serial.c

arm平台上的uclinux系统全部源代码

		info->hub6 = new_serial.hub6;
	}
	if(info->type != PORT_UNKNOWN)
		request_region(info->port,8,"serial(set)");

	
check_and_exit:
	if (!info->port || !info->type)
		return 0;
	if (info->flags & ASYNC_INITIALIZED) {
		if (((old_info.flags & ASYNC_SPD_MASK) !=
		     (info->flags & ASYNC_SPD_MASK)) ||
		    (old_info.custom_divisor != info->custom_divisor))
			change_speed(info);
	} else
		retval = startup(info);
	return retval;
}


/*
 * get_lsr_info - get line status register info
 *
 * Purpose: Let user call ioctl() to get info when the UART physically
 * 	    is emptied.  On bus types like RS485, the transmitter must
 * 	    release the bus after transmitting. This must be done when
 * 	    the transmit shift register is empty, not be done when the
 * 	    transmit holding register is empty.  This functionality
 * 	    allows an RS485 driver to be written in user space. 
 */
static int get_lsr_info(struct async_struct * info, unsigned int *value)
{
	unsigned char status;
	unsigned int result;

	cli();
	status = serial_in(info, UART_LSR);
	sti();
	result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
	put_user(result,value);
	return 0;
}


static int get_modem_info(struct async_struct * info, unsigned int *value)
{
	unsigned char control, status;
	unsigned int result;

	control = info->MCR;
	cli();
	status = serial_in(info, UART_MSR);
	sti();
	result =  ((control & UART_MCR_RTS) ? TIOCM_RTS : 0)
		| ((control & UART_MCR_DTR) ? TIOCM_DTR : 0)
		| ((status  & UART_MSR_DCD) ? TIOCM_CAR : 0)
		| ((status  & UART_MSR_RI) ? TIOCM_RNG : 0)
		| ((status  & UART_MSR_DSR) ? TIOCM_DSR : 0)
		| ((status  & UART_MSR_CTS) ? TIOCM_CTS : 0);
	put_user(result,value);
	return 0;
}

static int set_modem_info(struct async_struct * info, unsigned int cmd,
			  unsigned int *value)
{
	int error;
	unsigned int arg;

	error = verify_area(VERIFY_READ, value, sizeof(int));
	if (error)
		return error;
	arg = get_user(value);
	switch (cmd) {
	case TIOCMBIS: 
		if (arg & TIOCM_RTS) {
			info->MCR |= UART_MCR_RTS;
			info->MCR_noint |= UART_MCR_RTS;
		}
		if (arg & TIOCM_DTR) {
			info->MCR |= UART_MCR_DTR;
			info->MCR_noint |= UART_MCR_DTR;
		}
		break;
	case TIOCMBIC:
		if (arg & TIOCM_RTS) {
			info->MCR &= ~UART_MCR_RTS;
			info->MCR_noint &= ~UART_MCR_RTS;
		}
		if (arg & TIOCM_DTR) {
			info->MCR &= ~UART_MCR_DTR;
			info->MCR_noint &= ~UART_MCR_DTR;
		}
		break;
	case TIOCMSET:
		info->MCR = ((info->MCR & ~(UART_MCR_RTS | UART_MCR_DTR))
			     | ((arg & TIOCM_RTS) ? UART_MCR_RTS : 0)
			     | ((arg & TIOCM_DTR) ? UART_MCR_DTR : 0));
		info->MCR_noint = ((info->MCR_noint
				    & ~(UART_MCR_RTS | UART_MCR_DTR))
				   | ((arg & TIOCM_RTS) ? UART_MCR_RTS : 0)
				   | ((arg & TIOCM_DTR) ? UART_MCR_DTR : 0));
		break;
	default:
		return -EINVAL;
	}
	cli();
	serial_out(info, UART_MCR, info->MCR);
	sti();
	return 0;
}

static int do_autoconfig(struct async_struct * info)
{
	int			retval;
	
