kernel/include/linux/serial_8250.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 *  linux/include/linux/serial_8250.h
 *
 *  Copyright (C) 2004 Russell King
 */
#ifndef _LINUX_SERIAL_8250_H
#define _LINUX_SERIAL_8250_H

#include <linux/errno.h>
#include <linux/serial_core.h>
#include <linux/serial_reg.h>
#include <linux/platform_device.h>

struct uart_8250_port;

/*
 * This is the platform device platform_data structure
 *
 * @mapsize:	Port size for ioremap()
 * @bugs:	Port bugs
 *
 * @dl_read: ``u32 ()(struct uart_8250_port *up)``
 *
 *	UART divisor latch read.
 *
 * @dl_write: ``void ()(struct uart_8250_port *up, u32 value)``
 *
 *	Write @value into UART divisor latch.
 *
 *	Locking: Caller holds port's lock.
 */
struct plat_serial8250_port {
	unsigned long	iobase;		/* io base address */
	void __iomem	*membase;	/* ioremap cookie or NULL */
	resource_size_t	mapbase;	/* resource base */
	resource_size_t	mapsize;
	unsigned int	uartclk;	/* UART clock rate */
	unsigned int	irq;		/* interrupt number */
	unsigned long	irqflags;	/* request_irq flags */
	void            *private_data;
	unsigned char	regshift;	/* register shift */
	unsigned char	iotype;		/* UPIO_* */
	unsigned char	hub6;
	unsigned char	has_sysrq;	/* supports magic SysRq */
	unsigned int	type;		/* If UPF_FIXED_TYPE */
	upf_t		flags;		/* UPF_* flags */
	u16		bugs;		/* port bugs */
	unsigned int	(*serial_in)(struct uart_port *, int);
	void		(*serial_out)(struct uart_port *, int, int);
	u32		(*dl_read)(struct uart_8250_port *up);
	void		(*dl_write)(struct uart_8250_port *up, u32 value);
	void		(*set_termios)(struct uart_port *,
			               struct ktermios *new,
			               const struct ktermios *old);
	void		(*set_ldisc)(struct uart_port *,
				     struct ktermios *);
	unsigned int	(*get_mctrl)(struct uart_port *);
	int		(*handle_irq)(struct uart_port *);
	void		(*pm)(struct uart_port *, unsigned int state,
			      unsigned old);
	void		(*handle_break)(struct uart_port *);
};

/*
 * Allocate 8250 platform device IDs.  Nothing is implied by
 * the numbering here, except for the legacy entry being -1.
 */
enum {
	PLAT8250_DEV_LEGACY = -1,
	PLAT8250_DEV_PLATFORM,
	PLAT8250_DEV_PLATFORM1,
	PLAT8250_DEV_PLATFORM2,
	PLAT8250_DEV_FOURPORT,
	PLAT8250_DEV_ACCENT,
	PLAT8250_DEV_BOCA,
	PLAT8250_DEV_EXAR_ST16C554,
	PLAT8250_DEV_HUB6,
	PLAT8250_DEV_AU1X00,
	PLAT8250_DEV_SM501,
};

struct uart_8250_dma;
struct uart_8250_port;

/**
 * 8250 core driver operations
 *
 * @setup_irq()		Setup irq handling. The universal 8250 driver links this
 *			port to the irq chain. Other drivers may @request_irq().
 * @release_irq()	Undo irq handling. The universal 8250 driver unlinks
 *			the port from the irq chain.
 */
struct uart_8250_ops {
	int		(*setup_irq)(struct uart_8250_port *);
	void		(*release_irq)(struct uart_8250_port *);
	void		(*setup_timer)(struct uart_8250_port *);
};

struct uart_8250_em485 {
	struct hrtimer		start_tx_timer; /* "rs485 start tx" timer */
	struct hrtimer		stop_tx_timer;  /* "rs485 stop tx" timer */
	struct hrtimer		*active_timer;  /* pointer to active timer */
	struct uart_8250_port	*port;          /* for hrtimer callbacks */
	unsigned int		tx_stopped:1;	/* tx is currently stopped */
};

