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#include <linux/bitops.h>
24#include <linux/compiler.h>
25#include <linux/console.h>
26#include <linux/interrupt.h>
27#include <linux/circ_buf.h>
28#include <linux/spinlock.h>
29#include <linux/sched.h>
30#include <linux/tty.h>
31#include <linux/mutex.h>
32#include <linux/sysrq.h>
33#include <uapi/linux/serial_core.h>
34
35#ifdef CONFIG_SERIAL_CORE_CONSOLE
36#define uart_console(port) \
37 ((port)->cons && (port)->cons->index == (port)->line)
38#else
39#define uart_console(port) ({ (void)port; 0; })
40#endif
41
42struct uart_port;
43struct serial_struct;
44struct device;
45
46/*
47 * This structure describes all the operations that can be done on the
48 * physical hardware. See Documentation/serial/driver for details.
49 */
50struct uart_ops {
51 unsigned int (*tx_empty)(struct uart_port *);
52 void (*set_mctrl)(struct uart_port *, unsigned int mctrl);
53 unsigned int (*get_mctrl)(struct uart_port *);
54 void (*stop_tx)(struct uart_port *);
55 void (*start_tx)(struct uart_port *);
56 void (*throttle)(struct uart_port *);
57 void (*unthrottle)(struct uart_port *);
58 void (*send_xchar)(struct uart_port *, char ch);
59 void (*stop_rx)(struct uart_port *);
60 void (*enable_ms)(struct uart_port *);
61 void (*break_ctl)(struct uart_port *, int ctl);
62 int (*startup)(struct uart_port *);
63 void (*shutdown)(struct uart_port *);
64 void (*flush_buffer)(struct uart_port *);
65 void (*set_termios)(struct uart_port *, struct ktermios *new,
66 struct ktermios *old);
67 void (*set_ldisc)(struct uart_port *, struct ktermios *);
68 void (*pm)(struct uart_port *, unsigned int state,
69 unsigned int oldstate);
70
71 /*
72 * Return a string describing the type of the port
73 */
74 const char *(*type)(struct uart_port *);
75
76 /*
77 * Release IO and memory resources used by the port.
78 * This includes iounmap if necessary.
79 */
80 void (*release_port)(struct uart_port *);
81
82 /*
83 * Request IO and memory resources used by the port.
84 * This includes iomapping the port if necessary.
85 */
86 int (*request_port)(struct uart_port *);
87 void (*config_port)(struct uart_port *, int);
88 int (*verify_port)(struct uart_port *, struct serial_struct *);
89 int (*ioctl)(struct uart_port *, unsigned int, unsigned long);
90#ifdef CONFIG_CONSOLE_POLL
91 int (*poll_init)(struct uart_port *);
92 void (*poll_put_char)(struct uart_port *, unsigned char);
93 int (*poll_get_char)(struct uart_port *);
94#endif
95};
96
97#define NO_POLL_CHAR 0x00ff0000
98#define UART_CONFIG_TYPE (1 << 0)
99#define UART_CONFIG_IRQ (1 << 1)
100
101struct uart_icount {
102 __u32 cts;
103 __u32 dsr;
104 __u32 rng;
105 __u32 dcd;
106 __u32 rx;
107 __u32 tx;
108 __u32 frame;
109 __u32 overrun;
110 __u32 parity;
111 __u32 brk;
112 __u32 buf_overrun;
113};
114
115typedef unsigned int __bitwise upf_t;
116typedef unsigned int __bitwise upstat_t;
117
118struct uart_port {
119 spinlock_t lock; /* port lock */
120 unsigned long iobase; /* in/out[bwl] */
121 unsigned char __iomem *membase; /* read/write[bwl] */
122 unsigned int (*serial_in)(struct uart_port *, int);
123 void (*serial_out)(struct uart_port *, int, int);
124 void (*set_termios)(struct uart_port *,
125 struct ktermios *new,
126 struct ktermios *old);
127 void (*set_ldisc)(struct uart_port *,
128 struct ktermios *);
129 unsigned int (*get_mctrl)(struct uart_port *);
130 void (*set_mctrl)(struct uart_port *, unsigned int);
131 unsigned int (*get_divisor)(struct uart_port *,
132 unsigned int baud,
133 unsigned int *frac);
134 void (*set_divisor)(struct uart_port *,
135 unsigned int baud,
136 unsigned int quot,
137 unsigned int quot_frac);
138 int (*startup)(struct uart_port *port);
139 void (*shutdown)(struct uart_port *port);
140 void (*throttle)(struct uart_port *port);
141 void (*unthrottle)(struct uart_port *port);
142 int (*handle_irq)(struct uart_port *);
143 void (*pm)(struct uart_port *, unsigned int state,
144 unsigned int old);
145 void (*handle_break)(struct uart_port *);
146 int (*rs485_config)(struct uart_port *,
147 struct serial_rs485 *rs485);
148 int (*iso7816_config)(struct uart_port *,
149 struct serial_iso7816 *iso7816);
150 unsigned int irq; /* irq number */
