/* DANG_BEGIN_MODULE
 * 
 * ser_defs.h: Include file for all files in the 'serial' subdirectory.
 * Please send bug reports and bugfixes to mdrejhon@magi.com
 * Please read the files in this 'serial' subdirectory for more info.
 * 
 * This module is maintained by Mark Rejhon at these Email addresses:
 *     mdrejhon@magi.com
 *     ag115@freenet.carleton.ca
 *
 * COPYRIGHTS
 * ~~~~~~~~~~
 *   UART defs derived from Theodore Ts'o work: /linux/include/linux/serial.h
 *   Other code Copyright (C) 1995 by Mark Rejhon
 *
 *   The code in this module 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.
 *
 * DANG_END_MODULE
 */
#ifndef SER_DEFS_H
#define SER_DEFS_H

#include "base/serial.h"
 
/* DANG_BEGIN_REMARK 
 * Extensions to serial debugging.
 *
 * SER_DEBUG_MAIN   (0 or 1)
 *   - extra debug output on the most critical information.
 *
 * SER_DEBUG_HEAVY   (0 or 1)
 *   - super-heavy extra debug output, including all ports reads and writes, 
 *      and every character received and transmitted!
 *
 * SER_DEBUG_INTERRUPT   (0 or 1)
 *   - additional debug output related to serial interrupt code,
 *      including flagging serial interrupts, or PIC-driven code.
 *
 * You must recompile dosemu everytime one of these constants are modified.
 * Just type 'make' in the dosemu dir and it will recompile the changes only.
 * DANG_END_REMARK
 */
#define SER_DEBUG_MAIN       0		/* 0 or 1 */
#define SER_DEBUG_HEAVY      0		/* 0 or 1 */
#define SER_DEBUG_INTERRUPT  0		/* 0 or 1 */

/* For more information about the com[] structure, please see serial.h */
serial_t com[MAX_SER];
/* 
 * DANG_BEGIN_REMARK
 * 
 * IMPORTANT INFO about com[] variable array structure used in serial.c
 *
 * Most of the serial variables are stored in the com[] array.
 * The com[] array is a structure in itself.   Take a look at the
 * 'serial_t' struct declaration in the serial.h module for more info
 * about this.  Only the most commonly referenced global variables
 * are listed here:
 *
 *   config.num_ser         Number of serial ports active.
 *   com[x].base_port       The base port address of emulated serial port.
 *   com[x].real_comport    The COM port number.
 *   com[x].interrupt       The PIC interrupt level (based on IRQ number)
 *   com[x].mouse           Flag  mouse (to enable extended features)
 *   com[x].fd              File descriptor for port device 
 *   com[x].dev[]           Filename of port port device
 *   com[x].dev_locked      Flag whether device has been locked
 *
 * The arbritary example variable 'x' in com[x] can have a minimum value
 * of 0 and a maximum value of (config.numser - 1).  There can be no gaps
 * for the value 'x', even though gaps between actual COM ports are permitted.
 * It is strongly noted that the 'x' does not equal the COM port number.
 * This example code illustrates the fact, and how the com[] array works:
 *
 *   for (i = 0; i < config.numser; i++)
 *     s_printf("COM port number %d has a base address of %x", 
 *              com[i].real_comport, com[i].base_port);
 *
 * DANG_END_REMARK
 */

/* Defines to control existence of the debug outputting commands.
 * The C compiler is smart enough to not generate extra code when certain
 * debugging output commands are not defined to anything in particular.
 */
#if SER_DEBUG_MAIN 
#define s1_printf(a...) s_printf(##a)
#else
#define s1_printf(a...) (void)0
#endif

#if SER_DEBUG_HEAVY
#define s2_printf(a...) s_printf(##a)
#else
#define s2_printf(a...) (void)0
#endif

#if SER_DEBUG_INTERRUPT
#define s3_printf(a...) s_printf(##a)
#else
#define s3_printf(a...) (void)0
#endif

/************************************************************
 *  The following UART definitions are derived from         *
 *  linux/include/linux/serial.h, a work by Theodore Ts'o.  *
 *  These definitions should NOT be changed!                *
 ************************************************************/

/* These are the UART port assignments, expressed as offsets from the base
 * register.  These assignments should hold for any serial port based on
 * a 8250, 16450, or 16550(A).
