esp.c

linux 内核源代码

	change_irq = new_serial.irq != info->irq;

	if (change_irq && (info->line % 8))
		return -EINVAL;

	if (!capable(CAP_SYS_ADMIN)) {
		if (change_irq || 
		    (new_serial.close_delay != info->close_delay) ||
		    ((new_serial.flags & ~ASYNC_USR_MASK) !=
		     (info->flags & ~ASYNC_USR_MASK)))
			return -EPERM;
		info->flags = ((info->flags & ~ASYNC_USR_MASK) |
			       (new_serial.flags & ASYNC_USR_MASK));
		info->custom_divisor = new_serial.custom_divisor;
	} else {
		if (new_serial.irq == 2)
			new_serial.irq = 9;

		if (change_irq) {
			current_async = ports;

			while (current_async) {
				if ((current_async->line >= info->line) &&
				    (current_async->line < (info->line + 8))) {
					if (current_async == info) {
						if (current_async->count > 1)
							return -EBUSY;
					} else if (current_async->count)
						return -EBUSY;
				}

				current_async = current_async->next_port;
			}
		}

		/*
		 * OK, past this point, all the error checking has been done.
		 * At this point, we start making changes.....
		 */

		info->flags = ((info->flags & ~ASYNC_FLAGS) |
			       (new_serial.flags & ASYNC_FLAGS));
		info->custom_divisor = new_serial.custom_divisor;
		info->close_delay = new_serial.close_delay * HZ/100;
		info->closing_wait = new_serial.closing_wait * HZ/100;

		if (change_irq) {
			/*
			 * We need to shutdown the serial port at the old
			 * port/irq combination.
			 */
			shutdown(info);

			current_async = ports;

			while (current_async) {
				if ((current_async->line >= info->line) &&
				    (current_async->line < (info->line + 8)))
					current_async->irq = new_serial.irq;

				current_async = current_async->next_port;
			}

			serial_out(info, UART_ESI_CMD1, ESI_SET_ENH_IRQ);
			if (info->irq == 9)
				serial_out(info, UART_ESI_CMD2, 0x02);
			else
				serial_out(info, UART_ESI_CMD2, info->irq);
		}
	}

	if (info->flags & ASYNC_INITIALIZED) {
		if (((old_info.flags & ASYNC_SPD_MASK) !=
		     (info->flags & ASYNC_SPD_MASK)) ||
		    (old_info.custom_divisor != info->custom_divisor)) {
			if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
				info->tty->alt_speed = 57600;
			if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
				info->tty->alt_speed = 115200;
			if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
				info->tty->alt_speed = 230400;
			if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
				info->tty->alt_speed = 460800;
			change_speed(info);
		}
	} else
		retval = startup(info);

	return retval;
}

static int set_esp_config(struct esp_struct * info,
			  struct hayes_esp_config __user * new_info)
{
	struct hayes_esp_config new_config;
	unsigned int change_dma;
	int retval = 0;
	struct esp_struct *current_async;
	unsigned long flags;

	/* Perhaps a non-sysadmin user should be able to do some of these */
	/* operations.  I haven't decided yet. */

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	if (copy_from_user(&new_config, new_info, sizeof(new_config)))
		return -EFAULT;

	if ((new_config.flow_on >= new_config.flow_off) ||
	    (new_config.rx_trigger < 1) ||
	    (new_config.tx_trigger < 1) ||
	    (new_config.flow_off < 1) ||
	    (new_config.flow_on < 1) ||
	    (new_config.rx_trigger > 1023) ||
	    (new_config.tx_trigger > 1023) ||
	    (new_config.flow_off > 1023) ||
	    (new_config.flow_on > 1023) ||
	    (new_config.pio_threshold < 0) ||
	    (new_config.pio_threshold > 1024))
		return -EINVAL;

	if ((new_config.dma_channel != 1) && (new_config.dma_channel != 3))
		new_config.dma_channel = 0;

	if (info->stat_flags & ESP_STAT_NEVER_DMA)
		change_dma = new_config.dma_channel;
	else
		change_dma = (new_config.dma_channel != dma);

	if (change_dma) {
		if (new_config.dma_channel) {
			/* PIO mode to DMA mode transition OR */
			/* change current DMA channel */
			
			current_async = ports;

			while (current_async) {
				if (current_async == info) {
					if (current_async->count > 1)
						return -EBUSY;
				} else if (current_async->count)
					return -EBUSY;
					
				current_async =
					current_async->next_port;
			}

			shutdown(info);
			dma = new_config.dma_channel;
			info->stat_flags &= ~ESP_STAT_NEVER_DMA;
			
