diff options
Diffstat (limited to 'include/linux/serial_core.h')
| -rw-r--r-- | include/linux/serial_core.h | 929 |
1 files changed, 827 insertions, 102 deletions
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 8a99279a579b..914b5e97e056 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -11,7 +11,8 @@ #include <linux/compiler.h> #include <linux/console.h> #include <linux/interrupt.h> -#include <linux/circ_buf.h> +#include <linux/lockdep.h> +#include <linux/printk.h> #include <linux/spinlock.h> #include <linux/sched.h> #include <linux/tty.h> @@ -28,12 +29,348 @@ struct uart_port; struct serial_struct; +struct serial_port_device; struct device; struct gpio_desc; -/* +/** + * struct uart_ops -- interface between serial_core and the driver + * * This structure describes all the operations that can be done on the - * physical hardware. See Documentation/driver-api/serial/driver.rst for details. + * physical hardware. + * + * @tx_empty: ``unsigned int ()(struct uart_port *port)`` + * + * This function tests whether the transmitter fifo and shifter for the + * @port is empty. If it is empty, this function should return + * %TIOCSER_TEMT, otherwise return 0. If the port does not support this + * operation, then it should return %TIOCSER_TEMT. + * + * Locking: none. + * Interrupts: caller dependent. + * This call must not sleep + * + * @set_mctrl: ``void ()(struct uart_port *port, unsigned int mctrl)`` + * + * This function sets the modem control lines for @port to the state + * described by @mctrl. The relevant bits of @mctrl are: + * + * - %TIOCM_RTS RTS signal. + * - %TIOCM_DTR DTR signal. + * - %TIOCM_OUT1 OUT1 signal. + * - %TIOCM_OUT2 OUT2 signal. + * - %TIOCM_LOOP Set the port into loopback mode. + * + * If the appropriate bit is set, the signal should be driven + * active. If the bit is clear, the signal should be driven + * inactive. + * + * Locking: @port->lock taken. + * Interrupts: locally disabled. + * This call must not sleep + * + * @get_mctrl: ``unsigned int ()(struct uart_port *port)`` + * + * Returns the current state of modem control inputs of @port. The state + * of the outputs should not be returned, since the core keeps track of + * their state. The state information should include: + * + * - %TIOCM_CAR state of DCD signal + * - %TIOCM_CTS state of CTS signal + * - %TIOCM_DSR state of DSR signal + * - %TIOCM_RI state of RI signal + * + * The bit is set if the signal is currently driven active. If + * the port does not support CTS, DCD or DSR, the driver should + * indicate that the signal is permanently active. If RI is + * not available, the signal should not be indicated as active. + * + * Locking: @port->lock taken. + * Interrupts: locally disabled. + * This call must not sleep + * + * @stop_tx: ``void ()(struct uart_port *port)`` + * + * Stop transmitting characters. This might be due to the CTS line + * becoming inactive or the tty layer indicating we want to stop + * transmission due to an %XOFF character. + * + * The driver should stop transmitting characters as soon as possible. + * + * Locking: @port->lock taken. + * Interrupts: locally disabled. + * This call must not sleep + * + * @start_tx: ``void ()(struct uart_port *port)`` + * + * Start transmitting characters. + * + * Locking: @port->lock taken. + * Interrupts: locally disabled. + * This call must not sleep + * + * @throttle: ``void ()(struct uart_port *port)`` + * + * Notify the serial driver that input buffers for the line discipline are + * close to full, and it should somehow signal that no more characters + * should be sent to the serial port. + * This will be called only if hardware assisted flow control is enabled. + * + * Locking: serialized with @unthrottle() and termios modification by the + * tty layer. + * + * @unthrottle: ``void ()(struct uart_port *port)`` + * + * Notify the serial driver that characters can now be sent to the serial + * port without fear of overrunning the input buffers of the line + * disciplines. + * + * This will be called only if hardware assisted flow control is enabled. + * + * Locking: serialized with @throttle() and termios modification by the + * tty layer. + * + * @send_xchar: ``void ()(struct uart_port *port, char ch)`` + * + * Transmit a high priority character, even if the port is stopped. This + * is used to implement XON/XOFF flow