 */
#define UART_RX		0	/* In:  Receive buffer (DLAB=0) */
#define UART_TX		0	/* Out: Transmit buffer (DLAB=0) */
#define UART_DLL	0	/* Out: Devisor Latch Low (DLAB=1) */
#define UART_DLM	1	/* Out: Devisor Latch High (DLAB=1) */
#define UART_IER	1	/* Out: Interrupt Enable Register */
#define UART_IIR	2	/* In:  Interrupt ID Register */
#define UART_FCR	2	/* Out: FIFO Control Register */
#define UART_LCR	3	/* Out: Line Control Register */
#define UART_MCR	4	/* Out: Modem Control Register */
#define UART_LSR	5	/* In:  Line Status Register */
#define UART_MSR	6	/* In:  Modem Status Register */
#define UART_SCR	7	/* I/O: Scratch Register */

/* These are the definitions for the FIFO Control Register
 */
#define UART_FCR_ENABLE_FIFO	0x01	/* Enable the FIFO */
#define UART_FCR_CLEAR_RCVR	0x02	/* Clear the RCVR FIFO */
#define UART_FCR_CLEAR_XMIT	0x04	/* Clear the XMIT FIFO */
#define UART_FCR_DMA_SELECT	0x08	/* For DMA applications */
#define UART_FCR_TRIGGER_MASK	0xC0	/* Mask for the FIFO trigger range */
#define UART_FCR_TRIGGER_1	0x00	/* Mask for trigger set at 1 */
#define UART_FCR_TRIGGER_4	0x40	/* Mask for trigger set at 4 */
#define UART_FCR_TRIGGER_8	0x80	/* Mask for trigger set at 8 */
#define UART_FCR_TRIGGER_14	0xC0	/* Mask for trigger set at 14 */

#define UART_FCR_CLEAR_CMD	(UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT)
#define UART_FCR_SETUP_CMD	(UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_8)

/* These are the definitions for the Line Control Register
 *
 * Note: if the word length is 5 bits (UART_LCR_WLEN5), then setting
 * UART_LCR_STOP will select 1.5 stop bits, not 2 stop bits.
 * UART_LCR_SPAR is rarely used, but if this is set, it means to
 * stick the parity bit high or low, depending on UART_LCR_PARITY.
 */
#define UART_LCR_DLAB	0x80	/* Devisor latch access bit */
#define UART_LCR_SBC	0x40	/* Set break control */
#define UART_LCR_SPAR	0x20	/* Stick parity bit continously high or low */
#define UART_LCR_EPAR	0x10	/* Even paraity select */
#define UART_LCR_PARITY	0x08	/* Parity Enable */
#define UART_LCR_STOP	0x04	/* Stop bits: 0=1 stop bit, 1= 2 stop bits */
#define UART_LCR_WLEN5  0x00	/* Wordlength: 5 bits */
#define UART_LCR_WLEN6  0x01	/* Wordlength: 6 bits */
#define UART_LCR_WLEN7  0x02	/* Wordlength: 7 bits */
#define UART_LCR_WLEN8  0x03	/* Wordlength: 8 bits */
#define UART_LCR_PARA   0x1f    /* Parity, Stop bits and Wordlength */

/* These are the definitions for the Line Status Register
 */
#define UART_LSR_TEMT	0x40	/* Transmitter empty */
#define UART_LSR_THRE	0x20	/* Transmit-hold-register empty */
#define UART_LSR_BI	0x10	/* Break interrupt indicator */
#define UART_LSR_FE	0x08	/* Frame error indicator */
#define UART_LSR_PE	0x04	/* Parity error indicator */
#define UART_LSR_OE	0x02	/* Overrun error indicator */
#define UART_LSR_DR	0x01	/* Receiver data ready */
#define UART_LSR_ERR    0x1e    /* All the error indicators */

/* These are the definitions for the Interrupt Indentification Register
 */
#define UART_IIR_NO_INT	0x01	/* No interrupts pending */
#define UART_IIR_MSI	0x00	/* Modem status interrupt */
#define UART_IIR_THRI	0x02	/* Transmitter holding register empty */
#define UART_IIR_RDI	0x04	/* Receiver data interrupt */
#define UART_IIR_RLSI	0x06	/* Receiver line status interrupt */
#define UART_IIR_CTI    0x0c	/* Character timeout indication */
#define UART_IIR_ID	0x06	/* Mask for the interrupt ID */
#define UART_IIR_FIFO_ENABLE_1 0x40
#define UART_IIR_FIFO_ENABLE_2 0x80
#define UART_IIR_FIFO (UART_IIR_FIFO_ENABLE_1|UART_IIR_FIFO_ENABLE_2)

/* These are the definitions for the Interrupt Enable Register
 */
#define UART_IER_MSI	0x08	/* Enable Modem status interrupt */
#define UART_IER_RLSI	0x04	/* Enable receiver line status interrupt */