	if (!suser())
		return -EPERM;
	
	if (info->count > 1)
		return -EBUSY;
	
	shutdown(info);

	cli();
	autoconfig(info);
	sti();

	retval = startup(info);
	if (retval)
		return retval;
	return 0;
}


/*
 * This routine sends a break character out the serial port.
 */
static void send_break(	struct async_struct * info, int duration)
{
	if (!info->port)
		return;
	current->state = TASK_INTERRUPTIBLE;
	current->timeout = jiffies + duration;
	cli();
	serial_out(info, UART_LCR, serial_inp(info, UART_LCR) | UART_LCR_SBC);
	schedule();
	serial_out(info, UART_LCR, serial_inp(info, UART_LCR) & ~UART_LCR_SBC);
	sti();
}

/*
 * This routine returns a bitfield of "wild interrupts".  Basically,
 * any unclaimed interrupts which is flapping around.
 */
static int check_wild_interrupts(int doprint)
{
	int	i, mask;
	int	wild_interrupts = 0;
	int	irq_lines;
	unsigned long timeout;
	unsigned long flags;
	
	/* Turn on interrupts (they may be off) */
	save_flags(flags); sti();

	irq_lines = grab_all_interrupts(0);
	
	/*
	 * Delay for 0.1 seconds -- we use a busy loop since this may 
	 * occur during the bootup sequence
	 */
	timeout = jiffies+HZ/10;
	while (timeout >= jiffies)
		;
	
	rs_triggered = 0;	/* Reset after letting things settle */

	timeout = jiffies+HZ/10;
	while (timeout >= jiffies)
		;
	
	for (i = 0, mask = 1; i < 16; i++, mask <<= 1) {
		if ((rs_triggered & (1 << i)) &&
		    (irq_lines & (1 << i))) {
			wild_interrupts |= mask;
			if (doprint)
				printk("Wild interrupt?  (IRQ %d)\n", i);
		}
	}
	free_all_interrupts(irq_lines);
	restore_flags(flags);
	return wild_interrupts;
}

static int get_multiport_struct(struct async_struct * info,
				struct serial_multiport_struct *retinfo)
{
	struct serial_multiport_struct ret;
	struct rs_multiport_struct *multi;
	
	multi = &rs_multiport[info->irq];

	ret.port_monitor = multi->port_monitor;
	
	ret.port1 = multi->port1;
	ret.mask1 = multi->mask1;
	ret.match1 = multi->match1;
	
	ret.port2 = multi->port2;
	ret.mask2 = multi->mask2;
	ret.match2 = multi->match2;
	
	ret.port3 = multi->port3;
	ret.mask3 = multi->mask3;
	ret.match3 = multi->match3;
	
	ret.port4 = multi->port4;
	ret.mask4 = multi->mask4;
	ret.match4 = multi->match4;

	ret.irq = info->irq;

	memcpy_tofs(retinfo,&ret,sizeof(*retinfo));
	return 0;
	
}

static int set_multiport_struct(struct async_struct * info,
				struct serial_multiport_struct *in_multi)
{
	struct serial_multiport_struct new_multi;
	struct rs_multiport_struct *multi;
	int	was_multi, now_multi;
	int	retval;
	void (*handler)(int, void *, struct pt_regs *);

	if (!suser())
		return -EPERM;
	if (!in_multi)
		return -EFAULT;
	memcpy_fromfs(&new_multi, in_multi,
		      sizeof(struct serial_multiport_struct));

	if (new_multi.irq != info->irq || info->irq == 0 ||
	    !IRQ_ports[info->irq])
		return -EINVAL;

	multi = &rs_multiport[info->irq];
	was_multi = (multi->port1 != 0);
	
	multi->port_monitor = new_multi.port_monitor;
	
	if (multi->port1)
		release_region(multi->port1,1);
	multi->port1 = new_multi.port1;
	multi->mask1 = new_multi.mask1;
	multi->match1 = new_multi.match1;
	if (multi->port1)
		request_region(multi->port1,1,"serial(multiport1)");

