source: rtems/c/src/lib/libbsp/m68k/gen68360/console/console.c @ f52111f

/*
 *  SMC1 raw console serial I/O.
 *
 *  This driver is an example of `POLLING' or `INTERRUPT' I/O.
 *
 *  To run with interrupt-driven I/O, ensure m360_smc1_interrupt
 *  is set before calling the initialization routine.
 *
 *  Author:
 *    W. Eric Norum
 *    Saskatchewan Accelerator Laboratory
 *    University of Saskatchewan
 *    Saskatoon, Saskatchewan, CANADA
 *    eric@skatter.usask.ca
 *
 *  COPYRIGHT (c) 1989-1999.
 *  On-Line Applications Research Corporation (OAR).
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *
 *  http://www.OARcorp.com/rtems/license.html.
 *
 *  $Id$
 */

#include <termios.h>
#include <bsp.h>
#include <rtems/libio.h>
#include "m68360.h"

/*
 * Declare clock speed -- may be overwritten by downloader or debugger
 */
int m360_clock_rate     = 25000000;

/*
 * Interrupt-driven input buffer
 * Declare console baud rate -- may also be overwritten
 */
int console_baud_rate = 9600;

/*
 */
#define RXBUFSIZE       16

/*
 * Interrupt-driven callback
 */
static int m360_smc1_interrupt = 1;
static void *smc1ttyp;

/*
 * I/O buffers and pointers to buffer descriptors
 */
static volatile char rxBuf[RXBUFSIZE];
static volatile m360BufferDescriptor_t *smcRxBd, *smcTxBd;

/*
 * Device-specific routines
 */

/*
 * Compute baud-rate-generator configuration register value
 */
static int
smc1BRGC (int baud)
{
        int divisor;
        int div16 = 0;

        divisor = ((m360_clock_rate / 16) + (baud / 2)) / baud;
        if (divisor > 4096) {
                div16 = 1;
                divisor = (divisor + 8) / 16;
        }
        return M360_BRG_EN | M360_BRG_EXTC_BRGCLK | ((divisor - 1) << 1) | div16;
}

/*
 * Hardware-dependent portion of tcsetattr().
 */
static int
smc1SetAttributes (int minor, const struct termios *t)
{
        int baud;

        switch (t->c_cflag & CBAUD) {
        default:        baud = -1;      break;
        case B50:       baud = 50;      break;
        case B75:       baud = 75;      break;
        case B110:      baud = 110;     break;
        case B134:      baud = 134;     break;
        case B150:      baud = 150;     break;
        case B200:      baud = 200;     break;
        case B300:      baud = 300;     break;
        case B600:      baud = 600;     break;
        case B1200:     baud = 1200;    break;
        case B1800:     baud = 1800;    break;
        case B2400:     baud = 2400;    break;
        case B4800:     baud = 4800;    break;
        case B9600:     baud = 9600;    break;
        case B19200:    baud = 19200;   break;
        case B38400:    baud = 38400;   break;
        case B57600:    baud = 57600;   break;
        case B115200:   baud = 115200;  break;
        case B230400:   baud = 230400;  break;
        case B460800:   baud = 460800;  break;
        }
        if (baud > 0)
                m360.brgc1 = smc1BRGC (baud);
        return 0;
}

/*
 * Interrupt handler
 */
static rtems_isr
smc1InterruptHandler (rtems_vector_number v)
{
        /*
         * Buffer received?
         */
        if (m360.smc1.smce & 0x1) {
                m360.smc1.smce = 0x1;
                while ((smcRxBd->status & M360_BD_EMPTY) == 0) {
                        rtems_termios_enqueue_raw_characters (smc1ttyp,
                                                        (char *)smcRxBd->buffer,
                                                        smcRxBd->length);
                        smcRxBd->status = M360_BD_EMPTY | M360_BD_WRAP | M360_BD_INTERRUPT;
                }
        }

        /*
         * Buffer transmitted?
         */
        if (m360.smc1.smce & 0x2) {
                m360.smc1.smce = 0x2;
                if ((smcTxBd->status & M360_BD_READY) == 0)
                        rtems_termios_dequeue_characters (smc1ttyp, smcTxBd->length);
        }
        m360.cisr = 1UL << 4;   /* Clear SMC1 interrupt-in-service bit */
}

static int
smc1Initialize (int major, int minor, void *arg)
{
        /*
         * Allocate buffer descriptors
         */
        smcRxBd = M360AllocateBufferDescriptors (1);
        smcTxBd = M360AllocateBufferDescriptors (1);

        /*
         * Configure port B pins to enable SMTXD1 and SMRXD1 pins
         */
        m360.pbpar |=  0xC0;
        m360.pbdir &= ~0xC0;
        m360.pbodr &= ~0xC0;

        /*
         * Set up BRG1 (9,600 baud)
         */
        m360.brgc1 = M360_BRG_RST;
        m360.brgc1 = smc1BRGC (console_baud_rate);

        /*
         * Put SMC1 in NMSI mode, connect SMC1 to BRG1
         */
        m360.simode |= M360_SI_SMC1_BRG1;
         
        /*
         * Set up SMC1 parameter RAM common to all protocols
         */
        m360.smc1p.rbase = (char *)smcRxBd - (char *)&m360;
        m360.smc1p.tbase = (char *)smcTxBd - (char *)&m360;
        m360.smc1p.rfcr = M360_RFCR_MOT | M360_RFCR_DMA_SPACE;
        m360.smc1p.tfcr = M360_TFCR_MOT | M360_TFCR_DMA_SPACE;
        if (m360_smc1_interrupt)
                m360.smc1p.mrblr = RXBUFSIZE;
        else
                m360.smc1p.mrblr = 1;
         