#define UART_IER_THRI	0x02	/* Enable Transmitter holding register int. */
#define UART_IER_RDI	0x01	/* Enable receiver data interrupt */

/* These are the definitions for the Modem Control Register
 */
#define UART_MCR_LOOP	0x10	/* Enable loopback test mode */
#define UART_MCR_OUT2	0x08	/* Out2 complement */
#define UART_MCR_OUT1	0x04	/* Out1 complement */
#define UART_MCR_RTS	0x02	/* RTS complement */
#define UART_MCR_DTR	0x01	/* DTR complement */
#define UART_MCR_VALID	0x1F	/* The valid registers of the MCR */

/* These are the definitions for the Modem Status Register
 */
#define UART_MSR_DCD	0x80	/* Data Carrier Detect */
#define UART_MSR_RI	0x40	/* Ring Indicator */
#define UART_MSR_DSR	0x20	/* Data Set Ready */
#define UART_MSR_CTS	0x10	/* Clear to Send */
#define UART_MSR_DDCD	0x08	/* Delta DCD */
#define UART_MSR_TERI	0x04	/* Trailing edge ring indicator */
#define UART_MSR_DDSR	0x02	/* Delta DSR */
#define UART_MSR_DCTS	0x01	/* Delta CTS */
#define UART_MSR_DELTA	0x0F	/* Any of the delta bits! */
#define UART_MSR_STAT	0xF0	/* Any of the non-delta bits! */

/* These are baudrate divisors.  BaudRate = 1843200 / (DIVISOR * 16)
 */
#define DIV_50      0x900
#define	DIV_110     0x417
#define	DIV_150     0x300
#define	DIV_300     0x180
#define	DIV_600     0x0C0
#define	DIV_1200    0x060
#define	DIV_1800    0x040
#define	DIV_2000    0x03A
#define	DIV_2400    0x030
#define	DIV_3600    0x020
#define	DIV_4800    0x018
#define	DIV_7200    0x010
#define	DIV_9600    0x00C
#define	DIV_19200   0x006
#define	DIV_38400   0x003
#define	DIV_57600   0x002
#define	DIV_115200  0x001

/* Interrupts pending flag bits for com[num].int_type
 * These bits must match the UART_IER_xxx bits, above
 */
#define RX_INTR    UART_IER_RDI    /* 1 */
#define TX_INTR    UART_IER_THRI   /* 2 */
#define LS_INTR    UART_IER_RLSI   /* 4 */
#define MS_INTR    UART_IER_MSI    /* 8 */


/**********************************************************
 *  The following are definitions that can be fine-tuned  *
 **********************************************************/

/* The following are positive constants that adjust the soonness of the next
 * receive or transmit interrupt in FIFO mode.  These are a little
 * bit sensitive, and may dissappear when better timer code arrives.
 */
#define TIMEOUT_RX   3

/* Maximum number of 115200ths of a seconds worth of chars to buffer
 * If more characters than this is in the buffer, then wait till it
 * drops below this value, to trigger the next transmit interrupt
 * Right now this is set to 1/10th sec worth of buffered xmit bytes.
 */
#define TX_BUF_THRESHOLD        11520L

/* Frequency of read() on the serial device.  This is in format of 
 * 115200ths between every read().  Right now this is set to 1/60th 
 * of a second between reads, (1920/115200) if no data was waiting. 
 * This is to reduce system load caused by read() on the serial device.
 */
#define RX_READ_FREQ            1920L

/* Minimum frequency for modem status checks, in 115200ths seconds
 * between checks of the modem status.  Right now this is set to
 * 1/30th of a second (3840/115200)
 */
#define MS_MIN_FREQ		3840L


/*******************************************************************
 *  Function declarations in order to resolve function references  *
 *******************************************************************/

extern int convert_bit(int, int, int);
extern void serial_int_engine(int, int);
extern void serial_timer_update(void);
extern void uart_fill(int);
extern void pic_serial_run(void);
extern void uart_clear_fifo(int, int);
extern void ser_termios(int);
extern void modstat_engine(int);
extern int msr_compute_delta_bits(int, int);

#endif /* SER_DEFS_H */
