xref: /linux-6.15/include/linux/serial_core.h (revision 4e57b681)
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_IP3106	16
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 /* DZ */
66 #define PORT_DZ		47
67 
68 /* Parisc type numbers. */
69 #define PORT_MUX	48
70 
71 /* Macintosh Zilog type numbers */
72 #define PORT_MAC_ZILOG	50	/* m68k : not yet implemented */
73 #define PORT_PMAC_ZILOG	51
74 
75 /* SH-SCI */
76 #define PORT_SCI	52
77 #define PORT_SCIF	53
78 #define PORT_IRDA	54
79 
80 /* Samsung S3C2410 SoC and derivatives thereof */
81 #define PORT_S3C2410    55
82 
83 /* SGI IP22 aka Indy / Challenge S / Indigo 2 */
84 #define PORT_IP22ZILOG	56
85 
86 /* Sharp LH7a40x -- an ARM9 SoC series */
87 #define PORT_LH7A40X	57
88 
89 /* PPC CPM type number */
90 #define PORT_CPM        58
91 
92 /* MPC52xx type numbers */
93 #define PORT_MPC52xx	59
94 
95 /* IBM icom */
96 #define PORT_ICOM	60
97 
98 /* Samsung S3C2440 SoC */
99 #define PORT_S3C2440	61
100 
101 /* Motorola i.MX SoC */
102 #define PORT_IMX	62
103 
104 /* Marvell MPSC */
105 #define PORT_MPSC	63
106 
107 /* TXX9 type number */
108 #define PORT_TXX9	64
109 
110 /* NEC VR4100 series SIU/DSIU */
111 #define PORT_VR41XX_SIU		65
112 #define PORT_VR41XX_DSIU	66
113 
114 /* Samsung S3C2400 SoC */
115 #define PORT_S3C2400	67
116 
117 /* M32R SIO */
118 #define PORT_M32R_SIO	68
119 
120 /*Digi jsm */
121 #define PORT_JSM        65
122 
123 #ifdef __KERNEL__
124 
125 #include <linux/config.h>
126 #include <linux/compiler.h>
127 #include <linux/interrupt.h>
128 #include <linux/circ_buf.h>
129 #include <linux/spinlock.h>
130 #include <linux/sched.h>
131 #include <linux/tty.h>
132 
133 struct uart_port;
134 struct uart_info;
135 struct serial_struct;
136 struct device;
137 
138 /*
139  * This structure describes all the operations that can be
140  * done on the physical hardware.
141  */
142 struct uart_ops {
143 	unsigned int	(*tx_empty)(struct uart_port *);
144 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
145 	unsigned int	(*get_mctrl)(struct uart_port *);
146 	void		(*stop_tx)(struct uart_port *);
147 	void		(*start_tx)(struct uart_port *);
148 	void		(*send_xchar)(struct uart_port *, char ch);
149 	void		(*stop_rx)(struct uart_port *);
150 	void		(*enable_ms)(struct uart_port *);
151 	void		(*break_ctl)(struct uart_port *, int ctl);
152 	int		(*startup)(struct uart_port *);
153 	void		(*shutdown)(struct uart_port *);
154 	void		(*set_termios)(struct uart_port *, struct termios *new,
155 				       struct termios *old);
156 	void		(*pm)(struct uart_port *, unsigned int state,
157 			      unsigned int oldstate);
158 	int		(*set_wake)(struct uart_port *, unsigned int state);
159 
160 	/*
161 	 * Return a string describing the type of the port
162 	 */
163 	const char *(*type)(struct uart_port *);
164 
165 	/*
166 	 * Release IO and memory resources used by the port.
167 	 * This includes iounmap if necessary.
168 	 */
169 	void		(*release_port)(struct uart_port *);
170 
171 	/*
172 	 * Request IO and memory resources used by the port.
173 	 * This includes iomapping the port if necessary.
