1 /* SPDX-License-Identifier: GPL-2.0-or-later */
3 * linux/drivers/char/serial_core.h
5 * Copyright (C) 2000 Deep Blue Solutions Ltd.
7 #ifndef LINUX_SERIAL_CORE_H
8 #define LINUX_SERIAL_CORE_H
10 #include <linux/bitops.h>
11 #include <linux/compiler.h>
12 #include <linux/console.h>
13 #include <linux/interrupt.h>
14 #include <linux/circ_buf.h>
15 #include <linux/spinlock.h>
16 #include <linux/sched.h>
17 #include <linux/tty.h>
18 #include <linux/mutex.h>
19 #include <linux/sysrq.h>
20 #include <uapi/linux/serial_core.h>
22 #ifdef CONFIG_SERIAL_CORE_CONSOLE
23 #define uart_console(port) \
24 ((port)->cons && (port)->cons->index == (port)->line)
26 #define uart_console(port) ({ (void)port; 0; })
34 * This structure describes all the operations that can be done on the
35 * physical hardware. See Documentation/serial/driver.rst for details.
38 unsigned int (*tx_empty
)(struct uart_port
*);
39 void (*set_mctrl
)(struct uart_port
*, unsigned int mctrl
);
40 unsigned int (*get_mctrl
)(struct uart_port
*);
41 void (*stop_tx
)(struct uart_port
*);
42 void (*start_tx
)(struct uart_port
*);
43 void (*throttle
)(struct uart_port
*);
44 void (*unthrottle
)(struct uart_port
*);
45 void (*send_xchar
)(struct uart_port
*, char ch
);
46 void (*stop_rx
)(struct uart_port
*);
47 void (*enable_ms
)(struct uart_port
*);
48 void (*break_ctl
)(struct uart_port
*, int ctl
);
49 int (*startup
)(struct uart_port
*);
50 void (*shutdown
)(struct uart_port
*);
51 void (*flush_buffer
)(struct uart_port
*);
52 void (*set_termios
)(struct uart_port
*, struct ktermios
*new,
53 struct ktermios
*old
);
54 void (*set_ldisc
)(struct uart_port
*, struct ktermios
*);
55 void (*pm
)(struct uart_port
*, unsigned int state
,
56 unsigned int oldstate
);
59 * Return a string describing the type of the port
61 const char *(*type
)(struct uart_port
*);
64 * Release IO and memory resources used by the port.
65 * This includes iounmap if necessary.
67 void (*release_port
)(struct uart_port
*);
70 * Request IO and memory resources used by the port.
71 * This includes iomapping the port if necessary.
73 int (*request_port
)(struct uart_port
*);
74 void (*config_port
)(struct uart_port
*, int);
75 int (*verify_port
)(struct uart_port
*, struct serial_struct
*);
76 int (*ioctl
)(struct uart_port
*, unsigned int, unsigned long);
77 #ifdef CONFIG_CONSOLE_POLL
78 int (*poll_init
)(struct uart_port
*);
79 void (*poll_put_char
)(struct uart_port
*, unsigned char);
80 int (*poll_get_char
)(struct uart_port
*);
84 #define NO_POLL_CHAR 0x00ff0000
85 #define UART_CONFIG_TYPE (1 << 0)
86 #define UART_CONFIG_IRQ (1 << 1)
102 typedef unsigned int __bitwise upf_t
;
103 typedef unsigned int __bitwise upstat_t
;
106 spinlock_t lock
; /* port lock */
107 unsigned long iobase
; /* in/out[bwl] */
108 unsigned char __iomem
*membase
; /* read/write[bwl] */
109 unsigned int (*serial_in
)(struct uart_port
*, int);
110 void (*serial_out
)(struct uart_port
*, int, int);
111 void (*set_termios
)(struct uart_port
*,
112 struct ktermios
*new,
113 struct ktermios
*old
);
114 void (*set_ldisc
)(struct uart_port
*,
116 unsigned int (*get_mctrl
)(struct uart_port
*);
117 void (*set_mctrl
)(struct uart_port
*, unsigned int);
118 unsigned int (*get_divisor
)(struct uart_port
*,
121 void (*set_divisor
)(struct uart_port
*,
124 unsigned int quot_frac
);
125 int (*startup
)(struct uart_port
*port
);
126 void (*shutdown
)(struct uart_port
*port
);
127 void (*throttle
)(struct uart_port
*port
);
128 void (*unthrottle
)(struct uart_port
*port
);
129 int (*handle_irq
)(struct uart_port
*);
130 void (*pm
)(struct uart_port
*, unsigned int state
,
132 void (*handle_break
)(struct uart_port
*);
133 int (*rs485_config
)(struct uart_port
*,
134 struct serial_rs485
*rs485
);
135 int (*iso7816_config
)(struct uart_port
*,
136 struct serial_iso7816
*iso7816
);
137 unsigned int irq
; /* irq number */
138 unsigned long irqflags
; /* irq flags */
