// SPDX-License-Identifier: GPL-2.0
/*
 * USB Serial Converter stuff
 *
 *      Copyright (C) 1999 - 2012
 *          Greg Kroah-Hartman (greg@kroah.com)
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; version 2 of the License.
 *
 */

#ifndef __LINUX_USB_SERIAL_H
#define __LINUX_USB_SERIAL_H

#include <linux/kref.h>
#include <linux/mutex.h>
#include <linux/serial.h>
#include <linux/sysrq.h>
#include <linux/kfifo.h>

/* The maximum number of ports one device can grab at once */
#define MAX_NUM_PORTS           16

/* USB serial flags */
#define USB_SERIAL_WRITE_BUSY   0
#define USB_SERIAL_THROTTLED    1

/**
 * usb_serial_port: structure for the specific ports of a device.
 * @serial: pointer back to the struct usb_serial owner of this port.
 * @port: pointer to the corresponding tty_port for this port.
 * @lock: spinlock to grab when updating portions of this structure.
 * @minor: the minor number of the port
 * @port_number: the struct usb_serial port number of this port (starts at 0)
 * @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
 * @interrupt_in_urb: pointer to the interrupt in struct urb for this port.
 * @interrupt_in_endpointAddress: endpoint address for the interrupt in pipe
 *      for this port.
 * @interrupt_out_buffer: pointer to the interrupt out buffer for this port.
 * @interrupt_out_size: the size of the interrupt_out_buffer, in bytes.
 * @interrupt_out_urb: pointer to the interrupt out struct urb for this port.
 * @interrupt_out_endpointAddress: endpoint address for the interrupt out pipe
 *      for this port.
 * @bulk_in_buffer: pointer to the bulk in buffer for this port.
 * @bulk_in_size: the size of the bulk_in_buffer, in bytes.
 * @read_urb: pointer to the bulk in struct urb for this port.
 * @bulk_in_endpointAddress: endpoint address for the bulk in pipe for this
 *      port.
 * @bulk_in_buffers: pointers to the bulk in buffers for this port
 * @read_urbs: pointers to the bulk in urbs for this port
 * @read_urbs_free: status bitmap the for bulk in urbs
 * @bulk_out_buffer: pointer to the bulk out buffer for this port.
 * @bulk_out_size: the size of the bulk_out_buffer, in bytes.
 * @write_urb: pointer to the bulk out struct urb for this port.
 * @write_fifo: kfifo used to buffer outgoing data
 * @bulk_out_buffers: pointers to the bulk out buffers for this port
 * @write_urbs: pointers to the bulk out urbs for this port
 * @write_urbs_free: status bitmap the for bulk out urbs
 * @icount: interrupt counters
 * @tx_bytes: number of bytes currently in host stack queues
 * @bulk_out_endpointAddress: endpoint address for the bulk out pipe for this
 *      port.
 * @flags: usb serial port flags
 * @write_wait: a wait_queue_head_t used by the port.
 * @work: work queue entry for the line discipline waking up.
 * @dev: pointer to the serial device
 *
 * This structure is used by the usb-serial core and drivers for the specific
 * ports of a device.
 */
struct usb_serial_port {
        struct usb_serial       *serial;
        struct tty_port         port;
        spinlock_t              lock;
        u32                     minor;
        u8                      port_number;

        unsigned char           *interrupt_in_buffer;
        struct urb              *interrupt_in_urb;
        __u8                    interrupt_in_endpointAddress;

        unsigned char           *interrupt_out_buffer;
        int                     interrupt_out_size;
        struct urb              *interrupt_out_urb;
        __u8                    interrupt_out_endpointAddress;

        unsigned char           *bulk_in_buffer;
        int                     bulk_in_size;
        struct urb              *read_urb;
        __u8                    bulk_in_endpointAddress;

        unsigned char           *bulk_in_buffers[2];
        struct urb              *read_urbs[2];
        unsigned long           read_urbs_free;

        unsigned char           *bulk_out_buffer;
        int                     bulk_out_size;
        struct urb              *write_urb;
        struct kfifo            write_fifo;

        unsigned char           *bulk_out_buffers[2];
        struct urb              *write_urbs[2];
        unsigned long           write_urbs_free;
        __u8                    bulk_out_endpointAddress;

        struct async_icount     icount;
        int                     tx_bytes;

        unsigned long           flags;
        wait_queue_head_t       write_wait;
        struct work_struct      work;
        unsigned long           sysrq; /* sysrq timeout */
        struct device           dev;
};
#define to_usb_serial_port(d) container_of(d, struct usb_serial_port, dev)

