xref: /linux-6.15/include/linux/serial_core.h (revision 2b8232ce)
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 
150 #ifdef __KERNEL__
151 
152 #include <linux/compiler.h>
153 #include <linux/interrupt.h>
154 #include <linux/circ_buf.h>
155 #include <linux/spinlock.h>
156 #include <linux/sched.h>
157 #include <linux/tty.h>
158 #include <linux/mutex.h>
159 #include <linux/sysrq.h>
160 
161 struct uart_port;
162 struct uart_info;
163 struct serial_struct;
164 struct device;
165 
166 /*
167  * This structure describes all the operations that can be
168  * done on the physical hardware.
169  */
170 struct uart_ops {
171 	unsigned int	(*tx_empty)(struct uart_port *);
172 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
173 	unsigned int	(*get_mctrl)(struct uart_port *);
174 	void		(*stop_tx)(struct uart_port *);
175 	void		(*start_tx)(struct uart_port *);
176 	void		(*send_xchar)(struct uart_port *, char ch);
177 	void		(*stop_rx)(struct uart_port *);
178 	void		(*enable_ms)(struct uart_port *);
179 	void		(*break_ctl)(struct uart_port *, int ctl);
180 	int		(*startup)(struct uart_port *);
181 	void		(*shutdown)(struct uart_port *);
182 	void		(*set_termios)(struct uart_port *, struct ktermios *new,
183 				       struct ktermios *old);
184 	void		(*pm)(struct uart_port *, unsigned int state,
185 			      unsigned int oldstate);
186 	int		(*set_wake)(struct uart_port *, unsigned int state);
187 
188 	/*
189 	 * Return a string describing the type of the port
190 	 */
191 	const char *(*type)(struct uart_port *);
192 
193 	/*
194 	 * Release IO and memory resources used by the port.
195 	 * This includes iounmap if necessary.
196 	 */
197 	void		(*release_port)(struct uart_port *);
198 
199 	/*
200 	 * Request IO and memory resources used by the port.
201 	 * This includes iomapping the port if necessary.
202 	 */
203 	int		(*request_port)(struct uart_port *);
204 	void		(*config_port)(struct uart_port *, int);
205 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
206 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
207 };
208 
209 #define UART_CONFIG_TYPE	(1 << 0)
210 #define UART_CONFIG_IRQ		(1 << 1)
211 
212 struct uart_icount {
213 	__u32	cts;
214 	__u32	dsr;
215 	__u32	rng;
216 	__u32	dcd;
217 	__u32	rx;
218 	__u32	tx;
219 	__u32	frame;
220 	__u32	overrun;
221 	__u32	parity;
222 	__u32	brk;
223 	__u32	buf_overrun;
224 };
225 
226 typedef unsigned int __bitwise__ upf_t;
227 
228 struct uart_port {
229 	spinlock_t		lock;			/* port lock */
230 	unsigned int		iobase;			/* in/out[bwl] */
231 	unsigned char __iomem	*membase;		/* read/write[bwl] */
232 	unsigned int		irq;			/* irq number */
233 	unsigned int		uartclk;		/* base uart clock */
234 	unsigned int		fifosize;		/* tx fifo size */
235 	unsigned char		x_char;			/* xon/xoff char */
236 	unsigned char		regshift;		/* reg offset shift */
237 	unsigned char		iotype;			/* io access style */
238 	unsigned char		unused1;
239 
240 #define UPIO_PORT		(0)
241 #define UPIO_HUB6		(1)
242 #define UPIO_MEM		(2)
243 #define UPIO_MEM32		(3)
244 #define UPIO_AU			(4)			/* Au1x00 type IO */
245 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
246 #define UPIO_DWAPB		(6)			/* DesignWare APB UART */
247 #define UPIO_RM9000		(7)			/* RM9000 type IO */
248 
249 	unsigned int		read_status_mask;	/* driver specific */
250 	unsigned int		ignore_status_mask;	/* driver specific */
251 	struct uart_info	*info;			/* pointer to parent info */
252 	struct uart_icount	icount;			/* statistics */
253 
254 	struct console		*cons;			/* struct console, if any */
255 #ifdef CONFIG_SERIAL_CORE_CONSOLE
256 	unsigned long		sysrq;			/* sysrq timeout */
257 #endif
258 
259 	upf_t			flags;
260 
261 #define UPF_FOURPORT		((__force upf_t) (1 << 1))
262 #define UPF_SAK			((__force upf_t) (1 << 2))
263 #define UPF_SPD_MASK		((__force upf_t) (0x1030))
264 #define UPF_SPD_HI		((__force upf_t) (0x0010))
265 #define UPF_SPD_VHI		((__force upf_t) (0x0020))
266 #define UPF_SPD_CUST		((__force upf_t) (0x0030))
