xref: /linux-6.15/include/linux/serial_core.h (revision 27258e44)
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_MAX_8250	18	/* max port ID */
48 
49 /*
50  * ARM specific type numbers.  These are not currently guaranteed
51  * to be implemented, and will change in the future.  These are
52  * separate so any additions to the old serial.c that occur before
53  * we are merged can be easily merged here.
54  */
55 #define PORT_PXA	31
56 #define PORT_AMBA	32
57 #define PORT_CLPS711X	33
58 #define PORT_SA1100	34
59 #define PORT_UART00	35
60 #define PORT_21285	37
61 
62 /* Sparc type numbers.  */
63 #define PORT_SUNZILOG	38
64 #define PORT_SUNSAB	39
65 
66 /* DEC */
67 #define PORT_DZ		46
68 #define PORT_ZS		47
69 
70 /* Parisc type numbers. */
71 #define PORT_MUX	48
72 
73 /* Atmel AT91 / AT32 SoC */
74 #define PORT_ATMEL	49
75 
76 /* Macintosh Zilog type numbers */
77 #define PORT_MAC_ZILOG	50	/* m68k : not yet implemented */
78 #define PORT_PMAC_ZILOG	51
79 
80 /* SH-SCI */
81 #define PORT_SCI	52
82 #define PORT_SCIF	53
83 #define PORT_IRDA	54
84 
85 /* Samsung S3C2410 SoC and derivatives thereof */
86 #define PORT_S3C2410    55
87 
88 /* SGI IP22 aka Indy / Challenge S / Indigo 2 */
89 #define PORT_IP22ZILOG	56
90 
91 /* Sharp LH7a40x -- an ARM9 SoC series */
92 #define PORT_LH7A40X	57
93 
94 /* PPC CPM type number */
95 #define PORT_CPM        58
96 
97 /* MPC52xx type numbers */
98 #define PORT_MPC52xx	59
99 
100 /* IBM icom */
101 #define PORT_ICOM	60
102 
103 /* Samsung S3C2440 SoC */
104 #define PORT_S3C2440	61
105 
106 /* Motorola i.MX SoC */
107 #define PORT_IMX	62
108 
109 /* Marvell MPSC */
110 #define PORT_MPSC	63
111 
112 /* TXX9 type number */
113 #define PORT_TXX9	64
114 
115 /* NEC VR4100 series SIU/DSIU */
116 #define PORT_VR41XX_SIU		65
117 #define PORT_VR41XX_DSIU	66
118 
119 /* Samsung S3C2400 SoC */
120 #define PORT_S3C2400	67
121 
122 /* M32R SIO */
123 #define PORT_M32R_SIO	68
124 
125 /*Digi jsm */
126 #define PORT_JSM        69
127 
128 #define PORT_PNX8XXX	70
129 
130 /* Hilscher netx */
131 #define PORT_NETX	71
132 
133 /* SUN4V Hypervisor Console */
134 #define PORT_SUNHV	72
135 
136 #define PORT_S3C2412	73
137 
138 /* Xilinx uartlite */
139 #define PORT_UARTLITE	74
140 
141 /* Blackfin bf5xx */
142 #define PORT_BFIN	75
143 
144 /* Micrel KS8695 */
145 #define PORT_KS8695	76
146 
147 /* Broadcom SB1250, etc. SOC */
148 #define PORT_SB1250_DUART	77
149 
150 /* Freescale ColdFire */
151 #define PORT_MCF	78
152 
153 /* Blackfin SPORT */
154 #define PORT_BFIN_SPORT		79
155 
156 /* MN10300 on-chip UART numbers */
157 #define PORT_MN10300		80
158 #define PORT_MN10300_CTS	81
159 
160 #define PORT_SC26XX	82
161 
162 /* SH-SCI */
163 #define PORT_SCIFA	83
164 
165 #define PORT_S3C6400	84
166 
167 /* NWPSERIAL */
168 #define PORT_NWPSERIAL	85
169 
170 /* MAX3100 */
171 #define PORT_MAX3100    86
172 
173 /* Timberdale UART */
174 #define PORT_TIMBUART	87
175 
176 /* Qualcomm MSM SoCs */
177 #define PORT_MSM	88
178 
179 #ifdef __KERNEL__
180 
181 #include <linux/compiler.h>
182 #include <linux/interrupt.h>
183 #include <linux/circ_buf.h>
184 #include <linux/spinlock.h>
185 #include <linux/sched.h>
186 #include <linux/tty.h>
187 #include <linux/mutex.h>
188 #include <linux/sysrq.h>
189 
190 struct uart_port;
191 struct serial_struct;
192 struct device;
193 
194 /*
195  * This structure describes all the operations that can be
196  * done on the physical hardware.