/* get and set the port private data pointer helper functions */
static inline void *usb_get_serial_port_data(struct usb_serial_port *port)
{
        return dev_get_drvdata(&port->dev);
}

static inline void usb_set_serial_port_data(struct usb_serial_port *port,
                                            void *data)
{
        dev_set_drvdata(&port->dev, data);
}

/**
 * usb_serial - structure used by the usb-serial core for a device
 * @dev: pointer to the struct usb_device for this device
 * @type: pointer to the struct usb_serial_driver for this device
 * @interface: pointer to the struct usb_interface for this device
 * @num_ports: the number of ports this device has
 * @num_interrupt_in: number of interrupt in endpoints we have
 * @num_interrupt_out: number of interrupt out endpoints we have
 * @num_bulk_in: number of bulk in endpoints we have
 * @num_bulk_out: number of bulk out endpoints we have
 * @port: array of struct usb_serial_port structures for the different ports.
 * @private: place to put any driver specific information that is needed.  The
 *      usb-serial driver is required to manage this data, the usb-serial core
 *      will not touch this.  Use usb_get_serial_data() and
 *      usb_set_serial_data() to access this.
 */
struct usb_serial {
        struct usb_device               *dev;
        struct usb_serial_driver        *type;
        struct usb_interface            *interface;
        unsigned char                   disconnected:1;
        unsigned char                   suspending:1;
        unsigned char                   attached:1;
        unsigned char                   minors_reserved:1;
        unsigned char                   num_ports;
        unsigned char                   num_port_pointers;
        unsigned char                   num_interrupt_in;
        unsigned char                   num_interrupt_out;
        unsigned char                   num_bulk_in;
        unsigned char                   num_bulk_out;
        struct usb_serial_port          *port[MAX_NUM_PORTS];
        struct kref                     kref;
        struct mutex                    disc_mutex;
        void                            *private;
};
#define to_usb_serial(d) container_of(d, struct usb_serial, kref)

/* get and set the serial private data pointer helper functions */
static inline void *usb_get_serial_data(struct usb_serial *serial)
{
        return serial->private;
}

static inline void usb_set_serial_data(struct usb_serial *serial, void *data)
{
        serial->private = data;
}

struct usb_serial_endpoints {
        unsigned char num_bulk_in;
        unsigned char num_bulk_out;
        unsigned char num_interrupt_in;
        unsigned char num_interrupt_out;
        struct usb_endpoint_descriptor *bulk_in[MAX_NUM_PORTS];
        struct usb_endpoint_descriptor *bulk_out[MAX_NUM_PORTS];
        struct usb_endpoint_descriptor *interrupt_in[MAX_NUM_PORTS];
        struct usb_endpoint_descriptor *interrupt_out[MAX_NUM_PORTS];
};

/**
 * usb_serial_driver - describes a usb serial driver
 * @description: pointer to a string that describes this driver.  This string
 *      used in the syslog messages when a device is inserted or removed.
 * @id_table: pointer to a list of usb_device_id structures that define all
 *      of the devices this structure can support.
 * @num_ports: the number of different ports this device will have.
 * @num_bulk_in: minimum number of bulk-in endpoints
 * @num_bulk_out: minimum number of bulk-out endpoints
 * @num_interrupt_in: minimum number of interrupt-in endpoints
 * @num_interrupt_out: minimum number of interrupt-out endpoints
 * @bulk_in_size: minimum number of bytes to allocate for bulk-in buffer
 *      (0 = end-point size)
 * @bulk_out_size: bytes to allocate for bulk-out buffer (0 = end-point size)
 * @calc_num_ports: pointer to a function to determine how many ports this
 *      device has dynamically. It can also be used to verify the number of
 *      endpoints or to modify the port-endpoint mapping. It will be called
 *      after the probe() callback is called, but before attach().
 * @probe: pointer to the driver's probe function.
 *      This will be called when the device is inserted into the system,
 *      but before the device has been fully initialized by the usb_serial
 *      subsystem.  Use this function to download any firmware to the device,
 *      or any other early initialization that might be needed.
 *      Return 0 to continue on with the initialization sequence.  Anything
 *      else will abort it.
 * @attach: pointer to the driver's attach function.
 *      This will be called when the struct usb_serial structure is fully set
 *      set up.  Do any local initialization of the device, or any private
 *      memory structure allocation at this point in time.
 * @disconnect: pointer to the driver's disconnect function.  This will be
 *      called when the device is unplugged or unbound from the driver.
 * @release: pointer to the driver's release function.  This will be called
 *      when the usb_serial data structure is about to be destroyed.
 * @usb_driver: pointer to the struct usb_driver that controls this
 *      device.  This is necessary to allow dynamic ids to be added to
 *      the driver from sysfs.
 *
 * This structure is defines a USB Serial driver.  It provides all of
 * the information that the USB serial core code needs.  If the function
 * pointers are defined, then the USB serial core code will call them when
 * the corresponding tty port functions are called.  If they are not
 * called, the generic serial function will be used instead.
 *
 * The driver.owner field should be set to the module owner of this driver.
 * The driver.name field should be set to the name of this driver (remember
 * it will show up in sysfs, so it needs to be short and to the point.
 * Using the module name is a good idea.)
 */
struct usb_serial_driver {
        const char *description;
        const struct usb_device_id *id_table;

