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; })
35 * This structure describes all the operations that can be done on the
36 * physical hardware. See Documentation/driver-api/serial/driver.rst for details.
39 unsigned int (*tx_empty
)(struct uart_port
*);
40 void (*set_mctrl
)(struct uart_port
*, unsigned int mctrl
);
41 unsigned int (*get_mctrl
)(struct uart_port
*);
42 void (*stop_tx
)(struct uart_port
*);
43 void (*start_tx
)(struct uart_port
*);
44 void (*throttle
)(struct uart_port
*);
45 void (*unthrottle
)(struct uart_port
*);
46 void (*send_xchar
)(struct uart_port
*, char ch
);
47 void (*stop_rx
)(struct uart_port
*);
48 void (*enable_ms
)(struct uart_port
*);
49 void (*break_ctl
)(struct uart_port
*, int ctl
);
50 int (*startup
)(struct uart_port
*);
51 void (*shutdown
)(struct uart_port
*);
52 void (*flush_buffer
)(struct uart_port
*);
53 void (*set_termios
)(struct uart_port
*, struct ktermios
*new,
54 struct ktermios
*old
);
55 void (*set_ldisc
)(struct uart_port
*, struct ktermios
*);
56 void (*pm
)(struct uart_port
*, unsigned int state
,
57 unsigned int oldstate
);
60 * Return a string describing the type of the port
62 const char *(*type
)(struct uart_port
*);
65 * Release IO and memory resources used by the port.
66 * This includes iounmap if necessary.
68 void (*release_port
)(struct uart_port
*);
71 * Request IO and memory resources used by the port.
72 * This includes iomapping the port if necessary.
74 int (*request_port
)(struct uart_port
*);
75 void (*config_port
)(struct uart_port
*, int);
76 int (*verify_port
)(struct uart_port
*, struct serial_struct
*);
77 int (*ioctl
)(struct uart_port
*, unsigned int, unsigned long);
78 #ifdef CONFIG_CONSOLE_POLL
79 int (*poll_init
)(struct uart_port
*);
80 void (*poll_put_char
)(struct uart_port
*, unsigned char);
81 int (*poll_get_char
)(struct uart_port
*);
85 #define NO_POLL_CHAR 0x00ff0000
86 #define UART_CONFIG_TYPE (1 << 0)
87 #define UART_CONFIG_IRQ (1 << 1)
103 typedef unsigned int __bitwise upf_t
;
104 typedef unsigned int __bitwise upstat_t
;
107 spinlock_t lock
; /* port lock */
108 unsigned long iobase
; /* in/out[bwl] */
109 unsigned char __iomem
*membase
; /* read/write[bwl] */
110 unsigned int (*serial_in
)(struct uart_port
*, int);
111 void (*serial_out
)(struct uart_port
*, int, int);
112 void (*set_termios
)(struct uart_port
*,
113 struct ktermios
*new,
114 struct ktermios
*old
);
115 void (*set_ldisc
)(struct uart_port
*,
117 unsigned int (*get_mctrl
)(struct uart_port
*);
118 void (*set_mctrl
)(struct uart_port
*, unsigned int);
119 unsigned int (*get_divisor
)(struct uart_port
*,
122 void (*set_divisor
)(struct uart_port
*,
125 unsigned int quot_frac
);
126 int (*startup
)(struct uart_port
*port
);
127 void (*shutdown
)(struct uart_port
*port
);
128 void (*throttle
)(struct uart_port
*port
);
129 void (*unthrottle
)(struct uart_port
*port
);
130 int (*handle_irq
)(struct uart_port
*);
131 void (*pm
)(struct uart_port
*, unsigned int state
,
133 void (*handle_break
)(struct uart_port
*);
134 int (*rs485_config
)(struct uart_port
*,
135 struct serial_rs485
*rs485
);
136 int (*iso7816_config
)(struct uart_port
*,
137 struct serial_iso7816
*iso7816
);
138 unsigned int irq
; /* irq number */
139 unsigned long irqflags
; /* irq flags */
140 unsigned int uartclk
; /* base uart clock */
141 unsigned int fifosize
; /* tx fifo size */
142 unsigned char x_char
; /* xon/xoff char */
143 unsigned char regshift
; /* reg offset shift */
144 unsigned char iotype
; /* io access style */
145 unsigned char quirks
; /* internal quirks */
147 #define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
148 #define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
149 #define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */
150 #define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */
151 #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */
152 #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */
153 #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */
154 #define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */
156 /* quirks must be updated while holding port mutex */
157 #define UPQ_NO_TXEN_TEST BIT(0)
159 unsigned int read_status_mask
; /* driver specific */
160 unsigned int ignore_status_mask
; /* driver specific */
161 struct uart_state
*state
; /* pointer to parent state */
162 struct uart_icount icount
; /* statistics */
164 struct console
*cons
; /* struct console, if any */
165 /* flags must be updated while holding port mutex */
169 * These flags must be equivalent to the flags defined in
170 * include/uapi/linux/tty_flags.h which are the userspace definitions