139 unsigned int uartclk
; /* base uart clock */
140 unsigned int fifosize
; /* tx fifo size */
141 unsigned char x_char
; /* xon/xoff char */
142 unsigned char regshift
; /* reg offset shift */
143 unsigned char iotype
; /* io access style */
144 unsigned char quirks
; /* internal quirks */
146 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
147 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
148 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */
149 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */
150 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */
151 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */
152 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */
153 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */
155 /* quirks must be updated while holding port mutex */
156 #define UPQ_NO_TXEN_TEST BIT(0)
158 unsigned int read_status_mask
; /* driver specific */
159 unsigned int ignore_status_mask
; /* driver specific */
160 struct uart_state
*state
; /* pointer to parent state */
161 struct uart_icount icount
; /* statistics */
163 struct console
*cons
; /* struct console, if any */
164 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
165 unsigned long sysrq
; /* sysrq timeout */
166 unsigned int sysrq_ch
; /* char for sysrq */
169 /* flags must be updated while holding port mutex */
173 * These flags must be equivalent to the flags defined in
174 * include/uapi/linux/tty_flags.h which are the userspace definitions
175 * assigned from the serial_struct flags in uart_set_info()
176 * [for bit definitions in the UPF_CHANGE_MASK]
178 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
179 * The remaining bits are serial-core specific and not modifiable by
182 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ )
183 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ )
184 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ )
185 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ )
186 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ )
187 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ )
188 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ )
189 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ )
190 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ )
191 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ )
192 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ )
193 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ )
194 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ )
195 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
197 #define UPF_NO_THRE_TEST ((__force upf_t) (1 << 19))
198 /* Port has hardware-assisted h/w flow control */
199 #define UPF_AUTO_CTS ((__force upf_t) (1 << 20))
200 #define UPF_AUTO_RTS ((__force upf_t) (1 << 21))
201 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
202 /* Port has hardware-assisted s/w flow control */
203 #define UPF_SOFT_FLOW ((__force upf_t) (1 << 22))
204 #define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
205 #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
206 #define UPF_EXAR_EFR ((__force upf_t) (1 << 25))
207 #define UPF_BUG_THRE ((__force upf_t) (1 << 26))
208 /* The exact UART type is known and should not be probed. */
209 #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
210 #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
211 #define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
212 #define UPF_DEAD ((__force upf_t) (1 << 30))
213 #define UPF_IOREMAP ((__force upf_t) (1 << 31))
215 #define __UPF_CHANGE_MASK 0x17fff
216 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK)
217 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
219 #if __UPF_CHANGE_MASK > ASYNC_FLAGS
220 #error Change mask not equivalent to userspace-visible bit defines
224 * Must hold termios_rwsem, port mutex and port lock to change;
225 * can hold any one lock to read.