        struct list_head        driver_list;
        struct device_driver    driver;
        struct usb_driver       *usb_driver;
        struct usb_dynids       dynids;

        unsigned char           num_ports;

        unsigned char           num_bulk_in;
        unsigned char           num_bulk_out;
        unsigned char           num_interrupt_in;
        unsigned char           num_interrupt_out;

        size_t                  bulk_in_size;
        size_t                  bulk_out_size;

        int (*probe)(struct usb_serial *serial, const struct usb_device_id *id);
        int (*attach)(struct usb_serial *serial);
        int (*calc_num_ports)(struct usb_serial *serial,
                        struct usb_serial_endpoints *epds);

        void (*disconnect)(struct usb_serial *serial);
        void (*release)(struct usb_serial *serial);

        int (*port_probe)(struct usb_serial_port *port);
        int (*port_remove)(struct usb_serial_port *port);

        int (*suspend)(struct usb_serial *serial, pm_message_t message);
        int (*resume)(struct usb_serial *serial);
        int (*reset_resume)(struct usb_serial *serial);

        /* serial function calls */
        /* Called by console and by the tty layer */
        int  (*open)(struct tty_struct *tty, struct usb_serial_port *port);
        void (*close)(struct usb_serial_port *port);
        int  (*write)(struct tty_struct *tty, struct usb_serial_port *port,
                        const unsigned char *buf, int count);
        /* Called only by the tty layer */
        int  (*write_room)(struct tty_struct *tty);
        int  (*ioctl)(struct tty_struct *tty,
                      unsigned int cmd, unsigned long arg);
        int  (*get_serial)(struct tty_struct *tty, struct serial_struct *ss);
        int  (*set_serial)(struct tty_struct *tty, struct serial_struct *ss);
        void (*set_termios)(struct tty_struct *tty,
                        struct usb_serial_port *port, struct ktermios *old);
        void (*break_ctl)(struct tty_struct *tty, int break_state);
        int  (*chars_in_buffer)(struct tty_struct *tty);
        void (*wait_until_sent)(struct tty_struct *tty, long timeout);
        bool (*tx_empty)(struct usb_serial_port *port);
        void (*throttle)(struct tty_struct *tty);
        void (*unthrottle)(struct tty_struct *tty);
        int  (*tiocmget)(struct tty_struct *tty);
        int  (*tiocmset)(struct tty_struct *tty,
                         unsigned int set, unsigned int clear);
        int  (*tiocmiwait)(struct tty_struct *tty, unsigned long arg);
        int  (*get_icount)(struct tty_struct *tty,
                        struct serial_icounter_struct *icount);
        /* Called by the tty layer for port level work. There may or may not
           be an attached tty at this point */
        void (*dtr_rts)(struct usb_serial_port *port, int on);
        int  (*carrier_raised)(struct usb_serial_port *port);
        /* Called by the usb serial hooks to allow the user to rework the
           termios state */
        void (*init_termios)(struct tty_struct *tty);
        /* USB events */
        void (*read_int_callback)(struct urb *urb);
        void (*write_int_callback)(struct urb *urb);
        void (*read_bulk_callback)(struct urb *urb);
        void (*write_bulk_callback)(struct urb *urb);
        /* Called by the generic read bulk callback */
        void (*process_read_urb)(struct urb *urb);
        /* Called by the generic write implementation */
        int (*prepare_write_buffer)(struct usb_serial_port *port,
                                                void *dest, size_t size);
};
#define to_usb_serial_driver(d) \
        container_of(d, struct usb_serial_driver, driver)

extern int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
                const char *name, const struct usb_device_id *id_table);
extern void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[]);
extern void usb_serial_port_softint(struct usb_serial_port *port);

extern int usb_serial_suspend(struct usb_interface *intf, pm_message_t message);
extern int usb_serial_resume(struct usb_interface *intf);

