/* 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 */
        u32             (*serial_in)(struct uart_port *, unsigned int offset);
        void            (*serial_out)(struct uart_port *, unsigned int offset, u32 val);
        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);
void serial8250_handle_irq_locked(struct uart_port *port, unsigned int iir);
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