                        /* all ports must use the same DMA channel */

			spin_lock_irqsave(&info->lock, flags);
			current_async = ports;

			while (current_async) {
				esp_basic_init(current_async);
				current_async = current_async->next_port;
			}
			spin_unlock_irqrestore(&info->lock, flags);
		} else {
			/* DMA mode to PIO mode only */
			
			if (info->count > 1)
				return -EBUSY;

			shutdown(info);
			spin_lock_irqsave(&info->lock, flags);
			info->stat_flags |= ESP_STAT_NEVER_DMA;
			esp_basic_init(info);
			spin_unlock_irqrestore(&info->lock, flags);
		}
	}

	info->config.pio_threshold = new_config.pio_threshold;

	if ((new_config.flow_off != info->config.flow_off) ||
	    (new_config.flow_on != info->config.flow_on)) {
		unsigned long flags;

		info->config.flow_off = new_config.flow_off;
		info->config.flow_on = new_config.flow_on;

		spin_lock_irqsave(&info->lock, flags);
		serial_out(info, UART_ESI_CMD1, ESI_SET_FLOW_LVL);
		serial_out(info, UART_ESI_CMD2, new_config.flow_off >> 8);
		serial_out(info, UART_ESI_CMD2, new_config.flow_off);
		serial_out(info, UART_ESI_CMD2, new_config.flow_on >> 8);
		serial_out(info, UART_ESI_CMD2, new_config.flow_on);
		spin_unlock_irqrestore(&info->lock, flags);
	}

	if ((new_config.rx_trigger != info->config.rx_trigger) ||
	    (new_config.tx_trigger != info->config.tx_trigger)) {
		unsigned long flags;

		info->config.rx_trigger = new_config.rx_trigger;
		info->config.tx_trigger = new_config.tx_trigger;
		spin_lock_irqsave(&info->lock, flags);
		serial_out(info, UART_ESI_CMD1, ESI_SET_TRIGGER);
		serial_out(info, UART_ESI_CMD2,
			   new_config.rx_trigger >> 8);
		serial_out(info, UART_ESI_CMD2, new_config.rx_trigger);
		serial_out(info, UART_ESI_CMD2,
			   new_config.tx_trigger >> 8);
		serial_out(info, UART_ESI_CMD2, new_config.tx_trigger);
		spin_unlock_irqrestore(&info->lock, flags);
	}

	if (new_config.rx_timeout != info->config.rx_timeout) {
		unsigned long flags;

		info->config.rx_timeout = new_config.rx_timeout;
		spin_lock_irqsave(&info->lock, flags);

		if (info->IER & UART_IER_RDI) {
			serial_out(info, UART_ESI_CMD1,
				   ESI_SET_RX_TIMEOUT);
			serial_out(info, UART_ESI_CMD2,
				   new_config.rx_timeout);
		}

		spin_unlock_irqrestore(&info->lock, flags);
	}

	if (!(info->flags & ASYNC_INITIALIZED))
		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 esp_struct * info, unsigned int __user *value)
{
	unsigned char status;
	unsigned int result;
	unsigned long flags;

	spin_lock_irqsave(&info->lock, flags);
	serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
	status = serial_in(info, UART_ESI_STAT1);
	spin_unlock_irqrestore(&info->lock, flags);
	result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
	return put_user(result,value);
}


static int esp_tiocmget(struct tty_struct *tty, struct file *file)
{
	struct esp_struct * info = (struct esp_struct *)tty->driver_data;
	unsigned char control, status;
	unsigned long flags;

	if (serial_paranoia_check(info, tty->name, __FUNCTION__))
		return -ENODEV;
	if (tty->flags & (1 << TTY_IO_ERROR))
		return -EIO;

	control = info->MCR;

	spin_lock_irqsave(&info->lock, flags);
	serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
	status = serial_in(info, UART_ESI_STAT2);
	spin_unlock_irqrestore(&info->lock, flags);

	return    ((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);
}

static int esp_tiocmset(struct tty_struct *tty, struct file *file,
			unsigned int set, unsigned int clear)
{
	struct esp_struct * info = (struct esp_struct *)tty->driver_data;
	unsigned long flags;

	if (serial_paranoia_check(info, tty->name, __FUNCTION__))
		return -ENODEV;
	if (tty->flags & (1 << TTY_IO_ERROR))
		return -EIO;

	spin_lock_irqsave(&info->lock, flags);

	if (set & TIOCM_RTS)
		info->MCR |= UART_MCR_RTS;
	if (set & TIOCM_DTR)
		info->MCR |= UART_MCR_DTR;

