/* * serialGT.c * * BRIEF MODULE DESCRIPTION * Low Level Serial Port control for use * with the Galileo EVB64120A MIPS eval board and * its on board two channel 16552 Uart. * * Copyright (C) 2000 RidgeRun, Inc. * Author: RidgeRun, Inc. * glonnon@ridgerun.com, skranz@ridgerun.com, stevej@ridgerun.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; either version 2 of the License, or (at your * option) any later version. * * THIS SOFTWARE IS PROVIDED ``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 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. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 675 Mass Ave, Cambridge, MA 02139, USA. * */ // Note: // Serial CHANNELS - 0 is the bottom connector of evb64120A. // (The one that maps to the "B" channel of the // board's uart) // 1 is the top connector of evb64120A. // (The one that maps to the "A" channel of the // board's uart) int DEBUG_CHANNEL = 0; // See Note Above int CONSOLE_CHANNEL = 1; // See Note Above #define DUART 0xBD000000 /* Base address of Uart. */ #define CHANNELOFFSET 0x20 /* DUART+CHANNELOFFSET gets you to the ChanA register set of the 16552 Uart device. DUART+0 gets you to the ChanB register set. */ #define DUART_DELTA 0x4 #define FIFO_ENABLE 0x07 #define INT_ENABLE 0x04 /* default interrupt mask */ #define RBR 0x00 #define THR 0x00 #define DLL 0x00 #define IER 0x01 #define DLM 0x01 #define IIR 0x02 #define FCR 0x02 #define LCR 0x03 #define MCR 0x04 #define LSR 0x05 #define MSR 0x06 #define SCR 0x07 #define LCR_DLAB 0x80 #define XTAL 1843200 #define LSR_THRE 0x20 #define LSR_BI 0x10 #define LSR_DR 0x01 #define MCR_LOOP 0x10 #define ACCESS_DELAY 0x10000 /****************************** Routine: Description: ******************************/ int inreg(int channel, int reg) { int val; val = *((volatile unsigned char *) DUART + (channel * CHANNELOFFSET) + (reg * DUART_DELTA)); return val; } /****************************** Routine: Description: ******************************/ void outreg(int channel, int reg, unsigned char val) { *((volatile unsigned char *) DUART + (channel * CHANNELOFFSET) + (reg * DUART_DELTA)) = val; } /****************************** Routine: Description: Initialize the device driver. ******************************/ void serial_init(int channel) { /* * Configure active port, (CHANNELOFFSET already set.) * * Set 8 bits, 1 stop bit, no parity. * * LCR<7> 0 divisor latch access bit * LCR<6> 0 break control (1=send break) * LCR<5> 0 stick parity (0=space, 1=mark) * LCR<4> 0 parity even (0=odd, 1=even) * LCR<3> 0 parity enable (1=enabled) * LCR<2> 0 # stop bits (0=1, 1=1.5) * LCR<1:0> 11 bits per character(00=5, 01=6, 10=7, 11=8) */ outreg(channel, LCR, 0x3); outreg(channel, FCR, FIFO_ENABLE); /* Enable the FIFO */ outreg(channel, IER, INT_ENABLE); /* Enable appropriate interrupts */ } /****************************** Routine: Description: Set the baud rate. ******************************/ void serial_set(int channel, unsigned long baud) { unsigned char sav_lcr; /* * Enable access to the divisor latches by setting DLAB in LCR. * */ sav_lcr = inreg(channel, LCR); #if 0 /* * Set baud rate */ outreg(channel, LCR, LCR_DLAB | sav_lcr); // outreg(DLL,(XTAL/(16*2*(baud))-2)); outreg(channel, DLL, XTAL / (16 * baud)); // outreg(DLM,(XTAL/(16*2*(baud))-2)>>8); outreg(channel, DLM, (XTAL / (16 * baud)) >> 8); #else /* * Note: Set baud rate, hardcoded here for rate of 115200 * since became unsure of above "buad rate" algorithm (??). */ outreg(channel, LCR, 0x83); outreg(channel, DLM, 0x00); // See note above outreg(channel, DLL, 0x02); // See note above. outreg(channel, LCR, 0x03); #endif /* * Restore line control register */ outreg(channel, LCR, sav_lcr); } /****************************** Routine: Description: Transmit a character. ******************************/ void serial_putc(int channel, int c) { while ((inreg(channel, LSR) & LSR_THRE) == 0); outreg(channel, THR, c); } /****************************** Routine: Description: Read a received character if one is available. Return -1 otherwise. ******************************/ int serial_getc(int channel) { if (inreg(channel, LSR) & LSR_DR) { return inreg(channel, RBR); } return -1; } /****************************** Routine: Description: Used by embedded gdb client. (example; gdb-stub.c) ******************************/ char getDebugChar() { int val; while ((val = serial_getc(DEBUG_CHANNEL)) == -1); // loop until we get a character in. return (char) val; } /****************************** Routine: Description: Used by embedded gdb target. (example; gdb-stub.c) ******************************/ void putDebugChar(char c) { serial_putc(DEBUG_CHANNEL, (int) c); }