/* SPDX-License-Identifier: GPL-2.0+ */ /************************************************************************ * * IONSP.H Definitions for I/O Networks Serial Protocol * * Copyright (C) 1997-1998 Inside Out Networks, Inc. * * These definitions are used by both kernel-mode driver and the * peripheral firmware and MUST be kept in sync. *
************************************************************************/
The data to and from all ports on the peripheral is multiplexed through a single endpoint pair (EP1 since it supports 64-byte MaxPacketSize). Therefore, the data, commands, and status for each port must be preceded by a short header identifying the destination port. The header also identifies the bytes that follow as data or as command/status info.
Header format, first byte:
CLLLLPPP -------- | | |------ Port Number: 0-7 | |--------- Length: MSB bits of length |----------- Data/Command: 0 = Data header 1 = Cmd / Status (Cmd if OUT, Status if IN)
This gives 2 possible formats:
Data header: 0LLLLPPP LLLLLLLL ============
Where (LLLL,LLLLLLL) is 12-bit length of data that follows for port number (PPP). The length is 0-based (0-FFF means 0-4095 bytes). The ~4K limit allows the host driver (which deals in transfer requests instead of individual packets) to write a large chunk of data in a single request. Note, however, that the length must always be <= the current TxCredits for a given port due to buffering limitations on the peripheral.
Where (cccc) or (cccc,CCCCCCCC) is the cmd or status identifier. Frequently-used values are encoded as (cccc), longer ones using (cccc,CCCCCCCC). Subsequent bytes are optional parameters and are specific to the cmd or status code. This may include a length for command and status codes that need variable-length parameters.
In addition, we use another interrupt pipe (endpoint) which the host polls periodically for flow control information. The peripheral, when there has been a change, sends the following 10-byte packet:
The first field is the 16-bit RxBytesAvail field, which indicates the number of bytes which may be read by the host from EP1. This is necessary: (a) because OSR2.1 has a bug which causes data loss if the peripheral returns fewer bytes than the host expects to read, and (b) because, on Microsoft platforms at least, an outstanding read posted on EP1 consumes about 35% of the CPU just polling the device for data.
The next 4 fields are the 16-bit TxCredits for each port, which indicate how many bytes the host is allowed to send on EP1 for transmit to a given port. After an OPEN_PORT command, the Edgeport sends the initial TxCredits for that port.
All 16-bit fields are sent in little-endian (Intel) format.
// // Define format of InterruptStatus packet returned from the // Interrupt pipe //
struct int_status_pkt {
__u16 RxBytesAvail; // Additional bytes available to // be read from Bulk IN pipe
__u16 TxCredits[MAX_RS232_PORTS]; // Additional space available in // given port's TxBuffer
};
// Register numbers and contents // defined in 16554.H.
// 0x08 // Available for expansion. #define IOSP_EXT_CMD 0x09 // P1 = Command code (defined below)
// P2 = Parameter
// // Extended Command values, used with IOSP_EXT_CMD, may // or may not use parameter P2. //
#define IOSP_CMD_OPEN_PORT 0x00 // Enable ints, init UART. (NO PARAM) #define IOSP_CMD_CLOSE_PORT 0x01 // Disable ints, flush buffers. (NO PARAM) #define IOSP_CMD_CHASE_PORT 0x02 // Wait for Edgeport TX buffers to empty. (NO PARAM) #define IOSP_CMD_SET_RX_FLOW 0x03 // Set Rx Flow Control in Edgeport #define IOSP_CMD_SET_TX_FLOW 0x04 // Set Tx Flow Control in Edgeport #define IOSP_CMD_SET_XON_CHAR 0x05 // Set XON Character in Edgeport #define IOSP_CMD_SET_XOFF_CHAR 0x06 // Set XOFF Character in Edgeport #define IOSP_CMD_RX_CHECK_REQ 0x07 // Request Edgeport to insert a Checkpoint into
// the receive data stream (Parameter = 1 byte sequence number)
#define IOSP_CMD_SET_BREAK 0x08 // Turn on the BREAK (LCR bit 6) #define IOSP_CMD_CLEAR_BREAK 0x09 // Turn off the BREAK (LCR bit 6)
// // Define macros to simplify building of IOSP cmds //
//-------------------------------------------------------------- // // Define format of flow control commands // (sent from Host to Edgeport) // // 11001PPP FlowCmd FlowTypes // // Note that the 'FlowTypes' parameter is a bit mask; that is, // more than one flow control type can be active at the same time. // FlowTypes = 0 means 'no flow control'. //
// // IOSP_CMD_SET_RX_FLOW // // Tells Edgeport how it can stop incoming UART data // // Example for Port 0 // P0 = 11001000 // P1 = IOSP_CMD_SET_RX_FLOW // P2 = Bit mask as follows:
#define IOSP_RX_FLOW_RTS 0x01 // Edgeport drops RTS to stop incoming data #define IOSP_RX_FLOW_DTR 0x02 // Edgeport drops DTR to stop incoming data #define IOSP_RX_FLOW_DSR_SENSITIVITY 0x04 // Ignores Rx data unless DSR high
// Not currently implemented by firmware. #define IOSP_RX_FLOW_XON_XOFF 0x08 // Edgeport sends XOFF char to stop incoming data.
// Host must have previously programmed the // XON/XOFF values with SET_XON/SET_XOFF // before enabling this bit.
