xref: /linux-6.15/include/linux/serial_core.h (revision cd354f1a)
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_MAX_8250	15	/* max port ID */
43 
44 /*
45  * ARM specific type numbers.  These are not currently guaranteed
46  * to be implemented, and will change in the future.  These are
47  * separate so any additions to the old serial.c that occur before
48  * we are merged can be easily merged here.
49  */
50 #define PORT_PXA	31
51 #define PORT_AMBA	32
52 #define PORT_CLPS711X	33
53 #define PORT_SA1100	34
54 #define PORT_UART00	35
55 #define PORT_21285	37
56 
57 /* Sparc type numbers.  */
58 #define PORT_SUNZILOG	38
59 #define PORT_SUNSAB	39
60 
61 /* NEC v850.  */
62 #define PORT_V850E_UART	40
63 
64 /* DZ */
65 #define PORT_DZ		47
66 
67 /* Parisc type numbers. */
68 #define PORT_MUX	48
69 
70 /* Atmel AT91 / AT32 SoC */
71 #define PORT_ATMEL	49
72 
73 /* Macintosh Zilog type numbers */
74 #define PORT_MAC_ZILOG	50	/* m68k : not yet implemented */
75 #define PORT_PMAC_ZILOG	51
76 
77 /* SH-SCI */
78 #define PORT_SCI	52
79 #define PORT_SCIF	53
80 #define PORT_IRDA	54
81 
82 /* Samsung S3C2410 SoC and derivatives thereof */
83 #define PORT_S3C2410    55
84 
85 /* SGI IP22 aka Indy / Challenge S / Indigo 2 */
86 #define PORT_IP22ZILOG	56
87 
88 /* Sharp LH7a40x -- an ARM9 SoC series */
89 #define PORT_LH7A40X	57
90 
91 /* PPC CPM type number */
92 #define PORT_CPM        58
93 
94 /* MPC52xx type numbers */
95 #define PORT_MPC52xx	59
96 
97 /* IBM icom */
98 #define PORT_ICOM	60
99 
100 /* Samsung S3C2440 SoC */
101 #define PORT_S3C2440	61
102 
103 /* Motorola i.MX SoC */
104 #define PORT_IMX	62
105 
106 /* Marvell MPSC */
107 #define PORT_MPSC	63
108 
109 /* TXX9 type number */
110 #define PORT_TXX9	64
111 
112 /* NEC VR4100 series SIU/DSIU */
113 #define PORT_VR41XX_SIU		65
114 #define PORT_VR41XX_DSIU	66
115 
116 /* Samsung S3C2400 SoC */
117 #define PORT_S3C2400	67
118 
119 /* M32R SIO */
120 #define PORT_M32R_SIO	68
121 
122 /*Digi jsm */
123 #define PORT_JSM        69
124 
125 #define PORT_PNX8XXX	70
126 
127 /* Hilscher netx */
128 #define PORT_NETX	71
129 
130 /* SUN4V Hypervisor Console */
131 #define PORT_SUNHV	72
132 
133 #define PORT_S3C2412	73
134 
135 /* Xilinx uartlite */
136 #define PORT_UARTLITE	74
137 
138 #ifdef __KERNEL__
139 
140 #include <linux/compiler.h>
141 #include <linux/interrupt.h>
142 #include <linux/circ_buf.h>
143 #include <linux/spinlock.h>
144 #include <linux/sched.h>
145 #include <linux/tty.h>
146 #include <linux/mutex.h>
147 
148 struct uart_port;
149 struct uart_info;
150 struct serial_struct;
151 struct device;
152 
153 /*
154  * This structure describes all the operations that can be
155  * done on the physical hardware.