267 #define UPF_SPD_SHI		((__force upf_t) (0x1000))
268 #define UPF_SPD_WARP		((__force upf_t) (0x1010))
269 #define UPF_SKIP_TEST		((__force upf_t) (1 << 6))
270 #define UPF_AUTO_IRQ		((__force upf_t) (1 << 7))
271 #define UPF_HARDPPS_CD		((__force upf_t) (1 << 11))
272 #define UPF_LOW_LATENCY		((__force upf_t) (1 << 13))
273 #define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
274 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
275 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
276 #define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
277 #define UPF_BOOT_AUTOCONF	((__force upf_t) (1 << 28))
278 #define UPF_FIXED_PORT		((__force upf_t) (1 << 29))
279 #define UPF_DEAD		((__force upf_t) (1 << 30))
280 #define UPF_IOREMAP		((__force upf_t) (1 << 31))
281 
282 #define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
283 #define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
284 
285 	unsigned int		mctrl;			/* current modem ctrl settings */
286 	unsigned int		timeout;		/* character-based timeout */
287 	unsigned int		type;			/* port type */
288 	const struct uart_ops	*ops;
289 	unsigned int		custom_divisor;
290 	unsigned int		line;			/* port index */
291 	resource_size_t		mapbase;		/* for ioremap */
292 	struct device		*dev;			/* parent device */
293 	unsigned char		hub6;			/* this should be in the 8250 driver */
294 	unsigned char		unused[3];
295 	void			*private_data;		/* generic platform data pointer */
296 };
297 
298 /*
299  * This is the state information which is persistent across opens.
300  * The low level driver must not to touch any elements contained
301  * within.
302  */
303 struct uart_state {
304 	unsigned int		close_delay;		/* msec */
305 	unsigned int		closing_wait;		/* msec */
306 
307 #define USF_CLOSING_WAIT_INF	(0)
308 #define USF_CLOSING_WAIT_NONE	(~0U)
309 
310 	int			count;
311 	int			pm_state;
312 	struct uart_info	*info;
313 	struct uart_port	*port;
314 
315 	struct mutex		mutex;
316 };
317 
318 #define UART_XMIT_SIZE	PAGE_SIZE
319 
320 typedef unsigned int __bitwise__ uif_t;
321 
322 /*
323  * This is the state information which is only valid when the port
324  * is open; it may be freed by the core driver once the device has
325  * been closed.  Either the low level driver or the core can modify
326  * stuff here.
327  */
328 struct uart_info {
329 	struct tty_struct	*tty;
330 	struct circ_buf		xmit;
331 	uif_t			flags;
332 
333 /*
334  * Definitions for info->flags.  These are _private_ to serial_core, and
335  * are specific to this structure.  They may be queried by low level drivers.
336  */
337 #define UIF_CHECK_CD		((__force uif_t) (1 << 25))
338 #define UIF_CTS_FLOW		((__force uif_t) (1 << 26))
339 #define UIF_NORMAL_ACTIVE	((__force uif_t) (1 << 29))
340 #define UIF_INITIALIZED		((__force uif_t) (1 << 31))
341 #define UIF_SUSPENDED		((__force uif_t) (1 << 30))
342 
343 	int			blocked_open;
344 
345 	struct tasklet_struct	tlet;
346 
347 	wait_queue_head_t	open_wait;
348 	wait_queue_head_t	delta_msr_wait;
349 };
350 
351 /* number of characters left in xmit buffer before we ask for more */
352 #define WAKEUP_CHARS		256
353 
354 struct module;
355 struct tty_driver;
356 
357 struct uart_driver {
358 	struct module		*owner;
359 	const char		*driver_name;
360 	const char		*dev_name;
361 	int			 major;
362 	int			 minor;
363 	int			 nr;
364 	struct console		*cons;
365 
366 	/*
367 	 * these are private; the low level driver should not
368 	 * touch these; they should be initialised to NULL
369 	 */
370 	struct uart_state	*state;
371 	struct tty_driver	*tty_driver;
372 };
373 
374 void uart_write_wakeup(struct uart_port *port);
375 
376 /*
377  * Baud rate helpers.
378  */
379 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
380 			 unsigned int baud);
381 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
382 				struct ktermios *old, unsigned int min,
383 				unsigned int max);
384 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
385 
386 /*
387  * Console helpers.
