specialix.c

讲述linux的初始化过程

		printk(KERN_INFO "sx%d: specialix IO8+ Board at 0x%03x not found.\n",
		       board_No(bp), bp->base);
		return 1;
	}

	/* Check the DSR lines that Specialix uses as board 
	   identification */
	val1 = read_cross_byte (bp, CD186x_MSVR, MSVR_DSR);
	val2 = read_cross_byte (bp, CD186x_MSVR, MSVR_RTS);
#ifdef SPECIALIX_DEBUG
	printk (KERN_DEBUG "sx%d: DSR lines are: %02x, rts lines are: %02x\n", 
	        board_No(bp),  val1, val2);
#endif
	/* They managed to switch the bit order between the docs and
	   the IO8+ card. The new PCI card now conforms to old docs.
	   They changed the PCI docs to reflect the situation on the
	   old card. */
	val2 = (bp->flags & SX_BOARD_IS_PCI)?0x4d : 0xb2;
	if (val1 != val2) {
		printk(KERN_INFO "sx%d: specialix IO8+ ID %02x at 0x%03x not found (%02x).\n",
		       board_No(bp), val2, bp->base, val1);
		return 1;
	}


#if 0
	/* It's time to find IRQ for this board */
	for (retries = 0; retries < 5 && irqs <= 0; retries++) {
		irqs = probe_irq_on();
		sx_init_CD186x(bp);	       		/* Reset CD186x chip       */
		sx_out(bp, CD186x_CAR, 2);               /* Select port 2          */
		sx_wait_CCR(bp);
		sx_out(bp, CD186x_CCR, CCR_TXEN);        /* Enable transmitter     */
		sx_out(bp, CD186x_IER, IER_TXRDY);       /* Enable tx empty intr   */
		sx_long_delay(HZ/20);	       		
		irqs = probe_irq_off(irqs);

#if SPECIALIX_DEBUG > 2
		printk (KERN_DEBUG "SRSR = %02x, ",  sx_in(bp, CD186x_SRSR));
		printk (           "TRAR = %02x, ",  sx_in(bp, CD186x_TRAR));
		printk (           "GIVR = %02x, ",  sx_in(bp, CD186x_GIVR));
		printk (           "GICR = %02x, ",  sx_in(bp, CD186x_GICR));
		printk (           "\n");
#endif
		/* Reset CD186x again      */
		if (!sx_init_CD186x(bp)) {
			/* Hmmm. This is dead code anyway. */
		}
#if SPECIALIX_DEBUG > 2
		printk (KERN_DEBUG "val1 = %02x, val2 = %02x, val3 = %02x.\n", 
		        val1, val2, val3); 
#endif
	
	}
	
#if 0
	if (irqs <= 0) {
		printk(KERN_ERR "sx%d: Can't find IRQ for specialix IO8+ board at 0x%03x.\n",
		       board_No(bp), bp->base);
		return 1;
	}
#endif
	printk (KERN_INFO "Started with irq=%d, but now have irq=%d.\n", bp->irq, irqs);
	if (irqs > 0)
		bp->irq = irqs;
#endif
	/* Reset CD186x again  */
	if (!sx_init_CD186x(bp)) {
		return -EIO;
	}

	sx_request_io_range(bp);
	bp->flags |= SX_BOARD_PRESENT;
	
	/* Chip           revcode   pkgtype
	                  GFRCR     SRCR bit 7
	   CD180 rev B    0x81      0
	   CD180 rev C    0x82      0
	   CD1864 rev A   0x82      1
	   CD1865 rev A   0x83      1  -- Do not use!!! Does not work. 
	   CD1865 rev B   0x84      1
	 -- Thanks to Gwen Wang, Cirrus Logic.
	 */

	switch (sx_in_off(bp, CD186x_GFRCR)) {
	case 0x82:chip = 1864;rev='A';break;
	case 0x83:chip = 1865;rev='A';break;
	case 0x84:chip = 1865;rev='B';break;
	case 0x85:chip = 1865;rev='C';break; /* Does not exist at this time */
	default:chip=-1;rev='x';
	}

#if SPECIALIX_DEBUG > 2
	printk (KERN_DEBUG " GFCR = 0x%02x\n", sx_in_off(bp, CD186x_GFRCR) );
#endif