197  */
198 struct uart_ops {
199 	unsigned int	(*tx_empty)(struct uart_port *);
200 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
201 	unsigned int	(*get_mctrl)(struct uart_port *);
202 	void		(*stop_tx)(struct uart_port *);
203 	void		(*start_tx)(struct uart_port *);
204 	void		(*send_xchar)(struct uart_port *, char ch);
205 	void		(*stop_rx)(struct uart_port *);
206 	void		(*enable_ms)(struct uart_port *);
207 	void		(*break_ctl)(struct uart_port *, int ctl);
208 	int		(*startup)(struct uart_port *);
209 	void		(*shutdown)(struct uart_port *);
210 	void		(*flush_buffer)(struct uart_port *);
211 	void		(*set_termios)(struct uart_port *, struct ktermios *new,
212 				       struct ktermios *old);
213 	void		(*set_ldisc)(struct uart_port *);
214 	void		(*pm)(struct uart_port *, unsigned int state,
215 			      unsigned int oldstate);
216 	int		(*set_wake)(struct uart_port *, unsigned int state);
217 
218 	/*
219 	 * Return a string describing the type of the port
220 	 */
221 	const char *(*type)(struct uart_port *);
222 
223 	/*
224 	 * Release IO and memory resources used by the port.
225 	 * This includes iounmap if necessary.
226 	 */
227 	void		(*release_port)(struct uart_port *);
228 
229 	/*
230 	 * Request IO and memory resources used by the port.
231 	 * This includes iomapping the port if necessary.
232 	 */
233 	int		(*request_port)(struct uart_port *);
234 	void		(*config_port)(struct uart_port *, int);
235 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
236 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
237 #ifdef CONFIG_CONSOLE_POLL
238 	void	(*poll_put_char)(struct uart_port *, unsigned char);
239 	int		(*poll_get_char)(struct uart_port *);
240 #endif
241 };
242 
243 #define UART_CONFIG_TYPE	(1 << 0)
244 #define UART_CONFIG_IRQ		(1 << 1)
245 
246 struct uart_icount {
247 	__u32	cts;
248 	__u32	dsr;
249 	__u32	rng;
250 	__u32	dcd;
251 	__u32	rx;
252 	__u32	tx;
253 	__u32	frame;
254 	__u32	overrun;
255 	__u32	parity;
256 	__u32	brk;
257 	__u32	buf_overrun;
258 };
259 
260 typedef unsigned int __bitwise__ upf_t;
261 
262 struct uart_port {
263 	spinlock_t		lock;			/* port lock */
264 	unsigned long		iobase;			/* in/out[bwl] */
265 	unsigned char __iomem	*membase;		/* read/write[bwl] */
266 	unsigned int		(*serial_in)(struct uart_port *, int);
267 	void			(*serial_out)(struct uart_port *, int, int);
268 	unsigned int		irq;			/* irq number */
269 	unsigned long		irqflags;		/* irq flags  */
270 	unsigned int		uartclk;		/* base uart clock */
271 	unsigned int		fifosize;		/* tx fifo size */
272 	unsigned char		x_char;			/* xon/xoff char */
273 	unsigned char		regshift;		/* reg offset shift */
274 	unsigned char		iotype;			/* io access style */
275 	unsigned char		unused1;
276 
277 #define UPIO_PORT		(0)
278 #define UPIO_HUB6		(1)
279 #define UPIO_MEM		(2)
280 #define UPIO_MEM32		(3)
281 #define UPIO_AU			(4)			/* Au1x00 type IO */
282 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
283 #define UPIO_DWAPB		(6)			/* DesignWare APB UART */
284 #define UPIO_RM9000		(7)			/* RM9000 type IO */
285 
286 	unsigned int		read_status_mask;	/* driver specific */
287 	unsigned int		ignore_status_mask;	/* driver specific */
288 	struct uart_state	*state;			/* pointer to parent state */
289 	struct uart_icount	icount;			/* statistics */
290 
291 	struct console		*cons;			/* struct console, if any */
292 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
293 	unsigned long		sysrq;			/* sysrq timeout */
294 #endif
295 
296 	upf_t			flags;
297 
298 #define UPF_FOURPORT		((__force upf_t) (1 << 1))
299 #define UPF_SAK			((__force upf_t) (1 << 2))
300 #define UPF_SPD_MASK		((__force upf_t) (0x1030))
301 #define UPF_SPD_HI		((__force upf_t) (0x0010))
302 #define UPF_SPD_VHI		((__force upf_t) (0x0020))
303 #define UPF_SPD_CUST		((__force upf_t) (0x0030))
304 #define UPF_SPD_SHI		((__force upf_t) (0x1000))
305 #define UPF_SPD_WARP		((__force upf_t) (0x1010))
306 #define UPF_SKIP_TEST		((__force upf_t) (1 << 6))
307 #define UPF_AUTO_IRQ		((__force upf_t) (1 << 7))
308 #define UPF_HARDPPS_CD		((__force upf_t) (1 << 11))
309 #define UPF_LOW_LATENCY		((__force upf_t) (1 << 13))
310 #define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