/* USB Serial console functions */
#ifdef CONFIG_USB_SERIAL_CONSOLE
extern void usb_serial_console_init(int minor);
extern void usb_serial_console_exit(void);
extern void usb_serial_console_disconnect(struct usb_serial *serial);
#else
static inline void usb_serial_console_init(int minor) { }
static inline void usb_serial_console_exit(void) { }
static inline void usb_serial_console_disconnect(struct usb_serial *serial) {}
#endif

/* Functions needed by other parts of the usbserial core */
extern struct usb_serial_port *usb_serial_port_get_by_minor(unsigned int minor);
extern void usb_serial_put(struct usb_serial *serial);
extern int usb_serial_generic_open(struct tty_struct *tty,
        struct usb_serial_port *port);
extern int usb_serial_generic_write_start(struct usb_serial_port *port,
                                                        gfp_t mem_flags);
extern int usb_serial_generic_write(struct tty_struct *tty,
        struct usb_serial_port *port, const unsigned char *buf, int count);
extern void usb_serial_generic_close(struct usb_serial_port *port);
extern int usb_serial_generic_resume(struct usb_serial *serial);
extern int usb_serial_generic_write_room(struct tty_struct *tty);
extern int usb_serial_generic_chars_in_buffer(struct tty_struct *tty);
extern void usb_serial_generic_wait_until_sent(struct tty_struct *tty,
                                                                long timeout);
extern void usb_serial_generic_read_bulk_callback(struct urb *urb);
extern void usb_serial_generic_write_bulk_callback(struct urb *urb);
extern void usb_serial_generic_throttle(struct tty_struct *tty);
extern void usb_serial_generic_unthrottle(struct tty_struct *tty);
extern int usb_serial_generic_tiocmiwait(struct tty_struct *tty,
                                                        unsigned long arg);
extern int usb_serial_generic_get_icount(struct tty_struct *tty,
                                        struct serial_icounter_struct *icount);
extern int usb_serial_generic_register(void);
extern void usb_serial_generic_deregister(void);
extern int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
                                                 gfp_t mem_flags);
extern void usb_serial_generic_process_read_urb(struct urb *urb);
extern int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
                                                void *dest, size_t size);
extern int usb_serial_handle_sysrq_char(struct usb_serial_port *port,
                                        unsigned int ch);
extern int usb_serial_handle_break(struct usb_serial_port *port);
extern void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
                                         struct tty_struct *tty,
                                         unsigned int status);


extern int usb_serial_bus_register(struct usb_serial_driver *device);
extern void usb_serial_bus_deregister(struct usb_serial_driver *device);

extern struct bus_type usb_serial_bus_type;
extern struct tty_driver *usb_serial_tty_driver;

static inline void usb_serial_debug_data(struct device *dev,
                                         const char *function, int size,
                                         const unsigned char *data)
{
        dev_dbg(dev, "%s - length = %d, data = %*ph\n",
                function, size, size, data);
}

/*
 * Macro for reporting errors in write path to avoid inifinite loop
 * when port is used as a console.
 */
#define dev_err_console(usport, fmt, ...)                               \
do {                                                                    \
        static bool __print_once;                                       \
        struct usb_serial_port *__port = (usport);                      \
                                                                        \
        if (!__port->port.console || !__print_once) {                   \
                __print_once = true;                                    \
                dev_err(&__port->dev, fmt, ##__VA_ARGS__);              \
        }                                                               \
} while (0)

/*
 * module_usb_serial_driver() - Helper macro for registering a USB Serial driver
 * @__serial_drivers: list of usb_serial drivers to register
 * @__ids: all device ids that @__serial_drivers bind to
 *
 * Helper macro for USB serial drivers which do not do anything special
 * in module init/exit. This eliminates a lot of boilerplate. Each
 * module may only use this macro once, and calling it replaces
 * module_init() and module_exit()
 *
 */
#define usb_serial_module_driver(__name, __serial_drivers, __ids)       \
static int __init usb_serial_module_init(void)                          \
{                                                                       \
        return usb_serial_register_drivers(__serial_drivers,            \
                                           __name, __ids);              \
}                                                                       \
module_init(usb_serial_module_init);                                    \
static void __exit usb_serial_module_exit(void)                         \
{                                                                       \
        usb_serial_deregister_drivers(__serial_drivers);                \
}                                                                       \
module_exit(usb_serial_module_exit);

#define module_usb_serial_driver(__serial_drivers, __ids)               \
        usb_serial_module_driver(KBUILD_MODNAME, __serial_drivers, __ids)

#endif /* __LINUX_USB_SERIAL_H */