#ifdef SPECIALIX_TIMER
	init_timer (&missed_irq_timer);
	missed_irq_timer.function = missed_irq;
	missed_irq_timer.data = (unsigned long) bp;
	missed_irq_timer.expires = jiffies + HZ;
	add_timer (&missed_irq_timer);
#endif

	printk(KERN_INFO"sx%d: specialix IO8+ board detected at 0x%03x, IRQ %d, CD%d Rev. %c.\n",
	       board_No(bp),
	       bp->base, bp->irq,
	       chip, rev);

	return 0;
}

/* 
 * 
 *  Interrupt processing routines.
 * */

extern inline void sx_mark_event(struct specialix_port * port, int event)
{
	/* 
	 * I'm not quite happy with current scheme all serial
	 * drivers use their own BH routine.
	 * It seems this easily can be done with one BH routine
	 * serving for all serial drivers.
	 * For now I must introduce another one - SPECIALIX_BH.
	 * Still hope this will be changed in near future.
	 * -- Dmitry.
	 */
	set_bit(event, &port->event);
	queue_task(&port->tqueue, &tq_specialix);
	mark_bh(SPECIALIX_BH);
}


extern inline struct specialix_port * sx_get_port(struct specialix_board * bp,
					       unsigned char const * what)
{
	unsigned char channel;
	struct specialix_port * port;
	
	channel = sx_in(bp, CD186x_GICR) >> GICR_CHAN_OFF;
	if (channel < CD186x_NCH) {
		port = &sx_port[board_No(bp) * SX_NPORT + channel];
		if (port->flags & ASYNC_INITIALIZED) {
			return port;
		}
	}
	printk(KERN_INFO "sx%d: %s interrupt from invalid port %d\n", 
	       board_No(bp), what, channel);
	return NULL;
}


extern inline void sx_receive_exc(struct specialix_board * bp)
{
	struct specialix_port *port;
	struct tty_struct *tty;
	unsigned char status;
	unsigned char ch;

	if (!(port = sx_get_port(bp, "Receive")))
		return;

	tty = port->tty;
	if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
		printk(KERN_INFO "sx%d: port %d: Working around flip buffer overflow.\n",
		       board_No(bp), port_No(port));
		return;
	}
	
#ifdef SX_REPORT_OVERRUN	
	status = sx_in(bp, CD186x_RCSR);
	if (status & RCSR_OE) {
		port->overrun++;
#if SPECIALIX_DEBUG 
		printk(KERN_DEBUG "sx%d: port %d: Overrun. Total %ld overruns.\n", 
		       board_No(bp), port_No(port), port->overrun);
#endif		
	}
	status &= port->mark_mask;
#else	
	status = sx_in(bp, CD186x_RCSR) & port->mark_mask;
#endif	
	ch = sx_in(bp, CD186x_RDR);
	if (!status) {
		return;
	}
	if (status & RCSR_TOUT) {
		printk(KERN_INFO "sx%d: port %d: Receiver timeout. Hardware problems ?\n", 
		       board_No(bp), port_No(port));
		return;
		
	} else if (status & RCSR_BREAK) {
#ifdef SPECIALIX_DEBUG
		printk(KERN_DEBUG "sx%d: port %d: Handling break...\n",
		       board_No(bp), port_No(port));
#endif
		*tty->flip.flag_buf_ptr++ = TTY_BREAK;
		if (port->flags & ASYNC_SAK)
			do_SAK(tty);
		
	} else if (status & RCSR_PE) 
		*tty->flip.flag_buf_ptr++ = TTY_PARITY;
	
	else if (status & RCSR_FE) 
		*tty->flip.flag_buf_ptr++ = TTY_FRAME;
	
	else if (status & RCSR_OE)
		*tty->flip.flag_buf_ptr++ = TTY_OVERRUN;
	
	else
		*tty->flip.flag_buf_ptr++ = 0;
	
	*tty->flip.char_buf_ptr++ = ch;
	tty->flip.count++;
	queue_task(&tty->flip.tqueue, &tq_timer);
}


extern inline void sx_receive(struct specialix_board * bp)
{
	struct specialix_port *port;
	struct tty_struct *tty;
	unsigned char count;
	
	if (!(port = sx_get_port(bp, "Receive")))
		return;
	
	tty = port->tty;
	
	count = sx_in(bp, CD186x_RDCR);
	
