xref: /linux-6.15/include/linux/serial_core.h (revision 5134d8fe)
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 /* NEC v850.  */
63 #define PORT_V850E_UART	40
64 
65 /* DEC */
66 #define PORT_DZ		46
67 #define PORT_ZS		47
68 
69 /* Parisc type numbers. */
70 #define PORT_MUX	48
71 
72 /* Atmel AT91 / AT32 SoC */
73 #define PORT_ATMEL	49
74 
75 /* Macintosh Zilog type numbers */
76 #define PORT_MAC_ZILOG	50	/* m68k : not yet implemented */
77 #define PORT_PMAC_ZILOG	51
78 
79 /* SH-SCI */
80 #define PORT_SCI	52
81 #define PORT_SCIF	53
82 #define PORT_IRDA	54
83 
84 /* Samsung S3C2410 SoC and derivatives thereof */
85 #define PORT_S3C2410    55
86 
87 /* SGI IP22 aka Indy / Challenge S / Indigo 2 */
88 #define PORT_IP22ZILOG	56
89 
90 /* Sharp LH7a40x -- an ARM9 SoC series */
91 #define PORT_LH7A40X	57
92 
93 /* PPC CPM type number */
94 #define PORT_CPM        58
95 
96 /* MPC52xx type numbers */
97 #define PORT_MPC52xx	59
98 
99 /* IBM icom */
100 #define PORT_ICOM	60
101 
102 /* Samsung S3C2440 SoC */
103 #define PORT_S3C2440	61
104 
105 /* Motorola i.MX SoC */
106 #define PORT_IMX	62
107 
108 /* Marvell MPSC */
109 #define PORT_MPSC	63
110 
111 /* TXX9 type number */
112 #define PORT_TXX9	64
113 
114 /* NEC VR4100 series SIU/DSIU */
115 #define PORT_VR41XX_SIU		65
116 #define PORT_VR41XX_DSIU	66
117 
118 /* Samsung S3C2400 SoC */
119 #define PORT_S3C2400	67
120 
121 /* M32R SIO */
122 #define PORT_M32R_SIO	68
123 
124 /*Digi jsm */
125 #define PORT_JSM        69
126 
127 #define PORT_PNX8XXX	70
128 
129 /* Hilscher netx */
130 #define PORT_NETX	71
131 
132 /* SUN4V Hypervisor Console */
133 #define PORT_SUNHV	72
134 
135 #define PORT_S3C2412	73
136 
137 /* Xilinx uartlite */
138 #define PORT_UARTLITE	74
139 
140 /* Blackfin bf5xx */
141 #define PORT_BFIN	75
142 
143 /* Micrel KS8695 */
144 #define PORT_KS8695	76
145 
146 /* Broadcom SB1250, etc. SOC */
147 #define PORT_SB1250_DUART	77
148 
149 /* Freescale ColdFire */
150 #define PORT_MCF	78
151 
152 
153 /* MN10300 on-chip UART numbers */
154 #define PORT_MN10300		80
155 #define PORT_MN10300_CTS	81
156 
157 #ifdef __KERNEL__
158 
159 #include <linux/compiler.h>
160 #include <linux/interrupt.h>
161 #include <linux/circ_buf.h>
162 #include <linux/spinlock.h>
163 #include <linux/sched.h>
164 #include <linux/tty.h>
165 #include <linux/mutex.h>
166 #include <linux/sysrq.h>
167 
168 struct uart_port;
169 struct uart_info;
170 struct serial_struct;
171 struct device;
172 
173 /*
174  * This structure describes all the operations that can be
175  * done on the physical hardware.
176  */
177 struct uart_ops {
178 	unsigned int	(*tx_empty)(struct uart_port *);
179 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
180 	unsigned int	(*get_mctrl)(struct uart_port *);
181 	void		(*stop_tx)(struct uart_port *);
182 	void		(*start_tx)(struct uart_port *);
183 	void		(*send_xchar)(struct uart_port *, char ch);
184 	void		(*stop_rx)(struct uart_port *);
185 	void		(*enable_ms)(struct uart_port *);
186 	void		(*break_ctl)(struct uart_port *, int ctl);
187 	int		(*startup)(struct uart_port *);
188 	void		(*shutdown)(struct uart_port *);
189 	void		(*set_termios)(struct uart_port *, struct ktermios *new,
190 				       struct ktermios *old);
191 	void		(*pm)(struct uart_port *, unsigned int state,
192 			      unsigned int oldstate);
193 	int		(*set_wake)(struct uart_port *, unsigned int state);
194 
195 	/*
196 	 * Return a string describing the type of the port
197 	 */
198 	const char *(*type)(struct uart_port *);
199 
200 	/*
201 	 * Release IO and memory resources used by the port.