156  */
157 struct uart_ops {
158 	unsigned int	(*tx_empty)(struct uart_port *);
159 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
160 	unsigned int	(*get_mctrl)(struct uart_port *);
161 	void		(*stop_tx)(struct uart_port *);
162 	void		(*start_tx)(struct uart_port *);
163 	void		(*send_xchar)(struct uart_port *, char ch);
164 	void		(*stop_rx)(struct uart_port *);
165 	void		(*enable_ms)(struct uart_port *);
166 	void		(*break_ctl)(struct uart_port *, int ctl);
167 	int		(*startup)(struct uart_port *);
168 	void		(*shutdown)(struct uart_port *);
169 	void		(*set_termios)(struct uart_port *, struct ktermios *new,
170 				       struct ktermios *old);
171 	void		(*pm)(struct uart_port *, unsigned int state,
172 			      unsigned int oldstate);
173 	int		(*set_wake)(struct uart_port *, unsigned int state);
174 
175 	/*
176 	 * Return a string describing the type of the port
177 	 */
178 	const char *(*type)(struct uart_port *);
179 
180 	/*
181 	 * Release IO and memory resources used by the port.
182 	 * This includes iounmap if necessary.
183 	 */
184 	void		(*release_port)(struct uart_port *);
185 
186 	/*
187 	 * Request IO and memory resources used by the port.
188 	 * This includes iomapping the port if necessary.
189 	 */
190 	int		(*request_port)(struct uart_port *);
191 	void		(*config_port)(struct uart_port *, int);
192 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
193 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
194 };
195 
196 #define UART_CONFIG_TYPE	(1 << 0)
197 #define UART_CONFIG_IRQ		(1 << 1)
198 
199 struct uart_icount {
200 	__u32	cts;
201 	__u32	dsr;
202 	__u32	rng;
203 	__u32	dcd;
204 	__u32	rx;
205 	__u32	tx;
206 	__u32	frame;
207 	__u32	overrun;
208 	__u32	parity;
209 	__u32	brk;
210 	__u32	buf_overrun;
211 };
212 
213 typedef unsigned int __bitwise__ upf_t;
214 
215 struct uart_port {
216 	spinlock_t		lock;			/* port lock */
217 	unsigned int		iobase;			/* in/out[bwl] */
218 	unsigned char __iomem	*membase;		/* read/write[bwl] */
219 	unsigned int		irq;			/* irq number */
220 	unsigned int		uartclk;		/* base uart clock */
221 	unsigned int		fifosize;		/* tx fifo size */
222 	unsigned char		x_char;			/* xon/xoff char */
223 	unsigned char		regshift;		/* reg offset shift */
224 	unsigned char		iotype;			/* io access style */
225 	unsigned char		unused1;
226 
227 #define UPIO_PORT		(0)
228 #define UPIO_HUB6		(1)
229 #define UPIO_MEM		(2)
230 #define UPIO_MEM32		(3)
231 #define UPIO_AU			(4)			/* Au1x00 type IO */
232 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
233 
234 	unsigned int		read_status_mask;	/* driver specific */
235 	unsigned int		ignore_status_mask;	/* driver specific */
236 	struct uart_info	*info;			/* pointer to parent info */
237 	struct uart_icount	icount;			/* statistics */
238 
239 	struct console		*cons;			/* struct console, if any */
240 #ifdef CONFIG_SERIAL_CORE_CONSOLE
241 	unsigned long		sysrq;			/* sysrq timeout */
242 #endif
243 
244 	upf_t			flags;
245 
246 #define UPF_FOURPORT		((__force upf_t) (1 << 1))
247 #define UPF_SAK			((__force upf_t) (1 << 2))
248 #define UPF_SPD_MASK		((__force upf_t) (0x1030))
249 #define UPF_SPD_HI		((__force upf_t) (0x0010))
250 #define UPF_SPD_VHI		((__force upf_t) (0x0020))
251 #define UPF_SPD_CUST		((__force upf_t) (0x0030))
252 #define UPF_SPD_SHI		((__force upf_t) (0x1000))
253 #define UPF_SPD_WARP		((__force upf_t) (0x1010))
254 #define UPF_SKIP_TEST		((__force upf_t) (1 << 6))
255 #define UPF_AUTO_IRQ		((__force upf_t) (1 << 7))
256 #define UPF_HARDPPS_CD		((__force upf_t) (1 << 11))
257 #define UPF_LOW_LATENCY		((__force upf_t) (1 << 13))
258 #define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
259 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
260 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
261 #define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
262 #define UPF_BOOT_AUTOCONF	((__force upf_t) (1 << 28))
263 #define UPF_DEAD		((__force upf_t) (1 << 30))
264 #define UPF_IOREMAP		((__force upf_t) (1 << 31))
265 
266 #define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
267 #define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
268 
269 	unsigned int		mctrl;			/* current modem ctrl settings */
270 	unsigned int		timeout;		/* character-based timeout */
271 	unsigned int		type;			/* port type */
272 	const struct uart_ops	*ops;
273 	unsigned int		custom_divisor;
274 	unsigned int		line;			/* port index */
275 	unsigned long		mapbase;		/* for ioremap */
276 	struct device		*dev;			/* parent device */
277 	unsigned char		hub6;			/* this should be in the 8250 driver */
278 	unsigned char		unused[3];
279 };
280 
281 /*
282  * This is the state information which is persistent across opens.