174 	 */
175 	int		(*request_port)(struct uart_port *);
176 	void		(*config_port)(struct uart_port *, int);
177 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
178 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
179 };
180 
181 #define UART_CONFIG_TYPE	(1 << 0)
182 #define UART_CONFIG_IRQ		(1 << 1)
183 
184 struct uart_icount {
185 	__u32	cts;
186 	__u32	dsr;
187 	__u32	rng;
188 	__u32	dcd;
189 	__u32	rx;
190 	__u32	tx;
191 	__u32	frame;
192 	__u32	overrun;
193 	__u32	parity;
194 	__u32	brk;
195 	__u32	buf_overrun;
196 };
197 
198 struct uart_port {
199 	spinlock_t		lock;			/* port lock */
200 	unsigned int		iobase;			/* in/out[bwl] */
201 	unsigned char __iomem	*membase;		/* read/write[bwl] */
202 	unsigned int		irq;			/* irq number */
203 	unsigned int		uartclk;		/* base uart clock */
204 	unsigned char		fifosize;		/* tx fifo size */
205 	unsigned char		x_char;			/* xon/xoff char */
206 	unsigned char		regshift;		/* reg offset shift */
207 	unsigned char		iotype;			/* io access style */
208 
209 #define UPIO_PORT		(0)
210 #define UPIO_HUB6		(1)
211 #define UPIO_MEM		(2)
212 #define UPIO_MEM32		(3)
213 
214 	unsigned int		read_status_mask;	/* driver specific */
215 	unsigned int		ignore_status_mask;	/* driver specific */
216 	struct uart_info	*info;			/* pointer to parent info */
217 	struct uart_icount	icount;			/* statistics */
218 
219 	struct console		*cons;			/* struct console, if any */
220 #ifdef CONFIG_SERIAL_CORE_CONSOLE
221 	unsigned long		sysrq;			/* sysrq timeout */
222 #endif
223 
224 	unsigned int		flags;
225 
226 #define UPF_FOURPORT		(1 << 1)
227 #define UPF_SAK			(1 << 2)
228 #define UPF_SPD_MASK		(0x1030)
229 #define UPF_SPD_HI		(0x0010)
230 #define UPF_SPD_VHI		(0x0020)
231 #define UPF_SPD_CUST		(0x0030)
232 #define UPF_SPD_SHI		(0x1000)
233 #define UPF_SPD_WARP		(0x1010)
234 #define UPF_SKIP_TEST		(1 << 6)
235 #define UPF_AUTO_IRQ		(1 << 7)
236 #define UPF_HARDPPS_CD		(1 << 11)
237 #define UPF_LOW_LATENCY		(1 << 13)
238 #define UPF_BUGGY_UART		(1 << 14)
239 #define UPF_AUTOPROBE		(1 << 15)
240 #define UPF_MAGIC_MULTIPLIER	(1 << 16)
241 #define UPF_BOOT_ONLYMCA	(1 << 22)
242 #define UPF_CONS_FLOW		(1 << 23)
243 #define UPF_SHARE_IRQ		(1 << 24)
244 #define UPF_BOOT_AUTOCONF	(1 << 28)
245 #define UPF_IOREMAP		(1 << 31)
246 
247 #define UPF_CHANGE_MASK		(0x17fff)
248 #define UPF_USR_MASK		(UPF_SPD_MASK|UPF_LOW_LATENCY)
249 
250 	unsigned int		mctrl;			/* current modem ctrl settings */
251 	unsigned int		timeout;		/* character-based timeout */
252 	unsigned int		type;			/* port type */
253 	struct uart_ops		*ops;
254 	unsigned int		custom_divisor;
255 	unsigned int		line;			/* port index */
256 	unsigned long		mapbase;		/* for ioremap */
257 	struct device		*dev;			/* parent device */
258 	unsigned char		hub6;			/* this should be in the 8250 driver */
259 	unsigned char		unused[3];
260 };
261 
262 /*
263  * This is the state information which is persistent across opens.
264  * The low level driver must not to touch any elements contained
265  * within.
266  */
267 struct uart_state {
268 	unsigned int		close_delay;		/* msec */
269 	unsigned int		closing_wait;		/* msec */
270 
271 #define USF_CLOSING_WAIT_INF	(0)
272 #define USF_CLOSING_WAIT_NONE	(~0U)
273 
274 	int			count;
275 	int			pm_state;
276 	struct uart_info	*info;
277 	struct uart_port	*port;
278 
279 	struct semaphore	sem;
280 };
281 
282 #define UART_XMIT_SIZE	PAGE_SIZE
283 /*
284  * This is the state information which is only valid when the port
285  * is open; it may be freed by the core driver once the device has
286  * been closed.  Either the low level driver or the core can modify
287  * stuff here.
288  */
289 struct uart_info {
290 	struct tty_struct	*tty;
291 	struct circ_buf		xmit;
292 	unsigned int		flags;
293 
294 /*
295  * These are the flags that specific to info->flags, and reflect our
296  * internal state.  They can not be accessed via port->flags.  Low
297  * level drivers must not change these, but may query them instead.
298  */
299 #define UIF_CHECK_CD		(1 << 25)
300 #define UIF_CTS_FLOW		(1 << 26)
301 #define UIF_NORMAL_ACTIVE	(1 << 29)
302 #define UIF_INITIALIZED		(1 << 31)
303 
304 	int			blocked_open;
305 
306 	struct tasklet_struct	tlet;
307 
308 	wait_queue_head_t	open_wait;
309 	wait_queue_head_t	delta_msr_wait;
310 };
311 
312 /* number of characters left in xmit buffer before we ask for more */
313 #define WAKEUP_CHARS		256
314 
315 struct module;
316 struct tty_driver;
317 
318 struct uart_driver {
319 	struct module		*owner;
320 	const char		*driver_name;
321 	const char		*dev_name;
322 	const char		*devfs_name;
323 	int			 major;
324 	int			 minor;
325 	int			 nr;
326 	struct console		*cons;
327 
328 	/*
329 	 * these are private; the low level driver should not
330 	 * touch these; they should be initialised to NULL
331 	 */
332 	struct uart_state	*state;
333 	struct tty_driver	*tty_driver;
334 };
335 
336 void uart_write_wakeup(struct uart_port *port);
337 
338 /*
339  * Baud rate helpers.
