xref: /linux-6.15/include/linux/serial_core.h (revision 4bedea94)
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 /* Macintosh Zilog type numbers */
71 #define PORT_MAC_ZILOG	50	/* m68k : not yet implemented */
72 #define PORT_PMAC_ZILOG	51
73 
74 /* SH-SCI */
75 #define PORT_SCI	52
76 #define PORT_SCIF	53
77 #define PORT_IRDA	54
78 
79 /* Samsung S3C2410 SoC and derivatives thereof */
80 #define PORT_S3C2410    55
81 
82 /* SGI IP22 aka Indy / Challenge S / Indigo 2 */
83 #define PORT_IP22ZILOG	56
84 
85 /* Sharp LH7a40x -- an ARM9 SoC series */
86 #define PORT_LH7A40X	57
87 
88 /* PPC CPM type number */
89 #define PORT_CPM        58
90 
91 /* MPC52xx type numbers */
92 #define PORT_MPC52xx	59
93 
94 /* IBM icom */
95 #define PORT_ICOM	60
96 
97 /* Samsung S3C2440 SoC */
98 #define PORT_S3C2440	61
99 
100 /* Motorola i.MX SoC */
101 #define PORT_IMX	62
102 
103 /* Marvell MPSC */
104 #define PORT_MPSC	63
105 
106 /* TXX9 type number */
107 #define PORT_TXX9       64
108 
109 /* NEC VR4100 series SIU/DSIU */
110 #define PORT_VR41XX_SIU		65
111 #define PORT_VR41XX_DSIU	66
112 
113 /* Samsung S3C2400 SoC */
114 #define PORT_S3C2400	67
115 
116 /* M32R SIO */
117 #define PORT_M32R_SIO	68
118 
119 /*Digi jsm */
120 #define PORT_JSM        65
121 
122 #ifdef __KERNEL__
123 
124 #include <linux/config.h>
125 #include <linux/interrupt.h>
126 #include <linux/circ_buf.h>
127 #include <linux/spinlock.h>
128 #include <linux/sched.h>
129 #include <linux/tty.h>
130 
131 struct uart_port;
132 struct uart_info;
133 struct serial_struct;
134 struct device;
135 
136 /*
137  * This structure describes all the operations that can be
138  * done on the physical hardware.
139  */
140 struct uart_ops {
141 	unsigned int	(*tx_empty)(struct uart_port *);
142 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
143 	unsigned int	(*get_mctrl)(struct uart_port *);
144 	void		(*stop_tx)(struct uart_port *, unsigned int tty_stop);
145 	void		(*start_tx)(struct uart_port *, unsigned int tty_start);
146 	void		(*send_xchar)(struct uart_port *, char ch);
147 	void		(*stop_rx)(struct uart_port *);
148 	void		(*enable_ms)(struct uart_port *);
149 	void		(*break_ctl)(struct uart_port *, int ctl);
150 	int		(*startup)(struct uart_port *);
151 	void		(*shutdown)(struct uart_port *);
152 	void		(*set_termios)(struct uart_port *, struct termios *new,
153 				       struct termios *old);
154 	void		(*pm)(struct uart_port *, unsigned int state,
155 			      unsigned int oldstate);
156 	int		(*set_wake)(struct uart_port *, unsigned int state);
157 
158 	/*
159 	 * Return a string describing the type of the port
160 	 */
161 	const char *(*type)(struct uart_port *);
162 
163 	/*
164 	 * Release IO and memory resources used by the port.
165 	 * This includes iounmap if necessary.
166 	 */
167 	void		(*release_port)(struct uart_port *);
168 
169 	/*
170 	 * Request IO and memory resources used by the port.
171 	 * This includes iomapping the port if necessary.
