int uart_poll_timeout(struct uart_port *port)
431 {
432 	int timeout = port->timeout;
433 
434 	return timeout > 6 ? (timeout / 2 - 2) : 1;
435 }
436 
437 /*
438  * Console helpers.
439  */
440 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
441 				   struct console *c);
442 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
443 			int *flow);
444 int uart_set_options(struct uart_port *port, struct console *co, int baud,
445 		     int parity, int bits, int flow);
446 struct tty_driver *uart_console_device(struct console *co, int *index);
447 void uart_console_write(struct uart_port *port, const char *s,
448 			unsigned int count,
449 			void (*putchar)(struct uart_port *, int));
450 
451 /*
452  * Port/driver registration/removal
453  */
454 int uart_register_driver(struct uart_driver *uart);
455 void uart_unregister_driver(struct uart_driver *uart);
456 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
457 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
458 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
459 
460 /*
461  * Power Management
462  */
463 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
464 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
465 
466 #define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
467 #define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)
468 
469 #define uart_circ_chars_pending(circ)	\
470 	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
471 
472 #define uart_circ_chars_free(circ)	\
473 	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
474 
475 static inline int uart_tx_stopped(struct uart_port *port)
476 {
477 	struct tty_struct *tty = port->state->port.tty;
478 	if(tty->stopped || tty->hw_stopped)
479 		return 1;
480 	return 0;
481 }
482 
483 /*
484  * The following are helper functions for the low level drivers.
485  */
486 static inline int
487 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
488 {
489 #ifdef SUPPORT_SYSRQ
490 	if (port->sysrq) {
491 		if (ch && time_before(jiffies, port->sysrq)) {
492 			handle_sysrq(ch);
493 			port->sysrq = 0;
494 			return 1;
495 		}
496 		port->sysrq = 0;
497 	}
498 #endif
499 	return 0;
500 }
501 #ifndef SUPPORT_SYSRQ
502 #define uart_handle_sysrq_char(port,ch) uart_handle_sysrq_char(port, 0)
503 #endif
504 
505 /*
506  * We do the SysRQ and SAK checking like this...
507  */
508 static inline int uart_handle_break(struct uart_port *port)
509 {
510 	struct uart_state *state = port->state;
511 #ifdef SUPPORT_SYSRQ
512 	if (port->cons && port->cons->index == port->line) {
513 		if (!port->sysrq) {
514 			port->sysrq = jiffies + HZ*5;
515 			return 1;
516 		}
517 		port->sysrq = 0;
518 	}
519 #endif
520 	if (port->flags & UPF_SAK)
521 		do_SAK(state->port.tty);
522 	return 0;
523 }
524 
525 /**
526  *	uart_handle_dcd_change - handle a change of carrier detect state
527  *	@uport: uart_port structure for the open port
528  *	@status: new carrier detect status, nonzero if active
529  */
530 static inline void
531 uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
532 {
533 	struct uart_state *state = uport->state;
534 	struct tty_port *port = &state->port;
535 	struct tty_ldisc *ld = tty_ldisc_ref(port->tty);
536 	struct pps_event_time ts;
537 
538 	if (ld && ld->ops->dcd_change)
539 		pps_get_ts(&ts);
540 
541 	uport->icount.dcd++;
542 #ifdef CONFIG_HARD_PPS
543 	if ((uport->flags & UPF_HARDPPS_CD) && status)
544 		hardpps();
545 #endif
546 
547 	if (port->flags & ASYNC_CHECK_CD) {
548 		if (status)
549 			wake_up_interruptible(&port->open_wait);
550 		else if (port->tty)
551 			tty_hangup(port->tty);
552 	}
553 
554 	if (ld && ld->ops->dcd_change)
555 		ld->ops->dcd_change(port->tty, status, &ts);
556 	if (ld)
557 		tty_ldisc_deref(ld);
558 }
559 
560 /**
561  *	uart_handle_cts_change - handle a change of clear-to-send state
562  *	@uport: uart_port structure for the open port
563  *	@status: new clear to send status, nonzero if active
564  */
565 static inline void
566 uart_handle_cts_change(struct uart_port *uport, unsigned int status)
567 {
568 	struct tty_port *port = &uport->state->port;
569 	struct tty_struct *tty = port->tty;
570 
571 	uport->icount.cts++;
572 
573 	if (port->flags & ASYNC_CTS_FLOW) {
574 		if (tty->hw_stopped) {
575 			if (status) {
576 				tty->hw_stopped = 0;
577 				uport->ops->start_tx(uport);
578 				uart_write_wakeup(uport);
579 			}
580 		} else {
581 			if (!status) {
582 				tty->hw_stopped = 1;
583 				uport->ops->stop_tx(uport);
584 			}
585 		}
586 	}
587 }
588 
589 #include <linux/tty_flip.h>
590 
591 static inline void
592 uart_insert_char(struct uart_port *port, unsigned int status,
593 		 unsigned int overrun, unsigned int ch, unsigned int flag)
594 {
595 	struct tty_struct *tty = port->state->port.tty;
596 
597 	if ((status & port->ignore_status_mask & ~overrun) == 0)
598 		tty_insert_flip_char(tty, ch, flag);
599 
600 	/*
601 	 * Overrun is special.  Since it's reported immediately,
602 	 * it doesn't affect the current character.
603 	 */
604 	if (status & ~port->ignore_status_mask & overrun)
605 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
606 }
607 
608 /*
609  *	UART_ENABLE_MS - determine if port should enable modem status irqs
610  */
611 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
612 					 (cflag) & CRTSCTS || \
613 					 !((cflag) & CLOCAL))
614 
615 #endif
616 
617 #endif /* LINUX_SERIAL_CORE_H */
618