340  */
341 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
342 			 unsigned int baud);
343 unsigned int uart_get_baud_rate(struct uart_port *port, struct termios *termios,
344 				struct termios *old, unsigned int min,
345 				unsigned int max);
346 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
347 
348 /*
349  * Console helpers.
350  */
351 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
352 				   struct console *c);
353 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
354 			int *flow);
355 int uart_set_options(struct uart_port *port, struct console *co, int baud,
356 		     int parity, int bits, int flow);
357 struct tty_driver *uart_console_device(struct console *co, int *index);
358 
359 /*
360  * Port/driver registration/removal
361  */
362 int uart_register_driver(struct uart_driver *uart);
363 void uart_unregister_driver(struct uart_driver *uart);
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 static inline int
390 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch,
391 		       struct pt_regs *regs)
392 {
393 #ifdef SUPPORT_SYSRQ
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 #endif
403 	return 0;
404 }
405 #ifndef SUPPORT_SYSRQ
406 #define uart_handle_sysrq_char(port,ch,regs) uart_handle_sysrq_char(port, 0, NULL)
407 #endif
408 
409 /*
410  * We do the SysRQ and SAK checking like this...
411  */
412 static inline int uart_handle_break(struct uart_port *port)
413 {
414 	struct uart_info *info = port->info;
415 #ifdef SUPPORT_SYSRQ
416 	if (port->cons && port->cons->index == port->line) {
417 		if (!port->sysrq) {
418 			port->sysrq = jiffies + HZ*5;
419 			return 1;
420 		}
421 		port->sysrq = 0;
422 	}
423 #endif
424 	if (info->flags & UPF_SAK)
425 		do_SAK(info->tty);
426 	return 0;
427 }
428 
429 /**
430  *	uart_handle_dcd_change - handle a change of carrier detect state
431  *	@port: uart_port structure for the open port
432  *	@status: new carrier detect status, nonzero if active
433  */
434 static inline void
435 uart_handle_dcd_change(struct uart_port *port, unsigned int status)
436 {
437 	struct uart_info *info = port->info;
438 
439 	port->icount.dcd++;
440 
441 #ifdef CONFIG_HARD_PPS
442 	if ((port->flags & UPF_HARDPPS_CD) && status)
443 		hardpps();
444 #endif
445 
446 	if (info->flags & UIF_CHECK_CD) {
447 		if (status)
448 			wake_up_interruptible(&info->open_wait);
449 		else if (info->tty)
450 			tty_hangup(info->tty);
451 	}
452 }
453 
454 /**
455  *	uart_handle_cts_change - handle a change of clear-to-send state
456  *	@port: uart_port structure for the open port
457  *	@status: new clear to send status, nonzero if active
458  */
459 static inline void
460 uart_handle_cts_change(struct uart_port *port, unsigned int status)
461 {
462 	struct uart_info *info = port->info;
463 	struct tty_struct *tty = info->tty;
464 
465 	port->icount.cts++;
466 
467 	if (info->flags & UIF_CTS_FLOW) {
468 		if (tty->hw_stopped) {
469 			if (status) {
470 				tty->hw_stopped = 0;
471 				port->ops->start_tx(port);
472 				uart_write_wakeup(port);
473 			}
474 		} else {
475 			if (!status) {
476 				tty->hw_stopped = 1;
477 				port->ops->stop_tx(port);
478 			}
479 		}
480 	}
481 }
482 
483 #include <linux/tty_flip.h>
484 
485 static inline void
486 uart_insert_char(struct uart_port *port, unsigned int status,
487 		 unsigned int overrun, unsigned int ch, unsigned int flag)
488 {
489 	struct tty_struct *tty = port->info->tty;
490 
491 	if ((status & port->ignore_status_mask & ~overrun) == 0)
492 		tty_insert_flip_char(tty, ch, flag);
493 
494 	/*
495 	 * Overrun is special.  Since it's reported immediately,
496 	 * it doesn't affect the current character.
497 	 */
498 	if (status & ~port->ignore_status_mask & overrun)
499 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
500 }
501 
502 /*
503  *	UART_ENABLE_MS - determine if port should enable modem status irqs
504  */
505 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
506 					 (cflag) & CRTSCTS || \
507 					 !((cflag) & CLOCAL))
508 
509 #endif
510 
511 #endif /* LINUX_SERIAL_CORE_H */
512