cyclades.c

这是一个SIGMA方案的PMP播放器的UCLINUX程序,可播放DVD,VCD,CD MP3...有很好的参考价值.

    /* Check to see that the previous command has completed */
    for(i = 0 ; i < 100 ; i++){
	if (cy_readb(base_addr+(CyCCR<<index)) == 0){
	    break;
	}
	udelay(10L);
    }
    /* if the CCR never cleared, the previous command
       didn't finish within the "reasonable time" */
    if (i == 100)	return (-1);

    /* Issue the new command */
    cy_writeb((u_long)base_addr+(CyCCR<<index), cmd);

    return(0);
} /* cyy_issue_cmd */

#ifdef CONFIG_ISA
/* ISA interrupt detection code */
static unsigned 
detect_isa_irq (volatile ucchar *address)
{
  int irq;
  unsigned long irqs, flags;
  int save_xir, save_car;
  int index = 0; /* IRQ probing is only for ISA */

    /* forget possible initially masked and pending IRQ */
    irq = probe_irq_off(probe_irq_on());

    /* Clear interrupts on the board first */
    cy_writeb((u_long)address + (Cy_ClrIntr<<index), 0);
			      /* Cy_ClrIntr is 0x1800 */

    irqs = probe_irq_on();
    /* Wait ... */
    udelay(5000L);

    /* Enable the Tx interrupts on the CD1400 */
    save_flags(flags); cli();
	cy_writeb((u_long)address + (CyCAR<<index), 0);
	cyy_issue_cmd(address, CyCHAN_CTL|CyENB_XMTR, index);

	cy_writeb((u_long)address + (CyCAR<<index), 0);
	cy_writeb((u_long)address + (CySRER<<index), 
		cy_readb(address + (CySRER<<index)) | CyTxRdy);
    restore_flags(flags);

    /* Wait ... */
    udelay(5000L);

    /* Check which interrupt is in use */
    irq = probe_irq_off(irqs);

    /* Clean up */
    save_xir = (u_char) cy_readb(address + (CyTIR<<index));
    save_car = cy_readb(address + (CyCAR<<index));
    cy_writeb((u_long)address + (CyCAR<<index), (save_xir & 0x3));
    cy_writeb((u_long)address + (CySRER<<index),
	cy_readb(address + (CySRER<<index)) & ~CyTxRdy);
    cy_writeb((u_long)address + (CyTIR<<index), (save_xir & 0x3f));
    cy_writeb((u_long)address + (CyCAR<<index), (save_car));
    cy_writeb((u_long)address + (Cy_ClrIntr<<index), 0);
			      /* Cy_ClrIntr is 0x1800 */

    return (irq > 0)? irq : 0;
}
#endif /* CONFIG_ISA */

/* The real interrupt service routine is called
   whenever the card wants its hand held--chars
   received, out buffer empty, modem change, etc.
 */
static void
cyy_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
  struct tty_struct *tty;
  int status;
  struct cyclades_card *cinfo;
  struct cyclades_port *info;
  volatile unsigned char *base_addr, *card_base_addr;
  int chip;
  int save_xir, channel, save_car;
  char data;
  volatile int char_count;
  int outch;
  int i,j,index;
  int too_many;
  int had_work;
  int mdm_change;
  int mdm_status;

    if((cinfo = (struct cyclades_card *)dev_id) == 0){
#ifdef CY_DEBUG_INTERRUPTS
	printk("cyy_interrupt: spurious interrupt %d\n\r", irq);
#endif
        return; /* spurious interrupt */
    }

    card_base_addr = (unsigned char *)cinfo->base_addr;
    index = cinfo->bus_index;


    /* This loop checks all chips in the card.  Make a note whenever
       _any_ chip had some work to do, as this is considered an
       indication that there will be more to do.  Only when no chip
       has any work does this outermost loop exit.
     */
    do{
        had_work = 0;
        for ( chip = 0 ; chip < cinfo->num_chips ; chip ++) {
            base_addr = (unsigned char *)
		       (cinfo->base_addr + (cy_chip_offset[chip]<<index));
            too_many = 0;
            while ( (status = cy_readb(base_addr+(CySVRR<<index))) != 0x00) {
                had_work++;
                /* The purpose of the following test is to ensure that
                   no chip can monopolize the driver.  This forces the
                   chips to be checked in a round-robin fashion (after
                   draining each of a bunch (1000) of characters).
                 */
                if(1000<too_many++){
                    break;
                }
                if (status & CySRReceive) { /* reception interrupt */
#ifdef CY_DEBUG_INTERRUPTS
		    printk("cyy_interrupt: rcvd intr, chip %d\n\r", chip);
#endif
                    /* determine the channel & change to that context */
		    spin_lock(&cinfo->card_lock);
                    save_xir = (u_char) cy_readb(base_addr+(CyRIR<<index));
                    channel = (u_short ) (save_xir & CyIRChannel);
                    i = channel + chip * 4 + cinfo->first_line;
                    info = &cy_port[i];
                    info->last_active = jiffies;
                    save_car = cy_readb(base_addr+(CyCAR<<index));
                    cy_writeb((u_long)base_addr+(CyCAR<<index), save_xir);

