summaryrefslogtreecommitdiffstats
path: root/include/linux/serial_core.h
blob: 2f44e20136545162d15ee9a39c2eae38352580d1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
/*
 *  linux/drivers/char/serial_core.h
 *
 *  Copyright (C) 2000 Deep Blue Solutions Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#ifndef LINUX_SERIAL_CORE_H
#define LINUX_SERIAL_CORE_H


#include <linux/compiler.h>
#include <linux/interrupt.h>
#include <linux/circ_buf.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/mutex.h>
#include <linux/sysrq.h>
#include <uapi/linux/serial_core.h>

#ifdef CONFIG_SERIAL_CORE_CONSOLE
#define uart_console(port) \
	((port)->cons && (port)->cons->index == (port)->line)
#else
#define uart_console(port)      ({ (void)port; 0; })
#endif

struct uart_port;
struct serial_struct;
struct device;

/*
 * This structure describes all the operations that can be done on the
 * physical hardware.  See Documentation/serial/driver for details.
 */
struct uart_ops {
	unsigned int	(*tx_empty)(struct uart_port *);
	void		(*set_mctrl)(struct uart_port *, unsigned int mctrl);
	unsigned int	(*get_mctrl)(struct uart_port *);
	void		(*stop_tx)(struct uart_port *);
	void		(*start_tx)(struct uart_port *);
	void		(*throttle)(struct uart_port *);
	void		(*unthrottle)(struct uart_port *);
	void		(*send_xchar)(struct uart_port *, char ch);
	void		(*stop_rx)(struct uart_port *);
	void		(*enable_ms)(struct uart_port *);
	void		(*break_ctl)(struct uart_port *, int ctl);
	int		(*startup)(struct uart_port *);
	void		(*shutdown)(struct uart_port *);
	void		(*flush_buffer)(struct uart_port *);
	void		(*set_termios)(struct uart_port *, struct ktermios *new,
				       struct ktermios *old);
	void		(*set_ldisc)(struct uart_port *, struct ktermios *);
	void		(*pm)(struct uart_port *, unsigned int state,
			      unsigned int oldstate);

	/*
	 * Return a string describing the type of the port
	 */
	const char	*(*type)(struct uart_port *);

	/*
	 * Release IO and memory resources used by the port.
	 * This includes iounmap if necessary.
	 */
	void		(*release_port)(struct uart_port *);

	/*
	 * Request IO and memory resources used by the port.
	 * This includes iomapping the port if necessary.
	 */
	int		(*request_port)(struct uart_port *);
	void		(*config_port)(struct uart_port *, int);
	int		(*verify_port)(struct uart_port *, struct serial_struct *);
	int		(*ioctl)(struct uart_port *, unsigned int, unsigned long);
#ifdef CONFIG_CONSOLE_POLL
	int		(*poll_init)(struct uart_port *);
	void		(*poll_put_char)(struct uart_port *, unsigned char);
	int		(*poll_get_char)(struct uart_port *);
#endif
};

#define NO_POLL_CHAR		0x00ff0000
#define UART_CONFIG_TYPE	(1 << 0)
#define UART_CONFIG_IRQ		(1 << 1)

struct uart_icount {
	__u32	cts;
	__u32	dsr;
	__u32	rng;
	__u32	dcd;
	__u32	rx;
	__u32	tx;
	__u32	frame;
	__u32	overrun;
	__u32	parity;
	__u32	brk;
	__u32	buf_overrun;
};

typedef unsigned int __bitwise__ upf_t;
typedef unsigned int __bitwise__ upstat_t;

struct uart_port {
	spinlock_t		lock;			/* port lock */
	unsigned long		iobase;			/* in/out[bwl] */
	unsigned char __iomem	*membase;		/* read/write[bwl] */
	unsigned int		(*serial_in)(struct uart_port *, int);
	void			(*serial_out)(struct uart_port *, int, int);
	void			(*set_termios)(struct uart_port *,
				               struct ktermios *new,
				               struct ktermios *old);
	unsigned int		(*get_mctrl)(struct uart_port *);
	void			(*set_mctrl)(struct uart_port *, unsigned int);
	int			(*startup)(struct uart_port *port);
	void			(*shutdown)(struct uart_port *port);
	void			(*throttle)(struct uart_port *port);
	void			(*unthrottle)(struct uart_port *port);
	int			(*handle_irq)(struct uart_port *);
	void			(*pm)(struct uart_port *, unsigned int state,
				      unsigned int old);
	void			(*handle_break)(struct uart_port *);
	int			(*rs485_config)(struct uart_port *,
						struct serial_rs485 *rs485);
	unsigned int		irq;			/* irq number */
	unsigned long		irqflags;		/* irq flags  */
	unsigned int		uartclk;		/* base uart clock */
	unsigned int		fifosize;		/* tx fifo size */
	unsigned char		x_char;			/* xon/xoff char */
	unsigned char		regshift;		/* reg offset shift */
	unsigned char		iotype;			/* io access style */
	unsigned char		unused1;

