xref: /linux-6.15/include/linux/serial_core.h (revision 858259cf)
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        69
121 
122 #define PORT_IP3106	70
123 
124 #ifdef __KERNEL__
125 
126 #include <linux/config.h>
127 #include <linux/compiler.h>
128 #include <linux/interrupt.h>
129 #include <linux/circ_buf.h>
130 #include <linux/spinlock.h>
131 #include <linux/sched.h>
132 #include <linux/tty.h>
133 
134 struct uart_port;
135 struct uart_info;
136 struct serial_struct;
137 struct device;
138 
139 /*
140  * This structure describes all the operations that can be
141  * done on the physical hardware.
142  */
143 struct uart_ops {
144 	unsigned int	(*tx_empty)(struct uart_port *);
145 	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
146 	unsigned int	(*get_mctrl)(struct uart_port *);
147 	void		(*stop_tx)(struct uart_port *);
148 	void		(*start_tx)(struct uart_port *);
149 	void		(*send_xchar)(struct uart_port *, char ch);
150 	void		(*stop_rx)(struct uart_port *);
151 	void		(*enable_ms)(struct uart_port *);
152 	void		(*break_ctl)(struct uart_port *, int ctl);
153 	int		(*startup)(struct uart_port *);
154 	void		(*shutdown)(struct uart_port *);
155 	void		(*set_termios)(struct uart_port *, struct termios *new,
156 				       struct termios *old);
157 	void		(*pm)(struct uart_port *, unsigned int state,
158 			      unsigned int oldstate);
159 	int		(*set_wake)(struct uart_port *, unsigned int state);
160 
161 	/*
162 	 * Return a string describing the type of the port
163 	 */
164 	const char *(*type)(struct uart_port *);
165 
166 	/*
167 	 * Release IO and memory resources used by the port.
168 	 * This includes iounmap if necessary.
169 	 */
170 	void		(*release_port)(struct uart_port *);
171 
172 	/*
173 	 * Request IO and memory resources used by the port.
174 	 * This includes iomapping the port if necessary.
175 	 */
176 	int		(*request_port)(struct uart_port *);
177 	void		(*config_port)(struct uart_port *, int);
178 	int		(*verify_port)(struct uart_port *, struct serial_struct *);
179 	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
180 };
181 
182 #define UART_CONFIG_TYPE	(1 << 0)
183 #define UART_CONFIG_IRQ		(1 << 1)
184 
185 struct uart_icount {
186 	__u32	cts;
187 	__u32	dsr;
188 	__u32	rng;
189 	__u32	dcd;
190 	__u32	rx;
191 	__u32	tx;
192 	__u32	frame;
193 	__u32	overrun;
194 	__u32	parity;
195 	__u32	brk;
196 	__u32	buf_overrun;
197 };
198 
199 struct uart_port {
200 	spinlock_t		lock;			/* port lock */
201 	unsigned int		iobase;			/* in/out[bwl] */
202 	unsigned char __iomem	*membase;		/* read/write[bwl] */
203 	unsigned int		irq;			/* irq number */
204 	unsigned int		uartclk;		/* base uart clock */
205 	unsigned char		fifosize;		/* tx fifo size */
206 	unsigned char		x_char;			/* xon/xoff char */
207 	unsigned char		regshift;		/* reg offset shift */
208 	unsigned char		iotype;			/* io access style */
209 
210 #define UPIO_PORT		(0)
211 #define UPIO_HUB6		(1)
212 #define UPIO_MEM		(2)
213 #define UPIO_MEM32		(3)
214 #define UPIO_AU			(4)			/* Au1x00 type IO */
215 
216 	unsigned int		read_status_mask;	/* driver specific */
217 	unsigned int		ignore_status_mask;	/* driver specific */
218 	struct uart_info	*info;			/* pointer to parent info */
219 	struct uart_icount	icount;			/* statistics */
220 
221 	struct console		*cons;			/* struct console, if any */
222 #ifdef CONFIG_SERIAL_CORE_CONSOLE
223 	unsigned long		sysrq;			/* sysrq timeout */
224 #endif
225 
226 	unsigned int		flags;
227 
228 #define UPF_FOURPORT		(1 << 1)
229 #define UPF_SAK			(1 << 2)
230 #define UPF_SPD_MASK		(0x1030)
231 #define UPF_SPD_HI		(0x0010)
232 #define UPF_SPD_VHI		(0x0020)