311 #define UPF_NO_TXEN_TEST	((__force upf_t) (1 << 15))
312 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
313 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
314 #define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
315 /* The exact UART type is known and should not be probed.  */
316 #define UPF_FIXED_TYPE		((__force upf_t) (1 << 27))
317 #define UPF_BOOT_AUTOCONF	((__force upf_t) (1 << 28))
318 #define UPF_FIXED_PORT		((__force upf_t) (1 << 29))
319 #define UPF_DEAD		((__force upf_t) (1 << 30))
320 #define UPF_IOREMAP		((__force upf_t) (1 << 31))
321 
322 #define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
323 #define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
324 
325 	unsigned int		mctrl;			/* current modem ctrl settings */
326 	unsigned int		timeout;		/* character-based timeout */
327 	unsigned int		type;			/* port type */
328 	const struct uart_ops	*ops;
329 	unsigned int		custom_divisor;
330 	unsigned int		line;			/* port index */
331 	resource_size_t		mapbase;		/* for ioremap */
332 	struct device		*dev;			/* parent device */
333 	unsigned char		hub6;			/* this should be in the 8250 driver */
334 	unsigned char		suspended;
335 	unsigned char		unused[2];
336 	void			*private_data;		/* generic platform data pointer */
337 };
338 
339 /*
340  * This is the state information which is persistent across opens.
341  */
342 struct uart_state {
343 	struct tty_port		port;
344 
345 	int			pm_state;
346 	struct circ_buf		xmit;
347 
348 	struct tasklet_struct	tlet;
349 	struct uart_port	*uart_port;
350 };
351 
352 #define UART_XMIT_SIZE	PAGE_SIZE
353 
354 
355 /* number of characters left in xmit buffer before we ask for more */
356 #define WAKEUP_CHARS		256
357 
358 struct module;
359 struct tty_driver;
360 
361 struct uart_driver {
362 	struct module		*owner;
363 	const char		*driver_name;
364 	const char		*dev_name;
365 	int			 major;
366 	int			 minor;
367 	int			 nr;
368 	struct console		*cons;
369 
370 	/*
371 	 * these are private; the low level driver should not
372 	 * touch these; they should be initialised to NULL
373 	 */
374 	struct uart_state	*state;
375 	struct tty_driver	*tty_driver;
376 };
377 
378 void uart_write_wakeup(struct uart_port *port);
379 
380 /*
381  * Baud rate helpers.
382  */
383 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
384 			 unsigned int baud);
385 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
386 				struct ktermios *old, unsigned int min,
387 				unsigned int max);
388 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
389 
390 /*
391  * Console helpers.
392  */
393 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
394 				   struct console *c);
395 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
396 			int *flow);
397 int uart_set_options(struct uart_port *port, struct console *co, int baud,
398 		     int parity, int bits, int flow);
399 struct tty_driver *uart_console_device(struct console *co, int *index);
400 void uart_console_write(struct uart_port *port, const char *s,
401 			unsigned int count,
402 			void (*putchar)(struct uart_port *, int));
403 
404 /*
405  * Port/driver registration/removal
406  */
407 int uart_register_driver(struct uart_driver *uart);
408 void uart_unregister_driver(struct uart_driver *uart);
409 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
410 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
411 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
412 
413 /*
414  * Power Management
415  */
416 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
417 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
418 
419 #define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
420 #define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)
421 
422 #define uart_circ_chars_pending(circ)	\
423 	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
424 
425 #define uart_circ_chars_free(circ)	\
426 	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
427 
428 static inline int uart_tx_stopped(struct uart_port *port)
429 {
430 	struct tty_struct *tty = port->state->port.tty;
431 	if(tty->stopped || tty->hw_stopped)
432 		return 1;
433 	return 0;
434 }
435 
436 /*
437  * The following are helper functions for the low level drivers.