	if (multi->port2)
		release_region(multi->port2,1);
	multi->port2 = new_multi.port2;
	multi->mask2 = new_multi.mask2;
	multi->match2 = new_multi.match2;
	if (multi->port2)
		request_region(multi->port2,1,"serial(multiport2)");

	if (multi->port3)
		release_region(multi->port3,1);
	multi->port3 = new_multi.port3;
	multi->mask3 = new_multi.mask3;
	multi->match3 = new_multi.match3;
	if (multi->port3)
		request_region(multi->port3,1,"serial(multiport3)");

	if (multi->port4)
		release_region(multi->port4,1);
	multi->port4 = new_multi.port4;
	multi->mask4 = new_multi.mask4;
	multi->match4 = new_multi.match4;
	if (multi->port4)
		request_region(multi->port4,1,"serial(multiport4)");

	now_multi = (multi->port1 != 0);
	
	if (IRQ_ports[info->irq]->next_port &&
	    (was_multi != now_multi)) {
		free_irq(info->irq, NULL);
		if (now_multi)
			handler = rs_interrupt_multi;
		else
			handler = rs_interrupt;

		retval = request_irq(info->irq, handler, IRQ_T(info),
				     "serial", NULL);
		if (retval) {
			printk("Couldn't reallocate serial interrupt "
			       "driver!!\n");
		}
	}

	return 0;
}

static int rs_ioctl(struct tty_struct *tty, struct file * file,
		    unsigned int cmd, unsigned long arg)
{
	int error;
	struct async_struct * info = (struct async_struct *)tty->driver_data;
	int retval;
	struct async_icount cprev, cnow;	/* kernel counter temps */
	struct serial_icounter_struct *p_cuser;	/* user space */

	if (serial_paranoia_check(info, tty->device, "rs_ioctl"))
		return -ENODEV;

	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
	    (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT) &&
	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
		if (tty->flags & (1 << TTY_IO_ERROR))
		    return -EIO;
	}
	
	switch (cmd) {
		case TCSBRK:	/* SVID version: non-zero arg --> no break */
			retval = tty_check_change(tty);
			if (retval)
				return retval;
			tty_wait_until_sent(tty, 0);
			if (!arg)
				send_break(info, HZ/4);	/* 1/4 second */
			return 0;
		case TCSBRKP:	/* support for POSIX tcsendbreak() */
			retval = tty_check_change(tty);
			if (retval)
				return retval;
			tty_wait_until_sent(tty, 0);
			send_break(info, arg ? arg*(HZ/10) : HZ/4);
			return 0;
		case TIOCGSOFTCAR:
			error = verify_area(VERIFY_WRITE, (void *) arg,sizeof(long));
			if (error)
				return error;
			put_fs_long(C_CLOCAL(tty) ? 1 : 0,
				    (unsigned long *) arg);
			return 0;
		case TIOCSSOFTCAR:
			error = verify_area(VERIFY_READ, (void *) arg,sizeof(long));
			if (error)
				return error;
			arg = get_fs_long((unsigned long *) arg);
			tty->termios->c_cflag =
				((tty->termios->c_cflag & ~CLOCAL) |
				 (arg ? CLOCAL : 0));
			return 0;
		case TIOCMGET:
			error = verify_area(VERIFY_WRITE, (void *) arg,
				sizeof(unsigned int));
			if (error)
				return error;
			return get_modem_info(info, (unsigned int *) arg);
		case TIOCMBIS:
		case TIOCMBIC:
		case TIOCMSET:
			return set_modem_info(info, cmd, (unsigned int *) arg);
		case TIOCGSERIAL:
			error = verify_area(VERIFY_WRITE, (void *) arg,
						sizeof(struct serial_struct));
			if (error)
				return error;
			return get_serial_info(info,
					       (struct serial_struct *) arg);
		case TIOCSSERIAL:
			error = verify_area(VERIFY_READ, (void *) arg,
						sizeof(struct serial_struct));
			if (error)
				return error;
			return set_serial_info(info,
					       (struct serial_struct *) arg);
		case TIOCSERCONFIG:
			return do_autoconfig(info);