283  * The low level driver must not to touch any elements contained
284  * within.
285  */
286 struct uart_state {
287 	unsigned int		close_delay;		/* msec */
288 	unsigned int		closing_wait;		/* msec */
289 
290 #define USF_CLOSING_WAIT_INF	(0)
291 #define USF_CLOSING_WAIT_NONE	(~0U)
292 
293 	int			count;
294 	int			pm_state;
295 	struct uart_info	*info;
296 	struct uart_port	*port;
297 
298 	struct mutex		mutex;
299 };
300 
301 #define UART_XMIT_SIZE	PAGE_SIZE
302 
303 typedef unsigned int __bitwise__ uif_t;
304 
305 /*
306  * This is the state information which is only valid when the port
307  * is open; it may be freed by the core driver once the device has
308  * been closed.  Either the low level driver or the core can modify
309  * stuff here.
310  */
311 struct uart_info {
312 	struct tty_struct	*tty;
313 	struct circ_buf		xmit;
314 	uif_t			flags;
315 
316 /*
317  * Definitions for info->flags.  These are _private_ to serial_core, and
318  * are specific to this structure.  They may be queried by low level drivers.
319  */
320 #define UIF_CHECK_CD		((__force uif_t) (1 << 25))
321 #define UIF_CTS_FLOW		((__force uif_t) (1 << 26))
322 #define UIF_NORMAL_ACTIVE	((__force uif_t) (1 << 29))
323 #define UIF_INITIALIZED		((__force uif_t) (1 << 31))
324 #define UIF_SUSPENDED		((__force uif_t) (1 << 30))
325 
326 	int			blocked_open;
327 
328 	struct tasklet_struct	tlet;
329 
330 	wait_queue_head_t	open_wait;
331 	wait_queue_head_t	delta_msr_wait;
332 };
333 
334 /* number of characters left in xmit buffer before we ask for more */
335 #define WAKEUP_CHARS		256
336 
337 struct module;
338 struct tty_driver;
339 
340 struct uart_driver {
341 	struct module		*owner;
342 	const char		*driver_name;
343 	const char		*dev_name;
344 	int			 major;
345 	int			 minor;
346 	int			 nr;
347 	struct console		*cons;
348 
349 	/*
350 	 * these are private; the low level driver should not
351 	 * touch these; they should be initialised to NULL
352 	 */
353 	struct uart_state	*state;
354 	struct tty_driver	*tty_driver;
355 };
356 
357 void uart_write_wakeup(struct uart_port *port);
358 
359 /*
360  * Baud rate helpers.
361  */
362 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
363 			 unsigned int baud);
364 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
365 				struct ktermios *old, unsigned int min,
366 				unsigned int max);
367 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
368 
369 /*
370  * Console helpers.
371  */
372 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
373 				   struct console *c);
374 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
375 			int *flow);
376 int uart_set_options(struct uart_port *port, struct console *co, int baud,
377 		     int parity, int bits, int flow);
378 struct tty_driver *uart_console_device(struct console *co, int *index);
379 void uart_console_write(struct uart_port *port, const char *s,
380 			unsigned int count,
381 			void (*putchar)(struct uart_port *, int));
382 
383 /*
384  * Port/driver registration/removal
385  */
386 int uart_register_driver(struct uart_driver *uart);
387 void uart_unregister_driver(struct uart_driver *uart);
388 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
389 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
390 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
391 
392 /*
393  * Power Management
394  */
395 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
396 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
397 
398 #define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
399 #define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)
400 
401 #define uart_circ_chars_pending(circ)	\
402 	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
403 
404 #define uart_circ_chars_free(circ)	\
405 	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
406 
407 #define uart_tx_stopped(port)		\
408 	((port)->info->tty->stopped || (port)->info->tty->hw_stopped)
409 
410 /*
411  * The following are helper functions for the low level drivers.