#define UPIO_PORT		(SERIAL_IO_PORT)	/* 8b I/O port access */
#define UPIO_HUB6		(SERIAL_IO_HUB6)	/* Hub6 ISA card */
#define UPIO_MEM		(SERIAL_IO_MEM)		/* driver-specific */
#define UPIO_MEM32		(SERIAL_IO_MEM32)	/* 32b little endian */
#define UPIO_AU			(SERIAL_IO_AU)		/* Au1x00 and RT288x type IO */
#define UPIO_TSI		(SERIAL_IO_TSI)		/* Tsi108/109 type IO */
#define UPIO_MEM32BE		(SERIAL_IO_MEM32BE)	/* 32b big endian */
#define UPIO_MEM16		(SERIAL_IO_MEM16)	/* 16b little endian */

	unsigned int		read_status_mask;	/* driver specific */
	unsigned int		ignore_status_mask;	/* driver specific */
	struct uart_state	*state;			/* pointer to parent state */
	struct uart_icount	icount;			/* statistics */

	struct console		*cons;			/* struct console, if any */
#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
	unsigned long		sysrq;			/* sysrq timeout */
#endif

	/* flags must be updated while holding port mutex */
	upf_t			flags;

	/*
	 * These flags must be equivalent to the flags defined in
	 * include/uapi/linux/tty_flags.h which are the userspace definitions
	 * assigned from the serial_struct flags in uart_set_info()
	 * [for bit definitions in the UPF_CHANGE_MASK]
	 *
	 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
	 * except bit 15 (UPF_NO_TXEN_TEST) which is masked off.
	 * The remaining bits are serial-core specific and not modifiable by
	 * userspace.
	 */
#define UPF_FOURPORT		((__force upf_t) ASYNC_FOURPORT       /* 1  */ )
#define UPF_SAK			((__force upf_t) ASYNC_SAK            /* 2  */ )
#define UPF_SPD_HI		((__force upf_t) ASYNC_SPD_HI         /* 4  */ )
#define UPF_SPD_VHI		((__force upf_t) ASYNC_SPD_VHI        /* 5  */ )
#define UPF_SPD_CUST		((__force upf_t) ASYNC_SPD_CUST   /* 0x0030 */ )
#define UPF_SPD_WARP		((__force upf_t) ASYNC_SPD_WARP   /* 0x1010 */ )
#define UPF_SPD_MASK		((__force upf_t) ASYNC_SPD_MASK   /* 0x1030 */ )
#define UPF_SKIP_TEST		((__force upf_t) ASYNC_SKIP_TEST      /* 6  */ )
#define UPF_AUTO_IRQ		((__force upf_t) ASYNC_AUTO_IRQ       /* 7  */ )
#define UPF_HARDPPS_CD		((__force upf_t) ASYNC_HARDPPS_CD     /* 11 */ )
#define UPF_SPD_SHI		((__force upf_t) ASYNC_SPD_SHI        /* 12 */ )
#define UPF_LOW_LATENCY		((__force upf_t) ASYNC_LOW_LATENCY    /* 13 */ )
#define UPF_BUGGY_UART		((__force upf_t) ASYNC_BUGGY_UART     /* 14 */ )
#define UPF_NO_TXEN_TEST	((__force upf_t) (1 << 15))
#define UPF_MAGIC_MULTIPLIER	((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )

