xref: /linux-6.15/include/linux/serial_core.h (revision eb2bce7f)
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_RM9000	16	/* PMC-Sierra RM9xxx internal UART */
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 /* Atmel AT91 / AT32 SoC */
72 #define PORT_ATMEL	49
73 
74 /* Macintosh Zilog type numbers */
75 #define PORT_MAC_ZILOG	50	/* m68k : not yet implemented */
76 #define PORT_PMAC_ZILOG	51
77 
78 /* SH-SCI */
79 #define PORT_SCI	52
80 #define PORT_SCIF	53
81 #define PORT_IRDA	54
82 
83 /* Samsung S3C2410 SoC and derivatives thereof */
84 #define PORT_S3C2410    55
85 
86 /* SGI IP22 aka Indy / Challenge S / Indigo 2 */
87 #define PORT_IP22ZILOG	56
88 
89 /* Sharp LH7a40x -- an ARM9 SoC series */
90 #define PORT_LH7A40X	57
91 
92 /* PPC CPM type number */
93 #define PORT_CPM        58
94 
95 /* MPC52xx type numbers */
96 #define PORT_MPC52xx	59
97 
98 /* IBM icom */
99 #define PORT_ICOM	60
100 
101 /* Samsung S3C2440 SoC */
102 #define PORT_S3C2440	61
103 
104 /* Motorola i.MX SoC */
105 #define PORT_IMX	62
106 
107 /* Marvell MPSC */
108 #define PORT_MPSC	63
109 
110 /* TXX9 type number */
111 #define PORT_TXX9	64
112 
113 /* NEC VR4100 series SIU/DSIU */
114 #define PORT_VR41XX_SIU		65
115 #define PORT_VR41XX_DSIU	66
116 
117 /* Samsung S3C2400 SoC */
118 #define PORT_S3C2400	67
119 
120 /* M32R SIO */
121 #define PORT_M32R_SIO	68
122 
123 /*Digi jsm */
124 #define PORT_JSM        69
125 
126 #define PORT_PNX8XXX	70
127 
128 /* Hilscher netx */
129 #define PORT_NETX	71
130 
131 /* SUN4V Hypervisor Console */
132 #define PORT_SUNHV	72
133 
134 #define PORT_S3C2412	73
135 
136 /* Xilinx uartlite */
137 #define PORT_UARTLITE	74
138 
139 /* Blackfin bf5xx */
140 #define PORT_BFIN	75
141 
142 #ifdef __KERNEL__
143 
144 #include <linux/compiler.h>
145 #include <linux/interrupt.h>
146 #include <linux/circ_buf.h>
147 #include <linux/spinlock.h>
148 #include <linux/sched.h>
149 #include <linux/tty.h>
150 #include <linux/mutex.h>
151 
152 struct uart_port;
153 struct uart_info;
154 struct serial_struct;
155 struct device;
156 
157 /*
158  * This structure describes all the operations that can be
159  * done on the physical hardware.
160  */
161 struct uart_ops {
162 	unsigned int	(*tx_empty)(struct uart_port *);
163 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
164 	unsigned int	(*get_mctrl)(struct uart_port *);
165 	void		(*stop_tx)(struct uart_port *);
166 	void		(*start_tx)(struct uart_port *);
167 	void		(*send_xchar)(struct uart_port *, char ch);
168 	void		(*stop_rx)(struct uart_port *);
169 	void		(*enable_ms)(struct uart_port *);
170 	void		(*break_ctl)(struct uart_port *, int ctl);
171 	int		(*startup)(struct uart_port *);
172 	void		(*shutdown)(struct uart_port *);
173 	void		(*set_termios)(struct uart_port *, struct ktermios *new,
174 				       struct ktermios *old);
175 	void		(*pm)(struct uart_port *, unsigned int state,
176 			      unsigned int oldstate);
177 	int		(*set_wake)(struct uart_port *, unsigned int state);
178 
179 	/*
180 	 * Return a string describing the type of the port
181 	 */
182 	const char *(*type)(struct uart_port *);
183 
184 	/*
185 	 * Release IO and memory resources used by the port.