172 	 */
173 	int		(*request_port)(struct uart_port *);
174 	void		(*config_port)(struct uart_port *, int);
175 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
176 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
177 };
178 
179 #define UART_CONFIG_TYPE	(1 << 0)
180 #define UART_CONFIG_IRQ		(1 << 1)
181 
182 struct uart_icount {
183 	__u32	cts;
184 	__u32	dsr;
185 	__u32	rng;
186 	__u32	dcd;
187 	__u32	rx;
188 	__u32	tx;
189 	__u32	frame;
190 	__u32	overrun;
191 	__u32	parity;
192 	__u32	brk;
193 	__u32	buf_overrun;
194 };
195 
196 struct uart_port {
197 	spinlock_t		lock;			/* port lock */
198 	unsigned int		iobase;			/* in/out[bwl] */
199 	unsigned char __iomem	*membase;		/* read/write[bwl] */
200 	unsigned int		irq;			/* irq number */
201 	unsigned int		uartclk;		/* base uart clock */
202 	unsigned char		fifosize;		/* tx fifo size */
203 	unsigned char		x_char;			/* xon/xoff char */
204 	unsigned char		regshift;		/* reg offset shift */
205 	unsigned char		iotype;			/* io access style */
206 
207 #define UPIO_PORT		(0)
208 #define UPIO_HUB6		(1)
209 #define UPIO_MEM		(2)
210 #define UPIO_MEM32		(3)
211 
212 	unsigned int		read_status_mask;	/* driver specific */
213 	unsigned int		ignore_status_mask;	/* driver specific */
214 	struct uart_info	*info;			/* pointer to parent info */
215 	struct uart_icount	icount;			/* statistics */
216 
217 	struct console		*cons;			/* struct console, if any */
218 #ifdef CONFIG_SERIAL_CORE_CONSOLE
219 	unsigned long		sysrq;			/* sysrq timeout */
220 #endif
221 
222 	unsigned int		flags;
223 
224 #define UPF_FOURPORT		(1 << 1)
225 #define UPF_SAK			(1 << 2)
226 #define UPF_SPD_MASK		(0x1030)
227 #define UPF_SPD_HI		(0x0010)
228 #define UPF_SPD_VHI		(0x0020)
229 #define UPF_SPD_CUST		(0x0030)
230 #define UPF_SPD_SHI		(0x1000)
231 #define UPF_SPD_WARP		(0x1010)
232 #define UPF_SKIP_TEST		(1 << 6)
233 #define UPF_AUTO_IRQ		(1 << 7)
234 #define UPF_HARDPPS_CD		(1 << 11)
235 #define UPF_LOW_LATENCY		(1 << 13)
236 #define UPF_BUGGY_UART		(1 << 14)
237 #define UPF_AUTOPROBE		(1 << 15)
238 #define UPF_MAGIC_MULTIPLIER	(1 << 16)
239 #define UPF_BOOT_ONLYMCA	(1 << 22)
240 #define UPF_CONS_FLOW		(1 << 23)
241 #define UPF_SHARE_IRQ		(1 << 24)
242 #define UPF_BOOT_AUTOCONF	(1 << 28)
243 #define UPF_IOREMAP		(1 << 31)
244 
245 #define UPF_CHANGE_MASK		(0x17fff)
246 #define UPF_USR_MASK		(UPF_SPD_MASK|UPF_LOW_LATENCY)
247 
248 	unsigned int		mctrl;			/* current modem ctrl settings */
249 	unsigned int		timeout;		/* character-based timeout */
250 	unsigned int		type;			/* port type */
251 	struct uart_ops		*ops;
252 	unsigned int		custom_divisor;
253 	unsigned int		line;			/* port index */
254 	unsigned long		mapbase;		/* for ioremap */
255 	struct device		*dev;			/* parent device */
256 	unsigned char		hub6;			/* this should be in the 8250 driver */
257 	unsigned char		unused[3];
258 };
259 
260 /*
261  * This is the state information which is persistent across opens.
262  * The low level driver must not to touch any elements contained
263  * within.
264  */
265 struct uart_state {
266 	unsigned int		close_delay;		/* msec */
267 	unsigned int		closing_wait;		/* msec */
268 
269 #define USF_CLOSING_WAIT_INF	(0)
270 #define USF_CLOSING_WAIT_NONE	(~0U)
271 
272 	int			count;
273 	int			pm_state;
274 	struct uart_info	*info;
275 	struct uart_port	*port;
276 
277 	struct semaphore	sem;
278 };
279 
280 #define UART_XMIT_SIZE	PAGE_SIZE
281 /*
282  * This is the state information which is only valid when the port
283  * is open; it may be freed by the core driver once the device has
284  * been closed.  Either the low level driver or the core can modify
285  * stuff here.
286  */
287 struct uart_info {
288 	struct tty_struct	*tty;
289 	struct circ_buf		xmit;
290 	unsigned int		flags;
291 
292 /*
293  * These are the flags that specific to info->flags, and reflect our
294  * internal state.  They can not be accessed via port->flags.  Low
295  * level drivers must not change these, but may query them instead.
296  */
297 #define UIF_CHECK_CD		(1 << 25)
298 #define UIF_CTS_FLOW		(1 << 26)
299 #define UIF_NORMAL_ACTIVE	(1 << 29)
300 #define UIF_INITIALIZED		(1 << 31)
301 
302 	int			blocked_open;
303 
304 	struct tasklet_struct	tlet;
305 
306 	wait_queue_head_t	open_wait;
307 	wait_queue_head_t	delta_msr_wait;
308 };
309 
310 /* number of characters left in xmit buffer before we ask for more */
311 #define WAKEUP_CHARS		256
312 
313 struct module;
314 struct tty_driver;
315 
316 struct uart_driver {
317 	struct module		*owner;
318 	const char		*driver_name;
319 	const char		*dev_name;
320 	const char		*devfs_name;
321 	int			 major;
322 	int			 minor;
323 	int			 nr;
324 	struct console		*cons;
325 
326 	/*
327 	 * these are private; the low level driver should not
328 	 * touch these; they should be initialised to NULL
329 	 */
330 	struct uart_state	*state;
331 	struct tty_driver	*tty_driver;
332 };
333 
334 void uart_write_wakeup(struct uart_port *port);
335 
336 /*
337  * Baud rate helpers.