control and tcflow(). If the serial + * driver does not implement this function, the tty core will append the + * character to the circular buffer and then call start_tx() / stop_tx() + * to flush the data out. + * + * Do not transmit if @ch == '\0' (%__DISABLED_CHAR). + * + * Locking: none. + * Interrupts: caller dependent. + * + * @start_rx: ``void ()(struct uart_port *port)`` + * + * Start receiving characters. + * + * Locking: @port->lock taken. + * Interrupts: locally disabled. + * This call must not sleep + * + * @stop_rx: ``void ()(struct uart_port *port)`` + * + * Stop receiving characters; the @port is in the process of being closed. + * + * Locking: @port->lock taken. + * Interrupts: locally disabled. + * This call must not sleep + * + * @enable_ms: ``void ()(struct uart_port *port)`` + * + * Enable the modem status interrupts. + * + * This method may be called multiple times. Modem status interrupts + * should be disabled when the @shutdown() method is called. + * + * Locking: @port->lock taken. + * Interrupts: locally disabled. + * This call must not sleep + * + * @break_ctl: ``void ()(struct uart_port *port, int ctl)`` + * + * Control the transmission of a break signal. If @ctl is nonzero, the + * break signal should be transmitted. The signal should be terminated + * when another call is made with a zero @ctl. + * + * Locking: caller holds tty_port->mutex + * + * @startup: ``int ()(struct uart_port *port)`` + * + * Grab any interrupt resources and initialise any low level driver state. + * Enable the port for reception. It should not activate RTS nor DTR; + * this will be done via a separate call to @set_mctrl(). + * + * This method will only be called when the port is initially opened. + * + * Locking: port_sem taken. + * Interrupts: globally disabled. + * + * @shutdown: ``void ()(struct uart_port *port)`` + * + * Disable the @port, disable any break condition that may be in effect, + * and free any interrupt resources. It should not disable RTS nor DTR; + * this will have already been done via a separate call to @set_mctrl(). + * + * Drivers must not access @port->state once this call has completed. + * + * This method will only be called when there are no more users of this + * @port. + * + * Locking: port_sem taken. + * Interrupts: caller dependent. + * + * @flush_buffer: ``void ()(struct uart_port *port)`` + * + * Flush any write buffers, reset any DMA state and stop any ongoing DMA + * transfers. + * + * This will be called whenever the @port->state->xmit circular buffer is + * cleared. + * + * Locking: @port->lock taken. + * Interrupts: locally disabled. + * This call must not sleep + * + * @set_termios: ``void ()(struct uart_port *port, struct ktermios *new, + * struct ktermios *old)`` + * + * Change the @port parameters, including word length, parity, stop bits. + * Update @port->read_status_mask and @port->ignore_status_mask to + * indicate the types of events we are interested in receiving. Relevant + * ktermios::c_cflag bits are: + * + * - %CSIZE - word size + * - %CSTOPB - 2 stop bits + * - %PARENB - parity enable + * - %PARODD - odd parity (when %PARENB is in force) + * - %ADDRB - address bit (changed through uart_port::rs485_config()). + * - %CREAD - enable reception of characters (if not set, still receive + * characters from the port, but throw them away). + * - %CRTSCTS - if set, enable CTS status change reporting. + * - %CLOCAL - if not set, enable modem status change reporting. + * + * Relevant ktermios::c_iflag bits are: + * + * - %INPCK - enable frame and parity error events to be passed to the TTY + * layer. + * - %BRKINT / %PARMRK - both of these enable break events to be passed to + * the TTY layer. + * - %IGNPAR - ignore parity and framing errors. + * - %IGNBRK - ignore break errors. If %IGNPAR is also set, ignore overrun + * errors as well. + * + * The interaction of the ktermios::c_iflag bits is as follows (parity + * error given as an example): + * + * ============ ======= ======= ========================================= + * Parity error INPCK IGNPAR + * ============ ======= ======= ========================================= + * n/a 0 n/a character received, marked as %TTY_NORMAL + * None 1 n/a character received, marked as %TTY_NORMAL + * Yes 1 0 character received, marked as %TTY_PARITY + * Yes 1 1 character discarded + * ============ ======= ======= ========================================= + * + * Other flags may be used (eg, xon/xoff characters) if your hardware + * supports hardware "soft" flow control. + * + * Locking: caller holds tty_port->mutex + * Interrupts: caller dependent. + * This call must not sleep + * + * @set_ldisc: ``void ()(struct uart_port *port, struct ktermios *termios)`` + * + * Notifier for discipline change. See + * Documentation/driver-api/tty/tty_ldisc.rst. + * + * Locking: caller holds tty_port->mutex + * + * @pm: ``void ()(struct uart_port *port, unsigned int state, + * unsigned int oldstate)`` + * + * Perform any power management related activities on the specified @port. + * @state indicates the new state (defined by enum uart_pm_state), + * @oldstate indicates the previous state. + * + * This function should not be used to grab any resources. + * + * This will be called when the @port is initially opened and finally + * closed, except when the @port is also the system console. This will + * occur even if %CONFIG_PM is not set. + * + * Locking: none. + * Interrupts: caller dependent. + * + * @type: ``const char *()(struct uart_port *port)`` + * + * Return a pointer to a string constant describing the specified @port, + * or return %NULL, in which case the string 'unknown' is substituted. + * + * Locking: none. + * Interrupts: caller dependent. + * + * @release_port: ``void ()(struct uart_port *port)`` + * + * Release any memory and IO region resources currently in use by the + * @port. + * + * Locking: none. + * Interrupts: caller dependent. + * + * @request_port: ``int ()(struct uart_port *port)`` + * + * Request any memory and IO region resources required by the port. If any + * fail, no resources should be registered when this function returns, and + * it should return -%EBUSY on failure. + * + * Locking: none. + * Interrupts: caller dependent. + * + * @config_port: ``void ()(struct uart_port *port, int type)`` + * + * Perform any autoconfiguration steps required for the @port. @type + * contains a bit mask of the required configuration. %UART_CONFIG_TYPE + * indicates that the port requires detection and identification. + * @port->type should be set to the type found, or %PORT_UNKNOWN if no + * port was detected. + * + * %UART_CONFIG_IRQ indicates autoconfiguration of the interrupt signal, + * which should be probed using standard kernel autoprobing techniques. + * This is not necessary on platforms where ports have interrupts + * internally hard wired (eg, system on a chip implementations). + * + * Locking: none. + * Interrupts: caller dependent. + * + * @verify_port: ``int ()(struct uart_port *port, + * struct serial_struct *serinfo)`` + * + * Verify the new serial port information contained within @serinfo is + * suitable for this port type. + * + * Locking: none. + * Interrupts: caller dependent. + * + * @ioctl: ``int ()(struct uart_port *port, unsigned int cmd, + * unsigned long arg)`` + * + * Perform any port specific IOCTLs. IOCTL commands must be defined using + * the standard numbering system found in <asm/ioctl.h>. + * + * Locking: none. + * Interrupts: caller dependent. + * + * @poll_init: ``int ()(struct uart_port *port)`` + * + * Called by kgdb to perform the minimal hardware initialization needed to + * support @poll_put_char() and @poll_get_char(). Unlike @startup(), this + * should not request interrupts. + * + * Locking: %tty_mutex and tty_port->mutex taken. + * Interrupts: n/a. + * + * @poll_put_char: ``void ()(struct uart_port *port, unsigned char ch)`` + * + * Called by kgdb to write a single character @ch directly to the serial + * @port. It can and should block until there is space in the TX FIFO. + * + * Locking: none. + * Interrupts: caller dependent. + * This call must not sleep + * + * @poll_get_char: ``int ()(struct uart_port *port)`` + * + * Called by kgdb to read a single character directly from the serial + * port. If data is available, it should be returned; otherwise the + * function should return %NO_POLL_CHAR immediately. + * + * Locking: none. + * Interrupts: caller dependent. + * This call must not sleep */ struct uart_ops { unsigned int (*tx_empty)(struct uart_port *); @@ -45,32 +382,19 @@ struct uart_ops { void (*unthrottle)(struct uart_port *); void (*send_xchar)(struct uart_port *, char ch); void (*stop_rx)(struct