186 	 * This includes iounmap if necessary.
187 	 */
188 	void		(*release_port)(struct uart_port *);
189 
190 	/*
191 	 * Request IO and memory resources used by the port.
192 	 * This includes iomapping the port if necessary.
193 	 */
194 	int		(*request_port)(struct uart_port *);
195 	void		(*config_port)(struct uart_port *, int);
196 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
197 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
198 };
199 
200 #define UART_CONFIG_TYPE	(1 << 0)
201 #define UART_CONFIG_IRQ		(1 << 1)
202 
203 struct uart_icount {
204 	__u32	cts;
205 	__u32	dsr;
206 	__u32	rng;
207 	__u32	dcd;
208 	__u32	rx;
209 	__u32	tx;
210 	__u32	frame;
211 	__u32	overrun;
212 	__u32	parity;
213 	__u32	brk;
214 	__u32	buf_overrun;
215 };
216 
217 typedef unsigned int __bitwise__ upf_t;
218 
219 struct uart_port {
220 	spinlock_t		lock;			/* port lock */
221 	unsigned int		iobase;			/* in/out[bwl] */
222 	unsigned char __iomem	*membase;		/* read/write[bwl] */
223 	unsigned int		irq;			/* irq number */
224 	unsigned int		uartclk;		/* base uart clock */
225 	unsigned int		fifosize;		/* tx fifo size */
226 	unsigned char		x_char;			/* xon/xoff char */
227 	unsigned char		regshift;		/* reg offset shift */
228 	unsigned char		iotype;			/* io access style */
229 	unsigned char		unused1;
230 
231 #define UPIO_PORT		(0)
232 #define UPIO_HUB6		(1)
233 #define UPIO_MEM		(2)
234 #define UPIO_MEM32		(3)
235 #define UPIO_AU			(4)			/* Au1x00 type IO */
236 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
237 #define UPIO_DWAPB		(6)			/* DesignWare APB UART */
238 #define UPIO_RM9000		(7)			/* RM9000 type IO */
239 
240 	unsigned int		read_status_mask;	/* driver specific */
241 	unsigned int		ignore_status_mask;	/* driver specific */
242 	struct uart_info	*info;			/* pointer to parent info */
243 	struct uart_icount	icount;			/* statistics */
244 
245 	struct console		*cons;			/* struct console, if any */
246 #ifdef CONFIG_SERIAL_CORE_CONSOLE
247 	unsigned long		sysrq;			/* sysrq timeout */
248 #endif
249 
250 	upf_t			flags;
251 
252 #define UPF_FOURPORT		((__force upf_t) (1 << 1))
253 #define UPF_SAK			((__force upf_t) (1 << 2))
254 #define UPF_SPD_MASK		((__force upf_t) (0x1030))
255 #define UPF_SPD_HI		((__force upf_t) (0x0010))
256 #define UPF_SPD_VHI		((__force upf_t) (0x0020))
257 #define UPF_SPD_CUST		((__force upf_t) (0x0030))
258 #define UPF_SPD_SHI		((__force upf_t) (0x1000))
259 #define UPF_SPD_WARP		((__force upf_t) (0x1010))
260 #define UPF_SKIP_TEST		((__force upf_t) (1 << 6))
261 #define UPF_AUTO_IRQ		((__force upf_t) (1 << 7))
262 #define UPF_HARDPPS_CD		((__force upf_t) (1 << 11))
263 #define UPF_LOW_LATENCY		((__force upf_t) (1 << 13))
264 #define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
265 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
266 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
267 #define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
268 #define UPF_BOOT_AUTOCONF	((__force upf_t) (1 << 28))
269 #define UPF_FIXED_PORT		((__force upf_t) (1 << 29))
270 #define UPF_DEAD		((__force upf_t) (1 << 30))
271 #define UPF_IOREMAP		((__force upf_t) (1 << 31))
272 
273 #define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
274 #define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
275 
276 	unsigned int		mctrl;			/* current modem ctrl settings */
277 	unsigned int		timeout;		/* character-based timeout */
278 	unsigned int		type;			/* port type */
279 	const struct uart_ops	*ops;
280 	unsigned int		custom_divisor;
281 	unsigned int		line;			/* port index */
282 	unsigned long		mapbase;		/* for ioremap */
283 	struct device		*dev;			/* parent device */
284 	unsigned char		hub6;			/* this should be in the 8250 driver */
285 	unsigned char		unused[3];
286 	void			*private_data;		/* generic platform data pointer */
287 };
288 
289 /*
290  * This is the state information which is persistent across opens.