/* Port has hardware-assisted h/w flow control */
#define UPF_AUTO_CTS		((__force upf_t) (1 << 20))
#define UPF_AUTO_RTS		((__force upf_t) (1 << 21))
#define UPF_HARD_FLOW		((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
/* Port has hardware-assisted s/w flow control */
#define UPF_SOFT_FLOW		((__force upf_t) (1 << 22))
#define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
#define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
#define UPF_EXAR_EFR		((__force upf_t) (1 << 25))
#define UPF_BUG_THRE		((__force upf_t) (1 << 26))
/* The exact UART type is known and should not be probed.  */
#define UPF_FIXED_TYPE		((__force upf_t) (1 << 27))
#define UPF_BOOT_AUTOCONF	((__force upf_t) (1 << 28))
#define UPF_FIXED_PORT		((__force upf_t) (1 << 29))
#define UPF_DEAD		((__force upf_t) (1 << 30))
#define UPF_IOREMAP		((__force upf_t) (1 << 31))

#define __UPF_CHANGE_MASK	0x17fff
#define UPF_CHANGE_MASK		((__force upf_t) __UPF_CHANGE_MASK)
#define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))

#if __UPF_CHANGE_MASK > ASYNC_FLAGS
#error Change mask not equivalent to userspace-visible bit defines
#endif

	/*
	 * Must hold termios_rwsem, port mutex and port lock to change;
	 * can hold any one lock to read.
	 */
	upstat_t		status;

#define UPSTAT_CTS_ENABLE	((__force upstat_t) (1 << 0))
#define UPSTAT_DCD_ENABLE	((__force upstat_t) (1 << 1))
#define UPSTAT_AUTORTS		((__force upstat_t) (1 << 2))
#define UPSTAT_AUTOCTS		((__force upstat_t) (1 << 3))
#define UPSTAT_AUTOXOFF		((__force upstat_t) (1 << 4))

	int			hw_stopped;		/* sw-assisted CTS flow state */
	unsigned int		mctrl;			/* current modem ctrl settings */
	unsigned int		timeout;		/* character-based timeout */
	unsigned int		type;			/* port type */
	const struct uart_ops	*ops;
	unsigned int		custom_divisor;
	unsigned int		line;			/* port index */
	unsigned int		minor;
	resource_size_t		mapbase;		/* for ioremap */
	resource_size_t		mapsize;
	struct device		*dev;			/* parent device */
	unsigned char		hub6;			/* this should be in the 8250 driver */
	unsigned char		suspended;
	unsigned char		irq_wake;
	unsigned char		unused[2];
	struct attribute_group	*attr_group;		/* port specific attributes */
	const struct attribute_group **tty_groups;	/* all attributes (serial core use only) */
	struct serial_rs485     rs485;
	void			*private_data;		/* generic platform data pointer */
};

static inline int serial_port_in(struct uart_port *up, int offset)
{
	return up->serial_in(up, offset);
}

static inline void serial_port_out(struct uart_port *up, int offset, int value)
{
	up->serial_out(up, offset, value);
}

/**
 * enum uart_pm_state - power states for UARTs
 * @UART_PM_STATE_ON: UART is powered, up and operational
 * @UART_PM_STATE_OFF: UART is powered off
 * @UART_PM_STATE_UNDEFINED: sentinel
 */
enum uart_pm_state {
	UART_PM_STATE_ON = 0,
	UART_PM_STATE_OFF = 3, /* number taken from ACPI */
	UART_PM_STATE_UNDEFINED,
};

/*
 * This is the state information which is persistent across opens.
 */
struct uart_state {
	struct tty_port		port;

	enum uart_pm_state	pm_state;
	struct circ_buf		xmit;

	atomic_t		refcount;
	wait_queue_head_t	remove_wait;
	struct uart_port	*uart_port;
};

#define UART_XMIT_SIZE	PAGE_SIZE


/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS		256

struct module;
struct tty_driver;

struct uart_driver {
	struct module		*owner;
	const char		*driver_name;
	const char		*dev_name;
	int			 major;
	int			 minor;
	int			 nr;
	struct console		*cons;

	/*
	 * these are private; the low level driver should not
	 * touch these; they should be initialised to NULL
	 */
	struct uart_state	*state;
	struct tty_driver	*tty_driver;
};

void uart_write_wakeup(struct uart_port *port);

/*
 * Baud rate helpers.
 */
void uart_update_timeout(struct uart_port *port, unsigned int cflag,
			 unsigned int baud);
unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
				struct ktermios *old, unsigned int min,
				unsigned int max);
unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);