151 unsigned long irqflags; /* irq flags */
152 unsigned int uartclk; /* base uart clock */
153 unsigned int fifosize; /* tx fifo size */
154 unsigned char x_char; /* xon/xoff char */
155 unsigned char regshift; /* reg offset shift */
156 unsigned char iotype; /* io access style */
157 unsigned char quirks; /* internal quirks */
158
159#define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
160#define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
161#define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */
162#define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */
163#define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */
164#define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */
165#define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */
166#define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */
167
168 /* quirks must be updated while holding port mutex */
169#define UPQ_NO_TXEN_TEST BIT(0)
170
171 unsigned int read_status_mask; /* driver specific */
172 unsigned int ignore_status_mask; /* driver specific */
173 struct uart_state *state; /* pointer to parent state */
174 struct uart_icount icount; /* statistics */
175
176 struct console *cons; /* struct console, if any */
177#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
178 unsigned long sysrq; /* sysrq timeout */
179 unsigned int sysrq_ch; /* char for sysrq */
180#endif
181
182 /* flags must be updated while holding port mutex */
183 upf_t flags;
184
185 /*
186 * These flags must be equivalent to the flags defined in
187 * include/uapi/linux/tty_flags.h which are the userspace definitions
188 * assigned from the serial_struct flags in uart_set_info()
189 * [for bit definitions in the UPF_CHANGE_MASK]
190 *
191 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
192 * The remaining bits are serial-core specific and not modifiable by
193 * userspace.
194 */
195#define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ )
196#define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ )
197#define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ )
198#define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ )
199#define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ )
200#define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ )
201#define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ )
202#define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ )
203#define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ )
204#define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ )
205#define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ )
206#define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ )
207#define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ )
208#define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
209
210#define UPF_NO_THRE_TEST ((__force upf_t) (1 << 19))
211/* Port has hardware-assisted h/w flow control */
212#define UPF_AUTO_CTS ((__force upf_t) (1 << 20))
213#define UPF_AUTO_RTS ((__force upf_t) (1 << 21))
214#define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
215/* Port has hardware-assisted s/w flow control */
216#define UPF_SOFT_FLOW ((__force upf_t) (1 << 22))
217#define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
218#define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
219#define UPF_EXAR_EFR ((__force upf_t) (1 << 25))
220#define UPF_BUG_THRE ((__force upf_t) (1 << 26))
221/* The exact UART type is known and should not be probed. */
222#define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
223#define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
224#define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
225#define UPF_DEAD ((__force upf_t) (1 << 30))
226#define UPF_IOREMAP ((__force upf_t) (1 << 31))
227
228#define __UPF_CHANGE_MASK 0x17fff
229#define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK)
230#define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
231
232#if __UPF_CHANGE_MASK > ASYNC_FLAGS
233#error Change mask not equivalent to userspace-visible bit defines
234#endif
235
236 /*
237 * Must hold termios_rwsem, port mutex and port lock to change;
238 * can hold any one lock to read.