233 #define UPF_SPD_CUST		(0x0030)
234 #define UPF_SPD_SHI		(0x1000)
235 #define UPF_SPD_WARP		(0x1010)
236 #define UPF_SKIP_TEST		(1 << 6)
237 #define UPF_AUTO_IRQ		(1 << 7)
238 #define UPF_HARDPPS_CD		(1 << 11)
239 #define UPF_LOW_LATENCY		(1 << 13)
240 #define UPF_BUGGY_UART		(1 << 14)
241 #define UPF_AUTOPROBE		(1 << 15)
242 #define UPF_MAGIC_MULTIPLIER	(1 << 16)
243 #define UPF_BOOT_ONLYMCA	(1 << 22)
244 #define UPF_CONS_FLOW		(1 << 23)
245 #define UPF_SHARE_IRQ		(1 << 24)
246 #define UPF_BOOT_AUTOCONF	(1 << 28)
247 #define UPF_IOREMAP		(1 << 31)
248 
249 #define UPF_CHANGE_MASK		(0x17fff)
250 #define UPF_USR_MASK		(UPF_SPD_MASK|UPF_LOW_LATENCY)
251 
252 	unsigned int		mctrl;			/* current modem ctrl settings */
253 	unsigned int		timeout;		/* character-based timeout */
254 	unsigned int		type;			/* port type */
255 	struct uart_ops		*ops;
256 	unsigned int		custom_divisor;
257 	unsigned int		line;			/* port index */
258 	unsigned long		mapbase;		/* for ioremap */
259 	struct device		*dev;			/* parent device */
260 	unsigned char		hub6;			/* this should be in the 8250 driver */
261 	unsigned char		unused[3];
262 };
263 
264 /*
265  * This is the state information which is persistent across opens.
266  * The low level driver must not to touch any elements contained
267  * within.
268  */
269 struct uart_state {
270 	unsigned int		close_delay;		/* msec */
271 	unsigned int		closing_wait;		/* msec */
272 
273 #define USF_CLOSING_WAIT_INF	(0)
274 #define USF_CLOSING_WAIT_NONE	(~0U)
275 
276 	int			count;
277 	int			pm_state;
278 	struct uart_info	*info;
279 	struct uart_port	*port;
280 
281 	struct semaphore	sem;
282 };
283 
284 #define UART_XMIT_SIZE	PAGE_SIZE
285 /*
286  * This is the state information which is only valid when the port
287  * is open; it may be freed by the core driver once the device has
288  * been closed.  Either the low level driver or the core can modify
289  * stuff here.
290  */
291 struct uart_info {
292 	struct tty_struct	*tty;
293 	struct circ_buf		xmit;
294 	unsigned int		flags;
295 
296 /*
297  * These are the flags that specific to info->flags, and reflect our
298  * internal state.  They can not be accessed via port->flags.  Low
299  * level drivers must not change these, but may query them instead.
300  */
301 #define UIF_CHECK_CD		(1 << 25)
302 #define UIF_CTS_FLOW		(1 << 26)
303 #define UIF_NORMAL_ACTIVE	(1 << 29)
304 #define UIF_INITIALIZED		(1 << 31)
305 
306 	int			blocked_open;
307 
308 	struct tasklet_struct	tlet;
309 
310 	wait_queue_head_t	open_wait;
311 	wait_queue_head_t	delta_msr_wait;
312 };
313 
314 /* number of characters left in xmit buffer before we ask for more */
315 #define WAKEUP_CHARS		256
316 
317 struct module;
318 struct tty_driver;
319 
320 struct uart_driver {
321 	struct module		*owner;
322 	const char		*driver_name;
323 	const char		*dev_name;
324 	const char		*devfs_name;
325 	int			 major;
326 	int			 minor;
327 	int			 nr;
328 	struct console		*cons;
329 
330 	/*
331 	 * these are private; the low level driver should not
332 	 * touch these; they should be initialised to NULL
333 	 */
334 	struct uart_state	*state;
335 	struct tty_driver	*tty_driver;
336 };
337 
338 void uart_write_wakeup(struct uart_port *port);
339 
340 /*
341  * Baud rate helpers.
342  */
343 void uart_update_timeout(struct uart_port *port, unsigned int cflag,
344 			 unsigned int baud);
345 unsigned int uart_get_baud_rate(struct uart_port *port, struct termios *termios,
346 				struct termios *old, unsigned int min,
347 				unsigned int max);
348 unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
349 
350 /*
351  * Console helpers.