338  */
339 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
340 			 unsigned int baud);
341 unsigned int uart_get_baud_rate(struct uart_port *port, struct termios *termios,
342 				struct termios *old, unsigned int min,
343 				unsigned int max);
344 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
345 
346 /*
347  * Console helpers.
348  */
349 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
350 				   struct console *c);
351 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
352 			int *flow);
353 int uart_set_options(struct uart_port *port, struct console *co, int baud,
354 		     int parity, int bits, int flow);
355 struct tty_driver *uart_console_device(struct console *co, int *index);
356 
357 /*
358  * Port/driver registration/removal
359  */
360 int uart_register_driver(struct uart_driver *uart);
361 void uart_unregister_driver(struct uart_driver *uart);
362 void uart_unregister_port(struct uart_driver *reg, int line);
363 int uart_register_port(struct uart_driver *reg, struct uart_port *port);
364 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
365 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
366 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
367 
368 /*
369  * Power Management
370  */
371 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
372 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
373 
374 #define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
375 #define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)
376 
377 #define uart_circ_chars_pending(circ)	\
378 	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
379 
380 #define uart_circ_chars_free(circ)	\
381 	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
382 
383 #define uart_tx_stopped(port)		\
384 	((port)->info->tty->stopped || (port)->info->tty->hw_stopped)
385 
386 /*
387  * The following are helper functions for the low level drivers.
388  */
389 #ifdef SUPPORT_SYSRQ
390 static inline int
391 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch,
392 		       struct pt_regs *regs)
393 {
394 	if (port->sysrq) {
395 		if (ch && time_before(jiffies, port->sysrq)) {
396 			handle_sysrq(ch, regs, NULL);
397 			port->sysrq = 0;
398 			return 1;
399 		}
400 		port->sysrq = 0;
401 	}
402 	return 0;
403 }
404 #else
405 #define uart_handle_sysrq_char(port,ch,regs)	(0)
406 #endif
407 
408 /*
409  * We do the SysRQ and SAK checking like this...
410  */
411 static inline int uart_handle_break(struct uart_port *port)
412 {
413 	struct uart_info *info = port->info;
414 #ifdef SUPPORT_SYSRQ
415 	if (port->cons && port->cons->index == port->line) {
416 		if (!port->sysrq) {
417 			port->sysrq = jiffies + HZ*5;
418 			return 1;
419 		}
420 		port->sysrq = 0;
421 	}
422 #endif
423 	if (info->flags & UPF_SAK)
424 		do_SAK(info->tty);
425 	return 0;
426 }
427 
428 /**
429  *	uart_handle_dcd_change - handle a change of carrier detect state
430  *	@port: uart_port structure for the open port
431  *	@status: new carrier detect status, nonzero if active
432  */
433 static inline void
434 uart_handle_dcd_change(struct uart_port *port, unsigned int status)
435 {
436 	struct uart_info *info = port->info;
437 
438 	port->icount.dcd++;
439 
440 #ifdef CONFIG_HARD_PPS
441 	if ((port->flags & UPF_HARDPPS_CD) && status)
442 		hardpps();
443 #endif
444 
445 	if (info->flags & UIF_CHECK_CD) {
446 		if (status)
447 			wake_up_interruptible(&info->open_wait);
448 		else if (info->tty)
449 			tty_hangup(info->tty);
450 	}
451 }
452 
453 /**
454  *	uart_handle_cts_change - handle a change of clear-to-send state
455  *	@port: uart_port structure for the open port
456  *	@status: new clear to send status, nonzero if active
457  */
458 static inline void
459 uart_handle_cts_change(struct uart_port *port, unsigned int status)
460 {
461 	struct uart_info *info = port->info;
462 	struct tty_struct *tty = info->tty;
463 
464 	port->icount.cts++;
465 
466 	if (info->flags & UIF_CTS_FLOW) {
467 		if (tty->hw_stopped) {
468 			if (status) {
469 				tty->hw_stopped = 0;
470 				port->ops->start_tx(port, 0);
471 				uart_write_wakeup(port);
472 			}
473 		} else {
474 			if (!status) {
475 				tty->hw_stopped = 1;
476 				port->ops->stop_tx(port, 0);
477 			}
478 		}
479 	}
480 }
481 
482 #include <linux/tty_flip.h>
483 
484 static inline void
485 uart_insert_char(struct uart_port *port, unsigned int status,
486 		 unsigned int overrun, unsigned int ch, unsigned int flag)
487 {
488 	struct tty_struct *tty = port->info->tty;
489 
490 	if ((status & port->ignore_status_mask & ~overrun) == 0)
491 		tty_insert_flip_char(tty, ch, flag);
492 
493 	/*
494 	 * Overrun is special.  Since it's reported immediately,
495 	 * it doesn't affect the current character.
496 	 */
497 	if (status & ~port->ignore_status_mask & overrun)
498 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
499 }
500 
501 /*
502  *	UART_ENABLE_MS - determine if port should enable modem status irqs
503  */
504 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
505 					 (cflag) & CRTSCTS || \
506 					 !((cflag) & CLOCAL))
507 
508 #endif
509 
510 #endif /* LINUX_SERIAL_CORE_H */
511