root/drivers/usb/serial/keyspan_usa49msg.h
/* SPDX-License-Identifier: BSD-3-Clause */
/*
        usa49msg.h

        Copyright (C) 1998-2000 InnoSys Incorporated.  All Rights Reserved
        This file is available under a BSD-style copyright

        Keyspan USB Async Message Formats for the USA49W

        Redistribution and use in source and binary forms, with or without
        modification, are permitted provided that the following conditions are
        met:

        1. Redistributions of source code must retain this licence text
        without modification, this list of conditions, and the following
        disclaimer.  The following copyright notice must appear immediately at
        the beginning of all source files:

                Copyright (C) 1998-2000 InnoSys Incorporated.  All Rights Reserved

                This file is available under a BSD-style copyright

        2. The name of InnoSys Incorporated may not be used to endorse or promote
        products derived from this software without specific prior written
        permission.

        THIS SOFTWARE IS PROVIDED BY INNOSYS CORP. ``AS IS'' AND ANY EXPRESS OR
        IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
        OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
        NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
        INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
        (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
        SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
        CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
        LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
        OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
        SUCH DAMAGE.    

        4th revision: USA49W version

        Buffer formats for RX/TX data messages are not defined by
        a structure, but are described here:

        USB OUT (host -> USAxx, transmit) messages contain a 
        REQUEST_ACK indicator (set to 0xff to request an ACK at the 
        completion of transmit; 0x00 otherwise), followed by data:

                RQSTACK DAT DAT DAT ...

        with a total data length of 63.

        USB IN (USAxx -> host, receive) messages begin with a status
        byte in which the 0x80 bit is either:
                                        
                (a)     0x80 bit clear
                        indicates that the bytes following it are all data
                        bytes:

                                STAT DATA DATA DATA DATA DATA ...

                        for a total of up to 63 DATA bytes,

        or:

                (b)     0x80 bit set
                        indiates that the bytes following alternate data and
                        status bytes:

                                STAT DATA STAT DATA STAT DATA STAT DATA ...

                        for a total of up to 32 DATA bytes.

        The valid bits in the STAT bytes are:

                OVERRUN 0x02
                PARITY  0x04
                FRAMING 0x08
                BREAK   0x10

        Notes:
        
        (1) The OVERRUN bit can appear in either (a) or (b) format
                messages, but the but the PARITY/FRAMING/BREAK bits
                only appear in (b) format messages.
        (2) For the host to determine the exact point at which the
                overrun occurred (to identify the point in the data
                stream at which the data was lost), it needs to count
                128 characters, starting at the first character of the
                message in which OVERRUN was reported; the lost character(s)
                would have been received between the 128th and 129th
                characters.
        (3)     An RX data message in which the first byte has 0x80 clear
                serves as a "break off" indicator.
        (4)     a control message specifying disablePort will be answered
                with a status message, but no further status will be sent
                until a control messages with enablePort is sent

        revision history:

        1999feb10       add reportHskiaChanges to allow us to ignore them
        1999feb10       add txAckThreshold for fast+loose throughput enhancement
        1999mar30       beef up support for RX error reporting
        1999apr14       add resetDataToggle to control message
        2000jan04       merge with usa17msg.h
        2000mar08       clone from usa26msg.h -> usa49msg.h
        2000mar09       change to support 4 ports
        2000may03       change external clocking to match USA-49W hardware
        2000jun01       add extended BSD-style copyright text
        2001jul05       change message format to improve OVERRUN case
*/

#ifndef __USA49MSG__
#define __USA49MSG__


/*
        Host->device messages sent on the global control endpoint:

        portNumber      message
        ----------      --------------------
        0,1,2,3         portControlMessage
        0x80            globalControlMessage
*/

struct keyspan_usa49_portControlMessage
{
        /*
                0.      0/1/2/3         port control message follows
                        0x80 set        non-port control message follows
        */
        u8      portNumber,

        /*
                there are three types of "commands" sent in the control message:

                1.      configuration changes which must be requested by setting
                        the corresponding "set" flag (and should only be requested
                        when necessary, to reduce overhead on the USA26):
        */
                setClocking,    // host requests baud rate be set
                baudLo,                 // host does baud divisor calculation
                baudHi,                 // baudHi is only used for first port (gives lower rates)
                prescaler,              // specified as N/8; values 8-ff are valid
                                                // must be set any time internal baud rate is set;
                txClocking,             // 0=internal, 1=external/DSR
                rxClocking,             // 0=internal, 1=external/DSR

                setLcr,                 // host requests lcr be set
                lcr,                    // use PARITY, STOPBITS, DATABITS below

                setFlowControl, // host requests flow control be set
                ctsFlowControl, // 1=use CTS flow control, 0=don't
                xonFlowControl, // 1=use XON/XOFF flow control, 0=don't
                xonChar,                // specified in current character format
                xoffChar,               // specified in current character format

                setRts,                 // host requests RTS output be set
                rts,                    // 1=active, 0=inactive

                setDtr,                 // host requests DTR output be set
                dtr;                    // 1=on, 0=off