uart_port *); + void (*start_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); + const 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 *); @@ -100,9 +424,21 @@ struct uart_icount { __u32 buf_overrun; }; -typedef unsigned int __bitwise upf_t; +typedef u64 __bitwise upf_t; typedef unsigned int __bitwise upstat_t; +enum uart_iotype { + UPIO_UNKNOWN = -1, + UPIO_PORT = SERIAL_IO_PORT, /* 8b I/O port access */ + UPIO_HUB6 = SERIAL_IO_HUB6, /* Hub6 ISA card */ + UPIO_MEM = SERIAL_IO_MEM, /* driver-specific */ + UPIO_MEM32 = SERIAL_IO_MEM32, /* 32b little endian */ + UPIO_AU = SERIAL_IO_AU, /* Au1x00 and RT288x type IO */ + UPIO_TSI = SERIAL_IO_TSI, /* Tsi108/109 type IO */ + UPIO_MEM32BE = SERIAL_IO_MEM32BE, /* 32b big endian */ + UPIO_MEM16 = SERIAL_IO_MEM16, /* 16b little endian */ +}; + struct uart_port { spinlock_t lock; /* port lock */ unsigned long iobase; /* in/out[bwl] */ @@ -111,7 +447,7 @@ struct uart_port { void (*serial_out)(struct uart_port *, int, int); void (*set_termios)(struct uart_port *, struct ktermios *new, - struct ktermios *old); + const struct ktermios *old); void (*set_ldisc)(struct uart_port *, struct ktermios *); unsigned int (*get_mctrl)(struct uart_port *); @@ -132,30 +468,26 @@ struct uart_port { unsigned int old); void (*handle_break)(struct uart_port *); int (*rs485_config)(struct uart_port *, + struct ktermios *termios, struct serial_rs485 *rs485); int (*iso7816_config)(struct uart_port *, struct serial_iso7816 *iso7816); + unsigned int ctrl_id; /* optional serial core controller id */ + unsigned int port_id; /* optional serial core port id */ 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 */ + unsigned char quirks; /* internal quirks */ - /* quirks must be updated while holding port mutex */ + /* internal quirks must be updated while holding port mutex */ #define UPQ_NO_TXEN_TEST BIT(0) + enum uart_iotype iotype; /* io access style */ + unsigned int read_status_mask; /* driver specific */ unsigned int ignore_status_mask; /* driver specific */ struct uart_state *state; /* pointer to parent state */ @@ -171,11 +503,15 @@ struct uart_port { * 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 + * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable * The remaining bits are serial-core specific and not modifiable by * userspace. */ +#ifdef CONFIG_HAS_IOPORT #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ ) +#else +#define UPF_FOURPORT 0 +#endif #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 */ ) @@ -190,23 +526,24 @@ struct uart_port { #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)) +#define UPF_NO_THRE_TEST ((__force upf_t) BIT_ULL(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_AUTO_CTS ((__force upf_t) BIT_ULL(20)) +#define UPF_AUTO_RTS ((__force upf_t) BIT_ULL(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)) +#define UPF_SOFT_FLOW ((__force upf_t) BIT_ULL(22)) +#define UPF_CONS_FLOW ((__force upf_t) BIT_ULL(23)) +#define UPF_SHARE_IRQ ((__force upf_t) BIT_ULL(24)) +#define UPF_EXAR_EFR ((__force upf_t) BIT_ULL(25)) +#define UPF_BUG_THRE ((__force upf_t) BIT_ULL(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_FIXED_TYPE ((__force upf_t) BIT_ULL(27)) +#define UPF_BOOT_AUTOCONF ((__force upf_t) BIT_ULL(28)) +#define UPF_FIXED_PORT ((__force upf_t) BIT_ULL(29)) +#define UPF_DEAD ((__force upf_t) BIT_ULL(30)) +#define UPF_IOREMAP ((__force upf_t) BIT_ULL(31)) +#define UPF_FULL_PROBE ((__force upf_t) BIT_ULL(32)) #define __UPF_CHANGE_MASK 0x17fff #define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK) @@ -229,9 +566,9 @@ struct uart_port { #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 */ + bool hw_stopped; /* sw-assisted CTS flow state */ unsigned int mctrl; /* current modem ctrl settings */ - unsigned int timeout; /* character-based timeout */ + unsigned int frame_time; /* frame timing in ns */ unsigned int type; /* port type */ const struct uart_ops *ops; unsigned int custom_divisor; @@ -239,10 +576,11 @@ struct uart_port { unsigned int minor; resource_size_t mapbase; /* for ioremap */ resource_size_t mapsize; - struct device *dev; /* parent device */ + struct device *dev; /* serial port physical parent device */ + struct serial_port_device *port_dev; /* serial core port device */ unsigned long sysrq; /* sysrq timeout */ - unsigned int sysrq_ch; /* char for