412  */
413 static inline int
414 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
415 {
416 #ifdef SUPPORT_SYSRQ
417 	if (port->sysrq) {
418 		if (ch && time_before(jiffies, port->sysrq)) {
419 			handle_sysrq(ch, port->info->tty);
420 			port->sysrq = 0;
421 			return 1;
422 		}
423 		port->sysrq = 0;
424 	}
425 #endif
426 	return 0;
427 }
428 #ifndef SUPPORT_SYSRQ
429 #define uart_handle_sysrq_char(port,ch) uart_handle_sysrq_char(port, 0)
430 #endif
431 
432 /*
433  * We do the SysRQ and SAK checking like this...
434  */
435 static inline int uart_handle_break(struct uart_port *port)
436 {
437 	struct uart_info *info = port->info;
438 #ifdef SUPPORT_SYSRQ
439 	if (port->cons && port->cons->index == port->line) {
440 		if (!port->sysrq) {
441 			port->sysrq = jiffies + HZ*5;
442 			return 1;
443 		}
444 		port->sysrq = 0;
445 	}
446 #endif
447 	if (port->flags & UPF_SAK)
448 		do_SAK(info->tty);
449 	return 0;
450 }
451 
452 /**
453  *	uart_handle_dcd_change - handle a change of carrier detect state
454  *	@port: uart_port structure for the open port
455  *	@status: new carrier detect status, nonzero if active
456  */
457 static inline void
458 uart_handle_dcd_change(struct uart_port *port, unsigned int status)
459 {
460 	struct uart_info *info = port->info;
461 
462 	port->icount.dcd++;
463 
464 #ifdef CONFIG_HARD_PPS
465 	if ((port->flags & UPF_HARDPPS_CD) && status)
466 		hardpps();
467 #endif
468 
469 	if (info->flags & UIF_CHECK_CD) {
470 		if (status)
471 			wake_up_interruptible(&info->open_wait);
472 		else if (info->tty)
473 			tty_hangup(info->tty);
474 	}
475 }
476 
477 /**
478  *	uart_handle_cts_change - handle a change of clear-to-send state
479  *	@port: uart_port structure for the open port
480  *	@status: new clear to send status, nonzero if active
481  */
482 static inline void
483 uart_handle_cts_change(struct uart_port *port, unsigned int status)
484 {
485 	struct uart_info *info = port->info;
486 	struct tty_struct *tty = info->tty;
487 
488 	port->icount.cts++;
489 
490 	if (info->flags & UIF_CTS_FLOW) {
491 		if (tty->hw_stopped) {
492 			if (status) {
493 				tty->hw_stopped = 0;
494 				port->ops->start_tx(port);
495 				uart_write_wakeup(port);
496 			}
497 		} else {
498 			if (!status) {
499 				tty->hw_stopped = 1;
500 				port->ops->stop_tx(port);
501 			}
502 		}
503 	}
504 }
505 
506 #include <linux/tty_flip.h>
507 
508 static inline void
509 uart_insert_char(struct uart_port *port, unsigned int status,
510 		 unsigned int overrun, unsigned int ch, unsigned int flag)
511 {
512 	struct tty_struct *tty = port->info->tty;
513 
514 	if ((status & port->ignore_status_mask & ~overrun) == 0)
515 		tty_insert_flip_char(tty, ch, flag);
516 
517 	/*
518 	 * Overrun is special.  Since it's reported immediately,
519 	 * it doesn't affect the current character.
520 	 */
521 	if (status & ~port->ignore_status_mask & overrun)
522 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
523 }
524 
525 /*
526  *	UART_ENABLE_MS - determine if port should enable modem status irqs
527  */
528 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
529 					 (cflag) & CRTSCTS || \
530 					 !((cflag) & CLOCAL))
531 
532 #endif
533 
534 #endif /* LINUX_SERIAL_CORE_H */
535