xref: /linux-6.15/include/linux/serial_core.h (revision 5e8d780d)
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 AT91xxx SoC */
71 #define PORT_AT91	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_IP3106	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 
136 #ifdef __KERNEL__
137 
138 #include <linux/compiler.h>
139 #include <linux/interrupt.h>
140 #include <linux/circ_buf.h>
141 #include <linux/spinlock.h>
142 #include <linux/sched.h>
143 #include <linux/tty.h>
144 #include <linux/mutex.h>
145 
146 struct uart_port;
147 struct uart_info;
148 struct serial_struct;
149 struct device;
150 
151 /*
152  * This structure describes all the operations that can be
153  * done on the physical hardware.
154  */
155 struct uart_ops {
156 	unsigned int	(*tx_empty)(struct uart_port *);
157 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
158 	unsigned int	(*get_mctrl)(struct uart_port *);
159 	void		(*stop_tx)(struct uart_port *);
160 	void		(*start_tx)(struct uart_port *);
161 	void		(*send_xchar)(struct uart_port *, char ch);
162 	void		(*stop_rx)(struct uart_port *);
163 	void		(*enable_ms)(struct uart_port *);
164 	void		(*break_ctl)(struct uart_port *, int ctl);
165 	int		(*startup)(struct uart_port *);
166 	void		(*shutdown)(struct uart_port *);
167 	void		(*set_termios)(struct uart_port *, struct termios *new,
168 				       struct termios *old);
169 	void		(*pm)(struct uart_port *, unsigned int state,
170 			      unsigned int oldstate);
171 	int		(*set_wake)(struct uart_port *, unsigned int state);
172 
173 	/*
174 	 * Return a string describing the type of the port
175 	 */
176 	const char *(*type)(struct uart_port *);
177 
178 	/*
179 	 * Release IO and memory resources used by the port.
180 	 * This includes iounmap if necessary.
181 	 */
182 	void		(*release_port)(struct uart_port *);
183 
184 	/*
185 	 * Request IO and memory resources used by the port.
186 	 * This includes iomapping the port if necessary.
187 	 */
188 	int		(*request_port)(struct uart_port *);
189 	void		(*config_port)(struct uart_port *, int);
190 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
191 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
192 };
193 
194 #define UART_CONFIG_TYPE	(1 << 0)
195 #define UART_CONFIG_IRQ		(1 << 1)
196 
197 struct uart_icount {
198 	__u32	cts;
199 	__u32	dsr;
200 	__u32	rng;
201 	__u32	dcd;
202 	__u32	rx;
203 	__u32	tx;
204 	__u32	frame;
205 	__u32	overrun;
206 	__u32	parity;
207 	__u32	brk;
208 	__u32	buf_overrun;
209 };
210 
211 typedef unsigned int __bitwise__ upf_t;
212 
213 struct uart_port {
214 	spinlock_t		lock;			/* port lock */
215 	unsigned int		iobase;			/* in/out[bwl] */
216 	unsigned char __iomem	*membase;		/* read/write[bwl] */
217 	unsigned int		irq;			/* irq number */
218 	unsigned int		uartclk;		/* base uart clock */
219 	unsigned char		fifosize;		/* tx fifo size */
220 	unsigned char		x_char;			/* xon/xoff char */
221 	unsigned char		regshift;		/* reg offset shift */
222 	unsigned char		iotype;			/* io access style */
223 
224 #define UPIO_PORT		(0)
225 #define UPIO_HUB6		(1)
226 #define UPIO_MEM		(2)
227 #define UPIO_MEM32		(3)
228 #define UPIO_AU			(4)			/* Au1x00 type IO */
229 
230 	unsigned int		read_status_mask;	/* driver specific */
231 	unsigned int		ignore_status_mask;	/* driver specific */
232 	struct uart_info	*info;			/* pointer to parent info */
233 	struct uart_icount	icount;			/* statistics */
234 
235 	struct console		*cons;			/* struct console, if any */
236 #ifdef CONFIG_SERIAL_CORE_CONSOLE
237 	unsigned long		sysrq;			/* sysrq timeout */
238 #endif
239 
240 	upf_t			flags;
241 
242 #define UPF_FOURPORT		((__force upf_t) (1 << 1))
243 #define UPF_SAK			((__force upf_t) (1 << 2))
244 #define UPF_SPD_MASK		((__force upf_t) (0x1030))
245 #define UPF_SPD_HI		((__force upf_t) (0x0010))
246 #define UPF_SPD_VHI		((__force upf_t) (0x0020))