171 * assigned from the serial_struct flags in uart_set_info()
172 * [for bit definitions in the UPF_CHANGE_MASK]
174 * Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
175 * The remaining bits are serial-core specific and not modifiable by
178 #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ )
179 #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ )
180 #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ )
181 #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ )
182 #define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ )
183 #define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ )
184 #define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ )
185 #define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ )
186 #define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ )
187 #define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ )
188 #define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ )
189 #define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ )
190 #define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ )
191 #define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
193 #define UPF_NO_THRE_TEST ((__force upf_t) (1 << 19))
194 /* Port has hardware-assisted h/w flow control */
195 #define UPF_AUTO_CTS ((__force upf_t) (1 << 20))
196 #define UPF_AUTO_RTS ((__force upf_t) (1 << 21))
197 #define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
198 /* Port has hardware-assisted s/w flow control */
199 #define UPF_SOFT_FLOW ((__force upf_t) (1 << 22))
200 #define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
201 #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
202 #define UPF_EXAR_EFR ((__force upf_t) (1 << 25))
203 #define UPF_BUG_THRE ((__force upf_t) (1 << 26))
204 /* The exact UART type is known and should not be probed. */
205 #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
206 #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
207 #define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
208 #define UPF_DEAD ((__force upf_t) (1 << 30))
209 #define UPF_IOREMAP ((__force upf_t) (1 << 31))
211 #define __UPF_CHANGE_MASK 0x17fff
212 #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK)
213 #define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
215 #if __UPF_CHANGE_MASK > ASYNC_FLAGS
216 #error Change mask not equivalent to userspace-visible bit defines
220 * Must hold termios_rwsem, port mutex and port lock to change;
221 * can hold any one lock to read.
225 #define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0))
226 #define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1))
227 #define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2))
228 #define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3))
229 #define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4))
230 #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5))
232 int hw_stopped
; /* sw-assisted CTS flow state */
233 unsigned int mctrl
; /* current modem ctrl settings */
234 unsigned int timeout
; /* character-based timeout */
235 unsigned int type
; /* port type */
236 const struct uart_ops
*ops
;
237 unsigned int custom_divisor
;
238 unsigned int line
; /* port index */
240 resource_size_t mapbase
; /* for ioremap */
241 resource_size_t mapsize
;
242 struct device
*dev
; /* parent device */
244 unsigned long sysrq
; /* sysrq timeout */
245 unsigned int sysrq_ch
; /* char for sysrq */
246 unsigned char has_sysrq
;
247 unsigned char sysrq_seq
; /* index in sysrq_toggle_seq */
249 unsigned char hub6
; /* this should be in the 8250 driver */
250 unsigned char suspended
;
251 const char *name
; /* port name */
252 struct attribute_group
*attr_group
; /* port specific attributes */
253 const struct attribute_group
**tty_groups
; /* all attributes (serial core use only) */
254 struct serial_rs485 rs485
;
255 struct gpio_desc
*rs485_term_gpio
; /* enable RS485 bus termination */
256 struct serial_iso7816 iso7816
;
257 void *private_data
; /* generic platform data pointer */
260 static inline int serial_port_in(struct uart_port
*up
, int offset
)
262 return up
->serial_in(up
, offset
);
265 static inline void serial_port_out(struct uart_port
*up
, int offset
, int value
)
267 up
->serial_out(up
, offset
, value
);
271 * enum uart_pm_state - power states for UARTs
272 * @UART_PM_STATE_ON: UART is powered, up and operational
273 * @UART_PM_STATE_OFF: UART is powered off
274 * @UART_PM_STATE_UNDEFINED: sentinel
277 UART_PM_STATE_ON
= 0,
278 UART_PM_STATE_OFF
= 3, /* number taken from ACPI */
279 UART_PM_STATE_UNDEFINED
,
283 * This is the state information which is persistent across opens.