                    /* if there is nowhere to put the data, discard it */
                    if(info->tty == 0){
                        j = (cy_readb(base_addr+(CyRIVR<<index)) & CyIVRMask);
                        if ( j == CyIVRRxEx ) { /* exception */
                            data = cy_readb(base_addr+(CyRDSR<<index));
                        } else { /* normal character reception */
                            char_count = cy_readb(base_addr+(CyRDCR<<index));
                            while(char_count--){
                                data = cy_readb(base_addr+(CyRDSR<<index));
                            }
                        }
                    }else{ /* there is an open port for this data */
                        tty = info->tty;
                        j = (cy_readb(base_addr+(CyRIVR<<index)) & CyIVRMask);
                        if ( j == CyIVRRxEx ) { /* exception */
                            data = cy_readb(base_addr+(CyRDSR<<index));

			    /* For statistics only */
			    if (data & CyBREAK)
				info->icount.brk++;
			    else if(data & CyFRAME)
				info->icount.frame++;
			    else if(data & CyPARITY)
				info->icount.parity++;
			    else if(data & CyOVERRUN)
				info->icount.overrun++;

                            if(data & info->ignore_status_mask){
				info->icount.rx++;
                                continue;
                            }
                            if (tty->flip.count < TTY_FLIPBUF_SIZE){
                                tty->flip.count++;
                                if (data & info->read_status_mask){
                                    if(data & CyBREAK){
                                        *tty->flip.flag_buf_ptr++ =
	    						    TTY_BREAK;
                                        *tty->flip.char_buf_ptr++ =
					  cy_readb(base_addr+(CyRDSR<<index));
					info->icount.rx++;
                                        if (info->flags & ASYNC_SAK){
                                            do_SAK(tty);
                                        }
                                    }else if(data & CyFRAME){
                                        *tty->flip.flag_buf_ptr++ =
							    TTY_FRAME;
                                        *tty->flip.char_buf_ptr++ =
					  cy_readb(base_addr+(CyRDSR<<index));
					info->icount.rx++;
					info->idle_stats.frame_errs++;
                                    }else if(data & CyPARITY){
                                        *tty->flip.flag_buf_ptr++ =
							    TTY_PARITY;
                                        *tty->flip.char_buf_ptr++ =
					  cy_readb(base_addr+(CyRDSR<<index));
					info->icount.rx++;
					info->idle_stats.parity_errs++;
                                    }else if(data & CyOVERRUN){
                                        *tty->flip.flag_buf_ptr++ =
							    TTY_OVERRUN;
                                        *tty->flip.char_buf_ptr++ = 0;
					info->icount.rx++;
                                        /* If the flip buffer itself is
                                           overflowing, we still lose
                                           the next incoming character.
                                         */
                                        if(tty->flip.count
					           < TTY_FLIPBUF_SIZE){
                                            tty->flip.count++;
                                            *tty->flip.flag_buf_ptr++ =
							     TTY_NORMAL;
                                           *tty->flip.char_buf_ptr++ =
					    cy_readb(base_addr+(CyRDSR<<index));
					    info->icount.rx++;
                                        }
					info->idle_stats.overruns++;
                                    /* These two conditions may imply */
                                    /* a normal read should be done. */
                                    /* }else if(data & CyTIMEOUT){ */
                                    /* }else if(data & CySPECHAR){ */
                                    }else{
                                        *tty->flip.flag_buf_ptr++ = 0;
                                        *tty->flip.char_buf_ptr++ = 0;
					info->icount.rx++;
                                    }
                                }else{
                                    *tty->flip.flag_buf_ptr++ = 0;
                                    *tty->flip.char_buf_ptr++ = 0;
				    info->icount.rx++;
                                }
                            }else{
                                /* there was a software buffer
				   overrun and nothing could be
				   done about it!!! */
				info->icount.buf_overrun++;
				info->idle_stats.overruns++;
                            }
                        } else { /* normal character reception */
                            /* load # chars available from the chip */
                            char_count = cy_readb(base_addr+(CyRDCR<<index));

