/*++ Copyright (c) 1990 Microsoft Corporation Module Name: ixkdcom.c Abstract: This module contains a very simply package to do com I/O on machines with standard AT com-ports. It is C code derived from the debugger's com code. Likely does not work on a PS/2. (Only rewrote the thing into C so we wouldn't have to deal with random debugger macros.) Procedures to init a com object, set and query baud rate, output character, input character. Author: Bryan M. Willman (bryanwi) 24-Sep-1990 Revision History: John Vert (jvert) 12-Jun-1991 Added ability to check for com-port's existence and hook onto the highest com-port available. John Vert (jvert) 19-Jul-1991 Moved into HAL --*/ #include #include #include "kdcomp.h" #include "kdcom.h" #include "inbv.h" #define TIMEOUT_COUNT 1024 * 200 UCHAR CpReadLsr (PCPPORT, UCHAR); BOOLEAN KdCompDbgPortsPresent = TRUE; UCHAR KdCompDbgErrorCount = 0; #define DBG_ACCEPTABLE_ERRORS 25 static UCHAR LastLsr, LastMsr; extern pKWriteUchar KdWriteUchar; extern pKReadUchar KdReadUchar; VOID CpInitialize ( PCPPORT Port, PUCHAR Address, ULONG Rate ) /*++ Routine Description: Fill in the com port port object, set the initial baud rate, turn on the hardware. Arguments: Port - address of port object Address - port address of the com port (CP_COM1_PORT, CP_COM2_PORT) Rate - baud rate (CP_BD_150 ... CP_BD_19200) --*/ { PUCHAR hwport; UCHAR mcr, ier; Port->Address = Address; Port->Baud = 0; CpSetBaud(Port, Rate); // // Assert DTR, RTS. // hwport = Port->Address; hwport += COM_MCR; mcr = MC_DTRRTS; KdWriteUchar(hwport, mcr); hwport = Port->Address; hwport += COM_IEN; ier = 0; KdWriteUchar(hwport, ier); } VOID CpSetBaud ( PCPPORT Port, ULONG Rate ) /*++ Routine Description: Set the baud rate for the port and record it in the port object. Arguments: Port - address of port object Rate - baud rate (CP_BD_150 ... CP_BD_56000) --*/ { ULONG divisorlatch; PUCHAR hwport; UCHAR lcr; // // compute the divsor // divisorlatch = CLOCK_RATE / Rate; // // set the divisor latch access bit (DLAB) in the line control reg // hwport = Port->Address; hwport += COM_LCR; // hwport = LCR register lcr = KdReadUchar(hwport); lcr |= LC_DLAB; KdWriteUchar(hwport, lcr); // // set the divisor latch value. // hwport = Port->Address; hwport += COM_DLM; // divisor latch msb KdWriteUchar(hwport, (UCHAR)((divisorlatch >> 8) & 0xff)); hwport--; // divisor latch lsb KdWriteUchar(hwport, (UCHAR)(divisorlatch & 0xff)); // // Set LCR to 3. (3 is a magic number in the original assembler) // hwport = Port->Address; hwport += COM_LCR; KdWriteUchar(hwport, 3); // // Remember the baud rate // Port->Baud = Rate; } USHORT CpQueryBaud ( PCPPORT Port ) /*++ Routine Description: Return the last value baud rate was set to. Arguments: Port - address of cpport object which describes the hw port of interest. Return Value: Baud rate. 0 = none has been set. --*/ { return (USHORT) Port->Baud; } VOID CpSendModemString ( PCPPORT Port, IN PUCHAR String ) /*++ Routine Description: Sends a command string to the modem. This is down in order to aid the modem in determining