438  */
439 static inline int
440 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
441 {
442 #ifdef SUPPORT_SYSRQ
443 	if (port->sysrq) {
444 		if (ch && time_before(jiffies, port->sysrq)) {
445 			handle_sysrq(ch, port->state->port.tty);
446 			port->sysrq = 0;
447 			return 1;
448 		}
449 		port->sysrq = 0;
450 	}
451 #endif
452 	return 0;
453 }
454 #ifndef SUPPORT_SYSRQ
455 #define uart_handle_sysrq_char(port,ch) uart_handle_sysrq_char(port, 0)
456 #endif
457 
458 /*
459  * We do the SysRQ and SAK checking like this...
460  */
461 static inline int uart_handle_break(struct uart_port *port)
462 {
463 	struct uart_state *state = port->state;
464 #ifdef SUPPORT_SYSRQ
465 	if (port->cons && port->cons->index == port->line) {
466 		if (!port->sysrq) {
467 			port->sysrq = jiffies + HZ*5;
468 			return 1;
469 		}
470 		port->sysrq = 0;
471 	}
472 #endif
473 	if (port->flags & UPF_SAK)
474 		do_SAK(state->port.tty);
475 	return 0;
476 }
477 
478 /**
479  *	uart_handle_dcd_change - handle a change of carrier detect state
480  *	@port: uart_port structure for the open port
481  *	@status: new carrier detect status, nonzero if active
482  */
483 static inline void
484 uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
485 {
486 	struct uart_state *state = uport->state;
487 	struct tty_port *port = &state->port;
488 
489 	uport->icount.dcd++;
490 
491 #ifdef CONFIG_HARD_PPS
492 	if ((uport->flags & UPF_HARDPPS_CD) && status)
493 		hardpps();
494 #endif
495 
496 	if (port->flags & ASYNC_CHECK_CD) {
497 		if (status)
498 			wake_up_interruptible(&port->open_wait);
499 		else if (port->tty)
500 			tty_hangup(port->tty);
501 	}
502 }
503 
504 /**
505  *	uart_handle_cts_change - handle a change of clear-to-send state
506  *	@port: uart_port structure for the open port
507  *	@status: new clear to send status, nonzero if active
508  */
509 static inline void
510 uart_handle_cts_change(struct uart_port *uport, unsigned int status)
511 {
512 	struct tty_port *port = &uport->state->port;
513 	struct tty_struct *tty = port->tty;
514 
515 	uport->icount.cts++;
516 
517 	if (port->flags & ASYNC_CTS_FLOW) {
518 		if (tty->hw_stopped) {
519 			if (status) {
520 				tty->hw_stopped = 0;
521 				uport->ops->start_tx(uport);
522 				uart_write_wakeup(uport);
523 			}
524 		} else {
525 			if (!status) {
526 				tty->hw_stopped = 1;
527 				uport->ops->stop_tx(uport);
528 			}
529 		}
530 	}
531 }
532 
533 #include <linux/tty_flip.h>
534 
535 static inline void
536 uart_insert_char(struct uart_port *port, unsigned int status,
537 		 unsigned int overrun, unsigned int ch, unsigned int flag)
538 {
539 	struct tty_struct *tty = port->state->port.tty;
540 
541 	if ((status & port->ignore_status_mask & ~overrun) == 0)
542 		tty_insert_flip_char(tty, ch, flag);
543 
544 	/*
545 	 * Overrun is special.  Since it's reported immediately,
546 	 * it doesn't affect the current character.
547 	 */
548 	if (status & ~port->ignore_status_mask & overrun)
549 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
550 }
551 
552 /*
553  *	UART_ENABLE_MS - determine if port should enable modem status irqs
554  */
555 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
556 					 (cflag) & CRTSCTS || \
557 					 !((cflag) & CLOCAL))
558 
559 #endif
560 
561 #endif /* LINUX_SERIAL_CORE_H */
562