| /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| /* |
| * linux/drivers/char/serial_core.h |
| * |
| * Copyright (C) 2000 Deep Blue Solutions Ltd. |
| */ |
| #ifndef LINUX_SERIAL_CORE_H |
| #define LINUX_SERIAL_CORE_H |
| |
| #include <linux/bitops.h> |
| #include <linux/compiler.h> |
| #include <linux/console.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; |
| struct gpio_desc; |
| |
| /* |
| * This structure describes all the operations that can be done on the |
| * physical hardware. See Documentation/driver-api/serial/driver.rst 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); |
| void (*set_ldisc)(struct uart_port *, |
| struct ktermios *); |
| unsigned int (*get_mctrl)(struct uart_port *); |
| void (*set_mctrl)(struct uart_port *, unsigned int); |
| unsigned int (*get_divisor)(struct uart_port *, |
| unsigned int baud, |
| unsigned int *frac); |
| void (*set_divisor)(struct uart_port *, |
| unsigned int baud, |
| unsigned int quot, |
| unsigned int quot_frac); |
| 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); |
| int (*iso7816_config)(struct uart_port *, |
| struct serial_iso7816 *iso7816); |
| 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 quirks; /* internal quirks */ |
| |
| #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 */ |
| |
| /* quirks must be updated while holding port mutex */ |
| #define UPQ_NO_TXEN_TEST BIT(0) |
| |
| 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 */ |
| /* 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 |
| * 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_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ ) |
| |
| #define UPF_NO_THRE_TEST ((__force upf_t) (1 << 19)) |
| /* 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)) |
| #define UPSTAT_SYNC_FIFO ((__force upstat_t) (1 << 5)) |
| |
| 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 long sysrq; /* sysrq timeout */ |
| unsigned int sysrq_ch; /* char for sysrq */ |
| unsigned char has_sysrq; |
| unsigned char sysrq_seq; /* index in sysrq_toggle_seq */ |
| |
| unsigned char hub6; /* this should be in the 8250 driver */ |
| unsigned char suspended; |
| unsigned char console_reinit; |
| const char *name; /* port name */ |
| struct attribute_group *attr_group; /* port specific attributes */ |
| const struct attribute_group **tty_groups; /* all attributes (serial core use only) */ |
| struct serial_rs485 rs485; |
| struct gpio_desc *rs485_term_gpio; /* enable RS485 bus termination */ |
| struct serial_iso7816 iso7816; |
| 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[15]; |
| char name_term; /* In case compiler didn't '\0' term name */ |
| char compatible[128]; |
| int (*setup)(struct earlycon_device *, const char *options); |
| }; |
| |
| 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") \ |
| __aligned(__alignof__(struct earlycon_id)) \ |
| = { .name = __stringify(_name), \ |
| .compatible = compat, \ |
| .setup = fn } |
| |
| #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) |
| |
| extern int of_setup_earlycon(const struct earlycon_id *match, |
| unsigned long node, |
| const char *options); |
| |
| #ifdef CONFIG_SERIAL_EARLYCON |
| extern bool earlycon_acpi_spcr_enable __initdata; |
| int setup_earlycon(char *buf); |
| #else |
| static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED; |
| static inline int setup_earlycon(char *buf) { return 0; } |
| #endif |
| |
| struct uart_port *uart_get_console(struct uart_port *ports, int nr, |
| struct console *c); |
| int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, |
| char **options); |
| void uart_parse_options(const 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); |
| bool uart_match_port(const struct uart_port *port1, |
| const 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 && tty->flow.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 CONFIG_MAGIC_SYSRQ_SERIAL |
| #define SYSRQ_TIMEOUT (HZ * 5) |
| |
| bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch); |
| |
| static inline int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) |
| { |
| if (!port->sysrq) |
| return 0; |
| |
| if (ch && time_before(jiffies, port->sysrq)) { |
| if (sysrq_mask()) { |
| handle_sysrq(ch); |
| port->sysrq = 0; |
| return 1; |
| } |
| if (uart_try_toggle_sysrq(port, ch)) |
| return 1; |
| } |
| port->sysrq = 0; |
| |
| return 0; |
| } |
| |
| static inline int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) |
| { |
| if (!port->sysrq) |
| return 0; |
| |
| if (ch && time_before(jiffies, port->sysrq)) { |
| if (sysrq_mask()) { |
| port->sysrq_ch = ch; |
| port->sysrq = 0; |
| return 1; |
| } |
| if (uart_try_toggle_sysrq(port, ch)) |
| return 1; |
| } |
| port->sysrq = 0; |
| |
| return 0; |
| } |
| |
| static inline void uart_unlock_and_check_sysrq(struct uart_port *port) |
| { |
| int sysrq_ch; |
| |
| if (!port->has_sysrq) { |
| spin_unlock(&port->lock); |
| return; |
| } |
| |
| sysrq_ch = port->sysrq_ch; |
| port->sysrq_ch = 0; |
| |
| spin_unlock(&port->lock); |
| |
| if (sysrq_ch) |
| handle_sysrq(sysrq_ch); |
| } |
| |
| static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, |
| unsigned long flags) |
| { |
| int sysrq_ch; |
| |
| if (!port->has_sysrq) { |
| spin_unlock_irqrestore(&port->lock, flags); |
| return; |
| } |
| |
| sysrq_ch = port->sysrq_ch; |
| port->sysrq_ch = 0; |
| |
| spin_unlock_irqrestore(&port->lock, flags); |
| |
| if (sysrq_ch) |
| handle_sysrq(sysrq_ch); |
| } |
| #else /* CONFIG_MAGIC_SYSRQ_SERIAL */ |
| static inline int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) |
| { |
| return 0; |
| } |
| static inline int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) |
| { |
| return 0; |
| } |
| static inline void uart_unlock_and_check_sysrq(struct uart_port *port) |
| { |
| spin_unlock(&port->lock); |
| } |
| static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, |
| unsigned long flags) |
| { |
| spin_unlock_irqrestore(&port->lock, flags); |
| } |
| #endif /* CONFIG_MAGIC_SYSRQ_SERIAL */ |
| |
| /* |
| * 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 CONFIG_MAGIC_SYSRQ_SERIAL |
| if (port->has_sysrq && uart_console(port)) { |
| if (!port->sysrq) { |
| port->sysrq = jiffies + SYSRQ_TIMEOUT; |
| 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)) |
| |
| int uart_get_rs485_mode(struct uart_port *port); |
| #endif /* LINUX_SERIAL_CORE_H */ |