239 */
240 upstat_t status;
241
242#define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0))
243#define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1))
244#define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2))
245#define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3))
246#define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4))
247#define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5))
248
249 int hw_stopped; /* sw-assisted CTS flow state */
250 unsigned int mctrl; /* current modem ctrl settings */
251 unsigned int timeout; /* character-based timeout */
252 unsigned int type; /* port type */
253 const struct uart_ops *ops;
254 unsigned int custom_divisor;
255 unsigned int line; /* port index */
256 unsigned int minor;
257 resource_size_t mapbase; /* for ioremap */
258 resource_size_t mapsize;
259 struct device *dev; /* parent device */
260 unsigned char hub6; /* this should be in the 8250 driver */
261 unsigned char suspended;
262 unsigned char unused[2];
263 const char *name; /* port name */
264 struct attribute_group *attr_group; /* port specific attributes */
265 const struct attribute_group **tty_groups; /* all attributes (serial core use only) */
266 struct serial_rs485 rs485;
267 struct serial_iso7816 iso7816;
268 void *private_data; /* generic platform data pointer */
269};
270
271static inline int serial_port_in(struct uart_port *up, int offset)
272{
273 return up->serial_in(up, offset);
274}
275
276static inline void serial_port_out(struct uart_port *up, int offset, int value)
277{
278 up->serial_out(up, offset, value);
279}
280
281/**
282 * enum uart_pm_state - power states for UARTs
283 * @UART_PM_STATE_ON: UART is powered, up and operational
284 * @UART_PM_STATE_OFF: UART is powered off
285 * @UART_PM_STATE_UNDEFINED: sentinel
286 */
287enum uart_pm_state {
288 UART_PM_STATE_ON = 0,
289 UART_PM_STATE_OFF = 3, /* number taken from ACPI */
290 UART_PM_STATE_UNDEFINED,
291};
292
293/*
294 * This is the state information which is persistent across opens.
295 */
296struct uart_state {
297 struct tty_port port;
298
299 enum uart_pm_state pm_state;
300 struct circ_buf xmit;
301
302 atomic_t refcount;
303 wait_queue_head_t remove_wait;
304 struct uart_port *uart_port;
305};
306
307#define UART_XMIT_SIZE PAGE_SIZE
308
309
310/* number of characters left in xmit buffer before we ask for more */
311#define WAKEUP_CHARS 256
312
313struct module;
314struct tty_driver;
315
316struct uart_driver {
317 struct module *owner;
318 const char *driver_name;
319 const char *dev_name;
320 int major;
321 int minor;
322 int nr;
323 struct console *cons;
324
325 /*
326 * these are private; the low level driver should not
327 * touch these; they should be initialised to NULL
328 */
329 struct uart_state *state;
330 struct tty_driver *tty_driver;
331};
332
333void uart_write_wakeup(struct uart_port *port);
334
335/*
336 * Baud rate helpers.
337 */
338void uart_update_timeout(struct uart_port *port, unsigned int cflag,
339 unsigned int baud);
340unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
341 struct ktermios *old, unsigned int min,
342 unsigned int max);
343unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
344
345/* Base timer interval for polling */
346static inline int uart_poll_timeout(struct uart_port *port)
347{
348 int timeout = port->timeout;
349
350 return timeout > 6 ? (timeout / 2 - 2) : 1;
351}
352
353/*
354 * Console helpers.
355 */
356struct earlycon_device {
357 struct console *con;
358 struct uart_port port;
359 char options[16]; /* e.g., 115200n8 */
360 unsigned int baud;
361};
362
363struct earlycon_id {
364 char name[15];
365 char name_term; /* In case compiler didn't '\0' term name */
366 char compatible[128];
367 int (*setup)(struct earlycon_device *, const char *options);
368};
369
370extern const struct earlycon_id *__earlycon_table[];
371extern const struct earlycon_id *__earlycon_table_end[];
372
373#if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE)
374#define EARLYCON_USED_OR_UNUSED __used
375#else
376#define EARLYCON_USED_OR_UNUSED __maybe_unused
377#endif
378
379#define _OF_EARLYCON_DECLARE(_name, compat, fn, unique_id) \
380 static const struct earlycon_id unique_id \
381 EARLYCON_USED_OR_UNUSED __initconst \
382 = { .name = __stringify(_name), \
383 .compatible = compat, \
384 .setup = fn }; \
385 static const struct earlycon_id EARLYCON_USED_OR_UNUSED \
386 __section(__earlycon_table) \
387 * const __PASTE(__p, unique_id) = &unique_id
388
389#define OF_EARLYCON_DECLARE(_name, compat, fn) \
390 _OF_EARLYCON_DECLARE(_name, compat, fn, \
391 __UNIQUE_ID(__earlycon_##_name))
392
393#define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn)
394
395extern int of_setup_earlycon(const struct earlycon_id *match,