#ifdef CY_ENABLE_MONITORING
                            ++info->mon.int_count;
                            info->mon.char_count += char_count;
                            if (char_count > info->mon.char_max)
                               info->mon.char_max = char_count;
                            info->mon.char_last = char_count;
#endif
			    info->idle_stats.recv_bytes += char_count;
			    info->idle_stats.recv_idle   = jiffies;
                            while(char_count--){
                                if (tty->flip.count >= TTY_FLIPBUF_SIZE){
                                        break;
                                }
                                tty->flip.count++;
                                data = cy_readb(base_addr+(CyRDSR<<index));
                                *tty->flip.flag_buf_ptr++ = TTY_NORMAL;
                                *tty->flip.char_buf_ptr++ = data;
				info->icount.rx++;
#ifdef CY_16Y_HACK
                                udelay(10L);
#endif
                            }
                        }
                        queue_task(&tty->flip.tqueue, &tq_timer);
                    }
                    /* end of service */
                    cy_writeb((u_long)base_addr+(CyRIR<<index), (save_xir & 0x3f));
                    cy_writeb((u_long)base_addr+(CyCAR<<index), (save_car));
		    spin_unlock(&cinfo->card_lock);
                }


                if (status & CySRTransmit) { /* transmission interrupt */
                    /* Since we only get here when the transmit buffer
                       is empty, we know we can always stuff a dozen
                       characters. */
#ifdef CY_DEBUG_INTERRUPTS
		    printk("cyy_interrupt: xmit intr, chip %d\n\r", chip);
#endif

                    /* determine the channel & change to that context */
		    spin_lock(&cinfo->card_lock);
                    save_xir = (u_char) cy_readb(base_addr+(CyTIR<<index));
                    channel = (u_short ) (save_xir & CyIRChannel);
                    i = channel + chip * 4 + cinfo->first_line;
                    save_car = cy_readb(base_addr+(CyCAR<<index));
                    cy_writeb((u_long)base_addr+(CyCAR<<index), save_xir);

                    /* validate the port# (as configured and open) */
                    if( (i < 0) || (NR_PORTS <= i) ){
                        cy_writeb((u_long)base_addr+(CySRER<<index),
                             cy_readb(base_addr+(CySRER<<index)) & ~CyTxRdy);
                        goto txend;
                    }
                    info = &cy_port[i];
                    info->last_active = jiffies;
                    if(info->tty == 0){
                        cy_writeb((u_long)base_addr+(CySRER<<index),
                             cy_readb(base_addr+(CySRER<<index)) & ~CyTxRdy);
                        goto txdone;
                    }

                    /* load the on-chip space for outbound data */
                    char_count = info->xmit_fifo_size;

                    if(info->x_char) { /* send special char */
                        outch = info->x_char;
                        cy_writeb((u_long)base_addr+(CyTDR<<index), outch);
                        char_count--;
			info->icount.tx++;
                        info->x_char = 0;
                    }

                    if (info->breakon || info->breakoff) {
			if (info->breakon) {
			    cy_writeb((u_long)base_addr + (CyTDR<<index), 0); 
			    cy_writeb((u_long)base_addr + (CyTDR<<index), 0x81);
			    info->breakon = 0;
                            char_count -= 2;
			}
			if (info->breakoff) {
			    cy_writeb((u_long)base_addr + (CyTDR<<index), 0); 
			    cy_writeb((u_long)base_addr + (CyTDR<<index), 0x83);
			    info->breakoff = 0;
                            char_count -= 2;
			}
                    }

                    while (char_count-- > 0){
			if (!info->xmit_cnt){
			    if (cy_readb(base_addr+(CySRER<<index))&CyTxMpty) {
				cy_writeb((u_long)base_addr+(CySRER<<index),
					  cy_readb(base_addr+(CySRER<<index)) &
					  ~CyTxMpty);
			    } else {
				cy_writeb((u_long)base_addr+(CySRER<<index),
					  ((cy_readb(base_addr+(CySRER<<index))
					    & ~CyTxRdy)
					   | CyTxMpty));
			    }
			    goto txdone;
			}
			if (info->xmit_buf == 0){
                            cy_writeb((u_long)base_addr+(CySRER<<index),