![Aleksey Makarov](/assets/img/avatar_default.png)
'ARM Server Base Boot Requiremets' [1] mentions SPCR (Serial Port Console Redirection Table) [2] as a mandatory ACPI table that specifies the configuration of serial console. Defer initialization of DT earlycon until ACPI/DT decision is made. Parse the ACPI SPCR table, setup earlycon if required, enable specified console. Thanks to Peter Hurley for explaining how this should work. [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html [2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Tested-by: Christopher Covington <cov@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
501 lines
16 KiB
C
501 lines
16 KiB
C
/*
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* linux/drivers/char/serial_core.h
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*
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* Copyright (C) 2000 Deep Blue Solutions Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifndef LINUX_SERIAL_CORE_H
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#define LINUX_SERIAL_CORE_H
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#include <linux/compiler.h>
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#include <linux/interrupt.h>
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#include <linux/circ_buf.h>
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#include <linux/spinlock.h>
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#include <linux/sched.h>
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#include <linux/tty.h>
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#include <linux/mutex.h>
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#include <linux/sysrq.h>
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#include <uapi/linux/serial_core.h>
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#ifdef CONFIG_SERIAL_CORE_CONSOLE
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#define uart_console(port) \
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((port)->cons && (port)->cons->index == (port)->line)
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#else
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#define uart_console(port) ({ (void)port; 0; })
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#endif
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struct uart_port;
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struct serial_struct;
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struct device;
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/*
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* This structure describes all the operations that can be done on the
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* physical hardware. See Documentation/serial/driver for details.
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*/
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struct uart_ops {
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unsigned int (*tx_empty)(struct uart_port *);
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void (*set_mctrl)(struct uart_port *, unsigned int mctrl);
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unsigned int (*get_mctrl)(struct uart_port *);
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void (*stop_tx)(struct uart_port *);
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void (*start_tx)(struct uart_port *);
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void (*throttle)(struct uart_port *);
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void (*unthrottle)(struct uart_port *);
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void (*send_xchar)(struct uart_port *, char ch);
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void (*stop_rx)(struct uart_port *);
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void (*enable_ms)(struct uart_port *);
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void (*break_ctl)(struct uart_port *, int ctl);
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int (*startup)(struct uart_port *);
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void (*shutdown)(struct uart_port *);
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void (*flush_buffer)(struct uart_port *);
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void (*set_termios)(struct uart_port *, struct ktermios *new,
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struct ktermios *old);
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void (*set_ldisc)(struct uart_port *, struct ktermios *);
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void (*pm)(struct uart_port *, unsigned int state,
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unsigned int oldstate);
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/*
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* Return a string describing the type of the port
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*/
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const char *(*type)(struct uart_port *);
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/*
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* Release IO and memory resources used by the port.
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* This includes iounmap if necessary.
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*/
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void (*release_port)(struct uart_port *);
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/*
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* Request IO and memory resources used by the port.
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* This includes iomapping the port if necessary.
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*/
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int (*request_port)(struct uart_port *);
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void (*config_port)(struct uart_port *, int);
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int (*verify_port)(struct uart_port *, struct serial_struct *);
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int (*ioctl)(struct uart_port *, unsigned int, unsigned long);
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#ifdef CONFIG_CONSOLE_POLL
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int (*poll_init)(struct uart_port *);
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void (*poll_put_char)(struct uart_port *, unsigned char);
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int (*poll_get_char)(struct uart_port *);
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#endif
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};
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#define NO_POLL_CHAR 0x00ff0000
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#define UART_CONFIG_TYPE (1 << 0)
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#define UART_CONFIG_IRQ (1 << 1)
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struct uart_icount {
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__u32 cts;
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__u32 dsr;
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__u32 rng;
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__u32 dcd;
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__u32 rx;
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__u32 tx;
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__u32 frame;
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__u32 overrun;
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__u32 parity;
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__u32 brk;
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__u32 buf_overrun;
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};
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typedef unsigned int __bitwise__ upf_t;
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typedef unsigned int __bitwise__ upstat_t;
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struct uart_port {
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spinlock_t lock; /* port lock */
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unsigned long iobase; /* in/out[bwl] */
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unsigned char __iomem *membase; /* read/write[bwl] */
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unsigned int (*serial_in)(struct uart_port *, int);
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void (*serial_out)(struct uart_port *, int, int);
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void (*set_termios)(struct uart_port *,
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struct ktermios *new,
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struct ktermios *old);
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unsigned int (*get_mctrl)(struct uart_port *);
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void (*set_mctrl)(struct uart_port *, unsigned int);
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int (*startup)(struct uart_port *port);
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void (*shutdown)(struct uart_port *port);
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void (*throttle)(struct uart_port *port);
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void (*unthrottle)(struct uart_port *port);
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int (*handle_irq)(struct uart_port *);
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void (*pm)(struct uart_port *, unsigned int state,
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unsigned int old);
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void (*handle_break)(struct uart_port *);
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int (*rs485_config)(struct uart_port *,
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struct serial_rs485 *rs485);
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unsigned int irq; /* irq number */
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unsigned long irqflags; /* irq flags */
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unsigned int uartclk; /* base uart clock */
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unsigned int fifosize; /* tx fifo size */
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unsigned char x_char; /* xon/xoff char */
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unsigned char regshift; /* reg offset shift */
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unsigned char iotype; /* io access style */
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unsigned char unused1;
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#define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
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#define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
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#define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */
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#define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */
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#define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */
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#define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */
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#define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */
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#define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */
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unsigned int read_status_mask; /* driver specific */
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unsigned int ignore_status_mask; /* driver specific */
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struct uart_state *state; /* pointer to parent state */
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struct uart_icount icount; /* statistics */
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struct console *cons; /* struct console, if any */
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#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
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unsigned long sysrq; /* sysrq timeout */
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#endif
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/* flags must be updated while holding port mutex */
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upf_t flags;
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/*
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* These flags must be equivalent to the flags defined in
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* include/uapi/linux/tty_flags.h which are the userspace definitions
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* assigned from the serial_struct flags in uart_set_info()
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* [for bit definitions in the UPF_CHANGE_MASK]
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*
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* Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
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* except bit 15 (UPF_NO_TXEN_TEST) which is masked off.