202 	 * This includes iounmap if necessary.
203 	 */
204 	void		(*release_port)(struct uart_port *);
205 
206 	/*
207 	 * Request IO and memory resources used by the port.
208 	 * This includes iomapping the port if necessary.
209 	 */
210 	int		(*request_port)(struct uart_port *);
211 	void		(*config_port)(struct uart_port *, int);
212 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
213 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
214 };
215 
216 #define UART_CONFIG_TYPE	(1 << 0)
217 #define UART_CONFIG_IRQ		(1 << 1)
218 
219 struct uart_icount {
220 	__u32	cts;
221 	__u32	dsr;
222 	__u32	rng;
223 	__u32	dcd;
224 	__u32	rx;
225 	__u32	tx;
226 	__u32	frame;
227 	__u32	overrun;
228 	__u32	parity;
229 	__u32	brk;
230 	__u32	buf_overrun;
231 };
232 
233 typedef unsigned int __bitwise__ upf_t;
234 
235 struct uart_port {
236 	spinlock_t		lock;			/* port lock */
237 	unsigned int		iobase;			/* in/out[bwl] */
238 	unsigned char __iomem	*membase;		/* read/write[bwl] */
239 	unsigned int		irq;			/* irq number */
240 	unsigned int		uartclk;		/* base uart clock */
241 	unsigned int		fifosize;		/* tx fifo size */
242 	unsigned char		x_char;			/* xon/xoff char */
243 	unsigned char		regshift;		/* reg offset shift */
244 	unsigned char		iotype;			/* io access style */
245 	unsigned char		unused1;
246 
247 #define UPIO_PORT		(0)
248 #define UPIO_HUB6		(1)
249 #define UPIO_MEM		(2)
250 #define UPIO_MEM32		(3)
251 #define UPIO_AU			(4)			/* Au1x00 type IO */
252 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
253 #define UPIO_DWAPB		(6)			/* DesignWare APB UART */
254 #define UPIO_RM9000		(7)			/* RM9000 type IO */
255 
256 	unsigned int		read_status_mask;	/* driver specific */
257 	unsigned int		ignore_status_mask;	/* driver specific */
258 	struct uart_info	*info;			/* pointer to parent info */
259 	struct uart_icount	icount;			/* statistics */
260 
261 	struct console		*cons;			/* struct console, if any */
262 #ifdef CONFIG_SERIAL_CORE_CONSOLE
263 	unsigned long		sysrq;			/* sysrq timeout */
264 #endif
265 
266 	upf_t			flags;
267 
268 #define UPF_FOURPORT		((__force upf_t) (1 << 1))
269 #define UPF_SAK			((__force upf_t) (1 << 2))
270 #define UPF_SPD_MASK		((__force upf_t) (0x1030))
271 #define UPF_SPD_HI		((__force upf_t) (0x0010))
272 #define UPF_SPD_VHI		((__force upf_t) (0x0020))
273 #define UPF_SPD_CUST		((__force upf_t) (0x0030))
274 #define UPF_SPD_SHI		((__force upf_t) (0x1000))
275 #define UPF_SPD_WARP		((__force upf_t) (0x1010))
276 #define UPF_SKIP_TEST		((__force upf_t) (1 << 6))
277 #define UPF_AUTO_IRQ		((__force upf_t) (1 << 7))
278 #define UPF_HARDPPS_CD		((__force upf_t) (1 << 11))
279 #define UPF_LOW_LATENCY		((__force upf_t) (1 << 13))
280 #define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
281 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
282 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
283 #define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
284 #define UPF_BOOT_AUTOCONF	((__force upf_t) (1 << 28))
285 #define UPF_FIXED_PORT		((__force upf_t) (1 << 29))
286 #define UPF_DEAD		((__force upf_t) (1 << 30))
287 #define UPF_IOREMAP		((__force upf_t) (1 << 31))
288 
289 #define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
290 #define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
291 
292 	unsigned int		mctrl;			/* current modem ctrl settings */
293 	unsigned int		timeout;		/* character-based timeout */
294 	unsigned int		type;			/* port type */
295 	const struct uart_ops	*ops;
296 	unsigned int		custom_divisor;
297 	unsigned int		line;			/* port index */
298 	resource_size_t		mapbase;		/* for ioremap */
299 	struct device		*dev;			/* parent device */
300 	unsigned char		hub6;			/* this should be in the 8250 driver */
301 	unsigned char		suspended;
302 	unsigned char		unused[2];
303 	void			*private_data;		/* generic platform data pointer */
304 };
305 
306 /*
307  * This is the state information which is persistent across opens.