291  * The low level driver must not to touch any elements contained
292  * within.
293  */
294 struct uart_state {
295 	unsigned int		close_delay;		/* msec */
296 	unsigned int		closing_wait;		/* msec */
297 
298 #define USF_CLOSING_WAIT_INF	(0)
299 #define USF_CLOSING_WAIT_NONE	(~0U)
300 
301 	int			count;
302 	int			pm_state;
303 	struct uart_info	*info;
304 	struct uart_port	*port;
305 
306 	struct mutex		mutex;
307 };
308 
309 #define UART_XMIT_SIZE	PAGE_SIZE
310 
311 typedef unsigned int __bitwise__ uif_t;
312 
313 /*
314  * This is the state information which is only valid when the port
315  * is open; it may be freed by the core driver once the device has
316  * been closed.  Either the low level driver or the core can modify
317  * stuff here.
318  */
319 struct uart_info {
320 	struct tty_struct	*tty;
321 	struct circ_buf		xmit;
322 	uif_t			flags;
323 
324 /*
325  * Definitions for info->flags.  These are _private_ to serial_core, and
326  * are specific to this structure.  They may be queried by low level drivers.
327  */
328 #define UIF_CHECK_CD		((__force uif_t) (1 << 25))
329 #define UIF_CTS_FLOW		((__force uif_t) (1 << 26))
330 #define UIF_NORMAL_ACTIVE	((__force uif_t) (1 << 29))
331 #define UIF_INITIALIZED		((__force uif_t) (1 << 31))
332 #define UIF_SUSPENDED		((__force uif_t) (1 << 30))
333 
334 	int			blocked_open;
335 
336 	struct tasklet_struct	tlet;
337 
338 	wait_queue_head_t	open_wait;
339 	wait_queue_head_t	delta_msr_wait;
340 };
341 
342 /* number of characters left in xmit buffer before we ask for more */
343 #define WAKEUP_CHARS		256
344 
345 struct module;
346 struct tty_driver;
347 
348 struct uart_driver {
349 	struct module		*owner;
350 	const char		*driver_name;
351 	const char		*dev_name;
352 	int			 major;
353 	int			 minor;
354 	int			 nr;
355 	struct console		*cons;
356 
357 	/*
358 	 * these are private; the low level driver should not
359 	 * touch these; they should be initialised to NULL
360 	 */
361 	struct uart_state	*state;
362 	struct tty_driver	*tty_driver;
363 };
364 
365 void uart_write_wakeup(struct uart_port *port);
366 
367 /*
368  * Baud rate helpers.
369  */
370 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
371 			 unsigned int baud);
372 unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
373 				struct ktermios *old, unsigned int min,
374 				unsigned int max);
375 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
376 
377 /*
378  * Console helpers.
379  */
380 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
381 				   struct console *c);
382 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
383 			int *flow);
384 int uart_set_options(struct uart_port *port, struct console *co, int baud,
385 		     int parity, int bits, int flow);
386 struct tty_driver *uart_console_device(struct console *co, int *index);
387 void uart_console_write(struct uart_port *port, const char *s,
388 			unsigned int count,
389 			void (*putchar)(struct uart_port *, int));
390 
391 /*
392  * Port/driver registration/removal
393  */
394 int uart_register_driver(struct uart_driver *uart);
395 void uart_unregister_driver(struct uart_driver *uart);
396 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
397 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
398 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
399 
400 /*
401  * Power Management
402  */
403 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
404 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
405 
406 #define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
407 #define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)
408 
409 #define uart_circ_chars_pending(circ)	\
410 	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
411 
412 #define uart_circ_chars_free(circ)	\
413 	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
414 
415 #define uart_tx_stopped(port)		\
416 	((port)->info->tty->stopped || (port)->info->tty->hw_stopped)
417 
418 /*
419  * The following are helper functions for the low level drivers.