#ifdef SX_REPORT_FIFO
	port->hits[count > 8 ? 9 : count]++;
#endif	
	
	while (count--) {
		if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
			printk(KERN_INFO "sx%d: port %d: Working around flip buffer overflow.\n",
			       board_No(bp), port_No(port));
			break;
		}
		*tty->flip.char_buf_ptr++ = sx_in(bp, CD186x_RDR);
		*tty->flip.flag_buf_ptr++ = 0;
		tty->flip.count++;
	}
	queue_task(&tty->flip.tqueue, &tq_timer);
}


extern inline void sx_transmit(struct specialix_board * bp)
{
	struct specialix_port *port;
	struct tty_struct *tty;
	unsigned char count;
	
	
	if (!(port = sx_get_port(bp, "Transmit")))
		return;
	
	tty = port->tty;
	
	if (port->IER & IER_TXEMPTY) {
		/* FIFO drained */
		sx_out(bp, CD186x_CAR, port_No(port));
		port->IER &= ~IER_TXEMPTY;
		sx_out(bp, CD186x_IER, port->IER);
		return;
	}
	
	if ((port->xmit_cnt <= 0 && !port->break_length)
	    || tty->stopped || tty->hw_stopped) {
		sx_out(bp, CD186x_CAR, port_No(port));
		port->IER &= ~IER_TXRDY;
		sx_out(bp, CD186x_IER, port->IER);
		return;
	}
	
	if (port->break_length) {
		if (port->break_length > 0) {
			if (port->COR2 & COR2_ETC) {
				sx_out(bp, CD186x_TDR, CD186x_C_ESC);
				sx_out(bp, CD186x_TDR, CD186x_C_SBRK);
				port->COR2 &= ~COR2_ETC;
			}
			count = MIN(port->break_length, 0xff);
			sx_out(bp, CD186x_TDR, CD186x_C_ESC);
			sx_out(bp, CD186x_TDR, CD186x_C_DELAY);
			sx_out(bp, CD186x_TDR, count);
			if (!(port->break_length -= count))
				port->break_length--;
		} else {
			sx_out(bp, CD186x_TDR, CD186x_C_ESC);
			sx_out(bp, CD186x_TDR, CD186x_C_EBRK);
			sx_out(bp, CD186x_COR2, port->COR2);
			sx_wait_CCR(bp);
			sx_out(bp, CD186x_CCR, CCR_CORCHG2);
			port->break_length = 0;
		}
		return;
	}
	
	count = CD186x_NFIFO;
	do {
		sx_out(bp, CD186x_TDR, port->xmit_buf[port->xmit_tail++]);
		port->xmit_tail = port->xmit_tail & (SERIAL_XMIT_SIZE-1);
		if (--port->xmit_cnt <= 0)
			break;
	} while (--count > 0);
	
	if (port->xmit_cnt <= 0) {
		sx_out(bp, CD186x_CAR, port_No(port));
		port->IER &= ~IER_TXRDY;
		sx_out(bp, CD186x_IER, port->IER);
	}
	if (port->xmit_cnt <= port->wakeup_chars)
		sx_mark_event(port, RS_EVENT_WRITE_WAKEUP);
}


extern inline void sx_check_modem(struct specialix_board * bp)
{
	struct specialix_port *port;
	struct tty_struct *tty;
	unsigned char mcr;

#ifdef SPECIALIX_DEBUG
	printk (KERN_DEBUG "Modem intr. ");
#endif
	if (!(port = sx_get_port(bp, "Modem")))
		return;
	
	tty = port->tty;
	
	mcr = sx_in(bp, CD186x_MCR);
	printk ("mcr = %02x.\n", mcr);

	if ((mcr & MCR_CDCHG)) {
#ifdef SPECIALIX_DEBUG 
		printk (KERN_DEBUG "CD just changed... ");
#endif
		if (sx_in(bp, CD186x_MSVR) & MSVR_CD) {
#ifdef SPECIALIX_DEBUG
			printk ( "Waking up guys in open.\n");
#endif
			wake_up_interruptible(&port->open_wait);
		}
		else if (!((port->flags & ASYNC_CALLOUT_ACTIVE) &&
		           (port->flags & ASYNC_CALLOUT_NOHUP))) {
#ifdef SPECIALIX_DEBUG
			printk ( "Sending HUP.\n");
#endif
			MOD_INC_USE_COUNT;
			if (schedule_task(&port->tqueue_hangup) == 0)
				MOD_DEC_USE_COUNT;
		} else {
#ifdef SPECIALIX_DEBUG
			printk ( "Don't need to send HUP.\n");
#endif
		}
	}
	
