/* SPDX-License-Identifier: GPL-2.0 */
/*
 *
 * Includes for cdc-acm.c
 *
 * Mainly take from usbnet's cdc-ether part
 *
 */

/*
 * Major and minor numbers.
 */

#define ACM_TTY_MAJOR           166
#define ACM_TTY_MINORS          256

#define ACM_MINOR_INVALID       ACM_TTY_MINORS

/*
 * Requests.
 */

#define USB_RT_ACM              (USB_TYPE_CLASS | USB_RECIP_INTERFACE)

/*
 * Internal driver structures.
 */

/*
 * The only reason to have several buffers is to accommodate assumptions
 * in line disciplines. They ask for empty space amount, receive our URB size,
 * and proceed to issue several 1-character writes, assuming they will fit.
 * The very first write takes a complete URB. Fortunately, this only happens
 * when processing onlcr, so we only need 2 buffers. These values must be
 * powers of 2.
 */
#define ACM_NW  16
#define ACM_NR  16

struct acm_wb {
        u8 *buf;
        dma_addr_t dmah;
        unsigned int len;
        struct urb              *urb;
        struct acm              *instance;
        bool use;
};

struct acm_rb {
        int                     size;
        unsigned char           *base;
        dma_addr_t              dma;
        int                     index;
        struct acm              *instance;
};

struct acm {
        struct usb_device *dev;                         /* the corresponding usb device */
        struct usb_interface *control;                  /* control interface */
        struct usb_interface *data;                     /* data interface */
        unsigned in, out;                               /* i/o pipes */
        struct tty_port port;                           /* our tty port data */
        struct urb *ctrlurb;                            /* urbs */
        u8 *ctrl_buffer;                                /* buffers of urbs */
        dma_addr_t ctrl_dma;                            /* dma handles of buffers */
        u8 *country_codes;                              /* country codes from device */
        unsigned int country_code_size;                 /* size of this buffer */
        unsigned int country_rel_date;                  /* release date of version */
        struct acm_wb wb[ACM_NW];
        unsigned long read_urbs_free;
        struct urb *read_urbs[ACM_NR];
        struct acm_rb read_buffers[ACM_NR];
        int rx_buflimit;
        spinlock_t read_lock;
        u8 *notification_buffer;                        /* to reassemble fragmented notifications */
        unsigned int nb_index;
        unsigned int nb_size;
        int transmitting;
        spinlock_t write_lock;
        struct mutex mutex;
        bool disconnected;
        unsigned long flags;
#               define EVENT_TTY_WAKEUP 0
#               define EVENT_RX_STALL   1
#               define ACM_THROTTLED    2
#               define ACM_ERROR_DELAY  3
        unsigned long urbs_in_error_delay;              /* these need to be restarted after a delay */
        struct usb_cdc_line_coding line;                /* bits, stop, parity */
        struct delayed_work dwork;                      /* work queue entry for various purposes */
        unsigned int ctrlin;                            /* input control lines (DCD, DSR, RI, break, overruns) */
        unsigned int ctrlout;                           /* output control lines (DTR, RTS) */
        struct async_icount iocount;                    /* counters for control line changes */
        struct async_icount oldcount;                   /* for comparison of counter */
        wait_queue_head_t wioctl;                       /* for ioctl */
        unsigned int writesize;                         /* max packet size for the output bulk endpoint */
        unsigned int readsize,ctrlsize;                 /* buffer sizes for freeing */
        unsigned int minor;                             /* acm minor number */
        unsigned char clocal;                           /* termios CLOCAL */
        unsigned int ctrl_caps;                         /* control capabilities from the class specific header */
        unsigned int susp_count;                        /* number of suspended interfaces */
        unsigned int combined_interfaces:1;             /* control and data collapsed */
        u8 bInterval;
        struct usb_anchor delayed;                      /* writes queued for a device about to be woken */
        unsigned long quirks;
};

/* constants describing various quirks and errors */
#define NO_UNION_NORMAL                 BIT(0)
#define SINGLE_RX_URB                   BIT(1)
#define NO_CAP_LINE                     BIT(2)
#define IGNORE_DEVICE                   BIT(3)
#define QUIRK_CONTROL_LINE_STATE        BIT(4)
#define CLEAR_HALT_CONDITIONS           BIT(5)
#define SEND_ZERO_PACKET                BIT(6)
#define DISABLE_ECHO                    BIT(7)
#define MISSING_CAP_BRK                 BIT(8)
#define NO_UNION_12                     BIT(9)
#define VENDOR_CLASS_DATA_IFACE         BIT(10)  /* data interface uses vendor-specific class */
#define ALWAYS_POLL_CTRL                BIT(11) /* keep ctrl URB active even without an open TTY */