247 #define UPF_SPD_CUST		((__force upf_t) (0x0030))
248 #define UPF_SPD_SHI		((__force upf_t) (0x1000))
249 #define UPF_SPD_WARP		((__force upf_t) (0x1010))
250 #define UPF_SKIP_TEST		((__force upf_t) (1 << 6))
251 #define UPF_AUTO_IRQ		((__force upf_t) (1 << 7))
252 #define UPF_HARDPPS_CD		((__force upf_t) (1 << 11))
253 #define UPF_LOW_LATENCY		((__force upf_t) (1 << 13))
254 #define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
255 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
256 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
257 #define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
258 #define UPF_BOOT_AUTOCONF	((__force upf_t) (1 << 28))
259 #define UPF_DEAD		((__force upf_t) (1 << 30))
260 #define UPF_IOREMAP		((__force upf_t) (1 << 31))
261 
262 #define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
263 #define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
264 
265 	unsigned int		mctrl;			/* current modem ctrl settings */
266 	unsigned int		timeout;		/* character-based timeout */
267 	unsigned int		type;			/* port type */
268 	const struct uart_ops	*ops;
269 	unsigned int		custom_divisor;
270 	unsigned int		line;			/* port index */
271 	unsigned long		mapbase;		/* for ioremap */
272 	struct device		*dev;			/* parent device */
273 	unsigned char		hub6;			/* this should be in the 8250 driver */
274 	unsigned char		unused[3];
275 };
276 
277 /*
278  * This is the state information which is persistent across opens.
279  * The low level driver must not to touch any elements contained
280  * within.
281  */
282 struct uart_state {
283 	unsigned int		close_delay;		/* msec */
284 	unsigned int		closing_wait;		/* msec */
285 
286 #define USF_CLOSING_WAIT_INF	(0)
287 #define USF_CLOSING_WAIT_NONE	(~0U)
288 
289 	int			count;
290 	int			pm_state;
291 	struct uart_info	*info;
292 	struct uart_port	*port;
293 
294 	struct mutex		mutex;
295 };
296 
297 #define UART_XMIT_SIZE	PAGE_SIZE
298 
299 typedef unsigned int __bitwise__ uif_t;
300 
301 /*
302  * This is the state information which is only valid when the port
303  * is open; it may be freed by the core driver once the device has
304  * been closed.  Either the low level driver or the core can modify
305  * stuff here.
306  */
307 struct uart_info {
308 	struct tty_struct	*tty;
309 	struct circ_buf		xmit;
310 	uif_t			flags;
311 
312 /*
313  * Definitions for info->flags.  These are _private_ to serial_core, and
314  * are specific to this structure.  They may be queried by low level drivers.
315  */
316 #define UIF_CHECK_CD		((__force uif_t) (1 << 25))
317 #define UIF_CTS_FLOW		((__force uif_t) (1 << 26))
318 #define UIF_NORMAL_ACTIVE	((__force uif_t) (1 << 29))
319 #define UIF_INITIALIZED		((__force uif_t) (1 << 31))
320 
321 	int			blocked_open;
322 
323 	struct tasklet_struct	tlet;
324 
325 	wait_queue_head_t	open_wait;
326 	wait_queue_head_t	delta_msr_wait;
327 };
328 
329 /* number of characters left in xmit buffer before we ask for more */
330 #define WAKEUP_CHARS		256
331 
332 struct module;
333 struct tty_driver;
334 
335 struct uart_driver {
336 	struct module		*owner;
337 	const char		*driver_name;
338 	const char		*dev_name;
339 	int			 major;
340 	int			 minor;
341 	int			 nr;
342 	struct console		*cons;
343 
344 	/*
345 	 * these are private; the low level driver should not
346 	 * touch these; they should be initialised to NULL
347 	 */
348 	struct uart_state	*state;
349 	struct tty_driver	*tty_driver;
350 };
351 
352 void uart_write_wakeup(struct uart_port *port);
353 
354 /*
355  * Baud rate helpers.
356  */
357 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
358 			 unsigned int baud);
359 unsigned int uart_get_baud_rate(struct uart_port *port, struct termios *termios,
360 				struct termios *old, unsigned int min,
361 				unsigned int max);
362 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
363 
364 /*
365  * Console helpers.