// // IOSP_CMD_SET_TX_FLOW // // Tells Edgeport what signal(s) will stop it from transmitting UART data // // Example for Port 0 // P0 = 11001000 // P1 = IOSP_CMD_SET_TX_FLOW // P2 = Bit mask as follows:
// Host must have previously programmed the // XON/XOFF values with SET_XON/SET_XOFF // before enabling this bit. #define IOSP_TX_FLOW_XOFF_CONTINUE 0x10 // If not set, Edgeport stops Tx when
// sending XOFF in order to fix broken // systems that interpret the next // received char as XON. // If set, Edgeport continues Tx // normally after transmitting XOFF. // Not currently implemented by firmware. #define IOSP_TX_TOGGLE_RTS 0x20 // Edgeport drives RTS as a true half-duplex
// Request-to-Send signal: it is raised before // beginning transmission and lowered after // the last Tx char leaves the UART. // Not currently implemented by firmware.
// // IOSP_CMD_SET_XON_CHAR // // Sets the character which Edgeport transmits/interprets as XON. // Note: This command MUST be sent before sending a SET_RX_FLOW or // SET_TX_FLOW with the XON_XOFF bit set. // // Example for Port 0 // P0 = 11001000 // P1 = IOSP_CMD_SET_XON_CHAR // P2 = 0x11
// // IOSP_CMD_SET_XOFF_CHAR // // Sets the character which Edgeport transmits/interprets as XOFF. // Note: This command must be sent before sending a SET_RX_FLOW or // SET_TX_FLOW with the XON_XOFF bit set. // // Example for Port 0 // P0 = 11001000 // P1 = IOSP_CMD_SET_XOFF_CHAR // P2 = 0x13
// // IOSP_CMD_RX_CHECK_REQ // // This command is used to assist in the implementation of the // IOCTL_SERIAL_PURGE Windows IOCTL. // This IOSP command tries to place a marker at the end of the RX // queue in the Edgeport. If the Edgeport RX queue is full then // the Check will be discarded. // It is up to the device driver to timeout waiting for the // RX_CHECK_RSP. If a RX_CHECK_RSP is received, the driver is // sure that all data has been received from the edgeport and // may now purge any internal RX buffers. // Note tat the sequence numbers may be used to detect lost // CHECK_REQs.
// Example for Port 0 // P0 = 11001000 // P1 = IOSP_CMD_RX_CHECK_REQ // P2 = Sequence number
// Response will be: // P1 = IOSP_EXT_RX_CHECK_RSP // P2 = Request Sequence number
//-------------------------------------------------------------- // // Define values for status and status parameters // (received by Host from Edgeport) // // 1ssssPPP P1P1P1P1 [ P2P2P2P2P2 ]... // // ssss: 00-07 2-byte status. ssss identifies which UART register // has changed value, and the new value is in P1. // Note that the ssss values do not correspond to the // 16554 register numbers given in 16554.H. Instead, // see below for definitions of the ssss numbers // used in this status message. // // 08-0B 3-byte status: ==== P1 ==== ==== P2 ==== // 08 LSR_DATA: New LSR Errored byte // 09 1-param responses Response Code Param // 0A OPEN_RSP: InitialMsr TxBufferSize // 0B available for expansion // // 0C-0D 4-byte status. P1 = extended status code and P2,P3 = params // Not currently implemented. // // 0E-0F N-byte status: P1 = num bytes after P1 (ie, TotalLen - 2) // P2 = extended status, P3..Pn = parameters. // Not currently implemented. //
/**************************************************** * SSSS values for 2-byte status messages (0-8)
****************************************************/
#define IOSP_STATUS_LSR 0x00 // P1 is new value of LSR register.
// Bits defined in 16554.H. Edgeport // returns this in order to report // line status errors (overrun, // parity, framing, break). This form // is used when a errored receive data // character was NOT present in the // UART when the LSR error occurred // (ie, when LSR bit 0 = 0).
#define IOSP_STATUS_MSR 0x01 // P1 is new value of MSR register.
// Bits defined in 16554.H. Edgeport // returns this in order to report // changes in modem status lines // (CTS, DSR, RI, CD) //
/**************************************************** * SSSS values for 3-byte status messages (8-A)
****************************************************/
#define IOSP_STATUS_LSR_DATA 0x08 // P1 is new value of LSR register (same as STATUS_LSR)
// P2 is errored character read from // RxFIFO after LSR reported an error.
#define IOSP_EXT_STATUS 0x09 // P1 is status/response code, param in P2.
// Response Codes (P1 values) for 3-byte status messages
#define IOSP_EXT_STATUS_CHASE_RSP 0 // Reply to CHASE_PORT cmd. P2 is outcome: #define IOSP_EXT_STATUS_CHASE_PASS 0 // P2 = 0: All Tx data drained successfully #define IOSP_EXT_STATUS_CHASE_FAIL 1 // P2 = 1: Timed out (stuck due to flow
// control from remote device).
#define IOSP_EXT_STATUS_RX_CHECK_RSP 1 // Reply to RX_CHECK cmd. P2 is sequence number
#define IOSP_STATUS_OPEN_RSP 0x0A // Reply to OPEN_PORT cmd.
// P1 is Initial MSR value // P2 is encoded TxBuffer Size: // TxBufferSize = (P2 + 1) * 64
// 0x0B // Available for future expansion
#define GET_TX_BUFFER_SIZE(P2) (((P2) + 1) * 64)
/**************************************************** * SSSS values for 4-byte status messages
****************************************************/
#define IOSP_EXT4_STATUS 0x0C // Extended status code in P1,
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