/* Base timer interval for polling */
static inline int uart_poll_timeout(struct uart_port *port)
{
	int timeout = port->timeout;

	return timeout > 6 ? (timeout / 2 - 2) : 1;
}

/*
 * Console helpers.
 */
struct earlycon_device {
	struct console *con;
	struct uart_port port;
	char options[16];		/* e.g., 115200n8 */
	unsigned int baud;
};

struct earlycon_id {
	char	name[16];
	char	compatible[128];
	int	(*setup)(struct earlycon_device *, const char *options);
} __aligned(32);

extern const struct earlycon_id __earlycon_table[];
extern const struct earlycon_id __earlycon_table_end[];

#if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE)
#define EARLYCON_USED_OR_UNUSED	__used
#else
#define EARLYCON_USED_OR_UNUSED	__maybe_unused
#endif

#define OF_EARLYCON_DECLARE(_name, compat, fn)				\
	static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name)	\
	     EARLYCON_USED_OR_UNUSED __section(__earlycon_table)	\
		= { .name = __stringify(_name),				\
		    .compatible = compat,				\
		    .setup = fn  }

#define EARLYCON_DECLARE(_name, fn)	OF_EARLYCON_DECLARE(_name, "", fn)

extern int setup_earlycon(char *buf);
extern int of_setup_earlycon(const struct earlycon_id *match,
			     unsigned long node,
			     const char *options);

struct uart_port *uart_get_console(struct uart_port *ports, int nr,
				   struct console *c);
int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
			char **options);
void uart_parse_options(char *options, int *baud, int *parity, int *bits,
			int *flow);
int uart_set_options(struct uart_port *port, struct console *co, int baud,
		     int parity, int bits, int flow);
struct tty_driver *uart_console_device(struct console *co, int *index);
void uart_console_write(struct uart_port *port, const char *s,
			unsigned int count,
			void (*putchar)(struct uart_port *, int));

/*
 * Port/driver registration/removal
 */
int uart_register_driver(struct uart_driver *uart);
void uart_unregister_driver(struct uart_driver *uart);
int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
int uart_match_port(struct uart_port *port1, struct uart_port *port2);

/*
 * Power Management
 */
int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
int uart_resume_port(struct uart_driver *reg, struct uart_port *port);

#define uart_circ_empty(circ)		((circ)->head == (circ)->tail)
#define uart_circ_clear(circ)		((circ)->head = (circ)->tail = 0)

#define uart_circ_chars_pending(circ)	\
	(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))

#define uart_circ_chars_free(circ)	\
	(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))

static inline int uart_tx_stopped(struct uart_port *port)
{
	struct tty_struct *tty = port->state->port.tty;
	if (tty->stopped || port->hw_stopped)
		return 1;
	return 0;
}

static inline bool uart_cts_enabled(struct uart_port *uport)
{
	return !!(uport->status & UPSTAT_CTS_ENABLE);
}

static inline bool uart_softcts_mode(struct uart_port *uport)
{
	upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS;

	return ((uport->status & mask) == UPSTAT_CTS_ENABLE);
}

/*
 * The following are helper functions for the low level drivers.
 */

extern void uart_handle_dcd_change(struct uart_port *uport,
		unsigned int status);
extern void uart_handle_cts_change(struct uart_port *uport,
		unsigned int status);

extern void uart_insert_char(struct uart_port *port, unsigned int status,
		 unsigned int overrun, unsigned int ch, unsigned int flag);

#ifdef SUPPORT_SYSRQ
static inline int
uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
{
	if (port->sysrq) {
		if (ch && time_before(jiffies, port->sysrq)) {
			handle_sysrq(ch);
			port->sysrq = 0;
			return 1;
		}
		port->sysrq = 0;
	}
	return 0;
}
#else
#define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
#endif

/*
 * We do the SysRQ and SAK checking like this...
 */
static inline int uart_handle_break(struct uart_port *port)
{
	struct uart_state *state = port->state;

	if (port->handle_break)
		port->handle_break(port);

#ifdef SUPPORT_SYSRQ
	if (port->cons && port->cons->index == port->line) {
		if (!port->sysrq) {
			port->sysrq = jiffies + HZ*5;
			return 1;
		}
		port->sysrq = 0;
	}
#endif
	if (port->flags & UPF_SAK)
		do_SAK(state->port.tty);
	return 0;
}

/*
 *	UART_ENABLE_MS - determine if port should enable modem status irqs
 */
#define UART_ENABLE_MS(port,cflag)	((port)->flags & UPF_HARDPPS_CD || \
					 (cflag) & CRTSCTS || \
					 !((cflag) & CLOCAL))

#endif /* LINUX_SERIAL_CORE_H */
OpenPOWER on IntegriCloud