388  */
389 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
390 				   struct console *c);
391 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
392 			int *flow);
393 int uart_set_options(struct uart_port *port, struct console *co, int baud,
394 		     int parity, int bits, int flow);
395 struct tty_driver *uart_console_device(struct console *co, int *index);
396 void uart_console_write(struct uart_port *port, const char *s,
397 			unsigned int count,
398 			void (*putchar)(struct uart_port *, int));
399 
400 /*
401  * Port/driver registration/removal
402  */
403 int uart_register_driver(struct uart_driver *uart);
404 void uart_unregister_driver(struct uart_driver *uart);
405 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
406 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
407 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
408 
409 /*
410  * Power Management
411  */
412 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
413 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
414 
415 #define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
416 #define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)
417 
418 #define uart_circ_chars_pending(circ)	\
419 	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
420 
421 #define uart_circ_chars_free(circ)	\
422 	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
423 
424 #define uart_tx_stopped(port)		\
425 	((port)->info->tty->stopped || (port)->info->tty->hw_stopped)
426 
427 /*
428  * The following are helper functions for the low level drivers.
429  */
430 static inline int
431 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
432 {
433 #ifdef SUPPORT_SYSRQ
434 	if (port->sysrq) {
435 		if (ch && time_before(jiffies, port->sysrq)) {
436 			handle_sysrq(ch, port->info->tty);
437 			port->sysrq = 0;
438 			return 1;
439 		}
440 		port->sysrq = 0;
441 	}
442 #endif
443 	return 0;
444 }
445 #ifndef SUPPORT_SYSRQ
446 #define uart_handle_sysrq_char(port,ch) uart_handle_sysrq_char(port, 0)
447 #endif
448 
449 /*
450  * We do the SysRQ and SAK checking like this...
451  */
452 static inline int uart_handle_break(struct uart_port *port)
453 {
454 	struct uart_info *info = port->info;
455 #ifdef SUPPORT_SYSRQ
456 	if (port->cons && port->cons->index == port->line) {
457 		if (!port->sysrq) {
458 			port->sysrq = jiffies + HZ*5;
459 			return 1;
460 		}
461 		port->sysrq = 0;
462 	}
463 #endif
464 	if (port->flags & UPF_SAK)
465 		do_SAK(info->tty);
466 	return 0;
467 }
468 
469 /**
470  *	uart_handle_dcd_change - handle a change of carrier detect state
471  *	@port: uart_port structure for the open port
472  *	@status: new carrier detect status, nonzero if active
473  */
474 static inline void
475 uart_handle_dcd_change(struct uart_port *port, unsigned int status)
476 {
477 	struct uart_info *info = port->info;
478 
479 	port->icount.dcd++;
480 
481 #ifdef CONFIG_HARD_PPS
482 	if ((port->flags & UPF_HARDPPS_CD) && status)
483 		hardpps();
484 #endif
485 
486 	if (info->flags & UIF_CHECK_CD) {
487 		if (status)
488 			wake_up_interruptible(&info->open_wait);
489 		else if (info->tty)
490 			tty_hangup(info->tty);
491 	}
492 }
493 
494 /**
495  *	uart_handle_cts_change - handle a change of clear-to-send state
496  *	@port: uart_port structure for the open port
497  *	@status: new clear to send status, nonzero if active
498  */
499 static inline void
500 uart_handle_cts_change(struct uart_port *port, unsigned int status)
501 {
502 	struct uart_info *info = port->info;
503 	struct tty_struct *tty = info->tty;
504 
505 	port->icount.cts++;
506 
507 	if (info->flags & UIF_CTS_FLOW) {
508 		if (tty->hw_stopped) {
509 			if (status) {
510 				tty->hw_stopped = 0;
511 				port->ops->start_tx(port);
512 				uart_write_wakeup(port);
513 			}
514 		} else {
515 			if (!status) {
516 				tty->hw_stopped = 1;
517 				port->ops->stop_tx(port);
518 			}
519 		}
520 	}
521 }
522 
523 #include <linux/tty_flip.h>
524 
525 static inline void
526 uart_insert_char(struct uart_port *port, unsigned int status,
527 		 unsigned int overrun, unsigned int ch, unsigned int flag)
528 {
529 	struct tty_struct *tty = port->info->tty;
530 
531 	if ((status & port->ignore_status_mask & ~overrun) == 0)
532 		tty_insert_flip_char(tty, ch, flag);
533 
534 	/*
535 	 * Overrun is special.  Since it's reported immediately,
536 	 * it doesn't affect the current character.
537 	 */
538 	if (status & ~port->ignore_status_mask & overrun)
539 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
540 }
541 
542 /*
543  *	UART_ENABLE_MS - determine if port should enable modem status irqs
544  */
545 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
546 					 (cflag) & CRTSCTS || \
547 					 !((cflag) & CLOCAL))
548 
549 #endif
550 
551 #endif /* LINUX_SERIAL_CORE_H */
552