366  */
367 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
368 				   struct console *c);
369 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
370 			int *flow);
371 int uart_set_options(struct uart_port *port, struct console *co, int baud,
372 		     int parity, int bits, int flow);
373 struct tty_driver *uart_console_device(struct console *co, int *index);
374 void uart_console_write(struct uart_port *port, const char *s,
375 			unsigned int count,
376 			void (*putchar)(struct uart_port *, int));
377 
378 /*
379  * Port/driver registration/removal
380  */
381 int uart_register_driver(struct uart_driver *uart);
382 void uart_unregister_driver(struct uart_driver *uart);
383 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
384 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
385 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
386 
387 /*
388  * Power Management
389  */
390 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
391 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
392 
393 #define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
394 #define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)
395 
396 #define uart_circ_chars_pending(circ)	\
397 	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
398 
399 #define uart_circ_chars_free(circ)	\
400 	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
401 
402 #define uart_tx_stopped(port)		\
403 	((port)->info->tty->stopped || (port)->info->tty->hw_stopped)
404 
405 /*
406  * The following are helper functions for the low level drivers.
407  */
408 static inline int
409 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch,
410 		       struct pt_regs *regs)
411 {
412 #ifdef SUPPORT_SYSRQ
413 	if (port->sysrq) {
414 		if (ch && time_before(jiffies, port->sysrq)) {
415 			handle_sysrq(ch, regs, NULL);
416 			port->sysrq = 0;
417 			return 1;
418 		}
419 		port->sysrq = 0;
420 	}
421 #endif
422 	return 0;
423 }
424 #ifndef SUPPORT_SYSRQ
425 #define uart_handle_sysrq_char(port,ch,regs) uart_handle_sysrq_char(port, 0, NULL)
426 #endif
427 
428 /*
429  * We do the SysRQ and SAK checking like this...
430  */
431 static inline int uart_handle_break(struct uart_port *port)
432 {
433 	struct uart_info *info = port->info;
434 #ifdef SUPPORT_SYSRQ
435 	if (port->cons && port->cons->index == port->line) {
436 		if (!port->sysrq) {
437 			port->sysrq = jiffies + HZ*5;
438 			return 1;
439 		}
440 		port->sysrq = 0;
441 	}
442 #endif
443 	if (port->flags & UPF_SAK)
444 		do_SAK(info->tty);
445 	return 0;
446 }
447 
448 /**
449  *	uart_handle_dcd_change - handle a change of carrier detect state
450  *	@port: uart_port structure for the open port
451  *	@status: new carrier detect status, nonzero if active
452  */
453 static inline void
454 uart_handle_dcd_change(struct uart_port *port, unsigned int status)
455 {
456 	struct uart_info *info = port->info;
457 
458 	port->icount.dcd++;
459 
460 #ifdef CONFIG_HARD_PPS
461 	if ((port->flags & UPF_HARDPPS_CD) && status)
462 		hardpps();
463 #endif
464 
465 	if (info->flags & UIF_CHECK_CD) {
466 		if (status)
467 			wake_up_interruptible(&info->open_wait);
468 		else if (info->tty)
469 			tty_hangup(info->tty);
470 	}
471 }
472 
473 /**
474  *	uart_handle_cts_change - handle a change of clear-to-send state
475  *	@port: uart_port structure for the open port
476  *	@status: new clear to send status, nonzero if active
477  */
478 static inline void
479 uart_handle_cts_change(struct uart_port *port, unsigned int status)
480 {
481 	struct uart_info *info = port->info;
482 	struct tty_struct *tty = info->tty;
483 
484 	port->icount.cts++;
485 
486 	if (info->flags & UIF_CTS_FLOW) {
487 		if (tty->hw_stopped) {
488 			if (status) {
489 				tty->hw_stopped = 0;
490 				port->ops->start_tx(port);
491 				uart_write_wakeup(port);
492 			}
493 		} else {
494 			if (!status) {
495 				tty->hw_stopped = 1;
496 				port->ops->stop_tx(port);
497 			}
498 		}
499 	}
500 }
501 
502 #include <linux/tty_flip.h>
503 
504 static inline void
505 uart_insert_char(struct uart_port *port, unsigned int status,
506 		 unsigned int overrun, unsigned int ch, unsigned int flag)
507 {
508 	struct tty_struct *tty = port->info->tty;
509 
510 	if ((status & port->ignore_status_mask & ~overrun) == 0)
511 		tty_insert_flip_char(tty, ch, flag);
512 
513 	/*
514 	 * Overrun is special.  Since it's reported immediately,
515 	 * it doesn't affect the current character.
516 	 */
517 	if (status & ~port->ignore_status_mask & overrun)
518 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
519 }
520 
521 /*
522  *	UART_ENABLE_MS - determine if port should enable modem status irqs
523  */
524 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
525 					 (cflag) & CRTSCTS || \
526 					 !((cflag) & CLOCAL))
527 
528 #endif
529 
530 #endif /* LINUX_SERIAL_CORE_H */
531