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* The remaining bits are serial-core specific and not modifiable by
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* userspace.
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*/
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#define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ )
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#define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ )
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#define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ )
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#define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ )
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#define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ )
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#define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ )
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#define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ )
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#define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ )
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#define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ )
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#define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ )
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#define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ )
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#define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ )
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#define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ )
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#define UPF_NO_TXEN_TEST ((__force upf_t) (1 << 15))
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#define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
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/* Port has hardware-assisted h/w flow control */
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#define UPF_AUTO_CTS ((__force upf_t) (1 << 20))
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#define UPF_AUTO_RTS ((__force upf_t) (1 << 21))
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#define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
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/* Port has hardware-assisted s/w flow control */
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#define UPF_SOFT_FLOW ((__force upf_t) (1 << 22))
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#define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
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#define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
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#define UPF_EXAR_EFR ((__force upf_t) (1 << 25))
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#define UPF_BUG_THRE ((__force upf_t) (1 << 26))
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/* The exact UART type is known and should not be probed. */
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#define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
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#define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
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#define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
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#define UPF_DEAD ((__force upf_t) (1 << 30))
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#define UPF_IOREMAP ((__force upf_t) (1 << 31))
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#define __UPF_CHANGE_MASK 0x17fff
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#define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK)
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#define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
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#if __UPF_CHANGE_MASK > ASYNC_FLAGS
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#error Change mask not equivalent to userspace-visible bit defines
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#endif
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/*
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* Must hold termios_rwsem, port mutex and port lock to change;
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* can hold any one lock to read.
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*/
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upstat_t status;
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#define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0))
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#define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1))
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#define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2))
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#define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3))
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#define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4))
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int hw_stopped; /* sw-assisted CTS flow state */
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unsigned int mctrl; /* current modem ctrl settings */
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unsigned int timeout; /* character-based timeout */
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unsigned int type; /* port type */
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const struct uart_ops *ops;
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unsigned int custom_divisor;
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unsigned int line; /* port index */
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unsigned int minor;
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resource_size_t mapbase; /* for ioremap */
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resource_size_t mapsize;
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struct device *dev; /* parent device */
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unsigned char hub6; /* this should be in the 8250 driver */
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unsigned char suspended;
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unsigned char irq_wake;
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unsigned char unused[2];
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struct attribute_group *attr_group; /* port specific attributes */
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const struct attribute_group **tty_groups; /* all attributes (serial core use only) */
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struct serial_rs485 rs485;
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void *private_data; /* generic platform data pointer */
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};
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static inline int serial_port_in(struct uart_port *up, int offset)
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{
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return up->serial_in(up, offset);
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}
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static inline void serial_port_out(struct uart_port *up, int offset, int value)
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{
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up->serial_out(up, offset, value);
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}
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/**
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* enum uart_pm_state - power states for UARTs
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* @UART_PM_STATE_ON: UART is powered, up and operational
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* @UART_PM_STATE_OFF: UART is powered off
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* @UART_PM_STATE_UNDEFINED: sentinel
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*/
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enum uart_pm_state {
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UART_PM_STATE_ON = 0,
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UART_PM_STATE_OFF = 3, /* number taken from ACPI */
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UART_PM_STATE_UNDEFINED,
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};
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/*
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* This is the state information which is persistent across opens.