420  */
421 static inline int
422 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
423 {
424 #ifdef SUPPORT_SYSRQ
425 	if (port->sysrq) {
426 		if (ch && time_before(jiffies, port->sysrq)) {
427 			handle_sysrq(ch, port->info->tty);
428 			port->sysrq = 0;
429 			return 1;
430 		}
431 		port->sysrq = 0;
432 	}
433 #endif
434 	return 0;
435 }
436 #ifndef SUPPORT_SYSRQ
437 #define uart_handle_sysrq_char(port,ch) uart_handle_sysrq_char(port, 0)
438 #endif
439 
440 /*
441  * We do the SysRQ and SAK checking like this...
442  */
443 static inline int uart_handle_break(struct uart_port *port)
444 {
445 	struct uart_info *info = port->info;
446 #ifdef SUPPORT_SYSRQ
447 	if (port->cons && port->cons->index == port->line) {
448 		if (!port->sysrq) {
449 			port->sysrq = jiffies + HZ*5;
450 			return 1;
451 		}
452 		port->sysrq = 0;
453 	}
454 #endif
455 	if (port->flags & UPF_SAK)
456 		do_SAK(info->tty);
457 	return 0;
458 }
459 
460 /**
461  *	uart_handle_dcd_change - handle a change of carrier detect state
462  *	@port: uart_port structure for the open port
463  *	@status: new carrier detect status, nonzero if active
464  */
465 static inline void
466 uart_handle_dcd_change(struct uart_port *port, unsigned int status)
467 {
468 	struct uart_info *info = port->info;
469 
470 	port->icount.dcd++;
471 
472 #ifdef CONFIG_HARD_PPS
473 	if ((port->flags & UPF_HARDPPS_CD) && status)
474 		hardpps();
475 #endif
476 
477 	if (info->flags & UIF_CHECK_CD) {
478 		if (status)
479 			wake_up_interruptible(&info->open_wait);
480 		else if (info->tty)
481 			tty_hangup(info->tty);
482 	}
483 }
484 
485 /**
486  *	uart_handle_cts_change - handle a change of clear-to-send state
487  *	@port: uart_port structure for the open port
488  *	@status: new clear to send status, nonzero if active
489  */
490 static inline void
491 uart_handle_cts_change(struct uart_port *port, unsigned int status)
492 {
493 	struct uart_info *info = port->info;
494 	struct tty_struct *tty = info->tty;
495 
496 	port->icount.cts++;
497 
498 	if (info->flags & UIF_CTS_FLOW) {
499 		if (tty->hw_stopped) {
500 			if (status) {
501 				tty->hw_stopped = 0;
502 				port->ops->start_tx(port);
503 				uart_write_wakeup(port);
504 			}
505 		} else {
506 			if (!status) {
507 				tty->hw_stopped = 1;
508 				port->ops->stop_tx(port);
509 			}
510 		}
511 	}
512 }
513 
514 #include <linux/tty_flip.h>
515 
516 static inline void
517 uart_insert_char(struct uart_port *port, unsigned int status,
518 		 unsigned int overrun, unsigned int ch, unsigned int flag)
519 {
520 	struct tty_struct *tty = port->info->tty;
521 
522 	if ((status & port->ignore_status_mask & ~overrun) == 0)
523 		tty_insert_flip_char(tty, ch, flag);
524 
525 	/*
526 	 * Overrun is special.  Since it's reported immediately,
527 	 * it doesn't affect the current character.
528 	 */
529 	if (status & ~port->ignore_status_mask & overrun)
530 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
531 }
532 
533 /*
534  *	UART_ENABLE_MS - determine if port should enable modem status irqs
535  */
536 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
537 					 (cflag) & CRTSCTS || \
538 					 !((cflag) & CLOCAL))
539 
540 #endif
541 
542 #endif /* LINUX_SERIAL_CORE_H */
543