        /*
         * Set up SMC1 parameter RAM UART-specific parameters
         */
        m360.smc1p.un.uart.max_idl = 10;
        m360.smc1p.un.uart.brklen = 0;
        m360.smc1p.un.uart.brkec = 0;
        m360.smc1p.un.uart.brkcr = 0;
         
        /*
         * Set up the Receive Buffer Descriptor
         */
        smcRxBd->status = M360_BD_EMPTY | M360_BD_WRAP | M360_BD_INTERRUPT;
        smcRxBd->length = 0;
        smcRxBd->buffer = rxBuf;
         
        /*
         * Setup the Transmit Buffer Descriptor
         */
        smcTxBd->status = M360_BD_WRAP;
         
        /*
         * Set up SMC1 general and protocol-specific mode registers
         */
        m360.smc1.smce = ~0;    /* Clear any pending events */
        m360.smc1.smcm = 0;     /* Mask all interrupt/event sources */
        m360.smc1.smcmr = M360_SMCMR_CLEN(9) | M360_SMCMR_SM_UART;

        /*
         * Send "Init parameters" command
         */
        M360ExecuteRISC (M360_CR_OP_INIT_RX_TX | M360_CR_CHAN_SMC1);

        /*
         * Enable receiver and transmitter
         */
        m360.smc1.smcmr |= M360_SMCMR_TEN | M360_SMCMR_REN;

        if (m360_smc1_interrupt) {
        rtems_isr_entry old_handler;
        rtems_status_code sc;

        sc = rtems_interrupt_catch (smc1InterruptHandler,
                                                (m360.cicr & 0xE0) | 0x04,
                                                &old_handler);
        m360.smc1.smcm = 3;     /* Enable SMC1 TX and RX interrupts */
        m360.cimr |= 1UL << 4;  /* Enable SMC1 interrupts */
        }

        return 0;
}

static int
smc1PollRead (int minor)
{
        unsigned char c;

        if (smcRxBd->status & M360_BD_EMPTY)
                return -1;
        c = rxBuf[0];
        smcRxBd->status = M360_BD_EMPTY | M360_BD_WRAP;
        return c;
}

/*
 * Device-dependent write routine
 * Interrupt-driven devices:
 *      Begin transmission of as many characters as possible (minimum is 1).
 * Polling devices:
 *      Transmit all characters.
 */
static int
smc1InterruptWrite (int minor, const char *buf, int len)
{
        smcTxBd->buffer = (char *)buf;
        smcTxBd->length = len;
        smcTxBd->status = M360_BD_READY | M360_BD_WRAP | M360_BD_INTERRUPT;
        return 0;
}

static int
smc1PollWrite (int minor, const char *buf, int len)
{
        while (len--) {
                static char txBuf;
                while (smcTxBd->status & M360_BD_READY)
                        continue;
                txBuf = *buf++;
                smcTxBd->buffer = &txBuf;
                smcTxBd->length = 1;
                smcTxBd->status = M360_BD_READY | M360_BD_WRAP;
        }
        return 0;
}

/*
 ***************
 * BOILERPLATE *
 ***************
 */

/*
 * Reserve resources consumed by this driver
 *
 * NOTE: This is in another file to reduce dependencies on the minimum size.
 */

/*
 * Initialize and register the device
 */
rtems_device_driver console_initialize(
  rtems_device_major_number  major,
  rtems_device_minor_number  minor,
  void                      *arg
)
{
        rtems_status_code status;

        /*
         * Set up TERMIOS
         */
        rtems_termios_initialize ();

        /*
         * Register the device
         */
        status = rtems_io_register_name ("/dev/console", major, 0);
        if (status != RTEMS_SUCCESSFUL)
                rtems_fatal_error_occurred (status);
        return RTEMS_SUCCESSFUL;
}

/*
 * Open the device
 */
rtems_device_driver console_open(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void                    * arg
)
{
        rtems_status_code sc;
        static const rtems_termios_callbacks intrCallbacks = {
                smc1Initialize,         /* firstOpen */
                NULL,                   /* lastClose */
                NULL,                   /* pollRead */
                smc1InterruptWrite,     /* write */
                smc1SetAttributes,      /* setAttributes */
                NULL,                   /* stopRemoteTx */
                NULL,                   /* startRemoteTx */
                1                       /* outputUsesInterrupts */
        };
        static const rtems_termios_callbacks pollCallbacks = {
                smc1Initialize,         /* firstOpen */
                NULL,                   /* lastClose */
                smc1PollRead,           /* pollRead */
                smc1PollWrite,          /* write */
                smc1SetAttributes,      /* setAttributes */
                NULL,                   /* stopRemoteTx */
                NULL,                   /* startRemoteTx */
                0                       /* outputUsesInterrupts */
        };

        /*
         * Do generic termios initialization
         */
        if (m360_smc1_interrupt) {
                rtems_libio_open_close_args_t *args = arg;

                sc = rtems_termios_open (major, minor, arg, &intrCallbacks);
                smc1ttyp = args->iop->data1;
        }
        else {
                sc = rtems_termios_open (major, minor, arg, &pollCallbacks);
        }
        return sc;
}
 
/*
 * Close the device
 */
rtems_device_driver console_close(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void                    * arg
)
{
        return rtems_termios_close (arg);
}

/*
 * Read from the device
 */
rtems_device_driver console_read(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void                    * arg
)
{
        return rtems_termios_read (arg);
}

/*
 * Write to the device
 */
rtems_device_driver console_write(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void                    * arg
)
{
        return rtems_termios_write (arg);
}

/*
 * Handle ioctl request.
 */
rtems_device_driver console_control(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void                    * arg
)
{ 
        return rtems_termios_ioctl (arg);
}