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*/
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struct uart_state {
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struct tty_port port;
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enum uart_pm_state pm_state;
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struct circ_buf xmit;
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atomic_t refcount;
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wait_queue_head_t remove_wait;
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struct uart_port *uart_port;
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};
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#define UART_XMIT_SIZE PAGE_SIZE
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/* number of characters left in xmit buffer before we ask for more */
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#define WAKEUP_CHARS 256
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struct module;
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struct tty_driver;
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struct uart_driver {
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struct module *owner;
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const char *driver_name;
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const char *dev_name;
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int major;
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int minor;
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int nr;
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struct console *cons;
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/*
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* these are private; the low level driver should not
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* touch these; they should be initialised to NULL
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*/
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struct uart_state *state;
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struct tty_driver *tty_driver;
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};
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void uart_write_wakeup(struct uart_port *port);
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/*
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* Baud rate helpers.
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*/
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void uart_update_timeout(struct uart_port *port, unsigned int cflag,
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unsigned int baud);
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unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
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struct ktermios *old, unsigned int min,
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unsigned int max);
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unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
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/* Base timer interval for polling */
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static inline int uart_poll_timeout(struct uart_port *port)
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{
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int timeout = port->timeout;
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return timeout > 6 ? (timeout / 2 - 2) : 1;
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}
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/*
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* Console helpers.
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*/
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struct earlycon_device {
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struct console *con;
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struct uart_port port;
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char options[16]; /* e.g., 115200n8 */
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unsigned int baud;
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};
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struct earlycon_id {
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char name[16];
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char compatible[128];
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int (*setup)(struct earlycon_device *, const char *options);
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} __aligned(32);
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extern const struct earlycon_id __earlycon_table[];
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extern const struct earlycon_id __earlycon_table_end[];
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#if defined(CONFIG_SERIAL_EARLYCON) && !defined(MODULE)
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#define EARLYCON_USED_OR_UNUSED __used
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#else
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#define EARLYCON_USED_OR_UNUSED __maybe_unused
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#endif
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#define OF_EARLYCON_DECLARE(_name, compat, fn) \
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static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \
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EARLYCON_USED_OR_UNUSED __section(__earlycon_table) \
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= { .name = __stringify(_name), \
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.compatible = compat, \
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.setup = fn }
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#define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn)
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extern int of_setup_earlycon(const struct earlycon_id *match,
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unsigned long node,
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const char *options);
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#ifdef CONFIG_SERIAL_EARLYCON
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extern bool earlycon_init_is_deferred __initdata;
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int setup_earlycon(char *buf);
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#else
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static const bool earlycon_init_is_deferred;
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static inline int setup_earlycon(char *buf) { return 0; }
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#endif
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struct uart_port *uart_get_console(struct uart_port *ports, int nr,
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struct console *c);
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int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
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char **options);
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void uart_parse_options(char *options, int *baud, int *parity, int *bits,
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int *flow);
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int uart_set_options(struct uart_port *port, struct console *co, int baud,
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int parity, int bits, int flow);
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struct tty_driver *uart_console_device(struct console *co, int *index);
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void uart_console_write(struct uart_port *port, const char *s,
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unsigned int count,
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void (*putchar)(struct uart_port *, int));
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/*
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* Port/driver registration/removal
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*/
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int uart_register_driver(struct uart_driver *uart);
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void uart_unregister_driver(struct uart_driver *uart);
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int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
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int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
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int uart_match_port(struct uart_port *port1, struct uart_port *port2);
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/*
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* Power Management
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*/
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int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
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int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
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#define uart_circ_empty(circ) ((circ)->head == (circ)->tail)
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#define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0)
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#define uart_circ_chars_pending(circ) \
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(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
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#define uart_circ_chars_free(circ) \
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(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
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static inline int uart_tx_stopped(struct uart_port *port)
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{
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struct tty_struct *tty = port->state->port.tty;
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if ((tty && tty->stopped) || port->hw_stopped)
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return 1;
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return 0;
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}
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static inline bool uart_cts_enabled(struct uart_port *uport)
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{
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return !!(uport->status & UPSTAT_CTS_ENABLE);
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}
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static inline bool uart_softcts_mode(struct uart_port *uport)
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{
|
|
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 SUPPORT_SYSRQ
|
|
static inline int
|
|
uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
|
|
{
|
|
if (port->sysrq) {
|
|
if (ch && time_before(jiffies, port->sysrq)) {
|
|
handle_sysrq(ch);
|
|
port->sysrq = 0;
|
|
return 1;
|
|
}
|
|
port->sysrq = 0;
|
|
}
|
|
return 0;
|
|
}
|
|
#else
|
|
#define uart_handle_sysrq_char(port,ch) ({ (void)port; 0; })
|
|
#endif
|
|
|
|
/*
|
|
* 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 SUPPORT_SYSRQ
|
|
if (port->cons && port->cons->index == port->line) {
|
|
if (!port->sysrq) {
|
|
port->sysrq = jiffies + HZ*5;
|
|
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))
|
|
|
|
#endif /* LINUX_SERIAL_CORE_H */
|