352  */
353 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
354 				   struct console *c);
355 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
356 			int *flow);
357 int uart_set_options(struct uart_port *port, struct console *co, int baud,
358 		     int parity, int bits, int flow);
359 struct tty_driver *uart_console_device(struct console *co, int *index);
360 
361 /*
362  * Port/driver registration/removal
363  */
364 int uart_register_driver(struct uart_driver *uart);
365 void uart_unregister_driver(struct uart_driver *uart);
366 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
367 int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
368 int uart_match_port(struct uart_port *port1, struct uart_port *port2);
369 
370 /*
371  * Power Management
372  */
373 int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
374 int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
375 
376 #define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
377 #define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)
378 
379 #define uart_circ_chars_pending(circ)	\
380 	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
381 
382 #define uart_circ_chars_free(circ)	\
383 	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
384 
385 #define uart_tx_stopped(port)		\
386 	((port)->info->tty->stopped || (port)->info->tty->hw_stopped)
387 
388 /*
389  * The following are helper functions for the low level drivers.
390  */
391 static inline int
392 uart_handle_sysrq_char(struct uart_port *port, unsigned int ch,
393 		       struct pt_regs *regs)
394 {
395 #ifdef SUPPORT_SYSRQ
396 	if (port->sysrq) {
397 		if (ch && time_before(jiffies, port->sysrq)) {
398 			handle_sysrq(ch, regs, NULL);
399 			port->sysrq = 0;
400 			return 1;
401 		}
402 		port->sysrq = 0;
403 	}
404 #endif
405 	return 0;
406 }
407 #ifndef SUPPORT_SYSRQ
408 #define uart_handle_sysrq_char(port,ch,regs) uart_handle_sysrq_char(port, 0, NULL)
409 #endif
410 
411 /*
412  * We do the SysRQ and SAK checking like this...
413  */
414 static inline int uart_handle_break(struct uart_port *port)
415 {
416 	struct uart_info *info = port->info;
417 #ifdef SUPPORT_SYSRQ
418 	if (port->cons && port->cons->index == port->line) {
419 		if (!port->sysrq) {
420 			port->sysrq = jiffies + HZ*5;
421 			return 1;
422 		}
423 		port->sysrq = 0;
424 	}
425 #endif
426 	if (info->flags & UPF_SAK)
427 		do_SAK(info->tty);
428 	return 0;
429 }
430 
431 /**
432  *	uart_handle_dcd_change - handle a change of carrier detect state
433  *	@port: uart_port structure for the open port
434  *	@status: new carrier detect status, nonzero if active
435  */
436 static inline void
437 uart_handle_dcd_change(struct uart_port *port, unsigned int status)
438 {
439 	struct uart_info *info = port->info;
440 
441 	port->icount.dcd++;
442 
443 #ifdef CONFIG_HARD_PPS
444 	if ((port->flags & UPF_HARDPPS_CD) && status)
445 		hardpps();
446 #endif
447 
448 	if (info->flags & UIF_CHECK_CD) {
449 		if (status)
450 			wake_up_interruptible(&info->open_wait);
451 		else if (info->tty)
452 			tty_hangup(info->tty);
453 	}
454 }
455 
456 /**
457  *	uart_handle_cts_change - handle a change of clear-to-send state
458  *	@port: uart_port structure for the open port
459  *	@status: new clear to send status, nonzero if active
460  */
461 static inline void
462 uart_handle_cts_change(struct uart_port *port, unsigned int status)
463 {
464 	struct uart_info *info = port->info;
465 	struct tty_struct *tty = info->tty;
466 
467 	port->icount.cts++;
468 
469 	if (info->flags & UIF_CTS_FLOW) {
470 		if (tty->hw_stopped) {
471 			if (status) {
472 				tty->hw_stopped = 0;
473 				port->ops->start_tx(port);
474 				uart_write_wakeup(port);
475 			}
476 		} else {
477 			if (!status) {
478 				tty->hw_stopped = 1;
479 				port->ops->stop_tx(port);
480 			}
481 		}
482 	}
483 }
484 
485 #include <linux/tty_flip.h>
486 
487 static inline void
488 uart_insert_char(struct uart_port *port, unsigned int status,
489 		 unsigned int overrun, unsigned int ch, unsigned int flag)
490 {
491 	struct tty_struct *tty = port->info->tty;
492 
493 	if ((status & port->ignore_status_mask & ~overrun) == 0)
494 		tty_insert_flip_char(tty, ch, flag);
495 
496 	/*
497 	 * Overrun is special.  Since it's reported immediately,
498 	 * it doesn't affect the current character.
499 	 */
500 	if (status & ~port->ignore_status_mask & overrun)
501 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
502 }
503 
504 /*
505  *	UART_ENABLE_MS - determine if port should enable modem status irqs
506  */
507 #define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
508 					 (cflag) & CRTSCTS || \
509 					 !((cflag) & CLOCAL))
510 
511 #endif
512 
513 #endif /* LINUX_SERIAL_CORE_H */
514