229 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0))
230 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1))
231 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2))
232 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3))
233 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4))
234 #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5))
236 int hw_stopped
; /* sw-assisted CTS flow state */
237 unsigned int mctrl
; /* current modem ctrl settings */
238 unsigned int timeout
; /* character-based timeout */
239 unsigned int type
; /* port type */
240 const struct uart_ops
*ops
;
241 unsigned int custom_divisor
;
242 unsigned int line
; /* port index */
244 resource_size_t mapbase
; /* for ioremap */
245 resource_size_t mapsize
;
246 struct device
*dev
; /* parent device */
247 unsigned char hub6
; /* this should be in the 8250 driver */
248 unsigned char suspended
;
249 unsigned char unused
[2];
250 const char *name
; /* port name */
251 struct attribute_group
*attr_group
; /* port specific attributes */
252 const struct attribute_group
**tty_groups
; /* all attributes (serial core use only) */
253 struct serial_rs485 rs485
;
254 struct serial_iso7816 iso7816
;
255 void *private_data
; /* generic platform data pointer */
258 static inline int serial_port_in(struct uart_port
*up
, int offset
)
260 return up
->serial_in(up
, offset
);
263 static inline void serial_port_out(struct uart_port
*up
, int offset
, int value
)
265 up
->serial_out(up
, offset
, value
);
269 * enum uart_pm_state - power states for UARTs
270 * @UART_PM_STATE_ON: UART is powered, up and operational
271 * @UART_PM_STATE_OFF: UART is powered off
272 * @UART_PM_STATE_UNDEFINED: sentinel
275 UART_PM_STATE_ON
= 0,
276 UART_PM_STATE_OFF
= 3, /* number taken from ACPI */
277 UART_PM_STATE_UNDEFINED
,
281 * This is the state information which is persistent across opens.
284 struct tty_port port
;
286 enum uart_pm_state pm_state
;
287 struct circ_buf xmit
;
290 wait_queue_head_t remove_wait
;
291 struct uart_port
*uart_port
;
294 #define UART_XMIT_SIZE PAGE_SIZE
297 /* number of characters left in xmit buffer before we ask for more */
298 #define WAKEUP_CHARS 256
304 struct module
*owner
;
305 const char *driver_name
;
306 const char *dev_name
;
310 struct console
*cons
;
313 * these are private; the low level driver should not
314 * touch these; they should be initialised to NULL
316 struct uart_state
*state
;
317 struct tty_driver
*tty_driver
;
320 void uart_write_wakeup(struct uart_port
*port
);
325 void uart_update_timeout(struct uart_port
*port
, unsigned int cflag
,
327 unsigned int uart_get_baud_rate(struct uart_port
*port
, struct ktermios
*termios
,
328 struct ktermios
*old
, unsigned int min
,
330 unsigned int uart_get_divisor(struct uart_port
*port
, unsigned int baud
);
332 /* Base timer interval for polling */
333 static inline int uart_poll_timeout(struct uart_port
*port
)
335 int timeout
= port
->timeout
;
337 return timeout
> 6 ? (timeout
/ 2 - 2) : 1;
343 struct earlycon_device
{
345 struct uart_port port
;
346 char options
[16]; /* e.g., 115200n8 */
352 char name_term
; /* In case compiler didn't '\0' term name */
353 char compatible
[128];
354 int (*setup
)(struct earlycon_device
*, const char *options
);
357 extern const struct earlycon_id
*__earlycon_table
[];
358 extern const struct earlycon_id
*__earlycon_table_end
[];
360 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE)
361 #define EARLYCON_USED_OR_UNUSED __used
363 #define EARLYCON_USED_OR_UNUSED __maybe_unused
366 #define _OF_EARLYCON_DECLARE(_name, compat, fn, unique_id) \
367 static const struct earlycon_id unique_id \
368 EARLYCON_USED_OR_UNUSED __initconst \
369 = { .name = __stringify(_name), \
370 .compatible = compat, \
372 static const struct earlycon_id EARLYCON_USED_OR_UNUSED \
373 __section(__earlycon_table) \
374 * const __PASTE(__p, unique_id) = &unique_id
376 #define OF_EARLYCON_DECLARE(_name, compat, fn) \
377 _OF_EARLYCON_DECLARE(_name, compat, fn, \
378 __UNIQUE_ID(__earlycon_##_name))
380 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn)