sysrq */ + u8 sysrq_ch; /* char for sysrq */ unsigned char has_sysrq; unsigned char sysrq_seq; /* index in sysrq_toggle_seq */ @@ -253,11 +591,203 @@ struct uart_port { 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 serial_rs485 rs485_supported; /* Supported mask for serial_rs485 */ struct gpio_desc *rs485_term_gpio; /* enable RS485 bus termination */ + struct gpio_desc *rs485_rx_during_tx_gpio; /* Output GPIO that sets the state of RS485 RX during TX */ struct serial_iso7816 iso7816; void *private_data; /* generic platform data pointer */ }; +/* + * Only for console->device_lock()/_unlock() callbacks and internal + * port lock wrapper synchronization. + */ +static inline void __uart_port_lock_irqsave(struct uart_port *up, unsigned long *flags) +{ + spin_lock_irqsave(&up->lock, *flags); +} + +/* + * Only for console->device_lock()/_unlock() callbacks and internal + * port lock wrapper synchronization. + */ +static inline void __uart_port_unlock_irqrestore(struct uart_port *up, unsigned long flags) +{ + spin_unlock_irqrestore(&up->lock, flags); +} + +/** + * uart_port_set_cons - Safely set the @cons field for a uart + * @up: The uart port to set + * @con: The new console to set to + * + * This function must be used to set @up->cons. It uses the port lock to + * synchronize with the port lock wrappers in order to ensure that the console + * cannot change or disappear while another context is holding the port lock. + */ +static inline void uart_port_set_cons(struct uart_port *up, struct console *con) +{ + unsigned long flags; + + __uart_port_lock_irqsave(up, &flags); + up->cons = con; + __uart_port_unlock_irqrestore(up, flags); +} + +/* Only for internal port lock wrapper usage. */ +static inline bool __uart_port_using_nbcon(struct uart_port *up) +{ + lockdep_assert_held_once(&up->lock); + + if (likely(!uart_console(up))) + return false; + + /* + * @up->cons is only modified under the port lock. Therefore it is + * certain that it cannot disappear here. + * + * @up->cons->node is added/removed from the console list under the + * port lock. Therefore it is certain that the registration status + * cannot change here, thus @up->cons->flags can be read directly. + */ + if (hlist_unhashed_lockless(&up->cons->node) || + !(up->cons->flags & CON_NBCON) || + !up->cons->write_atomic) { + return false; + } + + return true; +} + +/* Only for internal port lock wrapper usage. */ +static inline bool __uart_port_nbcon_try_acquire(struct uart_port *up) +{ + if (!__uart_port_using_nbcon(up)) + return true; + + return nbcon_device_try_acquire(up->cons); +} + +/* Only for internal port lock wrapper usage. */ +static inline void __uart_port_nbcon_acquire(struct uart_port *up) +{ + if (!__uart_port_using_nbcon(up)) + return; + + while (!nbcon_device_try_acquire(up->cons)) + cpu_relax(); +} + +/* Only for internal port lock wrapper usage. */ +static inline void __uart_port_nbcon_release(struct uart_port *up) +{ + if (!__uart_port_using_nbcon(up)) + return; + + nbcon_device_release(up->cons); +} + +/** + * uart_port_lock - Lock the UART port + * @up: Pointer to UART port structure + */ +static inline void uart_port_lock(struct uart_port *up) +{ + spin_lock(&up->lock); + __uart_port_nbcon_acquire(up); +} + +/** + * uart_port_lock_irq - Lock the UART port and disable interrupts + * @up: Pointer to UART port structure + */ +static inline void uart_port_lock_irq(struct uart_port *up) +{ + spin_lock_irq(&up->lock); + __uart_port_nbcon_acquire(up); +} + +/** + * uart_port_lock_irqsave - Lock the UART port, save and disable interrupts + * @up: Pointer to UART port structure + * @flags: Pointer to interrupt flags storage + */ +static inline void uart_port_lock_irqsave(struct uart_port *up, unsigned long *flags) +{ + spin_lock_irqsave(&up->lock, *flags); + __uart_port_nbcon_acquire(up); +} + +/** + * uart_port_trylock - Try to lock the UART port + * @up: Pointer to UART port structure + * + * Returns: True if lock was acquired, false otherwise + */ +static inline bool uart_port_trylock(struct uart_port *up) +{ + if (!spin_trylock(&up->lock)) + return false; + + if (!