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/* 16450.h -- Definition of types and structures for 8250/16450 serial UART

   Copyright (C) 2000 Damjan Lampret, lampret@opencores.org

This file is part of OpenRISC 1000 Architectural Simulator.

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 program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU General Public License for more details.

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. */

/* Prototypes */

void uart_reset();

void uart_clock();

/* Definitions */

#define UART_ADDR_SPACE   (8)         /* UART memory address space size in bytes */

#define UART_RX_BUF       (8192)      /* VAPI should not send more that this amout of char before requesting something back */

#define UART_MAX_FIFO_LEN (16)        /* rx FIFO for uart 16550 */

#define MAX_SKEW          (1)         /* max. clock skew in subclocks */

/* Registers */

struct dev_16450 {

  struct {

    unsigned char txbuf[UART_MAX_FIFO_LEN];

    unsigned char rxbuf[UART_MAX_FIFO_LEN];

    unsigned char dll;

    unsigned char dlh;

    unsigned char ier;

    unsigned char iir;

    unsigned char lcr;

    unsigned char mcr;

    unsigned char lsr;

    unsigned char msr;

    unsigned char scr;

  } regs;   /* Visible registers */

  struct {

    unsigned long txser;    /* Character just sending */

    unsigned long rxser;    /* Character just receiving */

    unsigned char loopback;

  } iregs;  /* Internal registers */

  struct {

    int txbuf_head;

    int txbuf_tail;

    int rxbuf_head;

    int rxbuf_tail;

    unsigned int txser_full;

    unsigned int rxser_full;

    unsigned int txbuf_full;

    unsigned int rxbuf_full;

    unsigned char thre_int;

    unsigned long txser_clks;

    unsigned long rxser_clks;

  } istat;  /* Internal status */

  /* Clocks per char */

  unsigned long char_clks;

  /* VAPI internal registers */

  struct {

    unsigned long char_clks;

    int dll, dlh;

    int lcr;

    int skew;

  } vapi;

  /* Required by VAPI - circular buffer */

 unsigned long vapi_buf[UART_RX_BUF];  /* Buffer to store incoming characters to,

                                          since we cannot handle them so fast - we

                                          are serial */

  int vapi_buf_head_ptr;               /* Where we write to */

  int vapi_buf_tail_ptr;               /* Where we read from */

  /* Length of FIFO, 16 for 16550, 1 for 16450 */

  int fifo_len;

  /* Required by standard file streams */

  FILE * rxfs;

  FILE * txfs;

};

/*

 * Addresses of visible registers

 *

 */

#define UART_RXBUF  0 /* R: Rx buffer, DLAB=0 */

#define UART_TXBUF  0 /* W: Tx buffer, DLAB=0 */

#define UART_DLL  0 /* R/W: Divisor Latch Low, DLAB=1 */

#define UART_DLH  1 /* R/W: Divisor Latch High, DLAB=1 */

#define UART_IER  1 /* R/W: Interrupt Enable Register */

#define UART_IIR  2 /* R: Interrupt ID Register */

#define UART_LCR  3 /* R/W: Line Control Register */

#define UART_MCR  4 /* W: Modem Control Register */

#define UART_LSR  5 /* R: Line Status Register */

#define UART_MSR  6 /* R: Modem Status Register */

#define UART_SCR  7 /* R/W: Scratch Register */

/*

 * R/W masks for valid bits in 8250/16450 (mask out 16550 and later bits)

 *

 */

#define UART_VALID_LCR  0xff

#define UART_VALID_LSR  0x7f

#define UART_VALID_IIR  0x07

#define UART_VALID_IER  0x0f

#define UART_VALID_MCR  0x1f

#define UART_VALID_MSR  0xff

/*

 * Bit definitions for the Line Control Register

 *

 */

#define UART_LCR_DLAB 0x80  /* Divisor latch access bit */

#define UART_LCR_SBC  0x40  /* Set break control */

#define UART_LCR_SPAR 0x20  /* Stick parity (?) */

#define UART_LCR_EPAR 0x10  /* Even parity 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_RESET  0x03

/*

 * Bit definitions for the Line Status Register

 */

#define UART_LSR_TXSERE 0x40  /* Transmitter serial register empty */

#define UART_LSR_TXBUFE 0x20  /* Transmitter buffer register empty */

#define UART_LSR_BREAK  0x10  /* Break interrupt indicator */

#define UART_LSR_FRAME  0x08  /* Frame error indicator */

#define UART_LSR_PARITY 0x04  /* Parity error indicator */

#define UART_LSR_OVRRUN 0x02  /* Overrun error indicator */

#define UART_LSR_RDRDY  0x01  /* Receiver data ready */

/*

 * Bit definitions for the Interrupt Identification Register

 */

#define UART_IIR_NO_INT 0x01  /* No interrupts pending */

#define UART_IIR_ID 0x06  /* Mask for the interrupt ID */

#define UART_IIR_MSI  0x00  /* Modem status interrupt (Low priority) */

#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 (High p.) */

/*

 * Bit 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 */

/*

 * Bit definitions for the Modem Control Register

 */

#define UART_MCR_LOOP 0x10  /* Enable loopback mode */

#define UART_MCR_AUX2 0x08  /* Auxilary 2  */

#define UART_MCR_AUX1 0x04  /* Auxilary 1 */

#define UART_MCR_RTS  0x02  /* Force RTS */

#define UART_MCR_DTR  0x01  /* Force DTR */

/*

 * Bit 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 */