308  * The low level driver must not to touch any elements contained
309  * within.
310  */
311 struct uart_state {
312 	unsigned int		close_delay;		/* msec */
313 	unsigned int		closing_wait;		/* msec */
314 
315 #define USF_CLOSING_WAIT_INF	(0)
316 #define USF_CLOSING_WAIT_NONE	(~0U)
317 
318 	int			count;
319 	int			pm_state;
320 	struct uart_info	*info;
321 	struct uart_port	*port;
322 
323 	struct mutex		mutex;
324 };
325 
326 #define UART_XMIT_SIZE	PAGE_SIZE
327 
328 typedef unsigned int __bitwise__ uif_t;
329 
330 /*
331  * This is the state information which is only valid when the port
332  * is open; it may be freed by the core driver once the device has
333  * been closed.  Either the low level driver or the core can modify
334  * stuff here.
335  */
336 struct uart_info {
337 	struct tty_struct	*tty;
338 	struct circ_buf		xmit;
339 	uif_t			flags;
340 
341 /*
342  * Definitions for info->flags.  These are _private_ to serial_core, and
343  * are specific to this structure.  They may be queried by low level drivers.
344  */
345 #define UIF_CHECK_CD		((__force uif_t) (1 << 25))
346 #define UIF_CTS_FLOW		((__force uif_t) (1 << 26))
347 #define UIF_NORMAL_ACTIVE	((__force uif_t) (1 << 29))
348 #define UIF_INITIALIZED		((__force uif_t) (1 << 31))
349 #define UIF_SUSPENDED		((__force uif_t) (1 << 30))
350 
351 	int			blocked_open;
352 
353 	struct tasklet_struct	tlet;
354 
355 	wait_queue_head_t	open_wait;
356 	wait_queue_head_t	delta_msr_wait;
357 };
358 
359 /* number of characters left in xmit buffer before we ask for more */
360 #define WAKEUP_CHARS		256
361 
362 struct module;
363 struct tty_driver;
364 
365 struct uart_driver {
366 	struct module		*owner;
367 	const char		*driver_name;
368 	const char		*dev_name;
369 	int			 major;
370 	int			 minor;
371 	int			 nr;
372 	struct console		*cons;
373 
374 	/*
375 	 * these are private; the low level driver should not
376 	 * touch these; they should be initialised to NULL
377 	 */
378 	struct uart_state	*state;
379 	struct tty_driver	*tty_driver;
380 };
381 
382 void uart_write_wakeup(struct uart_port *port);
383 
384 /*
385  * Baud rate helpers.
386  */
387 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
388 			 unsigned int baud);
389 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
390 				struct ktermios *old, unsigned int min,
391 				unsigned int max);
392 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
393 
394 /*
395  * Console helpers.
396  */
397 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
398 				   struct console *c);
399 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
400 			int *flow);
401 int uart_set_options(struct uart_port *port, struct console *co, int baud,
402 		     int parity, int bits, int flow);
403 struct tty_driver *uart_console_device(struct console *co, int *index);
404 void uart_console_write(struct uart_port *port, const char *s,
405 			unsigned int count,
406 			void (*putchar)(struct uart_port *, int));
407 
408 /*
409  * Port/driver registration/removal
410  */
411 int uart_register_driver(struct uart_driver *uart);
412 void uart_unregister_driver(struct uart_driver *uart);
413 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
414 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
415 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
416 
417 /*
418  * Power Management
419  */
420 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
421 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
422 
423 #define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
424 #define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)
425 
426 #define uart_circ_chars_pending(circ)	\
427 	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
428 
429 #define uart_circ_chars_free(circ)	\
430 	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
431 
432 #define uart_tx_stopped(port)		\
433 	((port)->info->tty->stopped || (port)->info->tty->hw_stopped)
434 
435 /*
436  * The following are helper functions for the low level drivers.