__uart_port_nbcon_try_acquire(up)) { + spin_unlock(&up->lock); + return false; + } + + return true; +} + +/** + * uart_port_trylock_irqsave - Try to lock the UART port, save and disable interrupts + * @up: Pointer to UART port structure + * @flags: Pointer to interrupt flags storage + * + * Returns: True if lock was acquired, false otherwise + */ +static inline bool uart_port_trylock_irqsave(struct uart_port *up, unsigned long *flags) +{ + if (!spin_trylock_irqsave(&up->lock, *flags)) + return false; + + if (!__uart_port_nbcon_try_acquire(up)) { + spin_unlock_irqrestore(&up->lock, *flags); + return false; + } + + return true; +} + +/** + * uart_port_unlock - Unlock the UART port + * @up: Pointer to UART port structure + */ +static inline void uart_port_unlock(struct uart_port *up) +{ + __uart_port_nbcon_release(up); + spin_unlock(&up->lock); +} + +/** + * uart_port_unlock_irq - Unlock the UART port and re-enable interrupts + * @up: Pointer to UART port structure + */ +static inline void uart_port_unlock_irq(struct uart_port *up) +{ + __uart_port_nbcon_release(up); + spin_unlock_irq(&up->lock); +} + +/** + * uart_port_unlock_irqrestore - Unlock the UART port, restore interrupts + * @up: Pointer to UART port structure + * @flags: The saved interrupt flags for restore + */ +static inline void uart_port_unlock_irqrestore(struct uart_port *up, unsigned long flags) +{ + __uart_port_nbcon_release(up); + spin_unlock_irqrestore(&up->lock, flags); +} + static inline int serial_port_in(struct uart_port *up, int offset) { return up->serial_in(up, offset); @@ -287,7 +817,6 @@ 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; @@ -300,6 +829,46 @@ struct uart_state { /* number of characters left in xmit buffer before we ask for more */ #define WAKEUP_CHARS 256 +/** + * uart_xmit_advance - Advance xmit buffer and account Tx'ed chars + * @up: uart_port structure describing the port + * @chars: number of characters sent + * + * This function advances the tail of circular xmit buffer by the number of + * @chars transmitted and handles accounting of transmitted bytes (into + * @up's icount.tx). + */ +static inline void uart_xmit_advance(struct uart_port *up, unsigned int chars) +{ + struct tty_port *tport = &up->state->port; + + kfifo_skip_count(&tport->xmit_fifo, chars); + up->icount.tx += chars; +} + +static inline unsigned int uart_fifo_out(struct uart_port *up, + unsigned char *buf, unsigned int chars) +{ + struct tty_port *tport = &up->state->port; + + chars = kfifo_out(&tport->xmit_fifo, buf, chars); + up->icount.tx += chars; + + return chars; +} + +static inline unsigned int uart_fifo_get(struct uart_port *up, + unsigned char *ch) +{ + struct tty_port *tport = &up->state->port; + unsigned int chars; + + chars = kfifo_get(&tport->xmit_fifo, ch); + up->icount.tx += chars; + + return chars; +} + struct module; struct tty_driver; @@ -322,20 +891,154 @@ struct uart_driver { void uart_write_wakeup(struct uart_port *port); +/** + * enum UART_TX_FLAGS -- flags for uart_port_tx_flags() + * + * @UART_TX_NOSTOP: don't call port->ops->stop_tx() on empty buffer + */ +enum UART_TX_FLAGS { + UART_TX_NOSTOP = BIT(0), +}; + +#define __uart_port_tx(uport, ch, flags, tx_ready, put_char, tx_done, \ + for_test, for_post) \ +({ \ + struct uart_port *__port = (uport); \ + struct tty_port *__tport = &__port->state->port; \ + unsigned int pending; \ + \ + for (; (for_test) && (tx_ready); (for_post), __port->icount.tx++) { \ + if (__port->x_char) { \ + (ch) = __port->x_char; \ + (put_char); \ + __port->x_char = 0; \ + continue; \ + } \ + \ + if (uart_tx_stopped(__port)) \ + break; \ + \ + if (!kfifo_get(&__tport->xmit_fifo, &(ch))) \ + break; \ + \ + (put_char); \ + } \ + \ + (tx_done); \ + \ + pending = kfifo_len(&__tport->xmit_fifo); \ + if (pending < WAKEUP_CHARS) { \ + uart_write_wakeup(__port); \ + \ + if (!((flags) & UART_TX_NOSTOP) && pending == 0) \ + __port->ops->stop_tx(__port); \ + } \ + \ + pending; \ +}) + +/** + * uart_port_tx_limited -- transmit helper for uart_port with count limiting + * @port: uart port + * @ch: variable to store a character to be written to the HW + * @count: a limit of characters to send + * @tx_ready: can HW accept more data function + * @put_char: function to write a character + * @tx_done: function to call after the loop is done + * + * This helper transmits characters from the xmit buffer to the hardware using + * @put_char(). It does so until @count characters are sent and while @tx_ready + * evaluates to true. + * + * Returns: the number of characters in the xmit buffer when done. + * + * The