	if (clear & TIOCM_RTS)
		info->MCR &= ~UART_MCR_RTS;
	if (clear & TIOCM_DTR)
		info->MCR &= ~UART_MCR_DTR;

	serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
	serial_out(info, UART_ESI_CMD2, UART_MCR);
	serial_out(info, UART_ESI_CMD2, info->MCR);

	spin_unlock_irqrestore(&info->lock, flags);
	return 0;
}

/*
 * rs_break() --- routine which turns the break handling on or off
 */
static void esp_break(struct tty_struct *tty, int break_state)
{
	struct esp_struct * info = (struct esp_struct *)tty->driver_data;
	unsigned long flags;
	
	if (serial_paranoia_check(info, tty->name, "esp_break"))
		return;

	if (break_state == -1) {
		spin_lock_irqsave(&info->lock, flags);
		serial_out(info, UART_ESI_CMD1, ESI_ISSUE_BREAK);
		serial_out(info, UART_ESI_CMD2, 0x01);
		spin_unlock_irqrestore(&info->lock, flags);

		/* FIXME - new style wait needed here */
		interruptible_sleep_on(&info->break_wait);
	} else {
		spin_lock_irqsave(&info->lock, flags);
		serial_out(info, UART_ESI_CMD1, ESI_ISSUE_BREAK);
		serial_out(info, UART_ESI_CMD2, 0x00);
		spin_unlock_irqrestore(&info->lock, flags);
	}
}

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

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

	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
	    (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT) &&
	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT) &&
	    (cmd != TIOCGHAYESESP) && (cmd != TIOCSHAYESESP)) {
		if (tty->flags & (1 << TTY_IO_ERROR))
		    return -EIO;
	}
	
	switch (cmd) {
		case TIOCGSERIAL:
			return get_serial_info(info, argp);
		case TIOCSSERIAL:
			return set_serial_info(info, argp);
		case TIOCSERCONFIG:
			/* do not reconfigure after initial configuration */
			return 0;

		case TIOCSERGWILD:
			return put_user(0L, (unsigned long __user *)argp);

		case TIOCSERGETLSR: /* Get line status register */
			    return get_lsr_info(info, argp);

		case TIOCSERSWILD:
			if (!capable(CAP_SYS_ADMIN))
				return -EPERM;
			return 0;

		/*
		 * 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:
			spin_lock_irqsave(&info->lock, flags);
			cprev = info->icount;	/* note the counters on entry */
			spin_unlock_irqrestore(&info->lock, flags);
			while (1) {
				/* FIXME: convert to new style wakeup */
				interruptible_sleep_on(&info->delta_msr_wait);
				/* see if a signal did it */
				if (signal_pending(current))
					return -ERESTARTSYS;
				spin_lock_irqsave(&info->lock, flags);
				cnow = info->icount;	/* atomic copy */
				spin_unlock_irqrestore(&info->lock, flags);
				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:
			spin_lock_irqsave(&info->lock, flags);
			cnow = info->icount;
			spin_unlock_irqrestore(&info->lock, flags);
			p_cuser = argp;
			if (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 -EFAULT;

			return 0;
	case TIOCGHAYESESP:
		return get_esp_config(info, argp);
	case TIOCSHAYESESP:
		return set_esp_config(info, argp);

		default:
			return -ENOIOCTLCMD;
		}
	return 0;
}

static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
{
	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
	unsigned long flags;

	change_speed(info);

	spin_lock_irqsave(&info->lock, flags);

	/* Handle transition to B0 status */
	if ((old_termios->c_cflag & CBAUD) &&
		!(tty->termios->c_cflag & CBAUD)) {
		info->MCR &= ~(UART_MCR_DTR|UART_MCR_RTS);
		serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
		serial_out(info, UART_ESI_CMD2, UART_MCR);
		serial_out(info, UART_ESI_CMD2, info->MCR);
	}

	/* Handle transition away from B0 status */
	if (!(old_termios->c_cflag & CBAUD) &&
		(tty->termios->c_cflag & CBAUD)) {
		info->MCR |= (UART_MCR_DTR | UART_MCR_RTS);
		serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
		serial_out(info, UART_ESI_CMD2, UART_MCR);
		serial_out(info, UART_ESI_CMD2, info->MCR);
	}

	spin_unlock_irqrestore(&info->lock, flags);

	/* Handle turning of CRTSCTS */
	if ((old_termios->c_cflag & CRTSCTS) &&
	    !(tty->termios->c_cflag & CRTSCTS)) {
		rs_start(tty);
	}
}

/*