/*
 * This should be used by drivers which want to register
 * their own 8250 ports without registering their own
 * platform device.  Using these will make your driver
 * dependent on the 8250 driver.
 *
 * @dl_read: ``u32 ()(struct uart_8250_port *port)``
 *
 *	UART divisor latch read.
 *
 * @dl_write: ``void ()(struct uart_8250_port *port, u32 value)``
 *
 *	Write @value into UART divisor latch.
 *
 *	Locking: Caller holds port's lock.
 */
struct uart_8250_port {
	struct uart_port	port;
	struct timer_list	timer;		/* "no irq" timer */
	struct list_head	list;		/* ports on this IRQ */
	u32			capabilities;	/* port capabilities */
	u16			bugs;		/* port bugs */
	unsigned int		tx_loadsz;	/* transmit fifo load size */
	unsigned char		acr;
	unsigned char		fcr;
	unsigned char		ier;
	unsigned char		lcr;
	unsigned char		mcr;
	unsigned char		cur_iotype;	/* Running I/O type */
	unsigned int		rpm_tx_active;
	unsigned char		canary;		/* non-zero during system sleep
						 *   if no_console_suspend
						 */
	unsigned char		probe;
	struct mctrl_gpios	*gpios;
#define UART_PROBE_RSA	(1 << 0)

	/*
	 * Some bits in registers are cleared on a read, so they must
	 * be saved whenever the register is read but the bits will not
	 * be immediately processed.
	 */
#define LSR_SAVE_FLAGS UART_LSR_BRK_ERROR_BITS
	u16			lsr_saved_flags;
	u16			lsr_save_mask;
#define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
	unsigned char		msr_saved_flags;

	struct uart_8250_dma	*dma;
	const struct uart_8250_ops *ops;

	/* 8250 specific callbacks */
	u32			(*dl_read)(struct uart_8250_port *up);
	void			(*dl_write)(struct uart_8250_port *up, u32 value);

	struct uart_8250_em485 *em485;
	void			(*rs485_start_tx)(struct uart_8250_port *up, bool toggle_ier);
	void			(*rs485_stop_tx)(struct uart_8250_port *up, bool toggle_ier);

	/* Serial port overrun backoff */
	struct delayed_work overrun_backoff;
	u32 overrun_backoff_time_ms;
};

static inline struct uart_8250_port *up_to_u8250p(struct uart_port *up)
{
	return container_of(up, struct uart_8250_port, port);
}

int serial8250_register_8250_port(const struct uart_8250_port *);
void serial8250_unregister_port(int line);
void serial8250_suspend_port(int line);
void serial8250_resume_port(int line);

int early_serial_setup(struct uart_port *port);
int early_serial8250_setup(struct earlycon_device *device, const char *options);

void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk);
void serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
			       const struct ktermios *old);
void serial8250_do_set_ldisc(struct uart_port *port, struct ktermios *termios);
unsigned int serial8250_do_get_mctrl(struct uart_port *port);
int serial8250_do_startup(struct uart_port *port);
void serial8250_do_shutdown(struct uart_port *port);
void serial8250_do_pm(struct uart_port *port, unsigned int state,
		      unsigned int oldstate);
void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl);
void serial8250_do_set_divisor(struct uart_port *port, unsigned int baud,
			       unsigned int quot);
int fsl8250_handle_irq(struct uart_port *port);
int serial8250_handle_irq(struct uart_port *port, unsigned int iir);
u16 serial8250_rx_chars(struct uart_8250_port *up, u16 lsr);
void serial8250_read_char(struct uart_8250_port *up, u16 lsr);
void serial8250_tx_chars(struct uart_8250_port *up);
unsigned int serial8250_modem_status(struct uart_8250_port *up);
void serial8250_init_port(struct uart_8250_port *up);
void serial8250_set_defaults(struct uart_8250_port *up);
void serial8250_console_write(struct uart_8250_port *up, const char *s,
			      unsigned int count);
int serial8250_console_setup(struct uart_port *port, char *options, bool probe);
int serial8250_console_exit(struct uart_port *port);

void serial8250_set_isa_configurator(void (*v)(int port, struct uart_port *up,
					       u32 *capabilities));

#ifdef CONFIG_SERIAL_8250_CONSOLE
extern int hp300_setup_serial_console(void) __init;
#else
static inline int hp300_setup_serial_console(void) { return 0; }
#endif

#ifdef CONFIG_SERIAL_8250_RT288X
int rt288x_setup(struct uart_port *p);
int au_platform_setup(struct plat_serial8250_port *p);
#else
static inline int rt288x_setup(struct uart_port *p) { return -ENODEV; }
static inline int au_platform_setup(struct plat_serial8250_port *p) { return -ENODEV; }
#endif

#endif