expression in macro parameters shall be designed as follows: + * * **tx_ready:** should evaluate to true if the HW can accept more data to + * be sent. This parameter can be %true, which means the HW is always ready. + * * **put_char:** shall write @ch to the device of @port. + * * **tx_done:** when the write loop is done, this can perform arbitrary + * action before potential invocation of ops->stop_tx() happens. If the + * driver does not need to do anything, use e.g. ({}). + * + * For all of them, @port->lock is held, interrupts are locally disabled and + * the expressions must not sleep. + */ +#define uart_port_tx_limited(port, ch, count, tx_ready, put_char, tx_done) ({ \ + unsigned int __count = (count); \ + __uart_port_tx(port, ch, 0, tx_ready, put_char, tx_done, __count, \ + __count--); \ +}) + +/** + * uart_port_tx_limited_flags -- transmit helper for uart_port with count limiting with flags + * @port: uart port + * @ch: variable to store a character to be written to the HW + * @flags: %UART_TX_NOSTOP or similar + * @count: a limit of characters to send + * @tx_ready: can HW accept more data function + * @put_char: function to write a character + * @tx_done: function to call after the loop is done + * + * See uart_port_tx_limited() for more details. + */ +#define uart_port_tx_limited_flags(port, ch, flags, count, tx_ready, put_char, tx_done) ({ \ + unsigned int __count = (count); \ + __uart_port_tx(port, ch, flags, tx_ready, put_char, tx_done, __count, \ + __count--); \ +}) + +/** + * uart_port_tx -- transmit helper for uart_port + * @port: uart port + * @ch: variable to store a character to be written to the HW + * @tx_ready: can HW accept more data function + * @put_char: function to write a character + * + * See uart_port_tx_limited() for more details. + */ +#define uart_port_tx(port, ch, tx_ready, put_char) \ + __uart_port_tx(port, ch, 0, tx_ready, put_char, ({}), true, ({})) + + +/** + * uart_port_tx_flags -- transmit helper for uart_port with flags + * @port: uart port + * @ch: variable to store a character to be written to the HW + * @flags: %UART_TX_NOSTOP or similar + * @tx_ready: can HW accept more data function + * @put_char: function to write a character + * + * See uart_port_tx_limited() for more details. + */ +#define uart_port_tx_flags(port, ch, flags, tx_ready, put_char) \ + __uart_port_tx(port, ch, flags, tx_ready, put_char, ({}), true, ({})) /* * 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, + const struct ktermios *old, unsigned int min, unsigned int max); unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud); +/* + * Calculates FIFO drain time. + */ +static inline unsigned long uart_fifo_timeout(struct uart_port *port) +{ + u64 fifo_timeout = (u64)READ_ONCE(port->frame_time) * port->fifosize; + + /* Add .02 seconds of slop */ + fifo_timeout += 20 * NSEC_PER_MSEC; + + return max(nsecs_to_jiffies(fifo_timeout), 1UL); +} + /* Base timer interval for polling */ -static inline int uart_poll_timeout(struct uart_port *port) +static inline unsigned long uart_poll_timeout(struct uart_port *port) { - int timeout = port->timeout; + unsigned long timeout = uart_fifo_timeout(port); return timeout > 6 ? (timeout / 2 - 2) : 1; } @@ -346,7 +1049,7 @@ static inline int uart_poll_timeout(struct uart_port *port) struct earlycon_device { struct console *con; struct uart_port port; - char options[16]; /* e.g., 115200n8 */ + char options[32]; /* e.g., 115200n8 */ unsigned int baud; }; @@ -357,8 +1060,8 @@ struct earlycon_id { int (*setup)(struct earlycon_device *, const char *options); }; -extern const struct earlycon_id *__earlycon_table[]; -extern const struct earlycon_id *__earlycon_table_end[]; +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 @@ -366,25 +1069,18 @@ extern const struct earlycon_id *__earlycon_table_end[]; #define EARLYCON_USED_OR_UNUSED __maybe_unused #endif -#define _OF_EARLYCON_DECLARE(_name, compat, fn, unique_id) \ - static const struct earlycon_id unique_id \ - EARLYCON_USED_OR_UNUSED __initconst \ +#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 }; \ - static const struct earlycon_id EARLYCON_USED_OR_UNUSED \ - __section(__earlycon_table) \ - * const __PASTE(__p, unique_id) = &unique_id - -#define OF_EARLYCON_DECLARE(_name, compat, fn) \ - _OF_EARLYCON_DECLARE(_name, compat, fn, \ - __UNIQUE_ID(__earlycon_##_name)) + .