        /*
                3.      configuration data which is simply used as is (no overhead,
                        but must be specified correctly in every host message).
        */
        u8      forwardingLength,  // forward when this number of chars available
                dsrFlowControl, // 1=use DSR flow control, 0=don't
                txAckThreshold, // 0=not allowed, 1=normal, 2-255 deliver ACK faster
                loopbackMode;   // 0=no loopback, 1=loopback enabled

        /*
                4.      commands which are flags only; these are processed in order
                        (so that, e.g., if both _txOn and _txOff flags are set, the
                        port ends in a TX_OFF state); any non-zero value is respected
        */
        u8      _txOn,                  // enable transmitting (and continue if there's data)
                _txOff,                 // stop transmitting
                txFlush,                // toss outbound data
                txBreak,                // turn on break (cleared by _txOn)
                rxOn,                   // turn on receiver
                rxOff,                  // turn off receiver
                rxFlush,                // toss inbound data
                rxForward,              // forward all inbound data, NOW (as if fwdLen==1)
                returnStatus,   // return current status (even if it hasn't changed)
                resetDataToggle,// reset data toggle state to DATA0
                enablePort,             // start servicing port (move data, check status)
                disablePort;    // stop servicing port (does implicit tx/rx flush/off)
        
};

// defines for bits in lcr
#define USA_DATABITS_5          0x00
#define USA_DATABITS_6          0x01
#define USA_DATABITS_7          0x02
#define USA_DATABITS_8          0x03
#define STOPBITS_5678_1         0x00    // 1 stop bit for all byte sizes
#define STOPBITS_5_1p5          0x04    // 1.5 stop bits for 5-bit byte
#define STOPBITS_678_2          0x04    // 2 stop bits for 6/7/8-bit byte
#define USA_PARITY_NONE         0x00
#define USA_PARITY_ODD          0x08
#define USA_PARITY_EVEN         0x18
#define PARITY_1                        0x28
#define PARITY_0                        0x38

/*
        during normal operation, status messages are returned 
        to the host whenever the board detects changes.  In some
        circumstances (e.g. Windows), status messages from the
        device cause problems; to shut them off, the host issues
        a control message with the disableStatusMessages flags
        set (to any non-zero value).  The device will respond to
        this message, and then suppress further status messages;
        it will resume sending status messages any time the host
        sends any control message (either global or port-specific).
*/

struct keyspan_usa49_globalControlMessage
{
        u8      portNumber,                     // 0x80
                sendGlobalStatus,       // 1/2=number of status responses requested
                resetStatusToggle,      // 1=reset global status toggle
                resetStatusCount,       // a cycling value
                remoteWakeupEnable,             // 0x10=P1, 0x20=P2, 0x40=P3, 0x80=P4
                disableStatusMessages;  // 1=send no status until host talks
};

/*
        Device->host messages send on the global status endpoint

        portNumber                      message
        ----------                      --------------------
        0x00,0x01,0x02,0x03     portStatusMessage
        0x80                            globalStatusMessage
        0x81                            globalDebugMessage
*/

struct keyspan_usa49_portStatusMessage  // one for each port
{
        u8      portNumber,             // 0,1,2,3
                cts,                    // reports CTS pin
                dcd,                    // reports DCD pin
                dsr,                    // reports DSR pin
                ri,                             // reports RI pin
                _txOff,                 // transmit has been disabled (by host)
                _txXoff,                // transmit is in XOFF state (either host or RX XOFF)
                rxEnabled,              // as configured by rxOn/rxOff 1=on, 0=off
                controlResponse,// 1=a control message has been processed
                txAck,                  // ACK (data TX complete)
                rs232valid;             // RS-232 signal valid
};

// bits in RX data message when STAT byte is included
#define RXERROR_OVERRUN 0x02
#define RXERROR_PARITY  0x04
#define RXERROR_FRAMING 0x08
#define RXERROR_BREAK   0x10

struct keyspan_usa49_globalStatusMessage
{
        u8      portNumber,                     // 0x80=globalStatusMessage
                sendGlobalStatus,       // from request, decremented
                resetStatusCount;       // as in request
};

struct keyspan_usa49_globalDebugMessage
{
        u8      portNumber,                     // 0x81=globalDebugMessage
                n,                                      // typically a count/status byte
                b;                                      // typically a data byte
};

// ie: the maximum length of an EZUSB endpoint buffer
#define MAX_DATA_LEN                    64

// update status approx. 60 times a second (16.6666 ms)
#define STATUS_UPDATE_INTERVAL  16

// status rationing tuning value (each port gets checked each n ms)
#define STATUS_RATION   10

#endif