286 struct tty_port port
;
288 enum uart_pm_state pm_state
;
289 struct circ_buf xmit
;
292 wait_queue_head_t remove_wait
;
293 struct uart_port
*uart_port
;
296 #define UART_XMIT_SIZE PAGE_SIZE
299 /* number of characters left in xmit buffer before we ask for more */
300 #define WAKEUP_CHARS 256
306 struct module
*owner
;
307 const char *driver_name
;
308 const char *dev_name
;
312 struct console
*cons
;
315 * these are private; the low level driver should not
316 * touch these; they should be initialised to NULL
318 struct uart_state
*state
;
319 struct tty_driver
*tty_driver
;
322 void uart_write_wakeup(struct uart_port
*port
);
327 void uart_update_timeout(struct uart_port
*port
, unsigned int cflag
,
329 unsigned int uart_get_baud_rate(struct uart_port
*port
, struct ktermios
*termios
,
330 struct ktermios
*old
, unsigned int min
,
332 unsigned int uart_get_divisor(struct uart_port
*port
, unsigned int baud
);
334 /* Base timer interval for polling */
335 static inline int uart_poll_timeout(struct uart_port
*port
)
337 int timeout
= port
->timeout
;
339 return timeout
> 6 ? (timeout
/ 2 - 2) : 1;
345 struct earlycon_device
{
347 struct uart_port port
;
348 char options
[16]; /* e.g., 115200n8 */
354 char name_term
; /* In case compiler didn't '\0' term name */
355 char compatible
[128];
356 int (*setup
)(struct earlycon_device
*, const char *options
);
359 extern const struct earlycon_id
*__earlycon_table
[];
360 extern const struct earlycon_id
*__earlycon_table_end
[];
362 #if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE)
363 #define EARLYCON_USED_OR_UNUSED __used
365 #define EARLYCON_USED_OR_UNUSED __maybe_unused
368 #define _OF_EARLYCON_DECLARE(_name, compat, fn, unique_id) \
369 static const struct earlycon_id unique_id \
370 EARLYCON_USED_OR_UNUSED __initconst \
371 = { .name = __stringify(_name), \
372 .compatible = compat, \
374 static const struct earlycon_id EARLYCON_USED_OR_UNUSED \
375 __section(__earlycon_table) \
376 * const __PASTE(__p, unique_id) = &unique_id
378 #define OF_EARLYCON_DECLARE(_name, compat, fn) \
379 _OF_EARLYCON_DECLARE(_name, compat, fn, \
380 __UNIQUE_ID(__earlycon_##_name))
382 #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn)
384 extern int of_setup_earlycon(const struct earlycon_id
*match
,
386 const char *options
);
388 #ifdef CONFIG_SERIAL_EARLYCON
389 extern bool earlycon_acpi_spcr_enable __initdata
;
390 int setup_earlycon(char *buf
);
392 static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED
;
393 static inline int setup_earlycon(char *buf
) { return 0; }
396 struct uart_port
*uart_get_console(struct uart_port
*ports
, int nr
,
398 int uart_parse_earlycon(char *p
, unsigned char *iotype
, resource_size_t
*addr
,
400 void uart_parse_options(const char *options
, int *baud
, int *parity
, int *bits
,
402 int uart_set_options(struct uart_port
*port
, struct console
*co
, int baud
,
403 int parity
, int bits
, int flow
);
404 struct tty_driver
*uart_console_device(struct console
*co
, int *index
);
405 void uart_console_write(struct uart_port
*port
, const char *s
,
407 void (*putchar
)(struct uart_port
*, int));
410 * Port/driver registration/removal
412 int uart_register_driver(struct uart_driver
*uart
);
413 void uart_unregister_driver(struct uart_driver
*uart
);
414 int uart_add_one_port(struct uart_driver
*reg
, struct uart_port
*port
);
415 int uart_remove_one_port(struct uart_driver
*reg