		case TIOCSERGWILD:
			error = verify_area(VERIFY_WRITE, (void *) arg,
					    sizeof(int));
			if (error)
				return error;
			put_fs_long(rs_wild_int_mask, (unsigned long *) arg);
			return 0;

		case TIOCSERGETLSR: /* Get line status register */
			error = verify_area(VERIFY_WRITE, (void *) arg,
				sizeof(unsigned int));
			if (error)
				return error;
			else
			    return get_lsr_info(info, (unsigned int *) arg);

		case TIOCSERSWILD:
			if (!suser())
				return -EPERM;
			error = verify_area(VERIFY_READ, (void *) arg,sizeof(long));
			if (error)
				return error;
			rs_wild_int_mask = get_fs_long((unsigned long *) arg);
			if (rs_wild_int_mask < 0)
				rs_wild_int_mask = check_wild_interrupts(0);
			return 0;

		case TIOCSERGSTRUCT:
			error = verify_area(VERIFY_WRITE, (void *) arg,
						sizeof(struct async_struct));
			if (error)
				return error;
			memcpy_tofs((struct async_struct *) arg,
				    info, sizeof(struct async_struct));
			return 0;
			
		case TIOCSERGETMULTI:
			error = verify_area(VERIFY_WRITE, (void *) arg,
				    sizeof(struct serial_multiport_struct));
			if (error)
				return error;
			return get_multiport_struct(info,
				       (struct serial_multiport_struct *) arg);
		case TIOCSERSETMULTI:
			error = verify_area(VERIFY_READ, (void *) arg,
				    sizeof(struct serial_multiport_struct));
			if (error)
				return error;
			return set_multiport_struct(info,
				       (struct serial_multiport_struct *) arg);
		/*
		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
		 * - mask passed in arg for lines of interest
		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
		 * Caller should use TIOCGICOUNT to see which one it was
		 */
		case TIOCMIWAIT:
			cli();
			cprev = info->icount;	/* note the counters on entry */
			sti();
			while (1) {
				interruptible_sleep_on(&info->delta_msr_wait);
				/* see if a signal did it */
				if (current->signal & ~current->blocked)
					return -ERESTARTSYS;
				cli();
				cnow = info->icount;	/* atomic copy */
				sti();
				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && 
				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
					return -EIO; /* no change => error */
				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
					return 0;
				}
				cprev = cnow;
			}
			/* NOTREACHED */

		/*
		 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
		 * Return: write counters to the user passed counter struct
		 * NB: both 1->0 and 0->1 transitions are counted except for
		 *     RI where only 0->1 is counted.
		 */
		case TIOCGICOUNT:
			error = verify_area(VERIFY_WRITE, (void *) arg,
				sizeof(struct serial_icounter_struct));
			if (error)
				return error;
			cli();
			cnow = info->icount;
			sti();
			p_cuser = (struct serial_icounter_struct *) arg;
			put_user(cnow.cts, &p_cuser->cts);
			put_user(cnow.dsr, &p_cuser->dsr);
			put_user(cnow.rng, &p_cuser->rng);
			put_user(cnow.dcd, &p_cuser->dcd);
			return 0;

		default:
			return -ENOIOCTLCMD;
		}
	return 0;
}

static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
{
	struct async_struct *info = (struct async_struct *)tty->driver_data;

	if (   (tty->termios->c_cflag == old_termios->c_cflag)
	    && (   RELEVANT_IFLAG(tty->termios->c_iflag)
	        == RELEVANT_IFLAG(old_termios->c_iflag)))
	  return;

	change_speed(info);

	if ((old_termios->c_cflag & CRTSCTS) &&
	    !(tty->termios->c_cflag & CRTSCTS)) {