#ifdef SPECIALIX_BRAIN_DAMAGED_CTS
	if (mcr & MCR_CTSCHG) {
		if (sx_in(bp, CD186x_MSVR) & MSVR_CTS) {
			tty->hw_stopped = 0;
			port->IER |= IER_TXRDY;
			if (port->xmit_cnt <= port->wakeup_chars)
				sx_mark_event(port, RS_EVENT_WRITE_WAKEUP);
		} else {
			tty->hw_stopped = 1;
			port->IER &= ~IER_TXRDY;
		}
		sx_out(bp, CD186x_IER, port->IER);
	}
	if (mcr & MCR_DSSXHG) {
		if (sx_in(bp, CD186x_MSVR) & MSVR_DSR) {
			tty->hw_stopped = 0;
			port->IER |= IER_TXRDY;
			if (port->xmit_cnt <= port->wakeup_chars)
				sx_mark_event(port, RS_EVENT_WRITE_WAKEUP);
		} else {
			tty->hw_stopped = 1;
			port->IER &= ~IER_TXRDY;
		}
		sx_out(bp, CD186x_IER, port->IER);
	}
#endif /* SPECIALIX_BRAIN_DAMAGED_CTS */
	
	/* Clear change bits */
	sx_out(bp, CD186x_MCR, 0);
}


/* The main interrupt processing routine */
static void sx_interrupt(int irq, void * dev_id, struct pt_regs * regs)
{
	unsigned char status;
	unsigned char ack;
	struct specialix_board *bp;
	unsigned long loop = 0;
	int saved_reg;

	bp = dev_id;
	
	if (!bp || !(bp->flags & SX_BOARD_ACTIVE)) {
#ifdef SPECIALIX_DEBUG 
		printk (KERN_DEBUG "sx: False interrupt. irq %d.\n", irq);
#endif
		return;
	}

	saved_reg = bp->reg;

	while ((++loop < 16) && (status = (sx_in(bp, CD186x_SRSR) &
	                                   (SRSR_RREQint |
		                            SRSR_TREQint |
	                                    SRSR_MREQint)))) {	
		if (status & SRSR_RREQint) {
			ack = sx_in(bp, CD186x_RRAR);

			if (ack == (SX_ID | GIVR_IT_RCV))
				sx_receive(bp);
			else if (ack == (SX_ID | GIVR_IT_REXC))
				sx_receive_exc(bp);
			else
				printk(KERN_ERR "sx%d: Bad receive ack 0x%02x.\n",
				       board_No(bp), ack);
		
		} else if (status & SRSR_TREQint) {
			ack = sx_in(bp, CD186x_TRAR);

			if (ack == (SX_ID | GIVR_IT_TX))
				sx_transmit(bp);
			else
				printk(KERN_ERR "sx%d: Bad transmit ack 0x%02x.\n",
				       board_No(bp), ack);
		} else if (status & SRSR_MREQint) {
			ack = sx_in(bp, CD186x_MRAR);

			if (ack == (SX_ID | GIVR_IT_MODEM)) 
				sx_check_modem(bp);
			else
				printk(KERN_ERR "sx%d: Bad modem ack 0x%02x.\n",
				       board_No(bp), ack);
		
		} 

		sx_out(bp, CD186x_EOIR, 0);   /* Mark end of interrupt */
	}
	bp->reg = saved_reg;
	outb (bp->reg, bp->base + SX_ADDR_REG);
}


/*
 *  Routines for open & close processing.
 */

void turn_ints_off (struct specialix_board *bp)
{
	if (bp->flags & SX_BOARD_IS_PCI) {
		/* This was intended for enabeling the interrupt on the
		 * PCI card. However it seems that it's already enabled
		 * and as PCI interrupts can be shared, there is no real
		 * reason to have to turn it off. */
	}
	(void) sx_in_off (bp, 0); /* Turn off interrupts. */
}

void turn_ints_on (struct specialix_board *bp)
{
	if (bp->flags & SX_BOARD_IS_PCI) {
		/* play with the PCI chip. See comment above. */
	}
	(void) sx_in (bp, 0); /* Turn ON interrupts. */
}


/* Called with disabled interrupts */
extern inline int sx_setup_board(struct specialix_board * bp)
{
	int error;