th baud rate the local connect is at. Arguments: Port - Address of CPPORT String - String to send to modem --*/ { static ULONG Delay; TIME_FIELDS CurrentTime; UCHAR i; ULONG l; if (Port->Flags & PORT_SENDINGSTRING) return ; Port->Flags |= PORT_SENDINGSTRING; if (!Delay) { // see how long 1 second is HalQueryRealTimeClock (&CurrentTime); l = CurrentTime.Second; while (l == (ULONG) CurrentTime.Second) { CpReadLsr(Port, 0); HalQueryRealTimeClock (&CurrentTime); Delay++; } Delay = Delay / 3; } l = Delay; while (*String) { HalQueryRealTimeClock (&CurrentTime); i = CpReadLsr (Port, 0); if (i & COM_OUTRDY) { if ((--l) == 0) { KdWriteUchar(Port->Address+COM_DAT, *String); String++; l = Delay; } } if (i & COM_DATRDY) KdReadUchar(Port->Address + COM_DAT); } Port->Flags &= ~PORT_SENDINGSTRING; } UCHAR CpReadLsr ( PCPPORT Port, UCHAR waiting ) /*++ Routine Description: Read LSR byte from specified port. If HAL owns port & display it will also cause a debug status to be kept up to date. Handles entering & exiting modem control mode for debugger. Arguments: Port - Address of CPPORT Returns: Byte read from port --*/ { static UCHAR ringflag = 0; static UCHAR diagout[3]; static ULONG diagmsg[3] = { 'TRP ', 'LVO ', 'MRF ' }; static UCHAR ModemString[] = "\n\rAT\n\r"; TIME_FIELDS CurrentTime; UCHAR lsr, msr, i; ULONG diagstr[12]; lsr = KdReadUchar(Port->Address + COM_LSR); // // Check to see if the port still exists. // if (lsr == SERIAL_LSR_NOT_PRESENT) { KdCompDbgErrorCount++; if (KdCompDbgErrorCount >= DBG_ACCEPTABLE_ERRORS) { KdCompDbgPortsPresent = FALSE; KdCompDbgErrorCount = 0; } return SERIAL_LSR_NOT_PRESENT; } if (lsr & COM_PE) diagout[0] = 8; // Parity error if (lsr & COM_OE) diagout[1] = 8; // Overflow error if (lsr & COM_FE) diagout[2] = 8; // Framing error if (lsr & waiting) { LastLsr = ~COM_DATRDY | (lsr & COM_DATRDY); return lsr; } msr = KdReadUchar (Port->Address + COM_MSR); if (Port->Flags & PORT_MODEMCONTROL) { if (msr & SERIAL_MSR_DCD) { // // In modem control mode with carrier detect // Reset carrier lost time // Port->Flags |= PORT_NOCDLTIME | PORT_MDM_CD; } else { // // In modem control mode, but no carrier detect. After // 60 seconds drop out of modem control mode // if (Port->Flags & PORT_NOCDLTIME) { HalQueryRealTimeClock (&Port->CarrierLostTime); Port->Flags &= ~PORT_NOCDLTIME; ringflag = 0; } HalQueryRealTimeClock (&CurrentTime); if (CurrentTime.Minute != Port->CarrierLostTime.Minute && CurrentTime.Second >= Port->CarrierLostTime.Second) { // // It's been at least 60 seconds - drop out of // modem control mode until next RI // Port->Flags &= ~PORT_MODEMCONTROL; CpSendModemString (Port, ModemString); } if (Port->Flags & PORT_MDM_CD) { // // We had a connection - if it's the connection has been // down for a few seconds, then send a string to the modem // if (CurrentTime.Second < Port->CarrierLostTime.Second) CurrentTime.Second += 60; if (CurrentTime.Second > Port->CarrierLostTime.Second + 10) { Port->Flags &= ~PORT_MDM_CD; CpSendModemString (Port, ModemString); } } } } if (!