382 extern int of_setup_earlycon(const struct earlycon_id
*match
,
384 const char *options
);
386 #ifdef CONFIG_SERIAL_EARLYCON
387 extern bool earlycon_acpi_spcr_enable __initdata
;
388 int setup_earlycon(char *buf
);
390 static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED
;
391 static inline int setup_earlycon(char *buf
) { return 0; }
394 struct uart_port
*uart_get_console(struct uart_port
*ports
, int nr
,
396 int uart_parse_earlycon(char *p
, unsigned char *iotype
, resource_size_t
*addr
,
398 void uart_parse_options(const char *options
, int *baud
, int *parity
, int *bits
,
400 int uart_set_options(struct uart_port
*port
, struct console
*co
, int baud
,
401 int parity
, int bits
, int flow
);
402 struct tty_driver
*uart_console_device(struct console
*co
, int *index
);
403 void uart_console_write(struct uart_port
*port
, const char *s
,
405 void (*putchar
)(struct uart_port
*, int));
408 * Port/driver registration/removal
410 int uart_register_driver(struct uart_driver
*uart
);
411 void uart_unregister_driver(struct uart_driver
*uart
);
412 int uart_add_one_port(struct uart_driver
*reg
, struct uart_port
*port
);
413 int uart_remove_one_port(struct uart_driver
*reg
, struct uart_port
*port
);
414 int uart_match_port(struct uart_port
*port1
, struct uart_port
*port2
);
419 int uart_suspend_port(struct uart_driver
*reg
, struct uart_port
*port
);
420 int uart_resume_port(struct uart_driver
*reg
, struct uart_port
*port
);
422 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail)
423 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0)
425 #define uart_circ_chars_pending(circ) \
426 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
428 #define uart_circ_chars_free(circ) \
429 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
431 static inline int uart_tx_stopped(struct uart_port
*port
)
433 struct tty_struct
*tty
= port
->state
->port
.tty
;
434 if ((tty
&& tty
->stopped
) || port
->hw_stopped
)
439 static inline bool uart_cts_enabled(struct uart_port
*uport
)
441 return !!(uport
->status
& UPSTAT_CTS_ENABLE
);
444 static inline bool uart_softcts_mode(struct uart_port
*uport
)
446 upstat_t mask
= UPSTAT_CTS_ENABLE
| UPSTAT_AUTOCTS
;
448 return ((uport
->status
& mask
) == UPSTAT_CTS_ENABLE
);
452 * The following are helper functions for the low level drivers.
455 extern void uart_handle_dcd_change(struct uart_port
*uport
,
456 unsigned int status
);
457 extern void uart_handle_cts_change(struct uart_port
*uport
,
458 unsigned int status
);
460 extern void uart_insert_char(struct uart_port
*port
, unsigned int status
,
461 unsigned int overrun
, unsigned int ch
, unsigned int flag
);
463 #if defined(SUPPORT_SYSRQ) && defined(CONFIG_MAGIC_SYSRQ_SERIAL)
465 uart_handle_sysrq_char(struct uart_port
*port
, unsigned int ch
)
468 if (ch
&& time_before(jiffies
, port
->sysrq
)) {
478 uart_prepare_sysrq_char(struct uart_port
*port
, unsigned int ch
)
481 if (ch
&& time_before(jiffies
, port
->sysrq
)) {
491 uart_unlock_and_check_sysrq(struct uart_port
*port
, unsigned long irqflags
)
495 sysrq_ch
= port
->sysrq_ch
;
498 spin_unlock_irqrestore(&port
->lock
, irqflags
);
501 handle_sysrq(sysrq_ch
);
505 uart_handle_sysrq_char(struct uart_port
*port
, unsigned int ch
) { return 0; }
507 uart_prepare_sysrq_char(struct uart_port
*port
, unsigned int ch
) { return 0; }
509 uart_unlock_and_check_sysrq(struct uart_port
*port
, unsigned long irqflags
)
511 spin_unlock_irqrestore(&port
->lock
, irqflags
);
516 * We do the SysRQ and SAK checking like this...
518 static inline int uart_handle_break(struct uart_port
*port
)
520 struct uart_state
*state
= port
->state
;
522 if (port
->handle_break
)
523 port
->handle_break(port
);
526 if (port
->cons
&& port
->cons
->index
== port
->line
) {
528 port
->sysrq
= jiffies
+ HZ
*5;
534 if (port
->flags
& UPF_SAK
)
535 do_SAK(state
->port
.tty
);
540 * UART_ENABLE_MS - determine if port should enable modem status irqs
542 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \
543 (cflag) & CRTSCTS || \
546 void uart_get_rs485_mode(struct device
*dev
, struct serial_rs485
*rs485conf
);
547 #endif /* LINUX_SERIAL_CORE_H */