, struct uart_port
*port
);
416 int uart_match_port(struct uart_port
*port1
, struct uart_port
*port2
);
421 int uart_suspend_port(struct uart_driver
*reg
, struct uart_port
*port
);
422 int uart_resume_port(struct uart_driver
*reg
, struct uart_port
*port
);
424 #define uart_circ_empty(circ) ((circ)->head == (circ)->tail)
425 #define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0)
427 #define uart_circ_chars_pending(circ) \
428 (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
430 #define uart_circ_chars_free(circ) \
431 (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
433 static inline int uart_tx_stopped(struct uart_port
*port
)
435 struct tty_struct
*tty
= port
->state
->port
.tty
;
436 if ((tty
&& tty
->stopped
) || port
->hw_stopped
)
441 static inline bool uart_cts_enabled(struct uart_port
*uport
)
443 return !!(uport
->status
& UPSTAT_CTS_ENABLE
);
446 static inline bool uart_softcts_mode(struct uart_port
*uport
)
448 upstat_t mask
= UPSTAT_CTS_ENABLE
| UPSTAT_AUTOCTS
;
450 return ((uport
->status
& mask
) == UPSTAT_CTS_ENABLE
);
454 * The following are helper functions for the low level drivers.
457 extern void uart_handle_dcd_change(struct uart_port
*uport
,
458 unsigned int status
);
459 extern void uart_handle_cts_change(struct uart_port
*uport
,
460 unsigned int status
);
462 extern void uart_insert_char(struct uart_port
*port
, unsigned int status
,
463 unsigned int overrun
, unsigned int ch
, unsigned int flag
);
465 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL
466 #define SYSRQ_TIMEOUT (HZ * 5)
468 bool uart_try_toggle_sysrq(struct uart_port
*port
, unsigned int ch
);
470 static inline int uart_handle_sysrq_char(struct uart_port
*port
, unsigned int ch
)
475 if (ch
&& time_before(jiffies
, port
->sysrq
)) {
481 if (uart_try_toggle_sysrq(port
, ch
))
489 static inline int uart_prepare_sysrq_char(struct uart_port
*port
, unsigned int ch
)
494 if (ch
&& time_before(jiffies
, port
->sysrq
)) {
500 if (uart_try_toggle_sysrq(port
, ch
))
508 static inline void uart_unlock_and_check_sysrq(struct uart_port
*port
, unsigned long irqflags
)
512 if (!port
->has_sysrq
) {
513 spin_unlock_irqrestore(&port
->lock
, irqflags
);
517 sysrq_ch
= port
->sysrq_ch
;
520 spin_unlock_irqrestore(&port
->lock
, irqflags
);
523 handle_sysrq(sysrq_ch
);
525 #else /* CONFIG_MAGIC_SYSRQ_SERIAL */
526 static inline int uart_handle_sysrq_char(struct uart_port
*port
, unsigned int ch
)
530 static inline int uart_prepare_sysrq_char(struct uart_port
*port
, unsigned int ch
)
534 static inline void uart_unlock_and_check_sysrq(struct uart_port
*port
, unsigned long irqflags
)
536 spin_unlock_irqrestore(&port
->lock
, irqflags
);
538 #endif /* CONFIG_MAGIC_SYSRQ_SERIAL */
541 * We do the SysRQ and SAK checking like this...
543 static inline int uart_handle_break(struct uart_port
*port
)
545 struct uart_state
*state
= port
->state
;
547 if (port
->handle_break
)
548 port
->handle_break(port
);
550 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL
551 if (port
->has_sysrq
&& uart_console(port
)) {
553 port
->sysrq
= jiffies
+ SYSRQ_TIMEOUT
;
559 if (port
->flags
& UPF_SAK
)
560 do_SAK(state
->port
.tty
);
565 * UART_ENABLE_MS - determine if port should enable modem status irqs
567 #define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \
568 (cflag) & CRTSCTS || \
571 int uart_get_rs485_mode(struct uart_port
*port
);
572 #endif /* LINUX_SERIAL_CORE_H */