(Port->Flags & PORT_SAVED)) { return lsr; } KdCheckPowerButton(); if (lsr == LastLsr && msr == LastMsr) { return lsr; } ringflag |= (msr & SERIAL_MSR_RI) ? 1 : 2; if (ringflag == 3) { // // The ring indicate line has toggled // Use modem control from now on // ringflag = 0; Port->Flags |= PORT_MODEMCONTROL | PORT_NOCDLTIME; Port->Flags &= ~PORT_MDM_CD; if (Port->Flags & PORT_DEFAULTRATE && Port->Baud != BD_9600) { // // Baud rate was never specified switch // to 9600 baud as default (for modem usage). // InbvDisplayString (MSG_DEBUG_9600); CpSetBaud (Port, BD_9600); //Port->Flags |= PORT_DISBAUD; } } for (i=0; i < 3; i++) { if (diagout[i]) { diagout[i]--; diagstr[10-i] = diagmsg[i]; } else { diagstr[10-i] = ' '; } } diagstr[7] = (LastLsr & COM_DATRDY) ? 'VCR ' : ' '; diagstr[6] = (lsr & COM_OUTRDY) ? ' ' : 'DNS '; diagstr[5] = (msr & 0x10) ? 'STC ' : ' '; diagstr[4] = (msr & 0x20) ? 'RSD ' : ' '; diagstr[3] = (msr & 0x40) ? ' IR ' : ' '; diagstr[2] = (msr & 0x80) ? ' DC ' : ' '; diagstr[1] = (Port->Flags & PORT_MODEMCONTROL) ? 'MDM ' : ' '; diagstr[0] = ' '; #if 0 if (Port->Flags & PORT_DISBAUD) { switch (Port->Baud) { case BD_9600: diagstr[0] = ' 69 '; break; case BD_14400: diagstr[0] = 'K41 '; break; case BD_19200: diagstr[0] = 'K91 '; break; case BD_56000: diagstr[0] = 'K65 '; break; } } #endif //HalpDisplayDebugStatus ((PUCHAR) diagstr, 11*4); LastLsr = lsr; LastMsr = msr; return lsr; } VOID CpPutByte ( PCPPORT Port, UCHAR Byte ) /*++ Routine Description: Write a byte out to the specified com port. Arguments: Port - Address of CPPORT object Byte - data to emit --*/ { UCHAR msr, lsr; if (KdCompDbgPortsPresent == FALSE) { return; } // // If modem control, make sure DSR, CTS and CD are all set before // sending any data. // while ((Port->Flags & PORT_MODEMCONTROL) && (msr = KdReadUchar(Port->Address + COM_MSR) & MS_DSRCTSCD) != MS_DSRCTSCD) { // // If no CD, and there's a charactor ready, eat it // lsr = CpReadLsr (Port, 0); if ((msr & MS_CD) == 0 && (lsr & COM_DATRDY) == COM_DATRDY) { KdReadUchar(Port->Address + COM_DAT); } } // // Wait for port to not be busy // while (!(CpReadLsr(Port, COM_OUTRDY) & COM_OUTRDY)) ; // // Send the byte // KdWriteUchar(Port->Address + COM_DAT, Byte); } USHORT CpGetByte ( PCPPORT Port, PUCHAR Byte, BOOLEAN WaitForByte ) /*++ Routine Description: Fetch a byte and return it. Arguments: Port - address of port object that describes hw port Byte - address of variable to hold the result WaitForByte - flag indicates wait for byte or not. Return Value: CP_GET_SUCCESS if data returned. CP_GET_NODATA if no data available, but no error. CP_GET_ERROR if error (overrun, parity, etc.) --*/ { UCHAR lsr; UCHAR value; ULONG limitcount; // // Make sure DTR and CTS are set // // (What does CTS have to do with reading from a full duplex line???) // // Check to make sure the CPPORT we were passed has been initialized. // (The only time it won't be initialized is when the kernel debugger // is disabled, in which case we just return.) // if (Port->Address == NULL) { KdCheckPowerButton(); return(CP_GET_NODATA); } if (KdCompDbgPortsPresent == FALSE) { if (CpReadLsr(Port, COM_DATRDY) == SERIAL_LSR_NOT_PRESENT) { return(CP_GET_NODATA); } else { CpSetBaud(Port, Port->Baud); KdCompDbgPortsPresent = TRUE; } } limitcount = WaitForByte ? TIMEOUT_COUNT : 1; while (limitcount != 0) { limitcount--; lsr = CpReadLsr(Port, COM_DATRDY); if (lsr == SERIAL_LSR_NOT_PRESENT) { return(CP_GET_NODATA); } if ((lsr & COM_DATRDY) == COM_DATRDY) { // // Check for errors // if (lsr & (COM_FE | COM_PE | COM_OE)) { *Byte = 0; return(CP_GET_ERROR); } // // fetch the byte // value = KdReadUchar(Port->Address + COM_DAT); if (Port->Flags & PORT_MODEMCONTROL) { // // Using modem control. If no CD, then skip this byte. // if ((KdReadUchar(Port->Address + COM_MSR) & MS_CD) == 0) { continue; } } *Byte = value & (UCHAR)0xff; return CP_GET_SUCCESS; } } LastLsr = 0; CpReadLsr (Port, 0); return CP_GET_NODATA; } BOOLEAN CpDoesPortExist( IN PUCHAR Address ) /*++ Routine Description: This routine will attempt to place the port into its diagnostic mode. If it does it will twiddle a bit in the modem control register. If the port exists this twiddling should show up in the modem status register. NOTE: This routine must be called before the device is enabled for interrupts, this includes setting the output2 bit in the modem control register. This is blatantly stolen from TonyE's code in ntos\dd\serial\serial.c. Arguments: Address - address of hw port. Return Value: TRUE - Port exists. Party on. FALSE - Port doesn't exist. Don't use it. --*/ { UCHAR OldModemStatus; UCHAR ModemStatus; BOOLEAN ReturnValue = TRUE; // // Save the old value of the modem control register. // OldModemStatus = KdReadUchar(Address+COM_MCR); // // Set the port into diagnostic mode. // KdWriteUchar( Address+COM_MCR, SERIAL_MCR_LOOP ); // // Bang on it again to make sure that all the lower bits // are clear. // KdWriteUchar( Address+COM_MCR, SERIAL_MCR_LOOP ); // // Read the modem status register. The high for bits should // be clear. // ModemStatus = KdReadUchar(Address+COM_MSR); if (ModemStatus & (SERIAL_MSR_CTS | SERIAL_MSR_DSR | SERIAL_MSR_RI | SERIAL_MSR_DCD)) { ReturnValue = FALSE; goto AllDone; } // // So far so good. Now turn on OUT1 in the modem control register // and this should turn on ring indicator in the modem status register. // KdWriteUchar( Address+COM_MCR, (SERIAL_MCR_OUT1 | SERIAL_MCR_LOOP) ); ModemStatus = KdReadUchar(Address+COM_MSR); if (!(ModemStatus & SERIAL_MSR_RI)) { ReturnValue = FALSE; goto AllDone; } AllDone: ; // // Put the modem control back into a clean state. // KdWriteUchar( Address+COM_MCR, OldModemStatus ); return ReturnValue; } VOID CpWritePortUchar( IN PUCHAR Address, IN UCHAR Value ) { WRITE_PORT_UCHAR(Address, Value); } // CpWritePortUchar() UCHAR CpReadPortUchar( IN PUCHAR Address ) { return READ_PORT_UCHAR(Address); } // CpReadPortUchar() VOID CpWriteRegisterUchar( IN PUCHAR Address, IN UCHAR Value ) { WRITE_REGISTER_UCHAR(Address, Value); } // CpWriteRegisterValue() UCHAR CpReadRegisterUchar( IN PUCHAR Address ) { return READ_REGISTER_UCHAR(Address); } // CpReadRegisterUchar()