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); +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; @@ -394,10 +1090,21 @@ static const bool earlycon_acpi_spcr_enable EARLYCON_USED_OR_UNUSED; static inline int setup_earlycon(char *buf) { return 0; } #endif +/* Variant of uart_console_registered() when the console_list_lock is held. */ +static inline bool uart_console_registered_locked(struct uart_port *port) +{ + return uart_console(port) && console_is_registered_locked(port->cons); +} + +static inline bool uart_console_registered(struct uart_port *port) +{ + return uart_console(port) && console_is_registered(port->cons); +} + 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); +int uart_parse_earlycon(char *p, enum uart_iotype *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, @@ -405,7 +1112,7 @@ int uart_set_options(struct uart_port *port, struct console *co, int baud, 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)); + void (*putchar)(struct uart_port *, unsigned char)); /* * Port/driver registration/removal @@ -413,8 +1120,11 @@ void uart_console_write(struct uart_port *port, const char *s, 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); +void uart_remove_one_port(struct uart_driver *reg, struct uart_port *port); +int uart_read_port_properties(struct uart_port *port); +int uart_read_and_validate_port_properties(struct uart_port *port); +bool uart_match_port(const struct uart_port *port1, + const struct uart_port *port2); /* * Power Management @@ -422,19 +1132,10 @@ int uart_match_port(struct uart_port *port1, struct uart_port *port2); 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->stopped) || port->hw_stopped) + if ((tty && tty->flow.stopped) || port->hw_stopped) return 1; return 0; } @@ -455,20 +1156,20 @@ static inline bool uart_softcts_mode(struct uart_port *uport) * 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); +void uart_handle_dcd_change(struct uart_port *uport, bool active); +void uart_handle_cts_change(struct uart_port *uport, bool active); + +void uart_insert_char(struct uart_port *port, unsigned int status, + unsigned int overrun, u8 ch, u8 flag); -extern void uart_insert_char(struct uart_port *port, unsigned int status, - unsigned int overrun, unsigned int ch, unsigned int flag); +void uart_xchar_out(struct uart_port *uport, int offset); #ifdef CONFIG_MAGIC_SYSRQ_SERIAL #define SYSRQ_TIMEOUT (HZ * 5) -bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch); +bool uart_try_toggle_sysrq(struct uart_port *port, u8 ch); -static inline int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) +static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch) { if (!port->sysrq) return 0; @@ -487,7 +1188,7 @@ 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) +static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch) { if (!port->sysrq) return 0; @@ -506,35 +1207,59 @@ static inline int uart_prepare_sysrq_char(struct uart_port *port, unsigned int c return 0; } -static inline void uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags) +static inline void uart_unlock_and_check_sysrq(struct uart_port *port) +{ + u8 sysrq_ch; + + if (!port->has_sysrq) { + uart_port_unlock(port); + return; + } + + sysrq_ch = port->sysrq_ch; + port->sysrq_ch = 0; + + uart_port_unlock(port); + + 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; + u8 sysrq_ch; if (!port->has_sysrq) { - spin_unlock_irqrestore(&port->lock, irqflags); + uart_port_unlock_irqrestore(port, flags); return; } sysrq_ch = port->sysrq_ch; port->sysrq_ch = 0; - spin_unlock_irqrestore(&port->lock, irqflags); + uart_port_unlock_irqrestore(port, 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) +static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch) { return 0; } -static inline int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) +static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch) { return 0; } -static inline void uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags) +static inline void uart_unlock_and_check_sysrq(struct uart_port *port) +{ + uart_port_unlock(port); +} +static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port, + unsigned long flags) { - spin_unlock_irqrestore(&port->lock, irqflags); + uart_port_unlock_irqrestore(port, flags); } #endif /* CONFIG_MAGIC_SYSRQ_SERIAL */ |