396 unsigned long node,
397 const char *options);
398
399#ifdef CONFIG_SERIAL_EARLYCON
400extern bool earlycon_acpi_spcr_enable __initdata;
401int setup_earlycon(char *buf);
402#else
403static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED;
404static inline int setup_earlycon(char *buf) { return 0; }
405#endif
406
407struct uart_port *uart_get_console(struct uart_port *ports, int nr,
408 struct console *c);
409int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
410 char **options);
411void uart_parse_options(const char *options, int *baud, int *parity, int *bits,
412 int *flow);
413int uart_set_options(struct uart_port *port, struct console *co, int baud,
414 int parity, int bits, int flow);
415struct tty_driver *uart_console_device(struct console *co, int *index);
416void uart_console_write(struct uart_port *port, const char *s,
417 unsigned int count,
418 void (*putchar)(struct uart_port *, int));
419
420/*
421 * Port/driver registration/removal
422 */
423int uart_register_driver(struct uart_driver *uart);
424void uart_unregister_driver(struct uart_driver *uart);
425int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
426int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
427int uart_match_port(struct uart_port *port1, struct uart_port *port2);
428
429/*
430 * Power Management
431 */
432int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
433int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
434
435#define uart_circ_empty(circ) ((circ)->head == (circ)->tail)
436#define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0)
437
438#define uart_circ_chars_pending(circ) \
439 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
440
441#define uart_circ_chars_free(circ) \
442 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
443
444static inline int uart_tx_stopped(struct uart_port *port)
445{
446 struct tty_struct *tty = port->state->port.tty;
447 if ((tty && tty->stopped) || port->hw_stopped)
448 return 1;
449 return 0;
450}
451
452static inline bool uart_cts_enabled(struct uart_port *uport)
453{
454 return !!(uport->status & UPSTAT_CTS_ENABLE);
455}
456
457static inline bool uart_softcts_mode(struct uart_port *uport)
458{
459 upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS;
460
461 return ((uport->status & mask) == UPSTAT_CTS_ENABLE);
462}
463
464/*
465 * The following are helper functions for the low level drivers.
466 */
467
468extern void uart_handle_dcd_change(struct uart_port *uport,
469 unsigned int status);
470extern void uart_handle_cts_change(struct uart_port *uport,
471 unsigned int status);
472
473extern void uart_insert_char(struct uart_port *port, unsigned int status,
474 unsigned int overrun, unsigned int ch, unsigned int flag);
475
476#if defined(SUPPORT_SYSRQ) && defined(CONFIG_MAGIC_SYSRQ_SERIAL)
477static inline int
478uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
479{
480 if (port->sysrq) {
481 if (ch && time_before(jiffies, port->sysrq)) {
482 handle_sysrq(ch);
483 port->sysrq = 0;
484 return 1;
485 }
486 port->sysrq = 0;
487 }
488 return 0;
489}
490static inline int
491uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch)
492{
493 if (port->sysrq) {
494 if (ch && time_before(jiffies, port->sysrq)) {
495 port->sysrq_ch = ch;
496 port->sysrq = 0;
497 return 1;
498 }
499 port->sysrq = 0;
500 }
501 return 0;
502}
503static inline void
504uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags)
505{
506 int sysrq_ch;
507
508 sysrq_ch = port->sysrq_ch;
509 port->sysrq_ch = 0;
510
511 spin_unlock_irqrestore(&port->lock, irqflags);
512
513 if (sysrq_ch)
514 handle_sysrq(sysrq_ch);
515}
516#else
517static inline int
518uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; }
519static inline int
520uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; }
521static inline void
522uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags)
523{
524 spin_unlock_irqrestore(&port->lock, irqflags);
525}
526#endif
527
528/*
529 * We do the SysRQ and SAK checking like this...
530 */
531static inline int uart_handle_break(struct uart_port *port)
532{
533 struct uart_state *state = port->state;
534
535 if (port->handle_break)
536 port->handle_break(port);
537
538#ifdef SUPPORT_SYSRQ
539 if (port->cons && port->cons->index == port->line) {
540 if (!port->sysrq) {
541 port->sysrq = jiffies + HZ*5;
542 return 1;
543 }
544 port->sysrq = 0;
545 }
546#endif
547 if (port->flags & UPF_SAK)
548 do_SAK(state->port.tty);
549 return 0;
550}
551
552/*
553 * UART_ENABLE_MS - determine if port should enable modem status irqs
554 */
555#define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \
556 (cflag) & CRTSCTS || \
557 !((cflag) & CLOCAL))
558
559void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf);
560#endif /* LINUX_SERIAL_CORE_H */
561