437  */
438 static inline int
439 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
440 {
441 #ifdef SUPPORT_SYSRQ
442 	if (port->sysrq) {
443 		if (ch && time_before(jiffies, port->sysrq)) {
444 			handle_sysrq(ch, port->info ? port->info->tty : NULL);
445 			port->sysrq = 0;
446 			return 1;
447 		}
448 		port->sysrq = 0;
449 	}
450 #endif
451 	return 0;
452 }
453 #ifndef SUPPORT_SYSRQ
454 #define uart_handle_sysrq_char(port,ch) uart_handle_sysrq_char(port, 0)
455 #endif
456 
457 /*
458  * We do the SysRQ and SAK checking like this...
459  */
460 static inline int uart_handle_break(struct uart_port *port)
461 {
462 	struct uart_info *info = port->info;
463 #ifdef SUPPORT_SYSRQ
464 	if (port->cons && port->cons->index == port->line) {
465 		if (!port->sysrq) {
466 			port->sysrq = jiffies + HZ*5;
467 			return 1;
468 		}
469 		port->sysrq = 0;
470 	}
471 #endif
472 	if (port->flags & UPF_SAK)
473 		do_SAK(info->tty);
474 	return 0;
475 }
476 
477 /**
478  *	uart_handle_dcd_change - handle a change of carrier detect state
479  *	@port: uart_port structure for the open port
480  *	@status: new carrier detect status, nonzero if active
481  */
482 static inline void
483 uart_handle_dcd_change(struct uart_port *port, unsigned int status)
484 {
485 	struct uart_info *info = port->info;
486 
487 	port->icount.dcd++;
488 
489 #ifdef CONFIG_HARD_PPS
490 	if ((port->flags & UPF_HARDPPS_CD) && status)
491 		hardpps();
492 #endif
493 
494 	if (info->flags & UIF_CHECK_CD) {
495 		if (status)
496 			wake_up_interruptible(&info->open_wait);
497 		else if (info->tty)
498 			tty_hangup(info->tty);
499 	}
500 }
501 
502 /**
503  *	uart_handle_cts_change - handle a change of clear-to-send state
504  *	@port: uart_port structure for the open port
505  *	@status: new clear to send status, nonzero if active
506  */
507 static inline void
508 uart_handle_cts_change(struct uart_port *port, unsigned int status)
509 {
510 	struct uart_info *info = port->info;
511 	struct tty_struct *tty = info->tty;
512 
513 	port->icount.cts++;
514 
515 	if (info->flags & UIF_CTS_FLOW) {
516 		if (tty->hw_stopped) {
517 			if (status) {
518 				tty->hw_stopped = 0;
519 				port->ops->start_tx(port);
520 				uart_write_wakeup(port);
521 			}
522 		} else {
523 			if (!status) {
524 				tty->hw_stopped = 1;
525 				port->ops->stop_tx(port);
526 			}
527 		}
528 	}
529 }
530 
531 #include <linux/tty_flip.h>
532 
533 static inline void
534 uart_insert_char(struct uart_port *port, unsigned int status,
535 		 unsigned int overrun, unsigned int ch, unsigned int flag)
536 {
537 	struct tty_struct *tty = port->info->tty;
538 
539 	if ((status & port->ignore_status_mask & ~overrun) == 0)
540 		tty_insert_flip_char(tty, ch, flag);
541 
542 	/*
543 	 * Overrun is special.  Since it's reported immediately,
544 	 * it doesn't affect the current character.
545 	 */
546 	if (status & ~port->ignore_status_mask & overrun)
547 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
548 }
549 
550 /*
551  *	UART_ENABLE_MS - determine if port should enable modem status irqs
552  */
553 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
554 					 (cflag) & CRTSCTS || \
555 					 !((cflag) & CLOCAL))
556 
557 #endif
558 
559 #endif /* LINUX_SERIAL_CORE_H */
560